Environ Int , IF:9.621 , 2021 Jul , V152 : P106493 doi: 10.1016/j.envint.2021.106493
Chronic exposure to glyphosate in Florida manatee.
Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA; Aquatic Animal Health Program, College of Veterinary Medicine, University of Florida, PO Box 100136, Gainesville, FL 32610, USA. Electronic address: maitedmm@gmail.com.; Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. Electronic address: csilvasanchez@ncasi.org.; Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. Electronic address: krollk@ufl.edu.; Aquatic Animal Health Program, College of Veterinary Medicine, University of Florida, PO Box 100136, Gainesville, FL 32610, USA. Electronic address: walshm@ufl.edu.; Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. Electronic address: mnouridelavar@ufl.edu.; U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL 32653, United States. Electronic address: mhunter@usgs.gov.; Clearwater Marine Aquarium, 249 Windward Passage, Clearwater, FL 33767, USA. Electronic address: mross@cmaquarium.org.; Georgia Aquarium, Atlanta, Georgia, 225 Baker Street Northwest, Atlanta, GA 30313, USA. Electronic address: tclauss@georgiaaquarium.org.; Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA; Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA. Electronic address: ndenslow@ufl.edu.
Florida manatees depend on freshwater environments as a source of drinking water and as warm-water refuges. These freshwater environments are in direct contact with human activities where glyphosate-based herbicides are being used. Glyphosate is the most used herbicide worldwide and it is intensively used in Florida as a sugarcane ripener and to control invasive aquatic plants. The objective of the present study was to determine the concentration of glyphosate and its breakdown product, aminomethylphosphonic acid (AMPA), in Florida manatee plasma and assess their exposure to manatees seeking a warm-water refuge in Crystal River (west central Florida), and in South Florida. We analyzed glyphosate's and AMPA's concentrations in Florida manatee plasma (n = 105) collected during 2009-2019 using HPLC-MS/MS. We sampled eight Florida water bodies between 2019 and 2020, three times a year: before, during and after the sugarcane harvest using grab samples and molecular imprinted passive Polar Organic Chemical Integrative Samplers (MIP-POCIS). Glyphosate was present in 55.8% of the sampled Florida manatees' plasma. The concentration of glyphosate has significantly increased in Florida manatee samples from 2009 until 2019. Glyphosate and AMPA were ubiquitous in water bodies. The concentration of glyphosate and AMPA was higher in South Florida than in Crystal River, particularly before and during the sugarcane harvest when Florida manatees depend on warm water refuges. Based on our results, Florida manatees were chronically exposed to glyphosate and AMPA, during and beyond the glyphosate applications to sugarcane, possibly associated with multiple uses of glyphosate-based herbicides for other crops or to control aquatic weeds. This chronic exposure in Florida water bodies may have consequences for Florida manatees' immune and renal systems which may further be compounded by other environmental exposures such as red tide or cold stress.
PMID: 33740675
Free Radic Biol Med , IF:7.376 , 2021 Jun , V172 : P286-297 doi: 10.1016/j.freeradbiomed.2021.06.011
Cold plasma seed treatment improves chilling resistance of tomato plants through hydrogen peroxide and abscisic acid signaling pathway.
State Key Laboratory of Crop Biology / Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, Ministry of Agriculture / Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong / College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China.; China Agricultural University, Beijing, 100083, China.; State Key Laboratory of Crop Biology / Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, Ministry of Agriculture / Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong / College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China. Electronic address: gongbiao@sdau.edu.cn.
How to develop a simple and economic approach to improve plant cold stress tolerance is an important scientific problem. With the hope that we explored the effect and metabolism of cold plasma (CP) seed treatment on the chilling tolerance in tomato plants. 75 W CP seed treatment showed the best mitigative effect on cold-induced injury of tomato seedlings, as evidenced by the higher maximum photochemical efficiency of PSII (Fv/Fm), lower ion leakage and chilling injury index. Moreover, the results showed that CP-induced chilling tolerance was related to the hydrogen peroxide (H2O2) mediated by respiratory burst oxidase homologue 1 (RBOH1), which was proved by the decrease low temperature tolerance observed in RBOH1 silence or chemical scavenging of H2O2 seedlings. Furthermore, RBOH1-mediated H2O2 acted as the downstream signaling of CP treatment to enhance the levels of abscisic acid (ABA) by increasing the transcript of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1). Mutation of NCED1 completely abolished CP-induced cold resistance. Genetic evidence showed that H2O2 and ABA were positive regulators of cold stress tolerance. Thus, CP-induced H2O2 and ABA cascade signal up-regulated the regulatory genes (ICE1 and CBF1) of cold acclimation, which increased the osmotic adjustment substances (proline and soluble sugar) accumulation and antioxidant enzymes (SOD, APX and CAT) activities. Our results indicate that H2O2 and ABA signals are involved in conferring cold stress tolerance induced by CP seed treatment in tomato plants.
PMID: 34139310
Plant Cell Environ , IF:7.228 , 2021 Jun doi: 10.1111/pce.14138
HSP70-16 and VDAC3 jointly inhibit seed germination under cold stress in Arabidopsis.
Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.; CAS Key Laboratory of Receptor Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.; University of Chinese Academy of Sciences, Beijing, China.; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.; Department of Molecular Physiology, Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.
Abscisic acid (ABA) transport plays a crucial role in seed germination under unfavorable conditions such as cold stress. Heat shock protein 70 (HSP70) and voltage-dependent anion channel (VDAC) protein are both involved in cold stress responses in Arabidopsis. However, their roles in seed germination with regard to ABA signaling remains unknown. Here we demonstrated that Arabidopsis HSP70-16 and VDAC3 jointly suppress seed germination under cold stress conditions. At 4(o) C, both HSP70-16 and VDAC3 facilitated the efflux of ABA from the endosperm to the embryo and thus inhibited seed germination. HSP70-16 interacted with VDAC3 on the plasma membrane and in the nucleus, and the interplay between HSP70-16 and VDAC3 activated the opening of the VDAC3 ion channel. Our work established a novel function of HSP70-16 in seed germination under cold stress and a possible association of VDAC3 activity with ABA transportation from endosperm to embryo under cold stress conditions. This article is protected by copyright. All rights reserved.
PMID: 34173257
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab257
Temperature regulation of plant hormone signaling during stress and development.
Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada.
Global climate change has broad-ranging impacts on the natural environment and human civilization. Increasing average temperatures along with more frequent heat waves collectively have negative effects on cultivated crops in agricultural sectors and wild species in natural ecosystems. These aberrantly hot temperatures, together with cold stress, represent major abiotic stresses to plants. Molecular and physiological responses to high and low temperatures are intricately linked to the regulation of important plant hormones. In this review, we shall highlight our current understanding of how changing temperatures regulate plant hormone pathways during immunity, stress responses and development. This article will present an overview of known temperature-sensitive or temperature-reinforced molecular hubs in hormone biosynthesis, homeostasis, signaling and downstream responses. These include recent advances on temperature regulation at the genomic, transcriptional, post-transcriptional and post-translational levels - directly linking some plant hormone pathways to known thermosensing mechanisms. Where applicable, diverse plant species and various temperature ranges will be presented, along with emerging principles and themes. It is anticipated that a grand unifying synthesis of current and future fundamental outlooks on how fluctuating temperatures regulate important plant hormone signaling pathways can be leveraged towards forward-thinking solutions to develop climate-smart crops amidst our dynamically changing world.
PMID: 34081133
Front Plant Sci , IF:5.753 , 2021 , V12 : P672017 doi: 10.3389/fpls.2021.672017
Identification of Glutathione S-Transferase Genes in Hami Melon (Cucumis melo var. saccharinus) and Their Expression Analysis Under Cold Stress.
Engineering Research Center for Storage and Processing of Xinjiang Characteristic Fruit and Vegetables, Ministry of Education, College of Food, Shihezi University, Shihezi, China.; College of Life Science and Food Engineering, Hebei University of Engineering, Handan, China.
As a group of multifunctional enzymes, glutathione S-transferases (GSTs) participate in oxidative stress resistance and cellular detoxification. Here, we identified 39 CmGST genes with typical binding sites from the Hami melon genome, and they can be classified into seven subfamilies. Their molecular information, chromosomal locations, phylogenetic relationships, synteny relationships, gene structures, protein-protein interactions, structure of 3-D models, and expression levels under cold stress were analyzed. Expression analysis indicates that cold-tolerant Jia Shi-310 (JS) had higher GST enzyme activities and expression levels of 28 stress-related genes under cold stress. Some CmGSTs belonging to Tau, Phi, and DHAR classes play significant roles under cold stress, and they could be regarded as candidate genes for further studies. The present study systematically investigated the characterization of the Hami melon GST gene family, extending our understanding of Hami melon GST mediated stress-response mechanisms in this worldwide fruit.
PMID: 34168669
Front Plant Sci , IF:5.753 , 2021 , V12 : P687826 doi: 10.3389/fpls.2021.687826
RNA N6-Methyladenosine Responds to Low-Temperature Stress in Tomato Anthers.
Department of Horticulture, Zhejiang University, Hangzhou, China.; College of Horticulture, Northeast Agricultural University, Harbin, China.; Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agricultural, Zhejiang University, Hangzhou, China.
Cold stress is a serious threat to subtropical crop pollen development and induces yield decline. N6-methyladenosine (m(6)A) is the most frequent mRNA modification and plays multiple physiological functions in plant development. However, whether m(6)A regulates pollen development is unclear, and its putative role in cold stress response remains unknown. Here, we observed that moderate low-temperature (MLT) stress induced pollen abortion in tomato. This phenotype was caused by disruption of tapetum development and pollen exine formation, accompanied by reduced m(6)A levels in tomato anther. Analysis of m(6)A-seq data revealed 1,805 transcripts displayed reduced m(6)A levels and 978 transcripts showed elevated m(6)A levels in MLT-stressed anthers compared with those in anthers under normal temperature. These differentially m(6)A enriched transcripts under MLT stress were mainly related to lipid metabolism, adenosine triphosphatase (ATPase) activity, and ATP-binding pathways. An ATP-binding transcript, SlABCG31, had significantly upregulated m(6)A modification levels, which was inversely correlated to the dramatically downregulated expression level. These changes correlated with higher abscisic acid (ABA) levels in anthers and disrupted pollen wall formation under low-temperature stress. Our findings characterized m(6)A as a novel layer of complexity in gene expression regulation and established a molecular link between m(6)A methylation and tomato anther development under low-temperature conditions.
PMID: 34149789
Plant Sci , IF:4.729 , 2021 Jul , V308 : P110927 doi: 10.1016/j.plantsci.2021.110927
Genome-wide analysis of the bZIP gene family and the role of AchnABF1 from postharvest kiwifruit (Actinidia chinensis cv. Hongyang) in osmotic and freezing stress adaptations.
College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.; Biotechnology of Horticultural Crops, TUM School for Life Sciences Weihenstephan, Technische Universitat Munchen, Freising, D-85354, Germany.; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, China.; College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China. Electronic address: qinggangzhu@nwafu.edu.cn.; College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China. Electronic address: raojingpingxn@163.com.
Chilling injury (CI) is a barrier to the refrigeration of kiwifruit, resulting in decreased fruit quality and increased nutrient loss during storage. Understanding the molecular basis underlying the cold response and its regulation in refrigerated kiwifruit is therefore highly important. Basic (region) leucine zipper (bZIP) transcription factors (TFs) have been widely studied for their roles in abiotic stress resistance in various species. In this study, we identified 81 bZIP family proteins in kiwifruit and classified them into 11 groups. Further transcriptome analysis revealed that the expression of members of the AREB/ABF family was strongly induced by low temperature and abscisic acid (ABA). Ectopic expression of AchnABF1 enhanced plant cold tolerance by upregulating the expression of several key genes associated with ABA-dependent and ABA-independent pathways in Arabidopsis thaliana. Reactive oxygen species (ROS) metabolism was suggested to be involved in the AchnABF1-mediated osmotic stress response. For instance, enhanced ROS-scavenging ability was observed in transgenic plants with enhanced activity of catalase (CAT) and peroxidase (POD), which resulted in decreased in situ O2(.-) and H2O2 accumulation, ion leakage, and malondialdehyde (MDA) content under various abiotic stresses. In addition, AchnABF1 also participated in the osmotic stress response during both the germination and postgermination stages. We concluded that AchnABF1 may play an important role in kiwifruit during refrigeration.
PMID: 34034875
Plant Cell Rep , IF:4.57 , 2021 Jun doi: 10.1007/s00299-021-02726-0
Characterization of APX and APX-R gene family in Brassica juncea and B. rapa for tolerance against abiotic stresses.
Department of Biotechnology, BMS Block I, Panjab University, Sector 25, Chandigarh, 160014, India.; Department of Botany, Panjab University, Sector 14, Chandigarh, 160014, India.; Department of Biotechnology, BMS Block I, Panjab University, Sector 25, Chandigarh, 160014, India. kashmirbio@pu.ac.in.
KEY MESSAGE: APX and APX-R gene families were identified and characterized in two important oilseed species of Brassica. Gene expression under abiotic stress conditions, recombinant protein expression, and analysis further divulged their drought, heat, and salt-responsive behavior. Ascorbate peroxidases (APX) are heme-dependent enzymes that rid the cells of H2O2 and regulate diverse biological processes. In the present study, we performed APX gene family characterization in two Brassica sp. (B. juncea and B. rapa) as these are commercially important oilseed crops and affected severely by abiotic stresses. We identified 16 BjuAPX and 9 BraAPX genes and 2 APX-R genes each in B. juncea and B. rapa genomes, respectively. Phylogenetic analysis divided the APX genes into five distinct clades, which exhibited conservation in the gene structure, motif organization, and sub-cellular location within the clade. Structural analysis of APX and APX-R proteins revealed the amino acid substitutions in conserved domains of APX-R proteins. The expression profiling of BjuAPX and BraAPX genes showed that 3 BjuAPX, 7BraAPX, and 2 BraAPX-R genes were drought and heat responsive. Notably, BjuAAPX1a, BjuAPX1d, BjuAAPX6, BraAAPX1a, BraAAPX2, and BraAAPX3b showed high expression levels in RT-qPCR. Cis-regulatory elements in APX and APX-R gene promoters supported the differential behavior of these genes. Further, two stress-responsive genes BjuAPX1d and BraAAPX2 were cloned, characterized, and their roles were validated under heat, drought, salt, and cold stress in bacterial expression system. This study for the first time reports the presence of APX activity in dimeric and LMW form of purified BraAAPX2 protein. The study may help pave way for developing abiotic stress-tolerant Brassica crops.
PMID: 34115169
Plant Physiol Biochem , IF:4.27 , 2021 Jun , V166 : P549-557 doi: 10.1016/j.plaphy.2021.06.024
Tuberous roots of transgenic sweetpotato overexpressing IbCAD1 have enhanced low-temperature storage phenotypes.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon, 34113, Republic of Korea.; Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea; Department of Bio-Molecular Science, KRIBB School of Bioscience, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon, 34113, Republic of Korea.; R&D Center, Genolution Inc., 11, Beobwon-ro 11-gil, Songpa-gu, Seoul, 05836, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon, 34113, Republic of Korea. Electronic address: sskwak@kribb.re.kr.
Lignin is associated with cell wall rigidity, water and solute transport, and resistance to diverse stresses in plants. Lignin consists of polymerized monolignols (p-coumaryl, coniferyl, and sinapyl alcohols), which are synthesized by cinnamyl alcohol dehydrogenase (CAD) in the phenylpropanoid pathway. We previously investigated cold-induced IbCAD1 expression by transcriptome profiling of cold-stored tuberous roots of sweetpotato (Ipomoea batatas [L.] Lam). In this study, we confirmed that IbCAD1 expression levels depended on the sweetpotato root type and were strongly induced by several abiotic stresses. We generated transgenic sweetpotato plants overexpressing IbCAD1 (TC plants) to investigate CAD1 physiological functions in sweetpotato. TC plants displayed lower root weights and lower ratios of tuberous roots to pencil roots than non-transgenic (NT) plants. The lignin contents in tuberous roots of NT and TC plants differed slightly, but these differences were not significant. By contrast, monolignol levels and syringyl (S)/guaiacyl (G) ratios were higher in TC plants than NT plants, primarily owing to syringyl unit accumulation. Tuberous roots of TC plants displayed enhanced low-temperature (4 degrees C) storage with lower malondialdehyde and H2O2 contents than NT plants. We propose that high monolignol levels in TC tuberous roots served as substrates for increased peroxidase activity, thereby enhancing antioxidation capacity against cold stress-induced reactive oxygen species. Increased monolignol contents and/or increased S/G ratios might contribute to pathogen-induced stress tolerance as a secondary chilling-damage response in sweetpotato. These results provide novel information about CAD1 function in cold stress tolerance and root formation mechanisms in sweetpotato.
PMID: 34174660
BMC Plant Biol , IF:4.215 , 2021 Jun , V21 (1) : P278 doi: 10.1186/s12870-021-03076-5
Combining QTL-seq and linkage mapping to fine map a candidate gene in qCTS6 for cold tolerance at the seedling stage in rice.
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Ministry of Education, Northeast Agricultural University, Harbin, 150030, China.; Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Ministry of Education, Northeast Agricultural University, Harbin, 150030, China. zoudtneau@126.com.
BACKGROUND: Cold stress caused by low temperatures is an important factor restricting rice production. Identification of cold-tolerance genes that can stably express in cold environments is crucial for molecular rice breeding. RESULTS: In this study, we employed high-throughput quantitative trait locus sequencing (QTL-seq) analyses in a 460-individual F2:3 mapping population to identify major QTL genomic regions governing cold tolerance at the seedling stage in rice. A novel major QTL (qCTS6) controlling the survival rate (SR) under low-temperature conditions of 9 degrees C/10 days was mapped on the 2.60-Mb interval on chromosome 6. Twenty-seven single-nucleotide polymorphism (SNP) markers were designed for the qCST6 region based on re-sequencing data, and local QTL mapping was conducted using traditional linkage analysis. Eventually, we mapped qCTS6 to a 96.6-kb region containing 13 annotated genes, of which seven predicted genes contained 13 non-synonymous SNP loci. Quantitative reverse transcription PCR analysis revealed that only Os06g0719500, an OsbZIP54 transcription factor, was strongly induced by cold stress. Haplotype analysis confirmed that +376 bp (T>A) in the OsbZIP54 coding region played a key role in regulating cold tolerance in rice. CONCLUSION: We identified OsbZIP54 as a novel regulatory gene associated with rice cold-responsive traits, with its Dongfu-104 allele showing specific cold-induction expression serving as an important molecular variation for rice improvement. This result is expected to further exploration of the genetic mechanism of rice cold tolerance at the seedling stage and improve cold tolerance in rice varieties by marker-assisted selection.
PMID: 34147069
BMC Plant Biol , IF:4.215 , 2021 Jun , V21 (1) : P268 doi: 10.1186/s12870-021-03045-y
BRS1 mediates plant redox regulation and cold responses.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China. xushb@nwsuaf.edu.cn.
BACKGROUND: Brassinosteroid-insensitive 1 suppressor 1 (BRS1) is a serine carboxypeptidase that mediates brassinosteroid signaling and participates in multiple developmental processes in Arabidopsis. However, little is known about the precise role of BRS1 in this context. RESULTS: In this study, we analyzed transcriptional and proteomic profiles of Arabidopsis seedlings overexpressing BRS1 and found that this gene was involved in both cold stress responses and redox regulation. Further proteomic evidence showed that BRS1 regulated cell redox by indirectly interacting with cytosolic NADP + -dependent isocitrate dehydrogenase (cICDH). One novel alternative splice form of BRS1 was identified in over-expression mutants brs1-1D, which may confer a new role in plant development and stress responses. CONCLUSIONS: This study highlights the role of BRS1 in plant redox regulation and stress responses, which extends our understanding of extracellular serine carboxypeptidases.
PMID: 34116634
BMC Plant Biol , IF:4.215 , 2021 Jun , V21 (1) : P252 doi: 10.1186/s12870-021-03036-z
Effect of chilling acclimation on germination and seedlings response to cold in different seed coat colored wheat (Triticum aestivum L.).
Department of Plant Biotechnology, Korea University, Seoul, 02841, Korea.; Department of Biotechnology, Korea University, Seoul, 02841, Korea.; Department of Plant Biotechnology, Korea University, Seoul, 02841, Korea. seoag@korea.ac.kr.
BACKGROUND: Flavonoids can protect plants against extreme temperatures and ROS due to their antioxidant activities. We found that deep-purple seed coat color was controlled by two gene interaction (12:3:1) from the cross between yellow and deep-purple seed coat colored inbreds. F2:3 seeds were grouped in 3 by seed coat color and germinated under chilling (4 degrees C) and non-acclimated conditions (18 degrees C) for a week, followed by normal conditions (18 degrees C) for three weeks and a subsequent chilling stress (4 degrees C) induction. We analyzed mean daily germination in each group. Additionally, to study the acclimation in relationship to the different seed coat colors on the germination ability and seedling performances under the cold temperatures, we measured the chlorophyll content, ROS scavenging activity, and expression levels of genes involved in ROS scavenging, flavonoid biosynthetic pathway, and cold response in seedlings. RESULTS: The results of seed color segregation between yellow and deep purple suggested a two-gene model. In the germination study, normal environmental conditions induced the germination of yellow-seed, while under chilling conditions, the germination ratio of deep purple-seed was higher than that of yellow-colored seeds. We also found that the darker seed coat colors were highly responsive to cold acclimation based on the ROS scavenging enzymes activity and gene expression of ROS scavenging enzymes, flavonoid biosynthetic pathway and cold responsive genes. CONCLUSIONS: We suggest that deep purple colored seed might be in a state of innate pre-acquired stress response state under normal conditions to counteract stresses in a more effective way. Whereas, after the acclimation, another stress should enhance the cold genes expression response, which might result in a more efficient chilling stress response in deep purple seed seedlings. Low temperature has a large impact on the yield of crops. Thus, understanding the benefit of seed coat color response to chilling stress and the identification of limiting factors are useful for developing breeding strategies in order to improve the yield of wheat under chilling stress.
PMID: 34078280
Tree Physiol , IF:4.196 , 2021 Jun doi: 10.1093/treephys/tpab084
Poplar PsnICE1 enhances cold tolerance by binding to different cis-acting elements to improve reactive oxygen species-scavenging capability.
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 100091, China.; State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China.; Key Laboratory of Fast-Growing Tree Cultivating of Heilongjiang Province, Forestry Science Research Institute of Heilongjiang Province, Harbin 150081, China.; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
Low temperature is a major stress that severely affects plant growth and development. ICE1 (Inducer of CBF Expression 1) plays a key role in plant cold tolerance by regulating the expression of cold stress-responsive genes. In the present study, we characterized the function and underlying regulatory mechanism of PsnICE1 from Xiaohei poplar (Populus simonii x P. nigra). PsnICE1 was significantly induced in response to cold stress in the roots, stems and leaves. PsnICE1 proteins were found to localize to the nucleus and exert transactivation activity via thier N-terminal transactivation domain. Compared with non-transgenic poplar, transgenic poplar overexpressing PsnICE1 showed substantially enhanced tolerance to cold stress, with higher survival rates and antioxidant enzyme activity levels and reduced reactive oxygen species (ROS) accumulation. In contrast, plants with RNA inhibition-mediated silencing of PsnICE1 showed the opposite phenotype. PsnICE1 can bind to H-box and ABRE elements, and more importantly, it mainly binds to IBS1 (a newly discovered cis-acting element) and E-box elements to regulate stress-related genes involved in ROS scavenging. Overall, these results indicated that PsnICE1 functions as a positive regulator of cold tolerance and serves as a potential candidate gene for plant cold tolerance improvement via molecular breeding.
PMID: 34185092
BMC Genomics , IF:3.969 , 2021 Jun , V22 (1) : P462 doi: 10.1186/s12864-021-07763-3
Transcriptome analysis reveals Vernalization is independent of cold acclimation in Arabidopsis.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, 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.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, 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. jiangjiafu@njau.edu.cn.
BACKGROUND: Through vernalization, plants achieve flowering competence by sensing prolonged cold exposure (constant exposure approximately 2-5 degrees C). During this process, plants initiate defense responses to endure cold conditions. Here, we conducted transcriptome analysis of Arabidopsis plants subjected to prolonged cold exposure (6 weeks) to explore the physiological dynamics of vernalization and uncover the relationship between vernalization and cold stress. RESULTS: Time-lag initiation of the two pathways and weighted gene co-expression network analysis (WGCNA) revealed that vernalization is independent of cold acclimation. Moreover, WGCNA revealed three major networks involving ethylene and jasmonic acid response, cold acclimation, and chromatin modification in response to prolonged cold exposure. Finally, throughout vernalization, the cold stress response is regulated via an alternative splicing-mediated mechanism. CONCLUSION: These findings illustrate a comprehensive picture of cold stress- and vernalization-mediated global changes in Arabidopsis.
PMID: 34154522
Funct Integr Genomics , IF:3.41 , 2021 Jun doi: 10.1007/s10142-021-00790-z
The NAC-type transcription factor GmNAC20 improves cold, salinity tolerance, and lateral root formation in transgenic rice plants.
State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. rajeshyarra@rediffmail.com.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
NAC-type transcription factors are crucial players in the abiotic stress responses of plants. Soybean NAC-type transcription factor GmNAC20 was transformed into rice genome via Agrobacterium method of transformation to improve abiotic stress tolerance. Integration and expression of GmNAC20 were verified by the DNA blot hybridization, immunoblotting, RT-PCR, and quantitative RT-PCR in T3 generation of transgenic rice plants. Significant expression of GmNAC20 was found in transgenic plants under salinity, cold, and IAA treatments. The transgenic rice plants expressing GmNAC20 displayed enhanced salinity and cold stress tolerance via upregulating the abiotic stress-responsive genes. Furthermore, T3 transgenic plants retained relative water content, chlorophyll content with enhanced accumulation of proline content than wild-type plants under salinity, and cold stress environments. The decrease in MDA content and electrolyte leakage with a significant increase in antioxidant enzyme activities were noticed in transgenic rice plants under either salinity or cold stress conditions, compared to wild-type plants. Overexpression of GmNAC20 in rice plants also induced the lateral root formation, associated with upregulation of auxin signaling-related genes. Taken together, our results indicated that GmNAC20 acts as a positive regulator for conferring salinity and cold tolerance in rice plants and appropriate candidate for improving salinity and cold stress in other important food crops.
PMID: 34191184
DNA Cell Biol , IF:3.311 , 2021 Jun doi: 10.1089/dna.2021.0147
Physiological Changes and Differential Gene Expression of Tea Plants (Camellia sinensis (L.) Kuntze var. niaowangensis Q.H. Chen) Under Cold Stress.
The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang, China.; Guizhou Province Institute of Biology, Guizhou Academy of Sciences, Guiyang, China.; The Application Center for Plant Conservation Technology, Guizhou Academy of Agricultural Sciences, Guiyang, China.
Low temperature is an important factor that affects the growth and reproduction of tea plants [Camellia sinensis (L.) Kuntze]. In this study, Yunwu Tribute Tea cutting seedlings [Camellia sinensis (L.) Kuntze var. niaowangensis Q.H. Chen] were subjected to different low-temperature treatments in Guizhou Province, China, and the changes in physiological indicators of the leaves were measured to investigate the physiological response and cold tolerance of this variety. Under cold stress, the peak of antioxidant enzyme activity appeared on the third day of treatment at 1 degrees C, indicating that Yunwu Tribute Tea could improve the resistance to cold stress through an increase in enzyme activity within a low-temperature range. However, after 3 days treatment at 1 degrees C, the tolerance of plant had been exceeded; the ability to resist cold stress disappeared, and enzyme activity decreased. When the temperature or duration of stress exceeded the maximum tolerance of the plant, the synthesis of soluble substances decreased in concert with their protective effects. Under cold conditions, Yunwu Tribute Tea could increase the production of abscisic acid growth inhibitors and reduce those of indoleacetic acid, gibberellin, and other growth promoting substances to manage cold stress by regulating the balance of growth regulators in the plant. Five differential genes were screened as candidate genes from the Yunwu Tribute Tea cold stress transcriptome (DW, 1 degrees C) for fluorescence quantitative analysis. The results showed that the changes in levels of expression of these genes under continuous cold stress significantly positively correlated with the corresponding physiological indicators. Nevertheless, the levels of expression of the Yunwu Tribute Tea polyphenol oxidase (PPO) gene and the gibberellin 3beta-dioxygenase gene (G3O2) were reversely inhibited under cold stress. The result was consistent with the corresponding physiological indicators, and it provides a basis for the study of cold resistance mechanisms in tea plants.
PMID: 34129383
J Appl Genet , IF:3.24 , 2021 Jun doi: 10.1007/s13353-021-00634-3
Genome-wide characterization of carotenoid oxygenase gene family in three cotton species and functional identification of GaNCED3 in drought and salt stress.
Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences, 050051, Hebei, China.; National Cotton Improvement Center Hebei Branch, Key Laboratory of Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, 050051, Hebei, China.; Hebei Academy of Governance, Hebei, 050031, China.; Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences, 050051, Hebei, China. jmzhang@live.cn.; National Cotton Improvement Center Hebei Branch, Key Laboratory of Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, 050051, Hebei, China. jmzhang@live.cn.; Institute of Cotton, Hebei Academy of Agriculture and Forestry Sciences, 050051, Hebei, China. mhszjh@163.com.; National Cotton Improvement Center Hebei Branch, Key Laboratory of Biology and Genetic Improvement of Cotton in Huanghuaihai Semiarid Area, 050051, Hebei, China. mhszjh@163.com.
Cotton that serves natural fiber for the textile industry is an important industrial crop. However, abiotic stress imposed a significant negative impact on yield and quality of cotton fiber. Carotenoid cleavage oxygenases (CCOs) that specifically catalyze the cleavage of carotenoid are essential for plant growth and development and abiotic stress response. While information of cotton CCOs and their potential functions in abiotic stress is still far from satisfactory, which imposes restrictions on application in genetic breeding for stress resistance. In this study, 15, 15, and 30 CCOs were identified from Gossypium arboreum, Gossypium raimondii, and Gossypium hirsutum, respectively. Phylogenetic relationship indicated that CCO genes could be classified into two groups (NCEDs and CCDs). Cis-elements prediction showed that there were 18 types of stress-related cis-elements in promoter regions. Analysis with transcriptome data revealed tissue-specific expression pattern of cotton CCOs. qRT-PCR analysis revealed only that GhNCED3a_A/D and GhNCED3c_A/D had strong response to drought, salt, and cold stress, while GhCCD1_A/D and GhCCD4_A showed relatively slight expression changes. Virus-induced gene silencing of GaNCED3a, the ortholog gene of GhNCED3a_A/D, suggested that silenced plants exhibited decreased resistance not only to drought but also to salt, with significantly reduced proline content, and high malondialdehyde content and water loss rate. In addition, stress response genes RD29A, DREB1A, and SOS1 significantly downregulated under drought and salt stress in silenced plants compared to control plants, indicating that GaNCED3a played an important role in drought and salt response. The results provided valuable insights into function analysis of cotton CCOs in abiotic stress response, and suggested potential benefit genes for stress-resistant breeding.
PMID: 34109531
Plant Signal Behav , IF:2.247 , 2021 Jun , V16 (6) : P1913307 doi: 10.1080/15592324.2021.1913307
SnRK2.6 interacts with phytochrome B and plays a negative role in red light-induced stomatal opening.
College of Life Science, Hebei Normal University, Shijiazhuang, China.
Light is an important environmental factor for plant growth and development. Phytochrome B (phyB), a classical red/far-red light receptor, plays vital role in controlling plant photomorphogenesis and light-induced stomatal opening. Phytohormone abscisic acid (ABA) accumulates rapidly and triggers a series of physiological and molecular events during the responses to multiple abiotic stresses. Recent studies showed that phyB mutant synthesizes more ABA and exhibits improved tolerance to salt and cold stress, suggesting that a crosstalk exists between light and ABA signaling pathway. However, whether ABA signaling components mediate responses to light remains unclear. Here, we showed that SnRK2.6 (Sucrose Nonfermenting 1-Related Protein Kinase 2.6), a key regulator in ABA signaling, interacts with phyB and participates in light-induced stomatal opening. First, we checked the interaction between phyB and SnRK2s, and found that SnRK2.2/2.3/2.6 kinases physically interacted with phyB in yeast and in vitro. We also performed co-IP assay to support that SnRK2.6 interacts with phyB in plant. To investigate the role of SnRK2.6 in red light-induced stomatal opening, we obtained the snrk2.6 mutant and overexpression lines, and found that snrk2.6 mutant exhibited a significantly larger stomatal aperture under red light treatment, while the two independent overexpression lines showed significantly smaller stomatal aperture, indicative of a negative role for SnRK2.6 in red light-induced stomatal opening. The interaction of SnRK2.6 with red light receptor and the negative role of SnRK2.6 in red light-induced stomatal opening provide new evidence for the crosstalk between ABA and red light in guard cell signaling.
PMID: 33853508