J Hazard Mater , IF:10.588 , 2022 Mar , V426 : P127826 doi: 10.1016/j.jhazmat.2021.127826
Low temperature tolerance is impaired by polystyrene nanoplastics accumulated in cells of barley (Hordeum vulgare L.) plants.
Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China.; Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.; Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun 130024, China.; Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: lixiangnan@iga.ac.cn.
With increasing plastic consumption, the large amount of polystyrene nanoplastics (PS-NPs) in agricultural soil may not only directly affect the plant growth, but also indirectly affect the abiotic stress tolerance in crops. In this study, the barley (Hordeum vulgare L.) was irrigated with 2 g L(-1) PS-NPs (65.776 +/- 0.528 nm) solution for 7 days, then subjected to low temperature (2 ) for 24 h. The imaging of protoplasts indicated that polymethylmethacrylate nanoplastics could across the cell wall and accumulate in plant cells. The PS-NPs significantly decreased Rubisco activities and ATP production, hence limiting the photosynthetic carbon assimilation in barley under low temperature. The PS-NPs accumulated in cells also caused the significantly decreased activities of key enzymes involved in sucrolytic, glycolysis and starch metabolism pathways, including UDP-glucose pyrophorylase, ADP-Glucose pyrophosphorylase, phosphoglucomutase, glucose-6-phosphate dehydrogenase, phosphoglucoisomerase, fructokinase and phosphofructokinase. In addition, under low temperature, the PS-NPs presence significantly reduced the activities of superoxide dismutase, ascorbate peroxidase and catalase in chloroplasts, and significantly reduced the activities of ascorbate peroxidase and catalase in mitochondria. Thus, it is suggested that the PS-NPs accumulated in plant cells impaired the low temperature tolerance in barley mainly by the negative effects on photosynthetic carbon assimilation, carbohydrate metabolism and ROS homeostasis in sub-cellular level.
PMID: 34823951
Plant Biotechnol J , IF:9.803 , 2022 Apr , V20 (4) : P660-675 doi: 10.1111/pbi.13745
CdWRKY2-mediated sucrose biosynthesis and CBF-signalling pathways coordinately contribute to cold tolerance in bermudagrass.
CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, China.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, China.; University of Chinese Academy of Sciences, Beijing, China.; College of Animal Science and Technology, Yangzhou University, Yangzhou, China.
Bermudagrass (Cynodon dactylon) is one of the most widely cultivated warm-season turfgrass species around the world. Cold stress has been a key environmental factor that adversely affects the growth, development, and geographical distribution of bermudagrass; however, the underlying mechanism of bermudagrass responsive to cold stress remains largely unexplored. Here, we identified a cold-induced WRKY transcription factor CdWRKY2 from bermudagrass and demonstrated its function in cold stress response. Overexpression of CdWRKY2 enhanced cold tolerance in transgenic Arabidopsis and bermudagrass hairy roots, while knocking down CdWRKY2 expression via virus-induced gene silencing increased cold susceptibility. RNA sequencing showed that overexpression of CdWRKY2 in Arabidopsis activated the expression of genes involved in sucrose synthesis and metabolism, including sucrose synthase 1 (AtSUS1) and sucrose phosphate synthase 2F (AtSPS2F). CdSPS1, the homology gene of AtSPS2F in bermudagrass, was subsequently proven to be the direct target of CdWRKY2 by yeast one-hybrid, electrophoretic mobility shift assay, and transient expression analysis. As expected, overexpression of CdSPS1 conferred cold tolerance in transgenic Arabidopsis plants, whereas silencing CdSPS1 expression enhanced cold sensitivity in bermudagrass. Besides, CdCBF1 whose expression was dramatically up-regulated in CdWRKY2-overexpressing bermudagrass hairy roots but down-regulated in CdWRKY2-silencing bermudagrass both under normal and cold stress conditions was confirmed as another target of CdWRKY2. Collectively, this study reveals that CdWRKY2 is a positive regulator in cold stress by targeting CdSPS1 and CdCBF1 promoters and activating their expression to coordinately mediate sucrose biosynthesis and CBF-signalling pathway, which provides valuable information for breeding cold-resistant bermudagrass through gene manipulation.
PMID: 34743386
Plant Physiol , IF:8.34 , 2022 Mar , V188 (4) : P2012-2025 doi: 10.1093/plphys/kiac008
Brassinosteroid-regulated bHLH transcription factor CESTA induces the gibberellin 2-oxidase GA2ox7.
Biotechnology of Horticultural Crops, TUM School of Life Sciences, Technical University of Munich, Freising, Germany.; Sainsbury Laboratory, Cambridge University, Cambridge, UK.; Institute of Plant Biology, Technical University of Braunschweig, Braunschweig, Germany.
Brassinosteroids (BRs) are plant steroids that have growth-promoting capacities, which are partly enabled by an ability to induce biosynthesis of gibberellins (GAs), a second class of plant hormones. In addition, BRs can also activate GA catabolism; here we show that in Arabidopsis (Arabidopsis thaliana) the basic helix-loop-helix transcription factor CESTA (CES) and its homologues BRASSINOSTEROID-ENHANCED EXPRESSION (BEE) 1 and 3 contribute to this activity. CES and the BEEs are BR-regulated at the transcriptional and posttranslational level and participate in different physiological processes, including vegetative and reproduction development, shade avoidance, and cold stress responses. We show that CES/BEEs can induce the expression of the class III GA 2-oxidase GA2ox7 and that this activity is increased by BRs. In BR signaling - and CES/BEE-deficient mutants, GA2ox7 expression decreased, yielding reduced levels of GA110, a product of GA2ox7 activity. In plants that over-express CES, GA2ox7 expression is hyper-responsive to BR, GA110 levels are elevated and amounts of bioactive GA are reduced. We provide evidence that CES directly binds to the GA2ox7 promoter and is activated by BRs, but can also act by BR-independent means. Based on these results, we propose a model for CES activity in GA catabolism where CES can be recruited for GA2ox7 induction not only by BR, but also by other factors.
PMID: 35148416
Plant Cell Environ , IF:7.228 , 2022 Mar doi: 10.1111/pce.14313
Genetically-determined variations in photosynthesis indicate roles for specific fatty acid species in chilling responses.
MSU-DOE Plant Research Laboratory, East Lansing, Michigan, USA.; Cell & Molecular Biology Program, Michigan State University, East Lansing, Michigan, USA.; Department of Biology, East Carolina University, Greenville, North Carolina, USA.; Department of Chemistry, Michigan State University, East Lansing, Michigan, USA.; State Key Laboratory of Soil Erosion and Dryland Farming in the Loess Plateau, Northwest A&F University, Yangling, China.; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA.; Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA.
Using a population of recombinant inbred lines (RILs) cowpea (Vigna unguiculata. L. Walp), we tested for co-linkages between lipid contents and chilling responses of photosynthesis. Under low-temperature conditions (19 degrees C/13 degrees C, day/night), we observed co-linkages between quantitative trait loci intervals for photosynthetic light reactions and specific fatty acids, most strikingly, the thylakoid-specific fatty acid 16:1(Delta3trans) found exclusively in phosphatidylglycerol (PG 16:1t). By contrast, we did not observe co-associations with bulk polyunsaturated fatty acids or high-melting-point-PG (sum of PG 16:0, PG 18:0 and PG 16:1t) previously thought to be involved in chilling sensitivity. These results suggest that in cowpea, chilling sensitivity is modulated by specific lipid interactions rather than bulk properties. We were able to recapitulate the predicted impact of PG 16:1t levels on photosynthetic responses at low temperature using mutants and transgenic Arabidopsis lines. Because PG 16:1t synthesis requires the activity of peroxiredoxin-Q, which is activated by H2 O2 and known to be involved in redox signalling, we hypothesise that the accumulation of PG 16:1t occurs as a result of upstream effects on photosynthesis that alter redox status and production of reactive oxygen species.
PMID: 35297062
Plant Cell Environ , IF:7.228 , 2022 Mar doi: 10.1111/pce.14322
Photoprotection conferring plant tolerance to freezing stress through rescuing photosystem in evergreen Rhododendron.
Genomics and Genetic Engineering Laboratory of Ornamental Plants, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, P.R. China.
Light stress is one of the important stresses for winter survival in evergreens, especially for plants with broad leaves, like evergreen rhododendrons. Photoprotection has been shown to upregulate dramatically in rhododendrons during winter, but whether it directly contributes to enhancing the freezing tolerance is still unknown. In this study, we found that the expression and circadian rhythm of an early light-induced protein (ELIP)-RhELIP3-which exerts photoprotection in Rhododendron 'Elsie Lee', could be impacted by both photoperiod and low temperature, with low temperature being the predominant inducer. Arabidopsis overexpressing RhELIP3 displayed significantly stronger freezing tolerance and better photosystem II function after a 3-day recovery from freezing treatment. Moreover, RhHY5 binds with the RhELIP3 promoter to activate its expression. Arabidopsis overexpressing RhHY5 exhibited stronger freezing tolerance and better photosystem II function. AtELIP1 and AtELIP2 were significantly induced in RhHY5-overexpressed Arabidopsis at low temperatures. We also discovered that RhBBX24 binds directly to RhELIP3 promoter and suppresses its expression. RhBBX24 can also interact with RhHY5 and inhibit the interaction of RhHY5-RhELIP3. RhELIP3, RhHY5, and RhBBX24 exhibited similar circadian rhythms under low temperature with short period. Overall, our investigation highlights that photoprotection is involved in improving the freezing tolerance of evergreen rhododendrons.
PMID: 35357711
J Exp Bot , IF:6.992 , 2022 Mar , V73 (5) : P1655-1667 doi: 10.1093/jxb/erab505
The CBL-interacting protein kinase CaCIPK13 positively regulates defence mechanisms against cold stress in pepper.
College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.; Department of Horticulture, Zhejiang University, Hangzhou, P. R. China.
Cold stress is one of the main factors limiting growth and development in pepper. Calcineurin B-like proteins (CBLs) are specific calcium sensors with non-canonical EF-hands to capture calcium signals, and interact with CBL-interacting protein kinases (CIPKs) in the regulation of various stresses. In this study, we isolated a cold-induced CIPK gene from pepper named CaCIPK13, which encodes a protein of 487 amino acids. In silico analyses indicated that CaCIPK13 is a typical CIPK family member with a conserved NAF motif, which consists of the amino acids asparagine, alanine, and phenylalanine. The CaCIPK13 protein was located in the nucleus and plasma membrane. Knock down of CaCIPK13 resulted in enhanced sensitivity to cold stress in pepper, with increased malondialdehyde content, H2O2 accumulation, and electrolyte leakage, while the catalase, peroxidase, superoxide dismutase activities and anthocyanin content were decreased. The transcript level of cold and anthocyanin-related genes was substantially decreased in CaCIPK13-silenced pepper leaves relative to the empty vector control. On the contrary, overexpression of CaCIPK13 in tomato improved cold tolerance via increasing anthocyanin content and activities of reactive oxygen species scavenging enzymes. Furthermore, the interaction of CaCIPK13 with CaCBL1/6/7/8 was Ca2+-dependent. These results indicate that CaCIPK13 plays a positive role in cold tolerance mechanism via CBL-CIPK signalling.
PMID: 35137060
J Exp Bot , IF:6.992 , 2022 Apr , V73 (7) : P2222-2237 doi: 10.1093/jxb/erab555
Genome-wide association study identifies variants of GhSAD1 conferring cold tolerance in cotton.
State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.
Cold stress is a major environmental factor affecting plant growth and development. Although some plants have developed resistance to cold stress, the molecular mechanisms underlying this process are poorly understood. Using genome-wide association mapping with 200 cotton accessions collected from different regions, we identified variations in the short chain alcohol dehydrogenase gene, GhSAD1, that responds to cold stress. Virus-induced gene silencing and overexpression in Arabidopsis revealed that GhSAD1 fulfils important roles in cold stress responses. Ectopic expression of a haploid genotype of GhSAD1 (GhSAD1HapB) in Arabidopsis increased cold tolerance. Silencing of GhSAD1HapB resulted in a decrease in abscisic acid (ABA) content. Conversely, overexpression of GhSAD1HapB increased ABA content. GhSAD1HapB regulates cold stress responses in cotton through modulation of C-repeat binding factor activity, which regulates ABA signalling. GhSAD1HapB induces the expression of COLD-REGULATED (COR) genes and increases the amount of metabolites associated with cold stress tolerance. Overexpression of GhSAD1HapB partially complements the phenotype of the Arabidopsis ABA2 mutant, aba2-1. Collectively, these findings increase our understanding of the mechanisms underlying GhSAD1-mediated cold stress responses in cotton.
PMID: 34919655
J Exp Bot , IF:6.992 , 2022 Apr , V73 (8) : P2666-2681 doi: 10.1093/jxb/erac029
Overexpression mutants reveal a role for a chloroplast MPD protein in regulation of reactive oxygen species during chilling in Arabidopsis.
Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA.
Reactive oxygen species (ROS) contribute to cellular damage in several different contexts, but their role during chilling damage is poorly defined. Chilling sensitivity both limits the distribution of plant species and causes devastating crop losses worldwide. Our screen of chilling-tolerant Arabidopsis (Arabidopsis thaliana) for mutants that suffer chilling damage identified a gene (At4g03410) encoding a chloroplast Mpv17_PMP22 protein, MPD1, with no previous connection to chilling. The chilling-sensitive mpd1-1 mutant is an overexpression allele that we successfully phenocopied by creating transgenic lines with a similar level of MPD1 overexpression. In mammals and yeast, MPD1 homologs are associated with ROS management. In chilling conditions, Arabidopsis overexpressing MPD1 accumulated H2O2 to higher levels than wild-type controls and exhibited stronger induction of ROS response genes. Paraquat application exacerbated chilling damage, confirming that the phenotype occurs due to ROS dysregulation. We conclude that at low temperature increased MPD1 expression results in increased ROS production, causing chilling damage. Our discovery of the effect of MPD1 overexpression on ROS production under chilling stress implies that investigation of the nine other members of the Mpv17_PMP22 family in Arabidopsis may lead to new discoveries regarding ROS signaling and management in plants.
PMID: 35084440
Cells , IF:6.6 , 2022 Apr , V11 (7) doi: 10.3390/cells11071240
Total and Mitochondrial Transcriptomic and Proteomic Insights into Regulation of Bioenergetic Processes for Shoot Fast-Growth Initiation in Moso Bamboo.
National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.; College of Agriculture and Forestry Engineering and Planning, Tongren University, Tongren 554300, China.; International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry and Grassland Administration, Beijing 100102, China.
As a fast-growing, woody grass plant, Moso bamboo (Phyllostachys edulis) can supply edible shoots, building materials, fibrous raw material, raw materials for crafts and furniture and so on within a relatively short time. Rapid growth of Moso bamboo occurs after the young bamboo shoots are covered with a shell and emerge from the ground. However, the molecular reactions of bioenergetic processes essential for fast growth remain undefined. Herein, total and mitochondrial transcriptomes and proteomes were compared between spring and winter shoots. Numerous key genes and proteins responsible for energy metabolism were significantly upregulated in spring shoots, including those involved in starch and sucrose catabolism, glycolysis, the pentose phosphate pathway, the tricarboxylic acid cycle and oxidative phosphorylation. Accordingly, significant decreases in starch and soluble sugar, higher ATP content and higher rates of respiration and glycolysis were identified in spring shoots. Further, the upregulated genes and proteins related to mitochondrial fission significantly increased the number of mitochondria, indirectly promoting intracellular energy metabolism. Moreover, enhanced alternate-oxidase and uncoupled-protein pathways in winter shoots showed that an efficient energy-dissipating system was important for winter shoots to adapt to the low-temperature environment. Heterologous expression of PeAOX1b in Arabidopsis significantly affected seedling growth and enhanced cold-stress tolerance. Overall, this study highlights the power of comparing total and mitochondrial omics and integrating physiochemical data to understand how bamboo initiates fast growth through modulating bioenergetic processes.
PMID: 35406802
Cells , IF:6.6 , 2022 Mar , V11 (6) doi: 10.3390/cells11060931
HPLC-PDA-ESI-HRMS-Based Profiling of Secondary Metabolites of Rindera graeca Anatomical and Hairy Roots Treated with Drought and Cold Stress.
Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 12/16 Banacha St., 90-237 Lodz, Poland.; Faculty of Chemistry, University of Warsaw, 1 Pasteura St., 02-093 Warsaw, Poland.; Biological and Chemical Research Centre, 101 Zwirki i Wigury St., 02-097 Warsaw, Poland.; Department of Pharmaceutical Biology and Medicinal Plant Biotechnology, Faculty of Pharmacy, Medical University of Warsaw, 1 Banacha St., 02-097 Warsaw, Poland.
To cope with environmental harmful conditions, plant cells developed adaptive strategy that involves production of a wide variety of complex secondary metabolites. The spectrum and quantity of biosynthesized compounds in specific plant species is determined by its genotype, tissue, developmental and physiological stage and environmental factors. This phenomenon was used to exploit the potential of anatomical and hairy root cultures of Rindera graeca to produce bioactive compounds. Cultivated in vitro roots were subjected to abiotic stresses i.e., drought or coldness. Next the extract profiling was performed using HPLC-PDA-ESI-HRMS method, as well quantitative determination of caffeic, rosmarinic and lithospermic B acids, that were present in all root extracts. Phenolic acids, flavonoids and iridoids represent the major groups of compounds detected in chemical profiles growing under various conditions roots. The highest number of phytochemicals was determined in roots subjected to coldness. Lithospermic B acid proved to be the most abundant compound in all investigated extracts. Among applied abiotic stress factors it was demonstrated that coldness affected to the most secondary metabolites production. The results of current study suggest that root cultures of R. graeca could serve as a new and abundant source of lithospermic B acid.
PMID: 35326382
Cells , IF:6.6 , 2022 Apr , V11 (8) doi: 10.3390/cells11081321
Comparative Proteomics Combined with Morphophysiological Analysis Revealed Chilling Response Patterns in Two Contrasting Maize Genotypes.
College of Agriculture, Northeast Agricultural University, Harbin 150030, China.; Jilin Province Engineering Laboratory of Plant Genetic Improvement, College of Plant Science, Jilin University, Changchun 130062, China.; Basic Forestry and Proteomics Research Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Institute of Maize Research, Heilongjiang Academy of Agricultural Sciences, Harbin 150030, China.
Maize yield is significantly influenced by low temperature, particularly chilling stress at the maize seedling stage. Various physiological approaches have been established to resist chilling stress; however, the detailed proteins change patterns underlying the maize chilling stress response at the seedling stage remain unknown, preventing the development of breeding-based methods to resist chilling stress in maize. Thus, we performed comprehensive physiological, comparative proteomics and specific phytohormone abscisic acid (ABA) assay on different maize inbred lines (tolerant-line KR701 and sensitive-line hei8834) at different seedling stages (the first leaf stage and third leaf stage) under chilling stress. The results revealed several signalling proteins and pathways in response to chilling stress at the maize seedling stage. Meanwhile, we found ABA pathway was important for chilling resistance of tolerant-line KR701 at the first leaf stage. Related chilling-responsive proteins were further catalogued and analysed, providing a resource for further investigation and maize breeding.
PMID: 35456000
Plant J , IF:6.417 , 2022 Apr doi: 10.1111/tpj.15780
Heat shock induced cold acclimation in cucumber through CsHSFA1d activated JA biosynthesis and signaling.
College of Horticulture, China Agricultural University, Beijing, 100193, China.; Institute of Economic Crops, Hubei Academy of Agricultural Sciences, Hubei Province, Wuhan, 430064, China.; Shandong Huasheng Agriculture Co. Ltd, Qingzhou, Shandong, 262500, China.; School of Agriculture, Virginia State University, Petersburg, USA.
Cucumber (Cucumis sativus) originated in tropical areas and is very sensitive to low temperatures. Cold acclimation is a universal strategy that improves plant resistance to cold stress. In this study, we report that heat shock induces cold acclimation in cucumber seedlings, via a process involving the heat shock transcription factor HSFA1d. CsHSFA1d expression was improved by both heat shock and cold treatment. Moreover, CsHSFA1d transcripts accumulated more under cold treatment after a heat shock pretreatment than with either heat shock or cold treatment alone. After exposure to cold, cucumber lines overexpressing CsHSFA1d displayed stronger tolerance for cold stress than the wild type, whereas CsHSFA1d knockdown lines by RNA interference were more sensitive to cold stress. Furthermore, both overexpression of CsHSFA1d and heat shock pretreatment increased endogenous jasmonic acid (JA) content in cucumber seedlings after cold treatment. Exogenous application of JA rescued the cold-sensitive phenotype of CsHSFA1d knockdown lines, underscoring JA biosynthesis as key for CsHSFA1d-mediated cold tolerance. Higher JA content is likely to lead to the degradation of CsJAZ5, a repressor protein of the JA pathway. We also established that CsJAZ5 interacts with CsICE1. JA-induced degradation of CsJAZ5 would be expected to release CsICE1, which would then activate the ICE-CBF-COR pathway. After cold treatment, the relative expression levels of ICE-CBF-COR signal pathway genes such as CsICE1, CsCBF1, CsCBF2, and CsCOR1 in CsHSFA1d overexpression lines were significantly higher than those in wild type and knockdown lines. Taken together, our results help reveal the mechanism underlying heat-shock-induced cold acclimation in cucumber.
PMID: 35436390
Antioxidants (Basel) , IF:6.312 , 2022 Apr , V11 (4) doi: 10.3390/antiox11040700
Plant Response to Cold Stress: Cold Stress Changes Antioxidant Metabolism in Heading Type Kimchi Cabbage (Brassica rapa L. ssp. Pekinensis).
Department of Industrial Plant Science and Technology, College of Agricultural, Life and Environmental Sciences, Chungbuk National University, Cheongju 28644, Korea.; Vegetable Research Division, National Institute of Horticultural & Herbal Science, Wanju 55365, Korea.; Department of Horticultural Science, College of Agriculture and Life Science, Kyungpook National University, Daegu 41566, Korea.
Cold stress is known as the important yield-limiting factor of heading type Kimchi cabbage (HtKc, Brassica rapa L. ssp. pekinensis), which is an economically important crop worldwide. However, the biochemical and molecular responses to cold stress in HtKc are largely unknown. In this study, we conducted transcriptome analyses on HtKc grown under normal versus cold conditions to investigate the molecular mechanism underlying HtKc responses to cold stress. A total of 2131 genes (936 up-regulated and 1195 down-regulated) were identified as differentially expressed genes and were significantly annotated in the category of "response to stimulus". In addition, cold stress caused the accumulation of polyphenolic compounds, including p-coumaric, ferulic, and sinapic acids, in HtKc by inducing the phenylpropanoid pathway. The results of the chemical-based antioxidant assay indicated that the cold-induced polyphenolic compounds improved the free-radical scavenging activity and antioxidant capacity, suggesting that the phenylpropanoid pathway induced by cold stress contributes to resistance to cold-induced reactive oxygen species in HtKc. Taken together, our results will serve as an important base to improve the cold tolerance in plants via enhancing the antioxidant machinery.
PMID: 35453385
Antioxidants (Basel) , IF:6.312 , 2022 Mar , V11 (3) doi: 10.3390/antiox11030512
Melatonin Application Alleviates Stress-Induced Photosynthetic Inhibition and Oxidative Damage by Regulating Antioxidant Defense System of Maize: A Meta-Analysis.
Guangxi Colleges and Universities Key Laboratory of Crop Cultivation and Tillage, Agricultural College, Guangxi University, Nanning 530004, China.; Soil Fertility and Plant Nutrition Research Department, Soil, Water and Environment Research Institute, Agricultural Research Center, Giza 12619, Egypt.; Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.; Department of Environmental Sciences, COMSATS University Islamabad, Abbottabad Campus 22060, Pakistan.; University of Gastronomic Sciences, 12042 Pollenzo, Italy.
Melatonin is effective in modulating metabolism and regulating growth and development in many plants under biotic and abiotic stress. However, there is no systematic quantification of melatonin effects on maize growth, gas exchange, chlorophyll content, and the antioxidant defense system. A meta-analysis was conducted on thirty-two currently available published articles to evaluate the effect of stress types, study types, and maize varieties on response ratio (lnRR++) of "melatonin" to "control (no melatonin)" on plant growth, enzyme activities, gas exchange parameters, and photosynthetic pigments. Our findings revealed that melatonin application overall increased plant height, leaf area, root length, fresh and dry root weight and shoot weight, superoxide dismutase (SOD), peroxide (POD), catalase (CAT), ascorbate peroxidase (APX), soluble sugar and protein, photosynthetic rate, stomatal conductance, transpiration rate, chlorophyll, and carotenoid in maize leaf under stress conditions. In contrast, melatonin application decreased the levels of hydrogen peroxide (H2O2), superoxide anion (O2(-)), malondialdehyde (MDA), and electrolyte leakage. The categorical meta-analysis demonstrated that melatonin application to chilling stress resulted in higher SOD activity followed by salt stress. Melatonin application to all stress types resulted in higher POD, CAT and APX activities, except Cd stress, which had no effect on POD and decreased CAT by 38% compared to control. Compared to control, melatonin resulted in lower reactive oxygen species (ROS) and electrolyte leakage under no stress, Cd, drought, salt, lead, heat, and chilling stress in all study types (pot, growth chamber, hydroponic, and field), except O2 content which was not affected in pot and growth chamber studies. It was concluded that melatonin alleviates oxidative damage by improving stress tolerance, regulating the antioxidant defense system, and increasing leaf chlorophyll content compared to control.
PMID: 35326162
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (7) doi: 10.3390/ijms23073886
CsSWEET2, a Hexose Transporter from Cucumber (Cucumis sativus L.), Affects Sugar Metabolism and Improves Cold Tolerance in Arabidopsis.
Institute of Agri-Food Processing and Nutrition, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China.; Beijing Key Laboratory of Fruits and Vegetable Storage and Processing, Beijing 100097, China.; Key Laboratory of Vegetable Postharvest Processing of Ministry of Agriculture and Rural Areas, Beijing 100097, China.; Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
Sugars, which are critical osmotic compounds and signalling molecules in plants, and Sugars Will Eventually be Exported Transporters (SWEETs), which constitute a novel family of sugar transporters, play central roles in plant responses to multiple abiotic stresses. In the present study, a member of the SWEET gene family from cucumber (Cucumis sativus L.), CsSWEET2, was identified and characterized. Histochemical analysis of beta-glucuronidase expression in transgenic Arabidopsis plants showed that CsSWEET2 is highly expressed in the leaves; subcellular localization indicated that CsSWEET2 proteins are localized in the plasma membrane and endoplasmic reticulum. Heterologous expression assays in yeast demonstrated that CsSWEET2 encodes an energy-independent hexose/H(+) uniporter that can complement both glucose and fructose transport deficiencies. Compared with wild-type Arabidopsis plants, transgenic Arabidopsis plants overexpressing CsSWEET2 had much lower relative electrolyte leakage levels and were much more resistant to cold stress. Sugar content analysis showed that glucose and fructose levels in the transgenic Arabidopsis plants were significantly higher than those in the wild-type plants. Taken together, our results suggest that, by mediating sugar metabolism and compartmentation, CsSWEET2 plays a vital role in improving plant cold tolerance.
PMID: 35409244
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (6) doi: 10.3390/ijms23063380
Two Triacylglycerol Lipases Are Negative Regulators of Chilling Stress Tolerance in Arabidopsis.
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China.; Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Xianyang 712100, China.
Cold stress is one of the abiotic stress conditions that severely limit plant growth and development and productivity. Triacylglycerol lipases are important metabolic enzymes for the catabolism of triacylglycerols and, therefore, play important roles in cellular activities including seed germination and early seedling establishment. However, whether they play a role in cold stress responses remains unknown. In this study, we characterized two Arabidopsis triacylglycerol lipases, MPL1 and LIP1 and defined their role in cold stress. The expression of MPL1 and LIP1 is reduced by cold stress, suggesting that they may be negative factors related to cold stress. Indeed, we found that loss-of-function of MPL1 and LIP1 resulted in increased cold tolerance and that the mpl1lip1 double mutant displayed an additive effect on cold tolerance. We performed RNA-seq analysis to reveal the global effect of the mpl1 and lip1 mutations on gene expression under cold stress. The mpl1 mutation had a small effect on gene expression under both under control and cold stress conditions whereas the lip1 mutation caused a much stronger effect on gene expression under control and cold stress conditions. The mpl1lip1 double mutant had a moderate effect on gene expression under control and cold stress conditions. Together, our results indicate that MPL1 and LIP1 triacylglycerol lipases are negative regulators of cold tolerance without any side effects on growth in Arabidopsis and that they might be ideal candidates for breeding cold-tolerant crops through genome editing technology.
PMID: 35328798
Front Plant Sci , IF:5.753 , 2022 , V13 : P856527 doi: 10.3389/fpls.2022.856527
Antioxidant Regulation and DNA Methylation Dynamics During Mikania micrantha Seed Germination Under Cold Stress.
School of Life Sciences, Sun Yat-sen University, Guangzhou, China.; Research Institute of Sun Yat-sen University in Shenzhen, Shenzhen, China.; College of Life Sciences, South China Agricultural University, Guangzhou, China.
As a primary goal, adaptation to cold climate could expand an invasion range of exotic plants. Here, we aimed to explore the regulation strategy of M. micrantha seed development under cold stress through molecular physiology and multi-omics analysis. Significant increase of hydrogen peroxide, malondialdehyde, and electrolyte leakage observed under cold stress revealed that oxidative damage within M. micrantha seed cells was induced in the initial germination phase. Proteomic data underscored an activation of antioxidant activity to maintain redox homeostasis, with a cluster of antioxidant proteins identified. Genomic-wide transcriptome, in combination with time-series whole-genome bisulfite sequencing mining, elucidated that seven candidate genes, which were the target of DNA demethylation-dependent ROS scavenging, were possibly associated with an M. micrantha germ break. Progressive gain of CHH context DNA methylation identified in an early germination phrase suggested a role of a DNA methylation pathway, while an active DNA demethylation pathway was also initiated during late seed development, which was in line with the expression trend of methylation and demethylation-related genes verified through qRT-PCR. These data pointed out that cold-dependent DNA demethylation and an antioxidant regulatory were involved together in restoring seed germination. The expression level of total 441 genes presented an opposite trend to the methylation divergence, while the expression of total 395 genes was proved to be negatively associated with their methylation levels. These data provided new insights into molecular reprograming events during M. micrantha seed development.
PMID: 35463422
Front Plant Sci , IF:5.753 , 2022 , V13 : P850216 doi: 10.3389/fpls.2022.850216
Fine-Tuning Cold Stress Response Through Regulated Cellular Abundance and Mechanistic Actions of Transcription Factors.
Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Malaysia.; Laboratory of Agronomy and Sustainable Crop Protection, Institute of Plantation Studies, Universiti Putra Malaysia, Serdang, Malaysia.; Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia.
Inflictions caused by cold stress can result in disastrous effects on the productivity and survival of plants. Cold stress response in plants requires crosstalk between multiple signaling pathways including cold, heat, and reactive oxygen species (ROS) signaling networks. CBF, MYB, bHLH, and WRKY families are among the TFs that function as key players in the regulation of cold stress response at the molecular level. This review discusses some of the latest understanding on the regulation of expression and the mechanistic actions of plant TFs to address cold stress response. It was shown that the plant response consists of early and late responses as well as memory reprogramming for long-term protection against cold stress. The regulatory network can be differentiated into CBF-dependent and independent pathways involving different sets of TFs. Post-transcriptional regulation by miRNAs, control during ribosomal translation process, and post-translational regulation involving 26S proteosomic degradation are processes that affect the cellular abundance of key regulatory TFs, which is an important aspect of the regulation for cold acclimation. Therefore, fine-tuning of the regulation by TFs for adjusting to the cold stress condition involving the dynamic action of protein kinases, membrane ion channels, adapters, and modifiers is emphasized in this review.
PMID: 35422820
Front Plant Sci , IF:5.753 , 2022 , V13 : P819630 doi: 10.3389/fpls.2022.819630
Transcriptome and Metabolome Analyses Reveal Molecular Responses of Two Pepper (Capsicum annuum L.) Cultivars to Cold Stress.
College of Horticulture, Sichuan Agricultural University, Chengdu, China.; Institute for Processing and Storage of Agricultural Products, Chengdu Academy of Agricultural and Forest Sciences, Chengdu, China.; Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu, China.
Low temperature is a significant factor affecting field-grown pepper. The molecular mechanisms behind peppers' response to cold stress remain unknown. Transcriptomic and metabolomic analyses were used to investigate the responses of two pepper cultivars, XS (cold-sensitive) and GZ (cold-resistant), to cold stress; these were screened from 45 pepper materials. In this study, compared with the control group (0 h), we identified 10,931 differentially expressed genes (DEGs) in XS and GZ, 657 differentially expressed metabolites (DEMs) in the positive ion mode, and 390 DEMs in the negative ion mode. Most DEGs were involved in amino acid biosynthesis, plant hormone signal transduction, and the mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, metabolomic analysis revealed that the content of free polyamines (PAs), plant hormones, and osmolytes, mainly contained increased putrescine, spermine, spermidine, abscisic acid (ABA), jasmonic acid (JA), raffinose, and proline, in response to cold stress. Importantly, the regulation of the ICE (inducer of CBF expression)-CBF (C repeat binding factors)-COR (cold regulated) pathway by Ca(2+) signaling, MAPK signaling, and reactive oxygen species (ROS) signaling plays a key role in regulating responses of peppers to cold stress. Above all, the results of the present study provide important insights into the response of peppers to cold stress, which will reveal the potential molecular mechanisms and contribute to pepper screening and breeding in the future.
PMID: 35392507
Front Plant Sci , IF:5.753 , 2022 , V13 : P831839 doi: 10.3389/fpls.2022.831839
Reprogramming of the Hevea brasiliensis Epigenome and Transcriptome in Response to Cold Stress.
Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Institute of Hainan University, Sanya, China.; Hunan Rice Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China.
Low temperature is a key factor limiting the rubber plantation extending to high latitude area. Previous work has shown that cold-induced DNA demethylation was coordinated with the expression of cold-responsive (COR) genes in Hevea brasiliensis. In this work, reduced representation bisulphite sequencing analysis of H. brasiliensis showed that cold treatment induced global genomic DNA demethylation and altered the sequence contexts of methylated cytosines, but the levels of mCG methylation in transposable elements were slightly enhanced by cold treatment. Integrated analysis of the DNA methylome and transcriptome revealed 400 genes whose expression correlated with altered DNA methylation. DNA demethylation in the upstream region of gene seems to correlate with higher gene expression, whereas demethylation in the gene body has less association. Our results suggest that cold treatment globally change the genomic DNA methylation status of the rubber tree, which might coordinate reprogramming of the transcriptome.
PMID: 35386670
Front Plant Sci , IF:5.753 , 2022 , V13 : P775692 doi: 10.3389/fpls.2022.775692
Inositol Improves Cold Tolerance Through Inhibiting CBL1 and Increasing Ca(2+) Influx in Rapeseed (Brassica napus L.).
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China.
Rapeseed (Brassica napus L.) is an important oilseed crop worldwide. However, its productivity is significantly affected by various abiotic stresses, including cold stress. Among various stresses, cold stress is an important abiotic factor affecting plant growth, yield, and quality. The calcium channels are regarded as key pathways affecting cold tolerance in plants. Thus, improvement in cold tolerance is of great significance for crop improvement. The current study was designed to examine the beneficial role of exogenous inositol in improving cold stress tolerance in rapeseed. From the RNA-seq results, we identified 35 differently expressed genes encoding different inositol enzymes. The results show that inositol (a cyclic polyol) positively regulated cold tolerance by increasing calcium ion (Ca(2+)) influx in rapeseed. Furthermore, we found that the expression of calcineurin B-like (CBL1) gene was inhibited by inositol. On the other hand, overexpressed plant mediated the Ca(2+) flux under cold stress suggesting the key role of inositol-Ca(2+) pathway in cold tolerance. Moreover, the overexpression of BnCBL1-2 in Arabidopsis represented that transgenic plants mediated the Ca(2+) flux highlighting the vital role of the inositol-Ca(2+) pathway in conferring cold stress. Our study provides new insights into rapeseed cold tolerance mechanism and introduces a feasible method to improve the cold tolerance of rapeseed quickly.
PMID: 35371155
Front Plant Sci , IF:5.753 , 2022 , V13 : P857980 doi: 10.3389/fpls.2022.857980
Mechanistic Insights Into Trehalose-Mediated Cold Stress Tolerance in Rapeseed (Brassica napus L.) Seedlings.
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China.
Cold stress (CS) severely affects several physiological, biochemical, and molecular mechanisms and limits the growth and production of rapeseed (Brassica napus L.). Trehalose (Tre) acts as a growth modulator, which is extensively used to improve the tolerance to multiple plant stresses. Further, Tre also serves as an external force in inducing plant signaling molecules, regulating the expression of stress-responsive genes, and enhancing the CS tolerance in plants. Nevertheless, the importance of exogenous Tre in improving the CS tolerance in rapeseed is still unclear. Therefore, the current study was designed to get mechanistic insights into Tre-mediated CS tolerance in rapeseed seedlings. To explore the Tre role, we designed four treatments [control (CK), CK + 20 mM L(-1) Tre, Cold, and Cold + 20 mM L(-1) Tre] and three CS conditions (4, 0, and -4 degrees C). The results showed that Tre treatments significantly mitigated the adverse effects of CS on the seedlings and increased the survival rate of Tre-treated seedlings under CS conditions. The exogenous Tre dramatically increased the contents of osmoprotectants, including the soluble sugar (SS), soluble protein (SP), and proline (Pro), and the activities of antioxidant enzymes, such as catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were also increased under CS conditions. Additionally, Tre decreased the malondialdehyde (MDA) contents to protect the rapeseed seedlings. Moreover, Tre also remarkably augmented the expression levels of antioxidant genes (CAT12, POD34, and FSD7), CS-responsive marker genes (CBF1, CBF2, CBF4, COR6.6, COR15, COR25, COL1, and KIN1), and Tre-biosynthesis genes (TPS4, TPS8, and TPS9). Briefly, exogenous Tre not only regulates the antioxidant and osmotic balance, but it also significantly participates in Tre metabolism and signaling network to improve the CS tolerance in rapeseed. Thus, Tre-induced supervisory connections between physiological or/and biochemical attributes provide information to dissect the mechanisms of Tre-mediated CS tolerance.
PMID: 35360297
Front Plant Sci , IF:5.753 , 2022 , V13 : P840360 doi: 10.3389/fpls.2022.840360
Expression Patterns and Functional Analysis of 11 E3 Ubiquitin Ligase Genes in Rice.
College of Life Science, Taizhou University, Taizhou, China.; National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China.
E3 ubiquitin ligases are involved in many processes, regulating the response to biotic and abiotic stresses. In this study, 11 E3 ubiquitin ligase genes from Arabidopsis, which were hypothesized to function in response to biotic or abiotic stresses were selected, and the homologous genes in rice were found. Their functions were analyzed in rice. These 11 E3 ubiquitin ligase genes showed different patterns of expression under different treatments. The BMV:OsPUB39-infiltrated seedlings showed decreased resistance to Magnaporthe grisea (M. grisea) when compared with BMV:00-infiltrated seedlings, whereas the BMV:OsPUB34- and BMV:OsPUB33-infiltrated seedlings showed increased resistance. The involvement of these genes in the resistance against M. grisea may be attributed to the regulation of the accumulation of reactive oxygen species (ROS) and expression levels of defense-related genes. Seedlings infiltrated by BMV:OsATL69 showed decreased tolerance to drought stress, whereas BMV:OsPUB33-infiltraed seedlings showed increased tolerance, possibly through the regulation of proline content, sugar content, and expression of drought-responsive genes. BMV:OsATL32-infiltrated seedlings showed decreased tolerance to cold stress by regulating malondialdehyde (MDA) content and the expression of cold-responsive genes.
PMID: 35310657
Front Plant Sci , IF:5.753 , 2022 , V13 : P760460 doi: 10.3389/fpls.2022.760460
Transcriptome Analysis Revealed a Cold Stress-Responsive Transcription Factor, PaDREB1A, in Plumbago auriculata That Can Confer Cold Tolerance in Transgenic Arabidopsis thaliana.
College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China.; Chengdu Academy of Agriculture and Forestry Sciences, Chengdu, China.
The tropical plant Plumbago auriculata can tolerate subzero temperatures without induction of apoptosis after cold acclimation in autumn, making it more cold tolerant than conventional tropical plants. In this study, we found that low temperatures significantly affected the photosynthetic system of P. auriculata. Using transcriptome sequencing, PaDREB1A was identified as a key transcription factor involved in the response to cold stress in P. auriculata. This transcription factor may be regulated by upstream JA signaling and regulates downstream ERD4 and ERD7 expression to resist cold stress. Overexpression of PaDREB1A significantly enhanced freezing resistance, protected the photosynthetic system, and enhanced the ROS scavenging mechanism under cold stress in Arabidopsis thaliana. Additionally, PaDREB1A significantly enhanced the expression of CORs and CAT1 in A. thaliana, which further activated the downstream pathway to enhance plant cold tolerance. This study explored the possible different regulatory modes of CBFs in tropical plants and can serve as an important reference for the introduction of tropical plants to low-temperature regions.
PMID: 35310656
Front Plant Sci , IF:5.753 , 2022 , V13 : P798118 doi: 10.3389/fpls.2022.798118
Comparative Transcriptome Analysis Reveals New Insight of Alfalfa (Medicago sativa L.) Cultivars in Response to Abrupt Freezing Stress.
College of Grassland Science, Gansu Agricultural University, Lanzhou, China.
Freezing stress is a major limiting environmental factor that affects the productivity and distribution of alfalfa (Medicago sativa L.). There is growing evidence that enhancing freezing tolerance through resistance-related genes is one of the most efficient methods for solving this problem, whereas little is known about the complex regulatory mechanism of freezing stress. Herein, we performed transcriptome profiling of the leaves from two genotypes of alfalfa, freezing tolerance "Gannong NO.3" and freezing-sensitive "WL326GZ" exposure to -10 degrees C to investigate which resistance-related genes could improve the freezing tolerance. Our results showed that a total of 121,366 genes were identified, and there were 7,245 differentially expressed genes (DEGs) between the control and treated leaves. In particular, the DEGs in "Gannong NO.3" were mainly enriched in the metabolic pathways and biosynthesis of secondary metabolites, and most of the DEGs in "WL326GZ" were enriched in the metabolic pathways, the biosynthesis of secondary metabolites, and plant-pathogen interactions. Moreover, the weighted gene co-expression network analysis (WGCNA) showed that ATP-binding cassette (ABC) C subfamily genes were strongly impacted by freezing stress, indicating that ABCC8 and ABCC3 are critical to develop the freezing tolerance. Moreover, our data revealed that numerous Ca(2+) signal transduction and CBF/DREB1 pathway-related genes were severely impacted by the freezing resistance, which is believed to alleviate the damage caused by freezing stress. Altogether, these findings contribute the comprehensive information to understand the molecular mechanism of alfalfa adaptation to freezing stress and further provide functional candidate genes that can adapt to abiotic stress.
PMID: 35432429
Front Plant Sci , IF:5.753 , 2022 , V13 : P850064 doi: 10.3389/fpls.2022.850064
Innovation and Emerging Roles of Populus trichocarpa TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR Transcription Factors in Abiotic Stresses by Whole-Genome Duplication.
State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Hangzhou, China.; Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
The TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) family proteins are plant-specific transcription factors that have been well-acknowledged for designing the architectures of plant branch, shoot, and inflorescence. However, evidence for their innovation and emerging role in abiotic stress has been lacking. In this study, we identified a total of 36 TCP genes in Populus trichocarpa, 50% more than that in Arabidopsis (i.e., 24). Comparative intra-genomes showed that such significant innovation was mainly due to the most recent whole genome duplication (rWGD) in Populus lineage around Cretaceous-Paleogene (K-Pg) boundary after the divergence from Arabidopsis. Transcriptome analysis showed that the expressions of PtrTCP genes varied among leaf, stem, and root, and they could also be elaborately regulated by abiotic stresses (e.g., cold and salt). Moreover, co-expression network identified a cold-associated regulatory module including PtrTCP31, PtrTCP10, and PtrTCP36. Of them, PtrTCP10 was rWGD-duplicated from PtrTCP31 and evolved a strong capability of cold induction, which might suggest a neofunctionalization of PtrTCP genes and contribute to the adaptation of Populus lineage during the Cenozoic global cooling. Evidentially, overexpression of PtrTCP10 into Arabidopsis increased freezing tolerance and salt susceptibility. Integrating co-expression network and cis-regulatory element analysis confirmed that PtrTCP10 can regulate the well-known cold- and salt-relevant genes (e.g., ZAT10, GolS2, and SOS1), proving that PtrTCP10 is an evolutionary innovation in P. trichocarpa response to environmental changes. Altogether, our results provide evidence of the rWGD in P. trichocarpa responsible for the innovation of PtrTCP genes and their emerging roles in environmental stresses.
PMID: 35356113
Biology (Basel) , IF:5.079 , 2022 Mar , V11 (4) doi: 10.3390/biology11040507
Significance of Lipid Fatty Acid Composition for Resistance to Winter Conditions in Asplenium scolopendrium.
K. A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, IPP RAS, 35 Botanicheskaya St., 127276 Moscow, Russia.
Ferns are one of the oldest land plants. Among them, there are species that, during the course of evolution, have adapted to living in temperate climates and under winter conditions. Asplenium scolopendrium is one such species whose fronds are able to tolerate low subzero temperatures in winter. It is known that the resistance of ferns to freezing is associated with their prevention of desiccation via unique properties of the xylem and effective photoprotective mechanisms. In this work, the composition of A. scolopendrium lipid fatty acids (FAs) at different times of the year was studied by gas-liquid chromatography with mass spectrometry to determine their role in the resistance of this species to low temperatures. During the growing season, the polyunsaturated FA content increased significantly. This led to increases in the unsaturation and double-bond indices by winter. In addition, after emergence from snow, medium-chain FAs were found in the fronds. Thus, it can be speculated that the FA composition plays an important role in the adaptation of A. scolopendrium to growing conditions and preparation for successful wintering.
PMID: 35453707
Plant Sci , IF:4.729 , 2022 May , V318 : P111242 doi: 10.1016/j.plantsci.2022.111242
Proteomic analysis reveals the molecular mechanism underlying the cold acclimation and freezing tolerance of wheat (Triticum aestivum L.).
State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of Education Ministry, Hebei Agricultural University, Baoding 071000, Hebei, China.; State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of Education Ministry, Hebei Agricultural University, Baoding 071000, Hebei, China. Electronic address: zhaoyong_0423@163.com.; Hebei University, Baoding 071000, Hebei, China.; State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of Education Ministry, Hebei Agricultural University, Baoding 071000, Hebei, China; Cangzhou Academy of Agriculture and Forestry Sciences, Cangzhou 061001, Hebei, China.; State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of Education Ministry, Hebei Agricultural University, Baoding 071000, Hebei, China. Electronic address: shmyxj@126.com.
Cold acclimation (CA) is an important evolutionary adaptive mechanism for wheat freezing resistence. To clarify the molecular basis of wheat CA and freezing tolerance, the effects of CA (4 degrees C) and non-CA (20 degrees C) treatments and freezing stress (-5 degrees C) on the proteins in the wheat crown were characterized via an iTRAQ-based proteomic analysis. A total of 669 differentially accumulated proteins (DAPs) were identified after the CA, of which seven were also DAPs in the CA plants exposed to freezing stress. Additionally, the 15 DAPs in the CA group and the 23 DAPs in the non-CA group after the freezing treatment differed substantially. Functional analyses indicated that CA enhanced freezing tolerance by regulating proteins involved in signal transduction, carbohydrate metabolism, stress and defense responses, and phenylpropanoid biosynthesis. An integrated transcriptomic, proteomic, and metabolomic analysis revealed significant changes in various components of the glutathione metabolic pathway. The overexpression and silencing of Wdhn13 in Arabidopsis and wheat resulted in increased tolerance and sensitivity to freezing stress, respectively, suggesting Wdhn13 promotes freezing tolerance. Overall, our study offers insights into the regulatory network underlying the CA and freezing tolerance of wheat, which may be useful for elucidating wheat freezing resistance.
PMID: 35351310
Front Genet , IF:4.599 , 2022 , V13 : P797014 doi: 10.3389/fgene.2022.797014
Genome-Wide Characterization and Expression Analysis of HD-ZIP Gene Family in Dendrobium officinale.
College of Forestry, Shenyang Agricultural University, Shenyang, China.; Rare Plants Research Institute of Yangtze River, China Three Gorges Corporation, Yichang, China.; National Engineering Research Center of Eco-Environment Protection for Yangtze River Economic Belt, China Three Gorges Corporation, Beijing, China.; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing, China.; Natural Resources Affairs Service Center of Dalian, Dalian, China.; College of Horticulture, Hunan Agricultural University, Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, China.; State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
The homeodomain-leucine zipper (HD-ZIP) gene family, as one of the plant-specific transcription factor families, plays an important role in regulating plant growth and development as well as in response to diverse stresses. Although it has been extensively characterized in many plants, the HD-ZIP family is not well-studied in Dendrobium officinale, a valuable ornamental and traditional Chinese medicinal herb. In this study, 37 HD-ZIP genes were identified in Dendrobium officinale (Dohdzs) through the in silico genome search method, and they were classified into four subfamilies based on phylogenetic analysis. Exon-intron structure and conserved protein domain analyses further supported the prediction with the same group sharing similar gene and protein structures. Furthermore, their expression patterns were investigated in nine various tissues and under cold stress based on RNA-seq datasets to obtain the tissue-specific and cold-responsive candidates. Finally, Dohdz5, Dohdz9, and Dohdz12 were selected to validate their expression through qRT-PCR analysis, and they displayed significantly differential expression under sudden chilling stress, suggesting they might be the key candidates underlying cold stress response. These findings will contribute to better understanding of the regulatory roles of the HD-ZIP family playing in cold stress and also will provide the vital targets for further functional studies of HD-ZIP genes in D. officinale.
PMID: 35368655
Front Genet , IF:4.599 , 2022 , V13 : P875316 doi: 10.3389/fgene.2022.875316
Genome-Wide Identification of WRKY Genes and Their Responses to Chilling Stress in Kandelia obovata.
Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China.; Yuhuan Municipal Bureau of Natural Resources and Planning, Yuhuan, China.; Marine Academy of Zhejiang Province, Hangzhou, China.
Background: Kandelia obovata, a dominant mangrove species, is widely distributed in tropical and subtropical areas. Low temperature is the major abiotic stress that seriously limits the survival and growth of mangroves. WRKY transcription factors (TFs) play vital roles in responses to biotic and abiotic stresses. However, genome-wide analysis of WRKY genes in K. obovata and their responses to chilling stress have not been reported. Methods: Bioinformatic analysis was used to identify and characterize the K. obovata WRKY (KoWRKY) gene family, RNA-seq and qRT-PCR analyses were employed to screen KoWRKYs that respond to chilling stress. Results: Sixty-four KoWRKYs were identified and they were unevenly distributed across all 18 K. obovata chromosomes. Many orthologous WRKY gene pairs were identified between Arabidopsis thaliana and K. obovata, showing high synteny between the two genomes. Segmental duplication events were found to be the major force driving the expansion for the KoWRKY gene family. Most of the KoWRKY genes contained several kinds of hormone- and stress-responsive cis-elements in their promoter. KoWRKY proteins belonged to three groups (I, II, III) according to their conserved WRKY domains and zinc-finger structure. Expression patterns derived from the RNA-seq and qRT-PCR analyses revealed that 9 KoWRKYs were significantly upregulated during chilling acclimation in the leaves. KEGG pathway enrichment analysis showed that the target genes of KoWRKYs were significantly involved in 11 pathways, and coexpression network analysis showed that 315 coexpressed pairs (KoWRKYs and mRNAs) were positively correlated. Conclusion: Sixty-four KoWRKYs from the K. obovata genome were identified, 9 of which exhibited chilling stress-induced expression patterns. These genes represent candidates for future functional analysis of KoWRKYs involved in chilling stress related signaling pathways in K. obovata. Our results provide a basis for further analysis of KoWRKY genes to determine their functions and molecular mechanisms in K. obovata in response to chilling stress.
PMID: 35432463
Plant Cell Rep , IF:4.57 , 2022 Apr , V41 (4) : P1115-1130 doi: 10.1007/s00299-022-02841-6
H2O2 participates in ABA regulation of grafting-induced chilling tolerance in cucumber.
State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, Shandong, China.; State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, Shandong, China. bhg@sdau.edu.cn.
KEY MESSAGE: Rootstock provides more abscisic acid (ABA) content to scions to increase the chilling tolerance of seedlings. H2O2 is involved in ABA regulation of grafting-induced chilling tolerance of cucumber. Here we examined the role of ABA in the response of grafted cucumber to chilling stress. The data showed chilling induced an increase in leaf and root ABA content and there was a positive correlation between ABA content and the chilling tolerance of the varieties. The increase of ABA content and NCED mRNA abundance in the leaf of both Cs/Cs (self-root) and Cs/Cm (grafted with pumpkin as rootstock) showed a delay under aerial stress compared with those under whole plant and root-zone stress. Intriguingly, an increase in ABA in xylem was found under whole-plant and root-zone chilling stress but was not detected under aerial stress, implying the increases in ABA content in leaves were mainly from root ABA transportation. Compared to Cs/Cs, a higher ABA content and NCED mRNA abundance were observed in Cs/Cm, which showed that Cm could output more ABA than Cs. The removal of endogenous ABA decreased the difference in chilling tolerance induced by Cm, as evidenced by the observed similar oxidative stress levels and photosynthetic capacity between Cs/Cs and Cs/Cm after chilling stress. Moreover, we found that the H2O2 signal in grafted cucumber could respond to chilling stress earlier than the H2O2 signal in self-rooted cucumber. The inhibition of endogenous H2O2 decreased the chilling tolerance of grafted cucumber induced by ABA by reducing photosynthesis and the mRNA abundance of CBF1 and COR. Thus, our results indicate that H2O2, as the downstream signal, participated in the rootstock-induced chilling tolerance of grafted seedlings induced by ABA.
PMID: 35260922
Plant Cell Rep , IF:4.57 , 2022 Apr , V41 (4) : P1087-1101 doi: 10.1007/s00299-022-02839-0
Glycinebetaine mitigates tomato chilling stress by maintaining high-cyclic electron flow rate of photosystem I and stability of photosystem II.
College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, Shandong, China.; Xinzhou Teachers University, Xinzhou, 034000, Shanxi, China.; Maize Research Institution, Shanxi Academy of Agricultural Sciences, XinzhouShanxi, 034000, China.; Department of Horticulture, Oregon State University, ALS 4017, Corvallis, OR, 97331, USA.; Department of Plant Physiology, Slovak University of Agriculture, A. Hlinku 2, Nitra, 94976, Slovak Republic.; College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, Shandong, China. liuy@sdau.edu.cn.; College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, Shandong, China. xhyang@sdau.edu.cn.
KEY MESSAGE: Glycinebetaine alleviates chilling stress by protecting photosystems I and II in BADH-transgenic and GB-treated tomato plants, which can be an effective strategy for improving crop chilling tolerance. Tomato (Solanum lycopersicum) is one of the most cultivated vegetables in the world, but is highly susceptible to chilling stress and does not naturally accumulate glycinebetaine (GB), one of the most effective stress protectants. The protective mechanisms of GB on photosystem I (PSI) and photosystem II (PSII) against chilling stress, however, remain poorly understood. Here, we address this problem through exogenous GB application and generation of transgenic tomatoes (Moneymaker) with a gene encoding betaine aldehyde dehydrogenase (BADH), which is the key enzyme in the synthesis of GB, from spinach. Our results demonstrated that GB can protect chloroplast ultramicrostructure, alleviate PSII photoinhibition and maintain PSII stability under chilling stress. More importantly, GB increased the electron transfer between QA and QB and the redox potential of QB and maintained a high rate of cyclic electron flow around PSI, contributing to reduced production of reactive oxygen species, thereby mitigating PSI photodamage under chilling stress. Our results highlight the novel roles of GB in enhancing chilling tolerance via the protection of PSI and PSII in BADH transgenic and GB-treated tomato plants under chilling stress. Thus, introducing GB-biosynthetic pathway into tomato and exogenous GB application are effective strategies for improving chilling tolerance.
PMID: 35150305
Environ Sci Pollut Res Int , IF:4.223 , 2022 Mar doi: 10.1007/s11356-022-19759-x
Gold nanoparticles as adaptogens increazing the freezing tolerance of wheat seedlings.
K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, 127276, Russia. jul.venzhik@gmail.com.; K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, 127276, Russia.; Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences, Saratov, 410049, Russia.
The intensive development of nanotechnology led to the widespread application of various nanoparticles and nanomaterials. As a result, nanoparticles enter the environment and accumulate in ecosystems and living organisms. The consequences of possible impact of nanoparticles on living organisms are not obvious. Experimental data indicate that nanoparticles have both toxic and stimulating effects on organisms. In this study, we demonstrated for the first time that gold nanoparticles can act as adaptogens increasing plant freezing tolerance. Priming winter wheat (Triticum aestivum L., var. Moskovskaya 39, Poaceae) seeds for 1 day in solutions of gold nanoparticles (15-nm diameter, concentrations of 5, 10, 20, and 50 microg/ml) led to an increase in freezing tolerance of 7-day-old wheat seedlings. A relationship between an increase in wheat freezing tolerance and changes in some important indicators for its formation-growth intensity, the activity of the photosynthetic apparatus and oxidative processes, and the accumulation of soluble sugars in seedlings-was established. Assumptions on possible mechanisms of gold nanoparticles effects on plant freezing tolerance are discussed.
PMID: 35316488
BMC Plant Biol , IF:4.215 , 2022 Apr , V22 (1) : P211 doi: 10.1186/s12870-022-03609-6
Genome-wide identification and expression analysis of the SWEET gene family in daylily (Hemerocallis fulva) and functional analysis of HfSWEET17 in response to cold stress.
School of Ecological Technology and Engineering, Shanghai Institute of Technology, Shanghai, 201418, China.; School of Ecological Technology and Engineering, Shanghai Institute of Technology, Shanghai, 201418, China. qinqp@sit.edu.cn.
BACKGROUND: The Sugars Will Eventually be Exported Transporters (SWEETs) are a newly discovered family of sugar transporters whose members exist in a variety of organisms and are highly conserved. SWEETs have been reported to be involved in the growth and development of many plants, but little is known about SWEETs in daylily (Hemerocallis fulva), an important perennial ornamental flower. RESULTS: In this study, 19 daylily SWEETs were identified and named based on their homologous genes in Arabidopsis and rice. Phylogenetic analysis classified these HfSWEETs into four clades (Clades I to IV). The conserved motifs and gene structures showed that the HfSWEETs were very conservative during evolution. Chromosomal localization and synteny analysis found that HfSWEETs were unevenly distributed on 11 chromosomes, and there were five pairs of segmentally duplicated events and one pair of tandem duplication events. The expression patterns of the 19 HfSWEETs showed that the expression patterns of most HfSWEETs in different tissues were related to corresponding clades, and most HfSWEETs were up-regulated under low temperatures. Furthermore, HfSWEET17 was overexpressed in tobacco, and the cold resistance of transgenic plants was much higher than that of wild-type tobacco. CONCLUSION: This study identified the SWEET gene family in daylily at the genome-wide level. Most of the 19 HfSWEETs were expressed differently in different tissues and under low temperatures. Overexpression further suggests that HfSWEET17 participates in daylily low-temperature response. The results of this study provide a basis for further functional analysis of the SWEET family in daylily.
PMID: 35468723
BMC Plant Biol , IF:4.215 , 2022 Apr , V22 (1) : P209 doi: 10.1186/s12870-022-03578-w
Comparative transcriptomic analyses of citrus cold-resistant vs. sensitive rootstocks might suggest a relevant role of ABA signaling in triggering cold scion adaption.
Centro de Citricultura y Produccion Vegetal, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain. primo_amp@gva.es.; Centro de Citricultura y Produccion Vegetal, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain.; Centro de Genomica, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain.
BACKGROUND: The citrus genus comprises a number of sensitive tropical and subtropical species to cold stress, which limits global citrus distribution to certain latitudes and causes major economic loss. We used RNA-Seq technology to analyze changes in the transcriptome of Valencia delta seedless orange in response to long-term cold stress grafted on two frequently used citrus rootstocks: Carrizo citrange (CAR), considered one of the most cold-tolerant accessions; C. macrophylla (MAC), a very sensitive one. Our objectives were to identify the genetic mechanism that produce the tolerant or sensitive phenotypes in citrus, as well as to gain insights of the rootstock-scion interactions that induce the cold tolerance or sensitivity in the scion. RESULTS: Plants were kept at 1 masculineC for 30 days. Samples were taken at 0, 15 and 30 days. The metabolomic analysis showed a significant increase in the concentration of free sugars and proline, which was higher for the CAR plants. Hormone quantification in roots showed a substantially increased ABA concentration during cold exposure in the CAR roots, which was not observed in MAC. Different approaches were followed to analyze gene expression. During the stress treatment, the 0-15-day comparison yielded the most DEGs. The functional characterization of DEGs showed enrichment in GO terms and KEGG pathways related to abiotic stress responses previously described in plant cold adaption. The DEGs analysis revealed that several key genes promoting cold adaption were up-regulated in the CAR plants, and those repressing it had higher expression levels in the MAC samples. CONCLUSIONS: The metabolomic and transcriptomic study herein performed indicates that the mechanisms activated in plants shortly after cold exposure remain active in the long term. Both the hormone quantification and differential expression analysis suggest that ABA signaling might play a relevant role in promoting the cold hardiness or sensitiveness of Valencia sweet orange grafted onto Carrizo citrange or Macrophylla rootstocks, respectively. Our work provides new insights into the mechanisms by which rootstocks modulate resistance to abiotic stress in the production variety grafted onto them.
PMID: 35448939
BMC Plant Biol , IF:4.215 , 2022 Mar , V22 (1) : P114 doi: 10.1186/s12870-022-03507-x
Cold stress tolerance of the intertidal red alga Neoporphyra haitanensis.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, Zhejiang, China.; College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China.; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, 315211, Zhejiang, China.; Zhejiang Mariculture Research Institute, Wenzhou, 325005, China.; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, Zhejiang, China. chenhaimin@nbu.edu.cn.; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, 315211, Zhejiang, China. chenhaimin@nbu.edu.cn.
BACKGROUND: Red algae Porphyra sensu lato grow naturally in the unfavorable intertidal environment, in which they are exposed to substantial temperature fluctuations. The strategies of Porphyra to tolerate cold stress are poorly understood. RESULTS: Herein, investigations revealed that chilling and freezing induced alterations in the physiological properties, gene transcriptional profiles and metabolite levels in the economically important red algae species, Neoporphyra haitanensis. Control samples (kept at 20 degrees C) were compared to chilled thalli (10 and 4 degrees C) and to thalli under - 4 degrees C conditions. Chilling stress did not affect the health or photosynthetic efficiency of gametophytes, but freezing conditions resulted in the arrest of growth, death of some cells and a decrease in photosynthetic activity as calculated by Fv/Fm. Transcriptome sequencing analysis revealed that the photosynthetic system was down-regulated along with genes associated with carbon fixation and primary metabolic biosynthesis. Adaptive mechanisms included an increase in unsaturated fatty acids levels to improve membrane fluidity, an increase in floridoside and isofloridoside content to enhance osmotic resistance, and an elevation in levels of some resistance-associated phytohormones (abscisic acid, salicylic acid, and methyl jasmonic acid). These physiochemical alterations occurred together with the upregulation of ribosome biogenesis. CONCLUSIONS: N. haitanensis adopts multiple protective mechanisms to maintain homeostasis of cellular physiology in tolerance to cold stress.
PMID: 35287582
BMC Plant Biol , IF:4.215 , 2022 Mar , V22 (1) : P104 doi: 10.1186/s12870-022-03473-4
ROS1-mediated decrease in DNA methylation and increase in expression of defense genes and stress response genes in Arabidopsis thaliana due to abiotic stresses.
The School of Life Sciences, Jilin Normal University, Siping, China.; The School of Life Sciences, Northwest A&F University, Xianyang, Shanxi, China.; The School of Life Sciences, Jilin University, Changchun, China.; The School of Life Sciences, Jilin Normal University, Siping, China. jintaicheng2535@163.com.; The School of Life Sciences, Jilin Normal University, Siping, China. yangliping781124@163.com.
BACKGROUND: Small interfering RNAs (siRNAs) target homologous genomic DNA sequences for cytosine methylation, known as RNA-directed DNA methylation (RdDM), plays an important role in transposon control and regulation of gene expression in plants. Repressor of silencing 1 (ROS1) can negatively regulate the RdDM pathway. RESULTS: In this paper, we investigated the molecular mechanisms by which an upstream regulator ACD6 in the salicylic acid (SA) defense pathway, an ABA pathway-related gene ACO3, and GSTF14, an endogenous gene of the glutathione S-transferase superfamily, were induced by various abiotic stresses. The results demonstrated that abiotic stresses, including water deficit, cold, and salt stresses, induced demethylation of the repeats in the promoters of ACD6, ACO3, and GSTF14 and transcriptionally activated their expression. Furthermore, our results revealed that ROS1-mediated DNA demethylation plays an important role in the process of transcriptional activation of ACD6 and GSTF14 when Arabidopsis plants are subjected to cold stress. CONCLUSIONS: This study revealed that ROS1 plays an important role in the molecular mechanisms associated with genes involved in defense pathways in response to abiotic stresses.
PMID: 35255815
BMC Plant Biol , IF:4.215 , 2022 Mar , V22 (1) : P91 doi: 10.1186/s12870-022-03468-1
An integrated analysis of the rice transcriptome and lipidome reveals lipid metabolism plays a central role in rice cold tolerance.
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Ministry of Education, Northeast Agricultural University, 150030, Harbin, China.; Innovation Center, Suihua Branch of Heilongjiang Academy of Agricultural Science, 152052, Suihua, China. zoudtneau@126.com.; Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Ministry of Education, Northeast Agricultural University, 150030, Harbin, China. nsj-0821@163.com.
BACKGROUND: Rice (Oryza sativa L.) is one of the most widely grown food crops, and its yield and quality are particularly important for a warm-saturated diet. Cold stress restricts rice growth, development, and yield; however, the specific mechanism of cold tolerance in rice remains unknown. RESULTS: The analysis of leaf physiological and photosynthetic characteristics showed that the two rice varieties were significantly affected by cold stress, but the cold-tolerant variety KY131 had more stable physiological characteristics, maintaining relatively good photosynthetic capacity. To better explore the transcriptional regulation mechanism and biological basis of rice response to cold stress, a comprehensive analysis of the rice transcriptome and lipidome under low temperature and control temperature conditions was carried out. The transcriptomic analysis revealed that lipid metabolism, including membrane lipid and fatty acid metabolism, may be an important factor in rice cold tolerance, and 397 lipid metabolism related genes have been identified. Lipidomics data confirmed the importance of membrane lipid remodeling and fatty acid unsaturation for rice adaptation to cold stress. This indicates that the changes in the fluidity and integrity of the photosynthetic membrane under cold stress lead to the reduction of photosynthetic capacity, which could be relieved by increased levels of monogalactosyldiacylglycerol that mainly caused by markedly increased expression of levels of 1,2-diacylglycerol 3-beta-galactosyltransferase (MGD). The upregulation of phosphatidate phosphatase (PAP2) inhibited the excessive accumulation of phosphatidate (PA) to produce more phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG), thereby preventing of membrane phase transition under cold stress. In addition, fatty acid beta-oxidation is worth further study in rice cold tolerance. Finally, we constructed a metabolic model for the regulatory mechanism of cold tolerance in rice, in which the advanced lipid metabolism system plays a central role. CONCLUSIONS: Lipidome analysis showed that membrane lipid composition and unsaturation were significantly affected, especially phospholipids and galactolipids. Our study provides new information to further understand the response of rice to cold stress.
PMID: 35232394
Tree Physiol , IF:4.196 , 2022 Mar , V42 (3) : P646-663 doi: 10.1093/treephys/tpab130
Characterization of the early gene expression profile in Populus ussuriensis under cold stress using PacBio SMRT sequencing integrated with RNA-seq reads.
State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.; School of Pharmacy, Harbin University of Commerce, No.138 Tongdajie Street, Harbin 150028, China.
Populus ussuriensis is an important and fast-growing afforestation plant species in north-eastern China. The whole-genome sequencing of P. ussuriensis has not been completed. Also, the transcriptional network of P. ussuriensis response to cold stress remains unknown. To unravel the early response of P. ussuriensis to chilling (3 degrees C) stress and freezing (-3 degrees C) stresses at the transcriptional level, we performed single-molecule real-time (SMRT) and Illumina RNA sequencing for P. ussuriensis. The SMRT long-read isoform sequencing led to the identification of 29,243,277 subreads and 575,481 circular consensus sequencing reads. Approximately 50,910 high-quality isoforms were generated, and 2272 simple sequence repeats and 8086 long non-coding RNAs were identified. The Ca2+ content and abscisic acid (ABA) content in P. ussuriensis were significantly increased under cold stresses, while the value in the freezing stress treatment group was significantly higher than the chilling stress treatment group. A total of 49 genes that are involved in the signal transduction pathways related to perception and transmission of cold stress signals, such as the Ca2+ signaling pathway, ABA signaling pathway and MAPK signaling cascade, were found to be differentially expressed. In addition, 158 transcription factors from 21 different families, such as MYB, WRKY and AP2/ERF, were differentially expressed during chilling and freezing treatments. Moreover, the measurement of physiological indicators and bioinformatics observations demonstrated the altered expression pattern of genes involved in reactive oxygen species balance and the sugar metabolism pathway during chilling and freezing stresses. This is the first report of the early responses of P. ussuriensis to cold stress, which lays the foundation for future studies on the regulatory mechanisms in cold-stress response. In addition the full-length reference transcriptome of P. ussuriensis deciphered could be used in future studies on P. ussuriensis.
PMID: 34625806
Planta , IF:4.116 , 2022 Mar , V255 (4) : P81 doi: 10.1007/s00425-022-03858-7
The network centered on ICEs play roles in plant cold tolerance, growth and development.
College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China.; Department of Plant Physiology, Slovak University of Agriculture, A. Hlinku 2, Nitra, 94976, Slovak Republic.; College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China. xhyang@sdau.edu.cn.
MAIN CONCLUSION: ICEs are key transcription factors in response to cold in plant, they also balance plant growth and stress tolerance. Thus, we systematize the information about ICEs published to date. Low temperature is an important factor affecting plant growth and development. Exposing to cold condition results in a suit of effects on plants including reduction of plant growth and reproduction, and decrease in crop yield and quality. Plants have evolved a series of strategies to deal with cold stress such as reprogramming of the expression of genes and transcription factors. ICEs (Inducer of CBF Expression), as transcription factors regulating CBFs (C-repeat binding factor), play key roles in balancing plant growth and stress tolerance. Studies on ICEs focused on the function of ICEs on cold tolerance, growth and development; post-translational modifications of ICEs and crosstalk between the ICEs and phytohormones. In this review, we focus on systematizing the information published to date. We summarized the main advances of the functions of ICEs on the cold tolerance, growth and development. And we also elaborated the regulation of ICEs protein stability including phosphorylation, ubiquitination and SUMOylation of ICE. Finally, we described the function of ICEs in the crosstalk among different phytohormone signaling pathway and cold stress. This review provides perspectives for ongoing research about cold tolerance, growth and development in plant.
PMID: 35249133
Phytopathology , IF:4.025 , 2022 Mar , V112 (3) : P501-510 doi: 10.1094/PHYTO-07-21-0310-R
Xanthomonas oryzae pv. oryzae Exoribonuclease R Is Required for Complete Virulence in Rice, Optimal Motility, and Growth Under Stress.
CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, Telangana State, India 500007.; MRC Human Genetics Unit, University of Edinburgh, Crewe Road South, Edinburgh, UK, EH4 2XU.; Center for Plant Molecular Biology, Osmania University, Tarnaka, Hyderabad, Telangana State, India 500007.; Indian Institute of Science Education and Research, Tirupati, Andhra Pradesh, India 517507.
Exoribonuclease R (RNase R) is a 3' hydrolytic exoribonuclease that can degrade structured RNA. Mutation in RNase R affects virulence of certain human pathogenic bacteria. The aim of this study was to determine whether RNase R is necessary for virulence of the phytopathogen that causes bacterial blight in rice, Xanthomonas oryzae pv. oryzae (Xoo). In silico analysis has indicated that RNase R is highly conserved among various xanthomonads. Amino acid sequence alignment of Xoo RNase R with RNase R from various taxa indicated that Xoo RNase R clustered with RNase R of order Xanthomonadales. To study its role in virulence, we generated a gene disruption mutant of Xoo RNase R. The Xoo rnr(-) mutant is moderately virulence deficient, and the complementing strain (rnr(-)/pHM1::rnr) rescued the virulence deficiency of the mutant. We investigated swimming and swarming motilities in both nutrient-deficient minimal media and nutrient-optimal media. We observed that RNase R mutation has adversely affected the swimming and swarming motilities of Xoo in optimal media. However, in nutrient-deficient media only swimming motility was noticeably affected. Growth curves in optimal media at suboptimal temperature (15 degrees C cold stress) indicate that the Xoo rnr(-) mutant grows more slowly than the Xoo wild type and complementing strain (rnr(-)/pHM1::rnr). Given these findings, we report for the first time that RNase R function is necessary for complete virulence of Xoo in rice. It is also important for motility of Xoo in media and for growth of Xoo at suboptimal temperature.
PMID: 34384245
Phytopathology , IF:4.025 , 2022 May , V112 (5) : P1134-1140 doi: 10.1094/PHYTO-07-21-0287-R
Rhizoctonia Resistance Is Negatively Correlated to Early Root Growth Rate in Synthetic Hexaploid Wheat Derivatives.
U.S. Department of Agriculture Agricultural Research Service, Wheat Health, Genetics and Quality Research Unit, Pullman, WA 99164-6430.; Molecular Plant Sciences Program, Washington State University, Pullman, WA 99164-1030.; Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164-6420.
Resistance to the soilborne fungal pathogen Rhizoctonia solani AG-8 is desirable in adapted wheat and barley but remains an elusive trait for prebreeders and breeders. In a previous study, we observed that emergence and root growth was faster in the Rhizoctonia-susceptible 'Scarlet' than in its resistant counterpart, 'Scarlet-Rz1'. The objective of the current study was to quantify early root growth rate and total root length in resistant and susceptible synthetic hexaploid wheat lines, including parental lines and 22 recombinant inbred lines derived crosses between parental lines. In Petri dish assays, the susceptible lines displayed a faster rate of root growth during the first 40 h of root emergence compared with resistant lines. This growth differential was observed in 14-day and 48-h greenhouse assays, in which the total root length of susceptible parental lines was significantly (P < 0.05) greater than that of resistant parental lines. However, the resistant lines sustained less root loss compared with susceptible lines when R. solani AG-8 was present in the soil. Early root growth rate and total root length were not correlated to freezing tolerance in a set of wheat cultivars selected for cold tolerance. The findings indicated that early root growth was negatively correlated to R. solani AG-8 damage in resistant synthetic wheat lines developed for the Pacific Northwest, United States, and suggested that the dynamics of root emergence affect resistance to this soilborne pathogen.
PMID: 35378055
BMC Genomics , IF:3.969 , 2022 Apr , V23 (1) : P280 doi: 10.1186/s12864-022-08526-4
Physiological attributes and transcriptomics analyses reveal the mechanism response of Helictotrichon virescens to low temperature stress.
Institute of qinghai-tibetan Plateau, Southwest Minzu University, Chengdu, 610041, China.; Sichuan Grass Industry Technology Research and Promotion Center, Chengdu, 610041, China.; Sichuan Agricultural Technology Extension Station, Chengdu, 610041, China.; College of Chemistry and Life Sciences, Chengdu Normal University, Chengdu, 611130, China.; Maize Research Institute, Sichuan Agricultural University, Chengdu, 611130, China.; Institute of Agricultural Information and Rural Economy, Sichuan Academy of Agricultural Sciences, Sichuan, Chengdu, 610066, China.; Maize Research Institute, Sichuan Agricultural University, Chengdu, 611130, China. 243535990@qq.com.
BACKGROUND: Helictotrichon virescens is a perennial grass that is primarily distributed in high altitude areas of 2000 ~ 4500 m. It is widely cultivated in the Qinghai-Tibet Plateau of China, strongly resistant to cold, and an essential part of the wild herbs in this region. However, the molecular mechanism of the response of H. virescens to low temperature stress and the key regulatory genes for specific biological processes are poorly understood. RESULTS: Physiological and transcriptome analyses were used to study the cold stress response mechanism in H virescens. During the low temperature stress period, the content of chlorophyll a and b decreased more and more with the delay of the treatment time. Among them, the difference between the controls was not significant, and the difference between the control and the treatment was significant. At the same time, the expression of related differential genes was up-regulated during low temperature treatment. In addition, the plant circadian pathway is crucial for their response to cold stress. The expression of differentially expressed genes that encode LHY and HY5 were strongly up-regulated during cold stress. CONCLUSIONS: This study should help to fully understand how H. virescens responds to low temperatures. It answers pertinent questions in the response of perennial herbs to cold stress, i.e., how light and low temperature signals integrate to regulate plant circadian rhythms and Decrease of content of chlorophylls (which can be also accompanied with decrease of total quantity of reaction centers) leads to an increase in photosynthetic damage.
PMID: 35392804
BMC Genomics , IF:3.969 , 2022 Apr , V23 (1) : P251 doi: 10.1186/s12864-022-08438-3
Gene-coexpression network analysis identifies specific modules and hub genes related to cold stress in rice.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China.; College of Life Science and Technology, Guangxi University, Nanning, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China. chenyaoj@gxu.edu.cn.; College of Agriculture, Guangxi University, Nanning, China. chenyaoj@gxu.edu.cn.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China. liwenlan@whu.edu.cn.; College of Life Science and Technology, Guangxi University, Nanning, China. liwenlan@whu.edu.cn.
BACKGROUND: When plants are subjected to cold stress, they undergo a series of molecular and physiological changes to protect themselves from injury. Indica cultivars can usually withstand only mild cold stress in a relatively short period. Hormone-mediated defence response plays an important role in cold stress. Weighted gene co-expression network analysis (WGCNA) is a very useful tool for studying the correlation between genes, identifying modules with high phenotype correlation, and identifying Hub genes in different modules. Many studies have elucidated the molecular mechanisms of cold tolerance in different plants, but little information about the recovery process after cold stress is available. RESULTS: To understand the molecular mechanism of cold tolerance in rice, we performed comprehensive transcriptome analyses during cold treatment and recovery stage in two cultivars of near-isogenic lines (9311 and DC907). Twelve transcriptomes in two rice cultivars were determined. A total of 2509 new genes were predicted by fragment splicing and assembly, and 7506 differentially expressed genes were identified by pairwise comparison. A total of 26 modules were obtained by expression-network analysis, 12 of which were highly correlated with cold stress or recovery treatment. We further identified candidate Hub genes associated with specific modules and analysed their regulatory relationships based on coexpression data. Results showed that various plant-hormone regulatory genes acted together to protect plants from physiological damage under short-term low-temperature stress. We speculated that this may be common in rice. Under long-term cold stress, rice improved the tolerance to low-temperature stress by promoting autophagy, sugar synthesis, and metabolism. CONCLUSION: Through WGCNA analysis at the transcriptome level, we provided a potential regulatory mechanism for the cold stress and recovery of rice cultivars and identified candidate central genes. Our findings provided an important reference for the future cultivation of rice strains with good tolerance.
PMID: 35365095
BMC Genomics , IF:3.969 , 2022 Mar , V23 (1) : P205 doi: 10.1186/s12864-022-08443-6
Transcriptomic analysis of Vigna radiata in response to chilling stress and uniconazole application.
Department of Biotechnology, College of Coastal Agricultural Sciences, Guangdong Ocean University, Guangdong, 524088, Zhanjiang, China.; Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, 518108, China.; Department of Biotechnology, College of Coastal Agricultural Sciences, Guangdong Ocean University, Guangdong, 524088, Zhanjiang, China. zdffnj@263.net.; Shenzhen Research Institute of Guangdong Ocean University, Shenzhen, 518108, China. zdffnj@263.net.
BACKGROUND: Chilling injury of mung bean (Vigna radiata (L.)) during the blooming and podding stages is a major agricultural threat in Northeast China. Uniconazole (UNZ) can alleviate water deficit stress in soybean and waterlogging stress in mung bean. However, there has been no report on the effect of UNZ application on the growth and transcriptomic profile of mung bean under chilling stress. RESULTS: UNZ application before chilling stress at the R1 stage alleviated the decline in mung bean yield. UNZ delayed the decrease in leaf chlorophyll content under chilling stress at the R1 stage and accelerated the increase in leaf chlorophyll content during the recovery period. Eighteen separate RNA-Seq libraries were generated from RNA samples collected from leaves exposed to six different treatment schemes. The numbers of DEGs specific for UNZ treatment between D1 + S vs. D1 and D4 + S vs. D4 were 708 and 810, respectively. GO annotations showed that photosynthesis genes were obviously enriched among the genes affected by chilling stress and UNZ application. KEGG pathway enrichment analysis indicated that 4 pathways (cutin, suberin and wax biosynthesis; photosynthesis; porphyrin and chlorophyll metabolism; and ribosome) were downregulated, while plant-pathogen interaction was upregulated, by chilling stress. UNZ application effectively prevented the further downregulation of the gene expression of members of these 4 KEGG pathways under chilling stress. CONCLUSIONS: UNZ application effectively delayed the decrease in photosynthetic pigment content under chilling stress and accelerated the increase in photosynthetic pigment content during the recovery period, thus effectively limiting the decline in mung bean yield. UNZ application effectively prevented the further downregulation of the gene expression of members of 4 KEGG pathways under chilling stress and increased mung bean tolerance to chilling stress.
PMID: 35287570
Plants (Basel) , IF:3.935 , 2022 Apr , V11 (7) doi: 10.3390/plants11070961
Higher Phytohormone Contents and Weaker Phytohormone Signal Transduction Were Observed in Cold-Tolerant Cucumber.
College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China.; Faculty of Agriculture, Minya University, Minya 61511, Egypt.; Central Lab. of Organic Agriculture, Agricultural Research Center, Giza 12619, Egypt.; Institution of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, South Zhongguancun Street 12, Beijing 100081, China.
Cucumbers (Cucumis sativus L.) originated from the South Asian subcontinent, and most of them are fragile to cold stress. In this study, we evaluated the cold tolerance of 115 cucumber accessions and screened out 10 accessions showing high resistance to cold stress. We measured and compared plant hormone contents between cold-tolerant cucumber CT90R and cold-sensitive cucumber CT57S in cold treatment. Most of the detected plant hormones showed significantly higher content in CT90R. To elucidate the role of plant hormones, we compared the leaf- and root-transcriptomes of CT90R with those of CT57S in cold stress treatment. In leaves, there were 1209 differentially expressed genes (DEGs) between CT90R and CT57S, while there were 703 in roots. These DEGs were not evenly distributed across the chromosomes and there were significant enrichments at particular positions, including qLTT6.2, a known QTL controlling cucumber cold tolerance. The GO and KEGG enrichment analysis showed that there was a significant difference in the pathway of plant hormone transductions between CT90R and CT57S in leaves. In short, genes involved in plant hormone transductions showed lower transcription levels in CT90R. In roots, the most significantly different pathway was phenylpropanoid biosynthesis. CT90R seemed to actively accumulate more monolignols by upregulating cinnamyl-alcohol dehydrogenase (CAD) genes. These results above suggest a new perspective on the regulation mechanism of cold tolerance in cucumbers.
PMID: 35406941
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (7) doi: 10.3390/plants11070936
Characterization of the TCP Gene Family in Chrysanthemum nankingense and the Role of CnTCP4 in Cold Tolerance.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Flower Biology and Germplasm Innovation, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.; Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.
Plant-specific TCP transcription factors play a key role in plant development and stress responses. Chrysanthemum nankingense shows higher cold tolerance than its ornamental polyploid counterpart. However, whether the TCP gene family plays a role in conferring cold tolerance upon C. nankingense remains unknown. Here, we identified 23 CnTCP genes in C. nankingense, systematically analyzed their phylogenetic relationships and synteny with TCPs from other species, and evaluated their expression profiles at low temperature. Phylogenetic analysis of the protein sequences suggested that CnTCP proteins fall into two classes and three clades, with a typical bHLH domain. However, differences between C. nankingense and Arabidopsis in predicted protein structure and binding sites suggested a unique function of CnTCPs in C. nankingense. Furthermore, expression profiles showed that expression of most CnTCPs were downregulated under cold conditions, suggesting their importance in plant responses to cold stress. Notably, expression of miR319 and of its predicted target genes, CnTCP2/4/14, led to fast responses to cold. Overexpression of Arabidopsis CnTCP4 led to hypersensitivity to cold, suggesting that CnTCP4 might play a negative role in C. nankingense responses to cold stress. Our results provide a foundation for future functional genomic studies on this gene family in chrysanthemum.
PMID: 35406918
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (7) doi: 10.3390/plants11070933
Cellular Protein Trafficking: A New Player in Low-Temperature Response Pathway.
Biology Department, University of Massachusetts, Amherst, MA 01003, USA.; The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.; Department of Plant Biosciences, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.; Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada.
Unlike animals, plants are unable to escape unfavorable conditions, such as extremities of temperature. Among abiotic variables, the temperature is notableas it affects plants from the molecular to the organismal level. Because of global warming, understanding temperature effects on plants is salient today and should be focused not only on rising temperature but also greater variability in temperature that is now besetting the world's natural and agricultural ecosystems. Among the temperature stresses, low-temperature stress is one of the major stresses that limits crop productivity worldwide. Over the years, although substantial progress has been made in understanding low-temperature response mechanisms in plants, the research is more focused on aerial parts of the plants rather than on the root or whole plant, and more efforts have been made in identifying and testing the major regulators of this pathway preferably in the model organism rather than in crop plants. For the low-temperature stress response mechanism, ICE-CBF regulatory pathway turned out to be the solely established pathway, and historically most of the low-temperature research is focused on this single pathway instead of exploring other alternative regulators. In this review, we tried to take an in-depth look at our current understanding of low temperature-mediated plant growth response mechanism and present the recent advancement in cell biological studies that have opened a new horizon for finding promising and potential alternative regulators of the cold stress response pathway.
PMID: 35406913
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (6) doi: 10.3390/plants11060828
The Reactions of Photosynthetic Capacity and Plant Metabolites of Sedum hybridum L. in Response to Mild and Moderate Abiotic Stresses.
Faculty of Biology and Biotechnology and Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Al-Farabi Avenue 71, Almaty 050040, Kazakhstan.; Institute of Genetic and Physiology, Al-Farabi Avenue 93, Almaty 050040, Kazakhstan.
In this article, for the first time, an experimental study of the effect of mild and moderate osmotic stress, NaCl content and the effect of low positive temperature on photosynthetic activity and composition of metabolites of immature plants Sedum hybridum L. is reported. In this representative of the genus Sedum adapted to arid conditions and having the properties of a succulent, a change in photosynthetic activity and an increase in the level of protective metabolites in the shoots were revealed when exposed to mild and moderate stress factors. The results of this study can be used in work on the adaptation of succulent plants to arid conditions, environmental monitoring and work on the directed induction of valuable secondary metabolites in succulents to obtain new herbal medicines.
PMID: 35336710
Plants (Basel) , IF:3.935 , 2022 Apr , V11 (7) doi: 10.3390/plants11070977
An Integration of MicroRNA and Transcriptome Sequencing Analysis Reveal Regulatory Roles of miRNAs in Response to Chilling Stress in Wild Rice.
College of Life Science and Technology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, China.; Agriculture College, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, China.
A chromosome single segment substitution line (CSSL) DC90, which was generated by introgressing CTS-12, a locus derived from common wild rice (Oryza rufipogon Griff.), into the 9311 (Oryza sativa L. ssp. indica) background, exhibits a chilling tolerance phenotype under chilling stress. Here, an integration of microRNA (miRNA) deep sequencing and transcriptomic sequencing analysis was performed to explore the expression profiles of miRNAs and their target genes mediated by CTS-12 under chilling stress, and to reveal the possible regulatory mechanisms of miRNAs that are involved in chilling tolerance. Integration analysis revealed that a number of differentially expressed miRNAs (DEMs) and putative target genes with different expression patterns and levels were identified in 9311 and DC90 under chilling stress. KEGG enrichment analysis revealed that the target genes that are regulated by chilling-induced miRNAs are involved in the regulation of various biological processes/pathways, including protein biosynthesis, redox process, photosynthetic process, and chloroplast development in two genotypes. CRISPR/Cas9 editing of the target genes of the key DEMs in a chilling tolerant rice variety Zhonghua 11 (ZH11) found that LOC_Os11g48020 (OsGL1-11), one of the putative target genes of osa-miR1846a/b-5p and encoding a wax synthesis protein, is correlated with a chilling stress tolerance phenotype, implying osa-miR1846a/b-5p/OsGL1-11 plays an important role in CTS-12-mediated chilling stress tolerance regulatory pathway(s). Therefore, we speculate that the CTS-12 may regulate the key miRNA target genes in response to chilling stress by differential regulation of miRNAs in wild rice, thereby resulting in the variation of chilling tolerance phenotype between 9311 and DC90.
PMID: 35406957
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (6) doi: 10.3390/plants11060812
Molecular Insights into Freezing Stress in Peach Based on Multi-Omics and Biotechnology: An Overview.
Department of Horticultural Science, Gyeongsang National University, Jinju 52725, Korea.; Department of Biotechnology, Sri Shakthi Institute of Engineering and Technology, Coimbatore 641062, Tamil Nadu, India.; Department of Biotechnology, Science Campus, Alagappa University, Karaikudi 630003, Tamil Nadu, India.; Department of Life Sciences, National University of Kaohsiung, Kaohsiung 811, Taiwan.
In nature or field conditions, plants are frequently exposed to diverse environmental stressors. Among abiotic stresses, the low temperature of freezing conditions is a critical factor that influences plants, including horticultural crops, decreasing their growth, development, and eventually quality and productivity. Fortunately, plants have developed a mechanism to improve the tolerance to freezing during exposure to a range of low temperatures. In this present review, current findings on freezing stress physiology and genetics in peach (Prunus persica) were refined with an emphasis on adaptive mechanisms for cold acclimation, deacclimation, and reacclimation. In addition, advancements using multi-omics and genetic engineering approaches unravel the molecular physiological mechanisms, including hormonal regulations and their general perceptions of freezing tolerance in peach were comprehensively described. This review might pave the way for future research to the horticulturalists and research scientists to overcome the challenges of freezing temperature and improvement of crop management in these conditions.
PMID: 35336695
J Plant Physiol , IF:3.549 , 2022 Apr , V271 : P153664 doi: 10.1016/j.jplph.2022.153664
Interplay between glutathione and mitogen-activated protein kinase 3 via transcription factor WRKY40 under combined osmotic and cold stress in Arabidopsis.
Plant Biology Laboratory, CSIR- Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, West Bengal, India.; Department of Botany, JK College, Purulia, West bengal 723 101, India.; Plant Biology Laboratory, CSIR- Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, West Bengal, India. Electronic address: sharmila@iicb.res.in.
Glutathione (GSH) plays a fundamental role in plant defense. Recent reports showed that enhanced GSH content activates mitogen-activated protein kinases (MPKs). However, the molecular mechanism behind this GSH-mediated MPKs expression during environmental challenges is unexplored. Here, we found that under control and combined abiotic stress-treated conditions, GSH feeding activates MPK3 expression in Arabidopsis thaliana by inducing its promoter, as established through the promoter activation assay. Additionally, transgenic A. thaliana overexpressing the LeMPK3 gene (AtMPK3 line) showed increased gamma-ECS expression, which was decreased in mpk3, the MPK3-depleted mutant. An in-gel kinase assay exhibited hyperphosphorylation of Myelin Basic Protein (MBP) in the GSH-fed AtMPK3 transgenic line. Under control and combined abiotic stress treated conditions, expression of transcription factor WRKY40 binding to MPK3 promoter was up-regulated under enhanced GSH condition. Interestingly, GSH feeding was rendered ineffective in altering MPK3 expression in the Atwrky40 mutant, emphasizing the involvement of WRKY40 in GSH-MPK3 interplay. This was further confirmed by a wrky40 co-transformation assay. The immunoprecipitation assay followed by ChIP-qPCR showed a significant increase in the binding of WRKY40 to MPK3 promoter, which further established MPK3-WRKY40 association upon GSH feeding. In conclusion, this study demonstrated that GSH modulates MPK3 expression via WRKY40 in response to stress.
PMID: 35279560
Fungal Genet Biol , IF:3.495 , 2022 Apr : P103698 doi: 10.1016/j.fgb.2022.103698
Annotation survey and life-cycle transcriptomics of transcription factors in rust fungi (Pucciniales) identify a possible role for cold shock proteins in dormancy exit.
Universite de Lorraine, INRAE, IAM, F-54000 Nancy, France.; School of biological Sciences, University of Portsmouth, King Henry 1 Street, PO1 D2Y, Portsmouth, United Kingdom.; Universite de Lorraine, INRAE, IAM, F-54000 Nancy, France. Electronic address: Sebastien.duplessis@inrae.fr.
Fungi of the order Pucciniales are obligate plant biotrophs causing rust diseases. They exhibit a complex life cycle with the production of up to five spore types, infection of two unrelated hosts and an overwintering stage. Transcription factors (TFs) are key regulators of gene expression in eukaryote cells. In order to better understand genetic programs expressed during major transitions of the rust life cycle, we surveyed the complement of TFs in fungal genomes with an emphasis on Pucciniales. We found that despite their large gene numbers, rust genomes have a reduced repertoire of TFs compared to other fungi. The proportions of C2H2 and Zinc cluster -two of the most represented TF families in fungi- indicate differences in their evolutionary relationships in Pucciniales and other fungal taxa. The regulatory gene family encoding cold shock protein (CSP) showed a striking expansion in Pucciniomycotina with specific duplications in the order Pucciniales. The survey of expression profiles collected by transcriptomics along the life cycle of the poplar rust fungus revealed TF genes related to major biological transitions, e.g. response to environmental cues and host infection. Particularly, poplar rust CSPs were strongly expressed in basidia produced after the overwintering stage suggesting a possible role in dormancy exit. Expression during transition from dormant telia to basidia confirmed the specific expression of the three poplar rust CSP genes. Their heterologous expression in yeast improved cell growth after cold stress exposure, suggesting a probable regulatory function when the poplar rust fungus exits dormancy. This study addresses for the first time TF and regulatory genes involved in developmental transition in the rust life cycle opening perspectives to further explore molecular regulation in the biology of the Pucciniales.
PMID: 35483517
Protoplasma , IF:3.356 , 2022 Apr doi: 10.1007/s00709-022-01767-w
Superoxide dismutase (SOD) family in durum wheat: promising candidates for improving crop resilience.
Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax (CBS), University of Sfax, B.P "1177" 3018, Sfax, Tunisia. tounsisana@ymail.com.; Laboratory of Microbial Biotechnology Enzymatic and Biomolecules, Centre of Biotechnology of Sfax (CBS), University of Sfax, P.O Box 1177, 3018, Sfax, Tunisia.; Biology Department, Faculty of Sciences of Sfax, University of Sfax, Sfax, Tunisia.; Laboratory of Legumes and Sustainable Agrosystem (L2AD), Center of Biotechnology of Borj-Cedria, BP901, 2050, HammamLif, Tunisia.; Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax (CBS), University of Sfax, B.P "1177" 3018, Sfax, Tunisia. faical.brini@cbs.rnrt.tn.; Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax (CBS), University of Sfax, B.P "1177" 3018, Sfax, Tunisia.
The SOD family has been extensively analyzed at genome wide level in several crops. However, little is known about this family in durum wheat. In this study, a total of 14 TdSOD genes were identified in whole durum wheat genome including 8 TdCu-ZnSODs, 2 TdMnSODs, and 4 TdFeSODs. In silico analysis evinced that TdSOD family members displayed a closer evolutionary relationship, similar gene structure and protein features with their homologs from other plant species. Furthermore, the analysis of their promoter regions revealed the presence of a great number of cis-regulatory elements related to plant development, abiotic and biotic stresses, phytohormones, and several potential binding sites for transcription factors. Interestingly, 3D structure analysis revealed that TdCu-ZnSOD2A-2 and TdCu-ZnSOD2B-2, belonging to the Cu-Zn group, were modeled as copper chaperone for SOD like their homologs from rice and Arabidopsis. The expression profile of eight TdSOD candidate genes was investigated under salt, drought, cold, and ABA treatments. Notably, TdCu-ZnSOD2A-1, TdFeSOD4A-1, and TdFeSOD7A-1 were significantly up-regulated under all stress treatments. On the other hand, TdCu-ZnSOD7B and TdMnSOD2B were strongly expressed in roots and leaves under cold stress and TdCu-ZnSOD2B-2 was particularly up-regulated in leaves under ABA treatment. Ultimately, these findings provide valuable information for the identification of attractive candidate genes to improve wheat resilience.
PMID: 35484428
Mar Environ Res , IF:3.13 , 2022 Apr , V176 : P105611 doi: 10.1016/j.marenvres.2022.105611
Microcosm study on cold adaptation and recovery of an exotic mangrove plant, Laguncularia racemosa in China.
Shenzhen Key Laboratory of Marine Bio-resource and Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, 518071, Shenzhen, China; College of Physics and Optoelectronic Engineering, Shenzhen University, 518060, Shenzhen, China; Greater Bay Area Mangrove Wetland Research & Development Centre, Guangdong Neilingding Futian National Nature Reserve, 518040, Shenzhen, China.; Greater Bay Area Mangrove Wetland Research & Development Centre, Guangdong Neilingding Futian National Nature Reserve, 518040, Shenzhen, China; College of Fisheries, Jimei University, 361021, Xiamen, China.; Greater Bay Area Mangrove Wetland Research & Development Centre, Guangdong Neilingding Futian National Nature Reserve, 518040, Shenzhen, China; Department of Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Kowloon, 999077, Hong Kong, China.; Shenzhen Key Laboratory of Marine Bio-resource and Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, 518071, Shenzhen, China; Greater Bay Area Mangrove Wetland Research & Development Centre, Guangdong Neilingding Futian National Nature Reserve, 518040, Shenzhen, China.; Shenzhen Key Laboratory of Marine Bio-resource and Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, 518071, Shenzhen, China.; Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning, 530008, China.; Shenzhen Key Laboratory of Marine Bio-resource and Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, 518071, Shenzhen, China; Greater Bay Area Mangrove Wetland Research & Development Centre, Guangdong Neilingding Futian National Nature Reserve, 518040, Shenzhen, China. Electronic address: zhouhc@szu.edu.cn.
Laguncularia racemosa (a white mangrove) is an exotic mangrove species commonly distributed in southern intertidal zones in China since it was introduced for reforestation purposes in 1999. However, the invasiveness of this exotic species and its cold adaptability have rarely been reported. The present work determined the cold resistance level of L. racemosa and its recovery from cold stress, aiming to speculate its potential invasive capability in China. Results showed that the germination of L. racemosa seeds in sand or in simulated sea field models was significantly inhibited by a series of cold treatments, with no germination at 5 degrees C and decreased in germination at low temperatures (15-25 degrees C). Low temperature also reduced net photosynthetic rate (A), water use efficiency (WUE), transpiration rate (E), and stomatal conductance (Gs) of the seedlings of L. racemosa. On the other hand, cold stress up-regulated in leaves of malondialdehyde (MDA) and antioxidant activities, including superoxide dismutase (SOD), glutathione reductase (GR), and ascorbate peroxidase (APX). Additionally, these physiological and biochemical indexes of cold-stressed L. racemosa could recover to the original levels if the plants were returned to room temperature with a few exceptions. For instance, the cold exposure duration altered seedlings' physiology, but the photosynthetic related activities could not recover if cold treatment lasted for 120 h. This study suggests that L. racemosa can tolerate low temperatures to some extent, thus settle and even invade the coast of China at high latitudes having cold winter, which poses a challenge to the conservation and management of local mangrove ecosystems.
PMID: 35344783
Funct Plant Biol , IF:3.101 , 2022 Apr doi: 10.1071/FP21297
Identification and characterisation of blue light photoreceptor gene family and their expression in tomato (Solanum lycopersicum) under cold stress.
The Arabidopsis thaliana L. photoreceptor genes homologues in tomato (Solanum lycopersicum L.) genome were analysed using bioinformatic tools. The expression pattern of these genes under cold stress was also evaluated. Transcriptome analysis of the tomato sequence revealed that the photoreceptor gene family is involved in abiotic stress tolerance. They participate in various pathways and controlling multiple metabolic processes. They are structurally related to PAS, LIGHT-OXYGEN-VOLTAGE-SENSING (LOV), DNA photolyase, 5,10-methenyl tetrahydrofolate (MTHF), flavin-binding kelch F-box, GAF, PHY, Seven-bladed beta-propeller and C27 domains. They also interact with flavin adenine dinucleotide (FAD), (5S)-5-methyl-2-(methylsulfanyl)-5-phenyl-3-(phenylamino)-3,5-dihydro-4H-imidazol -4-one (FNM) and Phytochromobilin (PvarphiB) ligands. These interactions help to create a cascade of protein phosphorylation involving in cell defence transcription or stress-regulated genes. They localisation of these gene families on tomato chromosomes appeared to be uneven. Phylogenetic tree of tomato and Arabidopsis photoreceptor gene family were classified into eight subgroups, indicating gene expression diversity. Morphological and physiological assessment revealed no dead plant after 4h of cold treatment. All the plants were found to be alive, but there were some variations in the data across different parameters. Cold stress significantly reduced the rate of photosynthesis from 10.06 to 3.16mumolm-2 s-1, transpiration from 4.6 to 1.3mmolm-2 s-1, and stomatal conductance from 94.6 to 25.6mmolm-2 s-1. The cold stressed plants also had reduced height, root/shoot length, and fresh/dry biomass weight than the control plants. Relative expression analysis under cold stress revealed that after 4h, light stimulates the transcript level of Cry2 from 1.9 to 5.7 and PhyB from 0.98 to 6.9 compared to other photoreceptor genes.
PMID: 35437142
Funct Plant Biol , IF:3.101 , 2022 Apr doi: 10.1071/FP21230
Meta-analysis of transcriptomic responses to cold stress in plants.
Transcriptomic analyses are needful tools to gain insight into the molecular mechanisms underlying plant responses to abiotic stresses. The aim of this study was to identify key genes differentially regulated in response to chilling stress in various plant species with different levels of tolerance to low temperatures. A meta-analysis was performed using the RNA-Seq data of published studies whose experimental conditions were comparable. The results confirmed the importance of ethylene in the hormonal cross-talk modulating the defensive responses against chilling stress, especially in sensitive species. The transcriptomic activity of five Ethylene Response Factors genes and a REDOX Responsive Transcription Factor 1 involved in hormone-related pathways belonging to ethylene metabolism and signal transduction were induced. Transcription activity of two genes encoding for heat shock factors was enhanced, together with various genes associated with developmental processes. Several transcription factor families showed to be commonly induced between different plant species. Protein-protein interaction networks highlighted the role of the photosystems I and II, as well as genes encoding for HSF and WRKY transcription factors. A model of gene regulatory network underlying plant responses to chilling stress was developed, allowing the delivery of new candidate genes for genetic improvement of crops towards low temperatures tolerance.
PMID: 35379384
Plant Biol (Stuttg) , IF:3.081 , 2022 Mar doi: 10.1111/plb.13406
Hydrogen sulphide-mediated alleviation and its interplay with other signalling molecules during temperature stress.
Department of Botany, School of Life Sciences, Central University of Jammu, Samba, Jammu and Kashmir (UT), India.
The sessile habit of plants does not provide choices to escape the environmental constraints, leading to negative impacts on their growth and development. This causes significant losses in the agriculture sector and raises serious issues on global food security. Extreme temperatures (high or low) influence several aspects of plant life and can cause reproduction malfunction. Therefore, a strategy for temperature amelioration is necessary for the management of agricultural productivity. Supplementation with various chemicals (e.g. phytohormones, gasotransmitters, osmolytes) is considered a good choice to manage plant stress. Gasotransmitters are well-recognized for stress mitigation in plants, among which hydrogen sulphide (H2 S) has proved promising to alleviate stress. Temperature (heat/cold) stress can stimulate the endogenous production of H2 S in plants, and many studies have reported the significance of H2 S for temperature stress amelioration. Here, H2 S led to positive changes in plant physiological, biochemical and molecular responses, which are usually compromised during stress. Further, H2 S also coordinate with other signalling components that act either upstream or downstream during stress mitigation. This review focuses on the significance of H2 S for mitigation of temperature stress, with a comprehensive discussion on cross-talk with other signalling components or supplements (e.g. NO, H2 O2 , salicylic acid, trehalose, proline). Finally, the review provides a rational assessment and holistic understanding of H2 S-mediated mitigation of extreme temperature stress and addresses the prospects for development of an effective strategy to manage temperature stress.
PMID: 35238126
Comput Biol Chem , IF:2.877 , 2022 Apr , V97 : P107622 doi: 10.1016/j.compbiolchem.2022.107622
Identification of leucine-rich repeat receptor-like protein kinase (LRR-RLK) genes in paper mulberry and their potential roles in response to cold stress.
Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.; Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. Electronic address: pengxianjun@ibcas.ac.cn.; Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. Electronic address: shshen@ibcas.ac.cn.
Leucine-rich repeat receptor-like protein kinases (LRR-RLKs) represent the largest group of receptor-like kinases in plants, which have been previously reported to play vital roles in plant growth, development, stress adaptation and signal transduction. However, there is lack of comprehensive analysis of this family in paper mulberry (Broussonetia papyrifera). In the present investigation, a genome-wide scan revealed the presence of 236 LRR-RLK genes in paper mulberry, which were classified into 21 subgroups based on the maximum-likelihood phylogenetic tree. Gene structure and conserved motif analyses suggested genes in the same subgroup had highly consistent motif composition and intron/exon arrangement, but were divergent among subgroups. Total of 223 BpLRR-RLK genes were unevenly distributed across all 13 chromosomes, while the remaining 13 genes were localized to the unassembled scaffolds. Tandem and segmental duplications were confirmed to contribute to the expansion of BpLRR-RLK family. Further Ka/Ks showed that the duplicated BpLRR-RLKs had experienced strong purifying selection. The global promoter composition, transcriptome and phosphorylation analysis indicated that many of BpLRR-RLKs were associated with plant development, biotic and abiotic stress response, especially for cold stress. Furthermore, protein-protein interaction network was constructed for the 127 and 14 BpLRR-RLKs that responded to cold stress at the transcriptomics and phosphorylation level, respectively. All these findings will facilitate the studies on the evolutionary history of the LRR-RLK gene family in paper mulberry, also establish a solid foundation to further explore the potential functions of LRR-RLK genes in higher plants, particularly with regards to cold resistance.
PMID: 35033836
Transgenic Res , IF:2.788 , 2022 Apr doi: 10.1007/s11248-022-00307-9
MsSAMS, a cold stress-responsive gene, provides resistance to environmental stress in T2-generation transgenic plants.
Department of Bio-Resource Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea.; Interdisciplinary Program in Smart Science, Kangwon National University, Chuncheon, 2434, Republic of Korea.; Division of Bioresource Sciences, Kangwon National University, Chuncheon, 24341, South Korea. esseong@kangwon.ac.kr.
The SAMS (S-adenosylmethionine synthetase) gene is known to play an important role in the mechanism of cold resistance, as overexpression of this gene results in phenotypic changes in T1-generation transgenic plants. Accordingly, this study was conducted to test the expression of the MsSAMS gene in T2-generation transgenic plants and to investigate the resistance of these plants and the function of the transgene in response to various environmental stresses. For the morphological analysis of T2-generation transgenic plants overexpressing the MsSAMS gene, observations using scanning electron microscopy (SEM) were performed. T2-generation transgenic plants were obtained by planting a total of 5 lines, and their characteristics were tested by comparisons with those of the control. SEM revealed that the thickest leaves were produced by the T6 transgenic line-161.24 +/- 8.05 microm. The number of stomata ranged from 20.00 +/- 2.65 to 34.00 +/- 1.00 in the T2-generation transgenic plants, but the control had more stomata. Resistance to various factors, such as low temperature, drought, and oxidative stress, in the T2-generation transgenic plants was also confirmed. Under cold-stress conditions, the T6 transgenic line presented the lowest value (22.73%) of ion leakage, and under drought-stress conditions, compared with the control, the transgenic lines presented lower ion leakage after being treated with various concentrations of mannitol. Even under oxidative-stress conditions, the T2-generation transgenic plants presented ion leakage levels that were 32.91 +/- 4.24 to 48.33 +/- 3.54% lower than those of the control after treatment with various concentrations of methyl viologen. Regarding SAMS enzyme activity, as the duration of cold treatment increased, the activity in the transgenic plants tended to decrease and then increase. During 48 h of cold treatment, the control showed a decrease in SAM content, while the T2-generation transgenic plants presented an increase in SAM content, from 13.58 +/- 1.04 to 22.75 +/- 1.95 mg protein/g FW. The results suggest that the MsSAMS gene may be important to the mechanisms of resistance to oxidative and drought stresses in addition to its previously known association with cold resistance. Based on these results, it was suggested that the MsSAMS gene, whose expression is induced by cold stress, can serve as a marker of various responses to environmental stresses, because resistance to cold damage and various environmental stresses are stably inherited in the T2 generation.
PMID: 35461371
Vet Med Sci , IF:1.95 , 2022 Apr doi: 10.1002/vms3.804
Effect of sage (Salvia officinalis L.) extract in antioxidant status and intestinal morphology of pulmonary hypertensive chickens.
Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran.; Department of Basic Sciences, Physiology Division, Faculty of Veterinary Medicine, Shahrekord, Iran.; Department of Animal Science, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran.
OBJECTIVES: The effects of dietary sage on the growth performance, antioxidant status, intestinal mucosa morphology, and pulmonary hypertensive response were investigated in broiler chickens with pulmonary hypertension. METHODS: Chicks (Ross 308) were reared under cold stress for 35 days and treated with 0.05% vitamin C (positive control) and 0 (control), 0.1 or 0.2% sage extracts, then performance, oxidant and antioxidant status, and intestinal morphology were evaluated. RESULTS: The index of pulmonary hypertension (RV:TV) was decreased, and weight gain (days 22-35) was increased in all treatments (except for sage 0.1%) compared with control (P < 0.05). Lipid peroxidation was decreased, whereas the activity of antioxidant enzymes (GPX, CAT, and SOD) was increased in the sage 0.2% group compared with control (P < 0.05). In the lung, SOD, CAT, and GPX transcripts were decreased in the sage 0.2% group compared with control (P < 0.05). In the right ventricle of the heart, SOD and CAT transcripts were increased in the sage 0.2% group compared with other groups of chickens, whereas GPX transcript was decreased (P < 0.05). The jejunal villus length in the chickens fed sage was significantly lower than in control (P < 0.05). The ileal villus width, villus surface area, and lamina proporia thickness in the chickens fed sage (0.2%) were increased compared with control (P < 0.05). CONCLUSIONS: Dietary supplementation of sage (0.2%) could modulate pulmonary hypertensive response, improve antioxidant status (enzymatic activity), intestinal morphometry, and absorptive surface in the broiler chickens.
PMID: 35405032
J Microsc , IF:1.758 , 2022 Mar doi: 10.1111/jmi.13101
Visualising the effect of freezing on the vascular system of wheat in three dimensions by in-block imaging of dye-infiltrated plants.
United States Department of Agriculture, Agricultural Research Service, Raleigh, North Carolina, USA.; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, North Carolina, USA.
Infrared thermography has shown after roots of grasses freeze, ice spreads into the crown and then acropetally into leaves initially through vascular bundles. Leaves freeze singly with the oldest leaves freezing first and the youngest freezing later. Visualising the vascular system in its native 3-dimensional state will help in the understanding of this freezing process. A 2 cm section of the crown that had been infiltrated with aniline blue was embedded in paraffin and sectioned with a microtome. A photograph of the surface of the tissue in the paraffin block was taken after the microtome blade removed each 20 mum section. Two hundred to 300 images were imported into Adobe After Effects and a 3D volume of the region infiltrated by aniline blue dye was constructed. The reconstruction revealed that roots fed into what is functionally a region inside the crown that could act as a reservoir from which all the leaves are able to draw water. When a single root was fed dye solution, the entire region filled with dye and the vascular bundles of every leaf took up the dye; this indicated that the vascular system of roots was not paired with individual leaves. Fluorescence microscopy suggested the edge of the reservoir might be composed of phenolic compounds. When plants were frozen, the edges of the reservoir became leaky and dye solution spread into the mesophyll outside the reservoir. The significance of this change with regard to freezing tolerance is not known at this time. Thermal cameras that allow visualisation of water freezing in plants have shown that in crops like wheat, oats and barley, ice forms first at the bottom of the plant and then moves upwards into leaves through water conducting channels. Leaves freeze one at a time with the oldest leaves freezing first and then younger ones further up the stem freeze later. To better understand why plants freeze like this, we reconstructed a 3-dimensional view of the water conducting channels. After placing the roots of a wheat plant in a blue dye and allowing it to pull the dye upwards into leaves, we took a part of the stem just above the roots and embedded it in paraffin. We used a microtome to slice a thin layer of the paraffin containing the plant and then photographed the surface after each layer was removed. After taking about 300 images, we used Adobe After Effects software to re-construct the plant with the water conducting system in three dimensions. The 3D reconstruction showed that roots fed into a roughly spherical area at the bottom of the stem that could act as a kind of tank or reservoir from which the leaves pull up water. When we put just one root in dye, the entire reservoir filled up and the water conducting channels in every leaf took up the dye. This indicates that the water channels in roots were not directly connected to specific leaves as we had thought. When plants were frozen, the dye leaked out of the reservoir and spread into cells outside. Research is continuing to understand the significance of this change during freezing. It is possible that information about this effect can be used to help breeders develop more winter-hardy crop plants.
PMID: 35319110
Heliyon , 2022 Mar , V8 (3) : Pe09049 doi: 10.1016/j.heliyon.2022.e09049
Nanostructured mesoporous silica materials induce hormesis on chili pepper (Capsicum annuum L.) under greenhouse conditions.
Biosystems Engineering Group, School of Engineering, Autonomous University of Queretaro-Campus Amazcala, Highway Amazcala-Chichimequillas S/N, Km 1, C.P 76265, Amazcala, El Marques, Queretaro, Mexico.; Center of Applied Physics and Advanced Technology-National Autonomous University of Mexico, Department of Nanotechnology, A.P1-1010, Queretaro, Queretaro, Mexico.; The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, Connecticut, 06504, USA.; National Technologic of Mexico Campus Roque-Apaseo el Alto, C.P 38525, Apaseo el alto, Guanajuato, Mexico.; Postgraduate Studies Division, School of Engineering-Universitary Center, Autonomous University of Queretaro, C.P. 76010, Queretaro, Queretaro, Mexico.
Current agricultural practices for vegetable production are unsustainable, and the use of certain nanomaterials has shown significant potential for either plant growth promotion or defense induction in crop species. The aim of the present work was to evaluate the possible effects of two SBA nano-structured silica materials differing in morphology; SBA-15, with porous structure in parallel and with a highly ordered hexagonal array and SBA-16, with spheric nano-cages located in cubic arrays, as plant growth promoters/eustressors on chili pepper (Capsicum annuum L.) during cultivation under greenhouse conditions. The study was carried out at three foliarly applied concentrations (20, 50 and 100 ppm) of either SBA materials to determine effects on seed germination, seedling growth, plant performance and cold tolerance under greenhouse. Phytotoxicity tests were carried out using higher concentrations (100, 1000 and 200 ppm) applied by dipping or spraying onto chili pepper plants. Deionized water controls were included. The results showed that the SBA materials did not affect seed germination; however, SBA-15 at 50 ppm and 100 ppm applied by imbibition significantly increased seedling height (up to 8-fold) and provided enhanced growth performance in comparison with controls under select treatment regimes. Weekly application of SBA-15 at 20 ppm significantly increased stem diameter and cold tolerance; however, SBA-16 showed significant decreases in plant height (20 ppm biweekly applied) and stem diameter (20, 50 and 100 ppm biweekly applied). The results demonstrate that both SBA materials provided hormetic effects in a dose dependent manner on chili pepper production and protection to cold stress. No phytotoxic response was evident. These findings suggested the nanostructured mesoporous silica have potential as a sustainable amendment strategy to increase crop production under stress-inducing cultivation conditions.
PMID: 35287323