J Am Chem Soc , IF:14.612 , 2019 Aug , V141 (34) : P13311-13314 doi: 10.1021/jacs.9b06727
Common Source of Cryoprotection and Osmoprotection by Osmolytes.
Department of Physics and the Russell Berrie Nanotechnology Institute , Technion - Israel Institute of Technology , Technion City, Haifa 3200003 , Israel.
While recent studies clarify the effect of osmolytes on Coulomb interaction at elevated concentrations of salt, little is known about the way osmolytes affect the same interaction in cryoprotection. In this Communication we explore the effect of cold on the interaction between two charged surfaces immersed in ternary solution containing salt and osmolyte and find that the effect of cold parallels that of excess salt, i.e., low temperatures increase adsorption of salt counterions to the surface, thus neutralizing it. Two osmolytes, proline and glycine-betaine, are then shown to recharge the surface by releasing the adsorbed counterions. The ability to counteract effects of both cold and excess salt on Coulomb interactions renders these known osmolytes cryoprotectants as well as osmoprotectants, explaining why plants, fish, insects and bacteria accumulate them in response to either drought or cold stress.
PMID: 31411463
Plant Physiol , IF:6.902 , 2019 Aug , V180 (4) : P2061-2076 doi: 10.1104/pp.19.00088
Brassinosteroids Act as a Positive Regulator of Photoprotection in Response to Chilling Stress.
Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou 310058, People's Republic of China.; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou 310058, People's Republic of China.; Centre for Plant Sciences, Faculty of Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.; Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou 310058, People's Republic of China jqyu@zju.edu.cn.
Photoprotection is an important strategy adopted by plants to avoid photoinhibition under stress conditions. However, the way in which photoprotection is regulated is not fully understood. Here, we demonstrate that tomato (Solanum lycopersicum) mutants of brassinosteroid (BR) biosynthesis (dwf) and related signaling through BRASSINAZOLE-RESISTANT1 (bzr1) are more sensitive to (PSII and PSI photoinhibition, with decreased cyclic electron flow around PSI and lower nonphotochemical quenching, accumulation of PSII subunit S (PsbS), violaxanthin deepoxidase (VDE) activity, and D1 protein abundance. Chilling induced the accumulation of active BRs and activated BZR1, which directly activates the transcription of RESPIRATORY BURST OXIDASE HOMOLOG1 (RBOH1) and hydrogen peroxide production in the apoplast. While apoplastic hydrogen peroxide is essential for the induction of PROTON GRADIENT REGULATION5 (PGR5)-dependent cyclic electron flow, PGR5 participates in the regulation of chilling- and BR-dependent induction of nonphotochemical quenching, accumulation of D1, VDE, and PsbS proteins, transcription of genes involved in redox signaling, hormone signaling, and activity of several antioxidant enzymes. Mutations in BZR1 and PGR5 or suppressed transcription of RBOH1 compromised chilling- and BR-induced photoprotection, resulting in increased sensitivity to photoinhibition. These results demonstrate that BRs act as a positive regulator of photoprotection in a redox-PGR5-dependent manner in response to chilling stress in tomato.
PMID: 31189657
J Exp Bot , IF:5.908 , 2019 Aug , V70 (15) : P3851-3866 doi: 10.1093/jxb/erz192
A missense mutation in Large Grain Size 1 increases grain size and enhances cold tolerance in rice.
School of Life Sciences, Xiamen University, Xiamen, China.; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, China.; Quanzhou Institute of Agricultural Sciences, Quanzhou, China.; Department of Plant Sciences, University of Idaho, Moscow, ID, USA.
Grain shape is controlled by quantitative trait loci (QTLs) in rice (Oryza sativa L.). A rice mutant (JF178) with long and large grains has been used in a breeding program for over a decade, but its genetic basis has been unclear. Here, a semi-dominant QTL, designated Large Grain Size 1 (LGS1), was cloned and the potential molecular mechanism of LGS1 function was studied. Near-isogenic lines (NILs) and a map-based approach were employed to clone the LGS1 locus. LGS1 encodes the OsGRF4 transcription factor and contains a 2 bp missense mutation in the coding region that coincides with the putative pairing site of miRNA396. The LGS1 transcript levels in the mutant line were found to be higher than the lgs1 transcript levels in the control plants, suggesting that the mutation might disrupt the pairing of the LGS1 mRNA with miR396. In addition to producing larger grains, LGS1 also enhanced cold tolerance at the seedling stage and increased the survival rate of seedlings after cold stress treatment. These findings indicate that the mutation in LGS1 appears to disturb the GRF4-miR396 stress response network and results in the development of enlarged grains and enhancement of cold tolerance in rice.
PMID: 31020332
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (15) doi: 10.3390/ijms20153828
Comparative Analysis of two Sugarcane Ancestors Saccharum officinarum and S. spontaneum based on Complete Chloroplast Genome Sequences and Photosynthetic Ability in Cold Stress.
College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China.; Key Laboratory of Sugarcane Biology and Genetic Breeding, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China. lfs810@sina.com.; Key Laboratory of Sugarcane Biology and Genetic Breeding, Fujian Agriculture and Forestry University, Fuzhou 350002, China. lfs810@sina.com.; Key Laboratory of Sugarcane Biology and Genetic Breeding, Fujian Agriculture and Forestry University, Fuzhou 350002, China. xlpmail@126.com.
Polyploid Saccharum with complex genomes hindered the progress of sugarcane improvement, while their chloroplast genomes are much smaller and simpler. Chloroplast (cp), the vital organelle, is the site of plant photosynthesis, which also evolves other functions, such as tolerance to environmental stresses. In this study, the cp genome of two sugarcane ancestors Saccharum officinarum and S. spontaneum were sequenced, and genome comparative analysis between these two species was carried out, together with the photosynthetic ability. The length is 141,187 bp for S. officinarum and that is 7 bp longer than S. spontaneum, with the same GC content (38.44%) and annotated gene number (134), 13 with introns among them. There is a typical tetrad structure, including LSC, SSC, IRb and IRa. Of them, LSC and IRa/IRb are 18 bp longer and 6 bp shorter than those in S. spontaneum (83,047 bp and 22,795 bp), respectively, while the size of SSC is same (12,544 bp). Five genes exhibit contraction and expansion at the IR junctions, but only one gene ndhF with 29 bp expansion at the border of IRb/SSC. Nucleotide diversity (Pi) based on sliding window analysis showed that the single copy and noncoding regions were more divergent than IR- and coding regions, and the variant hotspots trnG-trnM, psbM-petN, trnR-rps14, ndhC-trnV and petA-psbJ in the LSC and trnL-ccsA in the SSC regions were detected, and petA-psbJ with the highest divergent value of 0.01500. Genetic distances of 65 protein genes vary from 0.00000 to 0.00288 between two species, and the selective pressure on them indicated that only petB was subjected to positive selection, while more genes including rpoC2, rps3, ccsA, ndhA, ndhA, psbI, atpH and psaC were subjected to purifying or very strong purifying selection. There are larger number of codons in S. spontaneum than that in S. officinarum, while both species have obvious codon preference and the codons with highest-(AUG) and lowest frequency (AUA) are same. Whilst, the most abundant amino acid is leucine in both S. officinarum and S. spontaneum, with number of 2175 (10.88% of total) and 2228 (10.90% of total) codons, respectively, and the lowest number is cysteine, with only 221 (1.105%) and 224 (1.096%), respectively. Protein collinearity analysis showed the high collinearity though several divergences were present in cp genomes, and identification of simple sequence repeats (SSRs) were included in this study. In addition, in order to compare cold tolerance and explore the expanding function of this environmental stress, the chlorophyll relative content (SPAD) and chlorophyll fluorescence Fv/Fm were measured. The significantly higher SPAD were observed in S. spontaneum than those in S. officinarum, no matter what the control conditions, exposure to low temperature or during recovery, and so was for Fv/Fm under exposure to low temperature, together with higher level of SPAD in S. spontaneum in each measurement. Aforementioned results suggest much stronger photosynthetic ability and cold tolerance in S. spontaneum. Our findings build a foundation to investigate the biological mechanism of two sugarcane ancestor chloroplasts and retrieve reliable molecular resources for phylogenetic and evolutionary studies, and will be conducive to genetic improvement of photosynthetic ability and cold resistance in modern sugarcane.
PMID: 31387284
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (15) doi: 10.3390/ijms20153796
GmFAD3A, A omega-3 Fatty Acid Desaturase Gene, Enhances Cold Tolerance and Seed Germination Rate under Low Temperature in Rice.
Key Laboratory of Molecular Biology and Gene Engineering of Jiangxi Province, College of Life Science, Nanchang University, Nanchang 330031, China.; National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China.; Key Laboratory of Crop Physiology, Ecology, and Genetic Breeding, Ministry of Education, College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, China.; Jiangxi Super-Rice Research and Development Center, Nanchang 330200, China.; State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.; Key Laboratory of Molecular Biology and Gene Engineering of Jiangxi Province, College of Life Science, Nanchang University, Nanchang 330031, China. xiaojuepeng@ncu.edu.cn.
Low temperature is an environmental stress factor that is always been applied in research on improving crop growth, productivity, and quality of crops. Polyunsaturated fatty acids (PUFAs) play an important role in cold tolerance, so its genetic manipulation of the PUFA contents in crops has led to the modification of cold sensitivity. In this study, we over-expressed an omega-3 fatty acid desaturase from Glycine max (GmFAD3A) drove by a maize ubiquitin promoter in rice. Compared to the wild type (ZH11), ectopic expression of GmFAD3A increased the contents of lipids and total PUFAs. Seed germination rates in GmFAD3A transgenic rice were enhanced under low temperature (15 degrees C). Moreover, cold tolerance and survival ratio were significantly improved in GmFAD3A transgenic seedlings. Malondialdehyde (MDA) content in GmFAD3A transgenic rice was lower than that in WT under cold stress, while proline content obviously increased. Meanwhile, the activities of superoxide dismutase (SOD), hydroperoxidase (CAT), and peroxidase (POD) increased substantially in GmFAD3A transgenic rice after 4 h of cold treatment. Taken together, our results suggest that GmFAD3A can enhances cold tolerance and the seed germination rate at a low temperature in rice through the accumulation of proline content, the synergistic increase of the antioxidant enzymes activity, which finally ameliorated the oxidative damage.
PMID: 31382584
BMC Genomics , IF:3.594 , 2019 Aug , V20 (1) : P687 doi: 10.1186/s12864-019-6045-y
Transcriptome profiling reveals candidate flavonol-related genes of Tetrastigma hemsleyanum under cold stress.
Institute of Biopharmaceutical Technology, Zhejiang Pharmaceutical College, Ningbo, 315100, Zhejiang, People's Republic of China.; Fujian Agriculture and Forestry University, Fuzhou, 350000, Fujian, People's Republic of China.; Ningbo Engineering College, Ningbo, 315100, China.; Fujian Agriculture and Forestry University, Fuzhou, 350000, Fujian, People's Republic of China. hauzzy@163.com.
BACKGROUND: Tetrastigma hemsleyanum Diels et Gilg is a valuable medicinal herb, whose main bioactive constituents are flavonoids. Chilling sensitivity is the dominant environmental factor limiting growth and development of the plants. But the mechanisms of cold sensitivity in this plant are still unclear. Also, not enough information on genes involved in flavonoid biosynthesis in T. hemsleyanum is available to understand the mechanisms of its physiological and pharmaceutical effects. RESULTS: The electrolyte leakage, POD activity, soluble protein, and MDA content showed a linear sustained increase under cold stress. The critical period of cold damage in T. hemsleyanum was from 12 h to 48 h. Expression profiles revealed 18,104 differentially expressed genes (DEGs) among these critical time points. Most of the cold regulated DEGs were early-response genes. A total of 114 unigenes were assigned to the flavonoid biosynthetic pathway. Fourteen genes most likely to encode flavonoid biosynthetic enzymes were identified. Flavonols of T. hemsleyanum might play a crucial role in combating cold stress. Genes encoding PAL, 4CL, CHS, ANR, FLS, and LAR were significantly up-regulated by cold stress, which could result in a significant increase in crucial flavonols (catechin, epicatechin, rutin, and quercetin) in T. hemsleyanum. CONCLUSIONS: Overall, our results show that the expression of genes related to flavonol biosynthesis as well as flavonol content increased in T. hemsleyanum under cold stress. These findings provide valuable information regarding the transcriptome changes in response to cold stress and give a clue for identifying candidate genes as promising targets that could be used for improving cold tolerance via molecular breeding. The study also provides candidate genes involved in flavonoid biosynthesis and may be useful for clarifying the biosynthetic pathway of flavonoids in T. hemsleyanum.
PMID: 31472675
BMC Genomics , IF:3.594 , 2019 Aug , V20 (1) : P651 doi: 10.1186/s12864-019-5972-y
Genome-wide analysis of the cotton G-coupled receptor proteins (GPCR) and functional analysis of GTOM1, a novel cotton GPCR gene under drought and cold stress.
State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Science (ICR-CAAS), Anyang, 455000, Henan, China.; School of Physical and Biological Sciences (SPBS), Main campus, Jaramogi Oginga Odinga University of Science and Technology, P.O Box 210-40601, Bondo, Kenya.; Research Base in Anyang Institute of Technology, State Key Laboratory of Cotton Biology/Anyang Institute of technology, Anyang, 455000, Henan, China.; State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Science (ICR-CAAS), Anyang, 455000, Henan, China. wkbcri@163.com.; State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Science (ICR-CAAS), Anyang, 455000, Henan, China. liufcri@163.com.; School of Agricultural Sciences, Zhengzhou University, 450001, Henan, China. liufcri@163.com.
BACKGROUND: The efficient detection and initiation of appropriate response to abiotic stresses are important to plants survival. The plant G-protein coupled receptors (GPCRs) are diverse membranous proteins that are responsible for signal transduction. RESULTS: In this research work, we identified a novel gene of the GPCR domain, transformed and carried out the functional analysis in Arabidopsis under drought and cold stresses. The transgenic lines exposed to drought and cold stress conditions showed higher germination rate, increased root length and higher fresh biomass accumulation. Besides, the levels of antioxidant enzymes, glutathione (GSH) and ascorbate peroxidase (APX) exhibited continuously increasing trends, with approximately threefold higher than the control, implying that these ROS-scavenging enzymes were responsible for the detoxification of ROS induced by drought and cold stresses. Similarly, the transgenic lines exhibited stable cell membrane stability (CMS), reduced water loss rate in the detached leaves and significant values for the saturated leaves compared to the wild types. Highly stress-responsive miRNAs were found to be targeted by the novel gene and based on GO analysis; the protein encoded by the gene was responsible for maintaining an integral component of membrane. In cotton, the virus-induced gene silencing (VIGS) plants exhibited a higher susceptibility to drought and cold stresses compared to the wild types. CONCLUSION: The novel GPCR gene enhanced drought and cold stress tolerance in transgenic Arabidopsis plants by promoting root growth and induction of ROS scavenging enzymes. The outcome showed that the gene had a role in enhancing drought and cold stress tolerance, and can be further exploited in breeding for more stress-resilient and tolerant crops.
PMID: 31412764
Plant Sci , IF:3.591 , 2019 Aug , V285 : P68-78 doi: 10.1016/j.plantsci.2019.05.003
Overexpression of soybean miR169c confers increased drought stress sensitivity in transgenic Arabidopsis thaliana.
College of Agronomy, Xinjiang Agricultural University, Urumqi, 830052, PR China.; College of Agronomy, Xinjiang Agricultural University, Urumqi, 830052, PR China. Electronic address: nizhiyong@126.com.; The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China.; The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China. Electronic address: zhanghui06@caas.cn.
The miR169 family, a large-scale microRNA gene family conserved in plants, is involved in stress responses, although how soybean miR169 functions in response to drought stress remains unclear. We show that gma-miR169c exerts a negative regulatory role in the response to drought stress by inhibiting the expression of its target gene, nuclear factor Y-A (NF-YA). A real-time RT-PCR analysis indicated that gma-miR169c is widely expressed in soybean tissues and induced by polyethylene glycol (PEG), high salt, cold stress and abscisic acid (ABA). Histochemical ss-glucuronidase (GUS) staining showed that the gma-miR169c promoter drives GUS reporter gene expression in various transgenic Arabidopsis tissues, and the stress-induced pattern was confirmed in transgenic Arabidopsis and transgenic soybean hairy roots. Arabidopsis overexpressing gma-miR169c is more sensitive to drought stress, with reduced survival, accelerated leaf water loss, and shorter root length than wild-type plants. We identified a precise cleavage site for 10 gma-miR169c targets and found reduced transcript levels of the AtNFYA1 and AtNFYA5 transcription factors in gma-miR169c-overexpressing Arabidopsis and reduced expression of the stress response genes AtRD29A, AtRD22, AtGSTU25 and AtCOR15A. These results indicate that gma-miR169c plays a negative regulatory role in drought stress and is a candidate miRNA for improving plant drought adaptation.
PMID: 31203895
BMC Plant Biol , IF:3.497 , 2019 Aug , V19 (1) : P352 doi: 10.1186/s12870-019-1922-8
Genes, pathways and transcription factors involved in seedling stage chilling stress tolerance in indica rice through RNA-Seq analysis.
Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India. pradhancrri@gmail.com.; Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India. elsambio@gmail.com.; Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India.; Indian Council of Agricultural Research, New Delhi, India.
BACKGROUND: Rice plants show yellowing, stunting, withering, reduced tillering and utimately low productivity in susceptible varieties under low temperature stress. Comparative transcriptome analysis was performed to identify novel transcripts, gain new insights into different gene expression and pathways involved in cold tolerance in rice. RESULTS: Comparative transcriptome analyses of 5 treatments based on chilling stress exposure revealed more down regulated genes in susceptible and higher up regulated genes in tolerant genotypes. A total of 13930 and 10599 differentially expressed genes (DEGs) were detected in cold susceptible variety (CSV) and cold tolerant variety (CTV), respectively. A continuous increase in DEGs at 6, 12, 24 and 48 h exposure of cold stress was detected in both the genotypes. Gene ontology (GO) analysis revealed 18 CSV and 28 CTV term significantly involved in molecular function, cellular component and biological process. GO classification showed a significant role of transcription regulation, oxygen, lipid binding, catalytic and hydrolase activity for tolerance response. Absence of photosynthesis related genes, storage products like starch and synthesis of other classes of molecules like fatty acids and terpenes during the stress were noticed in susceptible genotype. However, biological regulations, generation of precursor metabolites, signal transduction, photosynthesis, regulation of cellular process, energy and carbohydrate metabolism were seen in tolerant genotype during the stress. KEGG pathway annotation revealed more number of genes regulating different pathways resulting in more tolerant. During early response phase, 24 and 11 DEGs were enriched in CTV and CSV, respectively in energy metabolism pathways. Among the 1583 DEG transcription factors (TF) genes, 69 WRKY, 46 bZIP, 41 NAC, 40 ERF, 31/14 MYB/MYB-related, 22 bHLH, 17 Nin-like 7 HSF and 4C3H were involved during early response phase. Late response phase showed 30 bHLH, 65 NAC, 30 ERF, 26/20 MYB/MYB-related, 11 C3H, 12 HSF, 86 Nin-like, 41 AP2/ERF, 55 bZIP and 98 WRKY members TF genes. The recovery phase included 18 bHLH, 50 NAC, 31 ERF, 24/13 MYB/MYB-related, 4 C3H, 4 HSF, 14 Nin-like, 31 bZIP and 114 WRKY TF genes. CONCLUSIONS: Transcriptome analysis of contrasting genotypes for cold tolerance detected the genes, pathways and transcription factors involved in the stress tolerance.
PMID: 31412781
BMC Plant Biol , IF:3.497 , 2019 Aug , V19 (1) : P339 doi: 10.1186/s12870-019-1955-z
Diverse biological effects of glycosyltransferase genes from Tartary buckwheat.
College of Life Science, Sichuan Agricultural University, Ya'an, Sichuan Province, People's Republic of China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; VIB-UGent Center for Plant Systems Biology, Ghent, Belgium.; Department of Biomolecular Medicine, Ghent University, Ghent, Belgium.; VIB-UGent Center for Medical Biotechnology, Ghent, Belgium.; College of Life Science, Sichuan Agricultural University, Ya'an, Sichuan Province, People's Republic of China. zhaohaixia@sicau.edu.cn.
BACKGROUND: Tartary buckwheat (Fagopyrum tataricum) is an edible cereal crop whose sprouts have been marketed and commercialized for their higher levels of anti-oxidants, including rutin and anthocyanin. UDP-glucose flavonoid glycosyltransferases (UFGTs) play an important role in the biosynthesis of flavonoids in plants. So far, few studies are available on UFGT genes that may play a role in tartary buckwheat flavonoids biosynthesis. Here, we report on the identification and functional characterization of seven UFGTs from tartary buckwheat that are potentially involved in flavonoid biosynthesis (and have varying effects on plant growth and development when overexpressed in Arabidopsis thaliana.) RESULTS: Phylogenetic analysis indicated that the potential function of the seven FtUFGT proteins, FtUFGT6, FtUFGT7, FtUFGT8, FtUFGT9, FtUFGT15, FtUFGT40, and FtUFGT41, could be divided into three Arabidopsis thaliana functional subgroups that are involved in flavonoid biosynthesis of and anthocyanin accumulation. A significant positive correlation between FtUFGT8 and FtUFGT15 expression and anthocyanin accumulation capacity was observed in the tartary buckwheat seedlings after cold stress. Overexpression in Arabidopsis thaliana showed that FtUFGT8, FtUFGT15, and FtUFGT41 significantly increased the anthocyanin content in transgenic plants. Unexpectedly, overexpression of FtUFGT6, while not leading to enhanced anthocyanin accumulation, significantly enhanced the growth yield of transgenic plants. When wild-type plants have only cotyledons, most of the transgenic plants of FtUFGT6 had grown true leaves. Moreover, the growth speed of the oxFtUFGT6 transgenic plant root was also significantly faster than that of the wild type. At later growth, FtUFGT6 transgenic plants showed larger leaves, earlier twitching times and more tillers than wild type, whereas FtUFGT15 showed opposite results. CONCLUSIONS: Seven FtUFGTs were isolated from tartary buckwheat. FtUFGT8, FtUFGT15, and FtUFGT41 can significantly increase the accumulation of total anthocyanins in transgenic plants. Furthermore, overexpression of FtUFGT6 increased the overall yield of Arabidopsis transgenic plants at all growth stages. However, FtUFGT15 shows the opposite trend at later growth stage and delays the growth speed of plants. These results suggested that the biological function of FtUFGT genes in tartary buckwheat is diverse.
PMID: 31382883
Life (Basel) , IF:2.991 , 2019 Aug , V9 (3) doi: 10.3390/life9030067
Universal Molecular Triggers of Stress Responses in Cyanobacterium Synechocystis.
Department of Molecular Biosystems, K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya street 35, 127276 Moscow, Russian.; Department of Biology, School of Natural Sciences, Kean University, 1000 Morris Ave, Union, NJ 07083, USA.; Department of Molecular Biosystems, K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya street 35, 127276 Moscow, Russian. losda@ippras.ru.
Systemic analysis of stress-induced transcription in the cyanobacterium Synechocystis sp. strain PCC 6803 identifies a number of genes as being induced in response to most abiotic stressors (heat, osmotic, saline, acid stress, strong light, and ultraviolet radiation). Genes for heat-shock proteins (HSPs) are activated by all these stresses and form a group that universally responds to all environmental changes. The functions of universal triggers of stress responses in cyanobacteria can be performed by reactive oxygen species (ROS), in particular H2O2, as well as changes in the redox potential of the components of the photosynthetic electron transport chain. The double mutant of Synechocystis sp. PCC 6803 (katG/tpx, or sll1987/sll0755), which is defective in antioxidant enzymes catalase (KatG) and thioredoxin peroxidase (Tpx), cannot grow in the presence of exogenous hydrogen peroxide (H2O2); and it is extremely sensitive to low concentrations of H2O2, especially under conditions of cold stress. Experiments on this mutant demonstrate that H2O2 is involved in regulation of gene expression that responds to a decrease in ambient temperature, and affects both the perception and the signal transduction of cold stress. In addition, they suggest that formation of ROS largely depends on the physical state of the membranes such as fluidity or viscosity. In cyanobacteria, an increase in membrane turnover leads to a decrease in the formation of ROS and an increase in resistance to cold stress. Therefore: (1) H2O2 is the universal trigger of stress responses in cyanobacterial cells; (2) ROS formation (in particular, H2O2) depends on the physical properties of both cytoplasmic and thylakoid membranes; (3) The destructive effect of H2O2 is reduced by increasing of fluidity of biological membranes.
PMID: 31434306
G3 (Bethesda) , IF:2.781 , 2019 Aug , V9 (8) : P2723-2737 doi: 10.1534/g3.119.400229
Comparative Transcriptome Analyses Revealed Conserved and Novel Responses to Cold and Freezing Stress in Brassica napus L.
Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, Hunan, China 410128 and.; Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, Hunan, China 410128 and huawei@oilcrops.cn.; 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.
Oil rapeseed (Brassica napus L.) is a typical winter biennial plant, with high cold tolerance during vegetative stage. In recent years, more and more early-maturing rapeseed varieties were planted across China. Unfortunately, the early-maturing rapeseed varieties with low cold tolerance have higher risk of freeze injury in cold winter and spring. Little is known about the molecular mechanisms for coping with different low-temperature stress conditions in rapeseed. In this study, we investigated 47,328 differentially expressed genes (DEGs) of two early-maturing rapeseed varieties with different cold tolerance treated with cold shock at chilling (4 degrees ) and freezing (-4 degrees ) temperatures, as well as chilling and freezing stress following cold acclimation or control conditions. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that two conserved (the primary metabolism and plant hormone signal transduction) and two novel (plant-pathogen interaction pathway and circadian rhythms pathway) signaling pathways were significantly enriched with differentially-expressed transcripts. Our results provided a foundation for understanding the low-temperature stress response mechanisms of rapeseed. We also propose new ideas and candidate genes for genetic improvement of rapeseed tolerance to cold stresses.
PMID: 31167831
Plants (Basel) , IF:2.762 , 2019 Aug , V8 (8) doi: 10.3390/plants8080288
Identification of Genes Differentially Expressed in Response to Cold in Pisum sativum Using RNA Sequencing Analyses.
ICV-Institut Charles Viollette, EA 7394, USC 1411, Univ. Lille, F-59000 Lille, France.; ICV-Adaptation au Froid du Pois, USC 1411, INRA, F-80300 Peronne, France.; GCIE, UE 0972, INRA, F-80203 Peronne, France.; GeT-PlaGe, Genotoul, US 1426, INRA, F-31326 Castanet-Tolosan, France.; Evo-Eco-Paleo, UMR 8198, Univ. Lille, CNRS, F-59000 Lille, France. sylvain.legrand@univ-lille.fr.
Low temperature stress affects growth and development in pea (Pisum sativum L.) and decreases yield. In this study, RNA sequencing time series analyses performed on lines, Champagne frost-tolerant and Terese frost-sensitive, during a low temperature treatment versus a control condition, led us to identify 4981 differentially expressed genes. Thanks to our experimental design and statistical analyses, we were able to classify these genes into three sets. The first one was composed of 2487 genes that could be related to the constitutive differences between the two lines and were not regulated during cold treatment. The second gathered 1403 genes that could be related to the chilling response. The third set contained 1091 genes, including genes that could be related to freezing tolerance. The identification of differentially expressed genes related to cold, oxidative stress, and dehydration responses, including some transcription factors and kinases, confirmed the soundness of our analyses. In addition, we identified about one hundred genes, whose expression has not yet been linked to cold stress. Overall, our findings showed that both lines have different characteristics for their cold response (chilling response and/or freezing tolerance), as more than 90% of differentially expressed genes were specific to each of them.
PMID: 31443248
Funct Plant Biol , IF:2.617 , 2019 Aug , V46 (9) : P830-844 doi: 10.1071/FP19065
Transcriptomic profiling revealed genes involved in response to cold stress in maize.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, China; and Shandong Academy of Agricultural Sciences, Jinan, Shandong, China.; Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China.; Water Research Institute of Shandong Province, No. 125 Lishan Road, Jinan City, Shandong Province, China.; Shandong Provincial Key Laboratory of Microbial Engineering, School of Biologic Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, China; and Corresponding authors. Email: gina35@126.com; yhzhang9@163.com.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, China; and Corresponding authors. Email: gina35@126.com; yhzhang9@163.com.
Maize is an important food crop. Chilling stress can decrease maize production by affecting seed germination and seedling growth, especially in early spring. We analysed chlorophyll fluorescence, membrane lipids, secondary metabolites and the transcriptome of two maize inbred lines (chilling-tolerant M54 and chilling-sensitive 753F) after 0, 4 and 24 h cold stress. M54 showed better ability to protect PSII and accumulate secondary metabolites. From RNA sequencing data, we determined that the majority of cold-affected genes were involved in photosynthesis, secondary metabolism, and signal transduction. Genes important for maintaining photosystem structure and for regulating electron transport were less affected by cold stress in M54 than in 753F. Expression of genes related to secondary metabolism and unsaturated fatty acid synthesis were upregulated more strongly in M54 than in 753F and M54 accumulated more unsaturated fatty acids and secondary metabolites. As a result, M54 achieved relatively high cold tolerance by protecting the photosystems and maintaining the stability of cell membranes.
PMID: 31217070
Res Vet Sci , IF:1.892 , 2019 Aug , V125 : P390-396 doi: 10.1016/j.rvsc.2019.08.012
Amelioration effects of Kaempferol on immune response following chronic intermittent cold-stress.
College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot 010018, PR China.; College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, PR China.; College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot 010018, PR China. Electronic address: chunjiewang200@sohu.com.; College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot 010018, PR China; College of Basic Medical, Inner Mongolia Medical University, Hohhot 010110, PR China.
Cold-stress causes disturbance of the homeostatic regulation of animals, and gradually impairs the immune and antioxidant functions of animals. Therefore, increasing the effectiveness of the immune response and antioxidant function are the most attractive strategies against cold-stress. Kaempferol (KPF) exerts both an anti-inflammatory and antioxidant pharmacological effect. However, nor much is known of the effects of KPF on providing protection from cold-induced intestinal oxidative damage and improving immunity. This study investigated the effects of KPF on immune factors and intestinal antioxidation in the blood of cold-stressed mice. KPF was solubilized in diluted saline before administration. The mice were randomly divided into 4 groups: (1) control, (2) cold-stress, (3) KPF 25mg/kg, and (4) cinnamon (CAM) 30mg/kg groups. Groups (2)-(4) were exposed to cold stress once a day for 7days. Cold-stress was achieved by exposing the mice to a temperature of -15 degrees C and 70+/-10% humidity for 60min, once a day. The histopathological changes in the small intestine of the mice were analyzed. The T lymphocyte populations in blood were measured using flow cytometry. The level of SLC6a4, 5-HT3 and 5-HTT in small intestine tissue was assessed using RT-PCR analysis. Cow blood samples were obtained for the hematological analysis. Kaempferol (KPF) (25mg/kg) regularized the intestinal antioxidant activity in the cold stress animals. KPF was able to significantly (P<.05) return intestinal SLC6a4, 5-HT3 and 5-HTT levels to normal after it had increased due to cold-stress. KPF treatment prevented the cold stress-induced decrease in blood CD4(+)T cells and decrease CD8(+)T cells levels in mice. Improved hematological profiles were additionally observed on treatment cows with KPF. KPF compared favorably with cinnamon in cold stress management, suggesting cold stress disturbs the anti-inflammatory effect of KPF. Thus, KPF contributes to suppress the activated pro-inflammatory cytokines, IL-9, IL-13, CD8(+)T and neurochemicals, and to increase anti-inflammatory cytokines and CD4(+)T levels.
PMID: 31412308
Mar Genomics , IF:1.672 , 2019 Aug , V46 : P41-48 doi: 10.1016/j.margen.2019.03.004
Identification of alternative oxidase encoding genes in Caulerpa cylindracea by de novo RNA-Seq assembly analysis.
Bolu Abant Izzet Baysal University, Faculty of Arts and Science, Department of Chemistry, Bolu 14280, Turkey. Electronic address: esunlu@ibu.edu.tr.; Bolu Abant Izzet Baysal University, Faculty of Arts and Science, Department of Chemistry, Bolu 14280, Turkey.
Alternative oxidases (AOX) are defined in plants, fungi and algae. The main function of AOX proteins has been described for electron flow through electron transport chain and regulation of mitochondrial retrograde signaling pathway. The roles of AOX proteins have been characterized in reproduction and resistance against oxidative stress, cold stress, starvation, and biotic attacks. Caulerpa cylindracea is an invasive marine green alga. Although the natural habitats of the species are Australia coasts, the impact of the invasion has been monitored through the Mediterranean Sea and the Aegean Sea. C. cylindracea species have advantages against others by showing higher resistance to stress conditions such as cold, starvation, pathogen attacks and by their capability of sexual and vegetative reproduction. Comparing the advantages of C. cylindracea over the niche and defined functional roles of mitochondrial AOX proteins, it is evident that AOX proteins are likely involved in developing those advantageous skills in C. cylindracea. However, there is limited data about biochemical and molecular mechanisms that take part in stress resistance and invasion characteristics. We aimed to identify mitochondrial alternative oxidase encoding genes in C. cylindracea while annotating whole transcriptome data for the species. Samples were collected from Seferihisar/Izmir. Transcriptome analysis from pooled RNA samples revealed 47,400 assembled contigs represented by 33,340 unigenes. Using standalone Blast analysis, we were able to identify two alternative oxidase encoding genes.
PMID: 30922784
Mol Biol Rep , IF:1.402 , 2019 Aug , V46 (4) : P3937-3944 doi: 10.1007/s11033-019-04840-5
ZmMYB31, a R2R3-MYB transcription factor in maize, positively regulates the expression of CBF genes and enhances resistance to chilling and oxidative stress.
Shandong Academy of Agricultural Sciences, Jinan, Shandong, China.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China.; Water Research Institute of Shandong Province, Jinan, China.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China. yhzhang9@163.com.; Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan, 250014, China. suina800101@163.com.
Maize (Zea mays L.) is an important model plant with an important role in agriculture and national economies all over the world. The optimum growth temperature of maize is between 25 and 28 degrees C. At temperatures below 12 degrees C, maize is vulnerable to damage by chilling stress. MYB transcription factors play important roles in plants' response to low temperature stress. Maize ZmMYB31 encodes a R2R3-MYB transcription factor, ZmMYB31, which localized in the nucleus. ZmMYB31 expression was induced by chilling stress and the highest expression level was detected with the 24 h chilling treatment. ZmMYB31 expression also increased in overexpressing Arabidopsis lines. The minimal fluorescence (Fo) with all photosystem II reaction centers open increased in wild type (WT) and transgenic plants under chilling stress, with the highest increase in WT. The maximal photochemical efficiency of photosystem II (Fv/Fm) decreased more in WT than in transgenic plants during chilling stress. Furthermore, the ZmMYB31-overexpressing lines showed higher superoxide dismutase and ascorbate peroxidase activity and lower reactive oxygen species (ROS) content than the WT. The expression of genes related to chilling stress was higher in transgenic plants than in WT. These results suggest that ZmMYB31 plays a positive regulatory role in chilling and peroxide stress by regulating the expression of chilling stress-related genes to reduce ion extravasation, ROS content, and low-temperature photoinhibition, thereby improving low temperature resistance.
PMID: 31037550