Mol Plant , IF:12.084 , 2021 Feb , V14 (2) : P315-329 doi: 10.1016/j.molp.2020.11.022
Transcriptional activation and phosphorylation of OsCNGC9 confer enhanced chilling tolerance in rice.
National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.; National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.; MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China.; National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: wanjm@njau.edu.cn.
Low temperature is a major environmental factor that limits plant growth and productivity. Although transient elevation of cytoplasmic calcium has long been recognized as a critical signal for plant cold tolerance, the calcium channels responsible for this process have remained largely elusive. Here we report that OsCNGC9, a cyclic nucleotide-gated channel, positively regulates chilling tolerance by mediating cytoplasmic calcium elevation in rice (Oryza sativa). We showed that the loss-of-function mutant of OsCNGC9 is defective in cold-induced calcium influx and more sensitive to prolonged cold treatment, whereas OsCNGC9 overexpression confers enhanced cold tolerance. Mechanistically, we demonstrated that in response to chilling stress, OsSAPK8, a homolog of Arabidopsis thaliana OST1, phosphorylates and activates OsCNGC9 to trigger Ca(2+) influx. Moreover, we found that the transcription of OsCNGC9 is activated by a rice dehydration-responsive element-binding transcription factor, OsDREB1A. Taken together, our results suggest that OsCNGC9 enhances chilling tolerance in rice through regulating cold-induced calcium influx and cytoplasmic calcium elevation.
PMID: 33278597
New Phytol , IF:8.512 , 2021 Feb , V229 (4) : P1937-1945 doi: 10.1111/nph.17062
Differential nucleosome occupancy modulates alternative splicing in Arabidopsis thaliana.
School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, CT1 1QU, UK.; School of Biosciences and Medicine, University of Surrey, Guildford, GU2 7XH, UK.; Cardiff School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK.; Computational Sciences, The James Hutton Institute, Dundee, DD2 5DA, UK.; Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences - BOKU, Muthgasse 18, 1190, Vienna, Austria.; Department of Biology and Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1878, USA.; Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY, 14853-2703, USA.
Alternative splicing (AS) is a major gene regulatory mechanism in plants. Recent evidence supports co-transcriptional splicing in plants, hence the chromatin state can impact AS. However, how dynamic changes in the chromatin state such as nucleosome occupancy influence the cold-induced AS remains poorly understood. Here, we generated transcriptome (RNA-Seq) and nucleosome positioning (MNase-Seq) data for Arabidopsis thaliana to understand how nucleosome positioning modulates cold-induced AS. Our results show that characteristic nucleosome occupancy levels are strongly associated with the type and abundance of various AS events under normal and cold temperature conditions in Arabidopsis. Intriguingly, exitrons, alternatively spliced internal regions of protein-coding exons, exhibit distinctive nucleosome positioning pattern compared to other alternatively spliced regions. Likewise, nucleosome patterns differ between exitrons and retained introns, pointing to their distinct regulation. Collectively, our data show that characteristic changes in nucleosome positioning modulate AS in plants in response to cold.
PMID: 33135169
New Phytol , IF:8.512 , 2021 Feb , V229 (3) : P1615-1634 doi: 10.1111/nph.16945
Transcriptional memories mediate the plasticity of cold stress responses to enable morphological acclimation in Brachypodium distachyon.
Department of Plant Science, McGill University, 21, 111 Lakeshore, Sainte-Anne-de-Bellevue, Canada.
Plants that successfully acclimate to stress can resume growth under stressful conditions. The grass Brachypodium distachyon can grow a cold-adaptive morphology during cold acclimation. Studies on transcriptional memory (TM) have revealed that plants can be primed for stress by adjusting their transcriptional responses, but the function of TM in stress acclimation is not well understood. We investigated the function of TM during cold acclimation in B. distachyon. Quantitative polymerase chain reaction (qPCR), RNA-seq and chromatin immunoprecipitation qPCR analyses were performed on plants exposed to repeated episodes of cold to characterize the presence and stability of TM during the stress and growth responses of cold acclimation. Transcriptional memory mainly dampened stress responses as growth resumed and as B. distachyon became habituated to cold stress. Although permanent on vernalization gene VRN1, TMs were short-term and reversible on cold-stress genes. Growing under cold conditions also coincided with the acquisition of new and targeted cold-induced transcriptional responses. Overall, TM provided plasticity to cold stress responses during cold acclimation in B. distachyon, leading to stress habituation, acquired stress responses, and resumed growth. Our study shows that chromatin-associated TMs are involved in tuning plant responses to environmental change and, as such, regulate both stress and developmental components that characterize cold-climate adaptation in B. distachyon.
PMID: 32966623
Plant Physiol , IF:6.902 , 2021 Feb doi: 10.1093/plphys/kiab073
Genetic and epigenetic variation in transposable element expression responses to abiotic stress in maize.
Department of Plant and Microbial Biology; University of Minnesota; Saint Paul; MN; United States.; Department of Genetics, Development, and Cell Biology; Iowa State University; Ames, IA; United States.; School of Agriculture and Food Sciences; The University of Queensland; Brisbane; QLD; Australia.; Department of Biology; Hofstra University; Hempstead; NY; United States.
Transposable elements (TEs) pervade most eukaryotic genomes. The repetitive nature of TEs complicates the analysis of their expression. Evaluation of the expression of both TE families (using unique and multi-mapping reads) and specific elements (using uniquely mapping reads) in leaf tissue of three maize (Zea mays) inbred lines subjected to heat or cold stress reveals no evidence for genome-wide activation of TEs, however some specific TE families generate transcripts only in stress conditions. There is substantial variation for which TE families exhibit stress-responsive expression in the different genotypes. In order to understand the factors that drive expression of TEs, we focused on a subset of families in which we could monitor expression of individual elements. The stress-responsive activation of a TE family can often be attributed to a small number of elements in the family that contain regions lacking DNA methylation. Comparisons of the expression of TEs in different genotypes revealed both genetic and epigenetic variation. Many of the specific TEs that are activated in stress in one inbred are not present in the other inbred, explaining the lack of activation. Among the elements that are shared in both genomes but only expressed in one genotype, we found that many exhibit differences in DNA methylation such that the genotype without expression is fully methylated. This study provides insights into the regulation of expression of TEs in normal and stress conditions and highlights the role of chromatin variation between elements in a family or between genotypes for contributing to expression variation. The highly repetitive nature of many transposable elements (TEs) complicates the analysis of their expression. Although most TEs are not expressed, some exhibit expression in certain tissues or conditions. We monitored the expression of both TE families (using unique and multi-mapping reads) and specific elements (using uniquely mapping reads) in leaf tissue of three maize (Zea mays) inbred lines subjected to heat or cold stress. While genome-wide activation of TEs did not occur, some TE families generated transcripts only in stress conditions with variation by genotype. To better understand the factors that drive expression of TEs, we focused on a subset of families in which we could monitor expression of individual elements. In most cases stress-responsive activation of a TE family was attributed to a small number of elements in the family. The elements that contained small regions lacking DNA methylation regions showed enriched expression while fully methylated elements were rarely expressed in control or stress conditions. The cause of varied expression in the different genotypes was due to both genetic and epigenetic variation. Many specific TEs activated by stress in one inbred were not present in the other inbred. Among the elements shared in both genomes, full methylation inhibited expression in one of the genotypes. This study provides insights into the regulation of TE expression in normal and stress conditions and highlights the role of chromatin variation between elements in a family or between genotypes for contributing to expression.
PMID: 33591319
Plant Physiol , IF:6.902 , 2021 Feb doi: 10.1093/plphys/kiab050
Transcription-associated metabolomic adjustments in maize occur during combined drought and cold stress.
China Grassland Research Center, School of Grassland Science, Beijing Forestry University, Beijing 100083, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
Although simultaneous drought and cold stress occurs, especially in northwestern and eastern regions of China, and is an important factor limiting agricultural productivity, there are few studies focusing on plant responses to a combination of drought and cold stress. Here, by partially overlapping drought and cold stresses, we characterized the acclimation of maize (Zea mays B73) to these two stresses using physiological measurements, as well as comparative transcriptomics combined with metabolomics and hormonal analyses during the stress treatments and recovery stages. The combined drought and cold stress and drought stress alone were accompanied by a decline in photosynthetic capacity and enhanced transcriptional response, and subsequent recovery of these following removal from stress, whereas cold stress alone was accompanied by irreversible damage to photosynthetic capacity and chloroplast structure. The stress combination induced transcription-associated metabolomic alterations, in which raffinose, trehalose-6-phosphate, and proline accumulated, and monosaccharide abundance increased. Concomitantly, the increased abscisic acid (ABA) content and upregulated ABA signaling pathway may have provided the transcriptional regulation for the metabolic changes. In a parallel experiment, ABA treatments prior to exposure of the plants to cold stress primed the plants to survive the cold stress, thus confirming a key role for the endogenous ABA activated by the drought pretreatment in acclimation of the plants to cold. We present a model showing that the plant response to the combined stress is multi-faceted and reveal an ABA-dependent maize acclimation mechanism to the stress combination.
PMID: 33582802
Plant Cell Environ , IF:6.362 , 2021 Feb , V44 (2) : P491-505 doi: 10.1111/pce.13938
Phosphatase OsPP2C27 directly dephosphorylates OsMAPK3 and OsbHLH002 to negatively regulate cold tolerance in rice.
The Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.; University of the Chinese Academy of Sciences, Beijing, China.
Improving chilling tolerance is a major target of rice breeding. The OsMAPK3-OsbHLH002-OsTPP1 signalling pathway enhances chilling tolerance in rice: the kinase is activated by cold stress, and subsequently the transcription factor is phosphorylated by the activated kinase, triggering the expression of cold response genes. However, it is largely unknown how this pathway is suppressed in time to avoid it being in a continuously activated state. We found that a novel type 2C protein phosphatase, OsPP2C27, functions as a negative regulator of the OsMAPK3-OsbHLH002-OsTPP1 pathway. A dynamic change in OsMAPK3 activity was found during cold treatment. We show that OsPP2C27 interacts physically with and dephosphorylates OsMAPK3 in vitro and in vivo. Interestingly, OsPP2C27 can also directly dephosphorylate OsbHLH002, the target of OsMAPK3. After cold treatment, survival rates were higher in OsPP2C27-RNAi lines and a T-DNA insertion mutant, and lower in OsPP2C27-overexpression lines, compared to wild type. Moreover, expression of the OsTPP1 and OsDREBs were increased in OsPP2C27-RNAi lines and decreased in OsPP2C27-overexpression lines. These results indicate that cold-induced OsPP2C27 negatively regulates the OsMAPK3-OsbHLH002-OsTPP1 signalling pathway by directly dephosphorylating both phospho-OsMAPK3 and phospho-OsbHLH002, preventing the sustained activation of a positive pathway for cold stress and maintaining normal growth under chilling conditions.
PMID: 33150964
Food Chem , IF:6.306 , 2021 Feb , V338 : P128005 doi: 10.1016/j.foodchem.2020.128005
Jasmonic acid treatment alleviates chilling injury in peach fruit by promoting sugar and ethylene metabolism.
Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.; The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Private Bag 11600, Palmerston North 4442, New Zealand. Electronic address: david.brummell@plantandfood.co.nz.; Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China. Electronic address: duanyuquan@caas.cn.
Peach (Prunus persica L.) fruit are highly susceptible to chilling injury during cold storage, resulting in internal flesh browning and a failure to soften normally. We have examined the effect of a postharvest treatment consisting of a brief (30 s) dip in the natural plant hormone jasmonic acid, prior to storage at 4 degrees C. Jasmonic acid treatment reduced the severity of internal flesh browning and did not inhibit fruit softening over a 35 d storage period. Two major physiological effects of jasmonic acid on the fruit were observed, an increase in ethylene production and a prevention of the decline in soluble sugar content seen in controls. An increased soluble sugar content may have multiple benefits in resisting chilling stress, scavenging reactive oxygen species and acting to stabilize membranes. Our results show that a treatment with jasmonic acid can enhance chilling tolerance of peach fruit by regulating ethylene and sugar metabolism.
PMID: 32977138
Hortic Res , IF:5.404 , 2021 Feb , V8 (1) : P37 doi: 10.1038/s41438-021-00481-7
Genome sequence and evolution of Betula platyphylla.
State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, China.; BGI-Qingdao, BGI-Shenzhen, Qingdao, China.; BGI-Tech, BGI-Shenzhen, Shenzhen, China.; College of Forest Resources and Environmental Science, Institute of Computing and Cybersystems, Michigan Technological University, Houghton, MI, USA.; Department of Mathematics and Statistics, University of Ottawa, Ottawa, ON, Canada.; Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, China.; School of Plant Sciences, University of Arizona, Tucson, AZ, USA.; Noble Research Institute, 2510 Sam Noble Parkway, Ardmore, OK, USA.; Department of Vegetable Crops, College of Horticulture and Forestry, Huazhong Agricultural University, Wuhan, P.R. China.; Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia.; US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.; Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA.; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, P. R. China.; State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, China. liuguifeng@nefu.edu.cn.; State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, China. yangcp@nefu.edu.cn.
Betula L. (birch) is a pioneer hardwood tree species with ecological, economic, and evolutionary importance in the Northern Hemisphere. We sequenced the Betula platyphylla genome and assembled the sequences into 14 chromosomes. The Betula genome lacks evidence of recent whole-genome duplication and has the same paleoploidy level as Vitis vinifera and Prunus mume. Phylogenetic analysis of lignin pathway genes coupled with tissue-specific expression patterns provided clues for understanding the formation of higher ratios of syringyl to guaiacyl lignin observed in Betula species. Our transcriptome analysis of leaf tissues under a time-series cold stress experiment revealed the presence of the MEKK1-MKK2-MPK4 cascade and six additional mitogen-activated protein kinases that can be linked to a gene regulatory network involving many transcription factors and cold tolerance genes. Our genomic and transcriptome analyses provide insight into the structures, features, and evolution of the B. platyphylla genome. The chromosome-level genome and gene resources of B. platyphylla obtained in this study will facilitate the identification of important and essential genes governing important traits of trees and genetic improvement of B. platyphylla.
PMID: 33574224
Int J Biol Macromol , IF:5.162 , 2021 Feb , V169 : P264-273 doi: 10.1016/j.ijbiomac.2020.12.102
Genome-wide identification, structure analysis and expression profiling of phospholipases D under hormone and abiotic stress treatment in chickpea (Cicer arietinum).
National Institute of Plant Genome Research, New Delhi 110067, India.; National Institute of Plant Genome Research, New Delhi 110067, India. Electronic address: amarjeet.singh@nipgr.ac.in.
Phospholipases D (PLDs) are phospholipid hydrolyzing enzymes and crucial components of lipid signaling in plants. PLDs are implicated in stress responses in different plants however, characterization of PLDs in chickpea is missing. Here, we identify 13 PLD genes in the chickpea genome. PLD family could be divided into alpha, beta, delta, epsilon and zeta isoforms based on sequence and structure. Protein remodeling described that chickpea PLDs are composed of defined arrangements of alpha-helix, beta-sheets and short loops. Phylogenetic analysis suggested evolutionary conservation of chickpea PLD family with dicots. In-planta subcellular localization showed the plasma membrane localization of chickpea PLDs. All PLD promoters had hormone and stress related cis-regulatory elements, which suggested overlapping function of PLDs in hormone and abiotic stress signaling. The qRT-PCR expression analysis revealed that most PLD genes are differentially expressed in multiple abiotic stresses (drought, salt and cold stress). Moreover, several PLD genes had overlapping expression in abiotic stress and ABA and JA treatment. These observations indicate the involvement of PLD gene family in cross-talk of phytohormone and abiotic stress signaling in chickpea. Thus, present study opens new avenues of utilizing PLD related information for understanding hormone-regulated abiotic stress signaling in legume crops.
PMID: 33338528
Int J Mol Sci , IF:4.556 , 2021 Feb , V22 (4) doi: 10.3390/ijms22041673
OsCRP1, a Ribonucleoprotein Gene, Regulates Chloroplast mRNA Stability That Confers Drought and Cold Tolerance.
Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Korea.; Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore.; E GREEN GLOBAL, Gunpo 15843, Korea.; Department of Agriculture and Life Industry, Kangwon National University, Chuncheon 24341, Korea.
Chloroplast ribonucleoproteins (cpRNPs) are nuclear-encoded and highly abundant proteins that are proposed to function in chloroplast RNA metabolism. However, the molecular mechanisms underlying the regulation of chloroplast RNAs involved in stress tolerance are poorly understood. Here, we demonstrate that CHLOROPLAST RNA-BINDING PROTEIN 1 (OsCRP1), a rice (Oryza sativa) cpRNP gene, is essential for stabilization of RNAs from the NAD(P)H dehydrogenase (NDH) complex, which in turn enhances drought and cold stress tolerance. An RNA-immunoprecipitation assay revealed that OsCRP1 is associated with a set of chloroplast RNAs. Transcript profiling indicated that the mRNA levels of genes from the NDH complex significantly increased in the OsCRP1 overexpressing compared to non-transgenic plants, whereas the pattern in OsCRP1 RNAi plants were opposite. Importantly, the OsCRP1 overexpressing plants showed a higher cyclic electron transport (CET) activity, which is essential for elevated levels of ATP for photosynthesis. Additionally, overexpression of OsCRP1 resulted in significantly enhanced drought and cold stress tolerance with higher ATP levels compared to wild type. Thus, our findings suggest that overexpression of OsCRP1 stabilizes a set of mRNAs from genes of the NDH complex involved in increasing CET activity and production of ATP, which consequently confers enhanced drought and cold tolerance.
PMID: 33562320
Theor Appl Genet , IF:4.439 , 2021 Feb , V134 (2) : P419-433 doi: 10.1007/s00122-020-03725-7
Snow mold of winter cereals: a complex disease and a challenge for resistance breeding.
Laboratory of Plant Infectious Diseases, FRC Kazan Scientific Center of RAS, Ul. Lobachevskogo 2/31, Kazan, 420111, Tatarstan, Russian Federation.; KWS SAAT SE & Co. KGaA, Grimsehlstr. 31, 37555, Einbeck, Germany.; State Plant Breeding Institute, University of Hohenheim, Fruwirthstr. 21, 70599, Stuttgart, Germany. miedaner@uni-hohenheim.de.
KEY MESSAGE: Snow mold resistance is a complex quantitative trait highly affected by environmental conditions during winter that must be addressed by resistance breeding. Snow mold resistance in winter cereals is an important trait for many countries in the Northern Hemisphere. The disease is caused by at least four complexes of soilborne fungi and oomycetes of which Microdochium nivale and M. majus are among the most common pathogens. They have a broad host range covering all winter and spring cereals and can basically affect all plant growth stages and organs. Their attack leads to a low germination rate, and/or pre- and post-emergence death of seedlings after winter and, depending on largely unknown environmental conditions, also to foot rot, leaf blight, and head blight. Resistance in winter wheat and triticale is governed by a multitude of quantitative trait loci (QTL) with mainly additive effects highly affected by genotype x environment interaction. Snow mold resistance interacts with winter hardiness in a complex way leading to a co-localization of resistance QTLs with QTLs/genes for freezing tolerance. In practical breeding, a multistep procedure is necessary with (1) freezing tolerance tests, (2) climate chamber tests for snow mold resistance, and (3) field tests in locations with and without regularly occurring snow cover. In the future, resistance sources should be genetically characterized also in rye by QTL mapping or genome-wide association studies. The development of genomic selection procedures should be prioritized in breeding research.
PMID: 33221940
Front Plant Sci , IF:4.402 , 2020 , V11 : P608711 doi: 10.3389/fpls.2020.608711
Light Regulates the Cytokinin-Dependent Cold Stress Responses in Arabidopsis.
Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia.; Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czechia.; Department of Plant Physiology, Agricultural Institute, Centre for Agricultural Research, Martonvasar, Hungary.; CEITEC MENDELU: Central European Institute of Technology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czechia.
To elucidate the effect of light intensity on the cold response (5 degrees C; 7 days) in Arabidopsis thaliana, we compared the following parameters under standard light (150 mumol m(-2) s(-1)), low light (20 mumol m(-2) s(-1)), and dark conditions: membrane damage, photosynthetic parameters, cytokinin oxidase/dehydrogenase (CKX) activity, phytohormone levels, and transcription of selected stress- and hormone-related genes and proteome. The impact of cytokinins (CKs), hormones directly interacting with the light signaling pathway, on cold responses was evaluated using transformants overexpressing CK biosynthetic gene isopentenyl transferase (DEX:IPT) or CK degradation gene HvCKX2 (DEX:CKX) under a dexamethasone-inducible promoter. In wild-type plants, cold treatment under light conditions caused down-regulation of CKs (in shoots) and auxin, while abscisic acid (ABA), jasmonates, and salicylic acid (SA) were up-regulated, especially under low light. Cold treatment in the dark strongly suppressed all phytohormones, except ABA. DEX:IPT plants showed enhanced stress tolerance associated with elevated CK and SA levels in shoots and auxin in apices. Contrarily, DEX:CKX plants had weaker stress tolerance accompanied by lowered levels of CKs and auxins. Nevertheless, cold substantially diminished the impact from the inserted genes. Cold stress in dark minimized differences among the genotypes. Cold treatments in light strongly up-regulated stress marker genes RD29A, especially in roots, and CBF1-3 in shoots. Under control conditions, their levels were higher in DEX:CKX plants, but after 7-day stress, DEX:IPT plants exhibited the highest transcription. Transcription of genes related to CK metabolism and signaling showed a tendency to re-establish, at least partially, CK homeostasis in both transformants. Up-regulation of strigolactone-related genes in apices and leaves indicated their role in suppressing shoot growth. The analysis of leaf proteome revealed over 20,000 peptides, representing 3,800 proteins and 2,212 protein families (data available via ProteomeXchange, identifier PXD020480). Cold stress induced proteins involved in ABA and jasmonate metabolism, antioxidant enzymes, and enzymes of flavonoid and glucosinolate biosynthesis. DEX:IPT plants up-regulated phospholipase D and MAP-kinase 4. Cold stress response at the proteome level was similar in all genotypes under optimal light intensity, differing significantly under low light. The data characterized the decisive effect of light-CK cross-talk in the regulation of cold stress responses.
PMID: 33613584
Front Plant Sci , IF:4.402 , 2020 , V11 : P599111 doi: 10.3389/fpls.2020.599111
Exogenous DA-6 Improves the Low Night Temperature Tolerance of Tomato Through Regulating Cytokinin.
College of Horticulture, Shenyang Agricultural University, Shenyang, China.; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, China.; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, China.
Low night temperature (LNT) causes environmental stress and has a severe and negative impact on plant growth and productivity. Synthetic elicitors can regulate plant growth and induce defense mechanisms from this type of stress. Here, we evaluated the effect of the exogenous growth regulator diethyl aminoethyl hexanoate (DA-6) in tomato leaf response to LNT stress. Our results showed that exogenous DA-6 activates the expression of chlorophyll synthesis and photosystem-related genes, and results in higher photosynthetic activity and chlorophyll production. Furthermore, DA-6 can regulate the synthesis of endogenous cytokinin (CTK) and the expression of decomposition genes to stabilize chloroplast structure, reduce oxidative damage, and maintain the photochemical activity of tomato leaves under LNT stress. DA-6 maintains a high level of ABA content and induces the expression of CBF genes, indicating that DA-6 may participate in the cold response signaling pathway and induce the expression of downstream low temperature response genes and accumulation of compatible osmolytes. This study unravels a mode of action by which plant growth regulators can improve low temperature tolerance and provides important considerations for their application to alleviate the harmful effects of cold stress.
PMID: 33613581
Plant Cell Physiol , IF:4.062 , 2021 Feb doi: 10.1093/pcp/pcab013
Natural Variation among Arabidopsis Accessions in the Regulation of Flavonoid Metabolism and Stress Gene Expression by Combined UV Radiation and Cold.
Max-Planck-Institut fur Molekulare Pflanzenphysiologie, Am Muhlenberg 1, Potsdam, 14476, Germany.; Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Ingolstadter Landstr. 1, Neuherberg, 85764, Germany.; Institute of Biochemical Plant Pathology, Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Ingolstadter Landstr. 1, Neuherberg, 85764, Germany.
Plants are constantly exposed to stressful environmental conditions. Plant stress reactions were mainly investigated for single stress factors. However, under natural conditions plants may be simultaneously exposed to different stresses. Responses to combined stresses cannot be predicted from the reactions to the single stresses. Flavonoids accumulate in Arabidopsis thaliana during exposure to UV-A, UV-B, or cold, but the interactions of these factors on flavonoid biosynthesis were unknown. We therefore investigated the interaction of UV radiation and cold in regulating the expression of well-characterized stress-regulated genes, and on transcripts and metabolites of the flavonoid biosynthetic pathway in 52 natural Arabidopsis accessions that differ widely in their freezing tolerance. The data revealed interactions of cold and UV on the regulation of stress-related and flavonoid biosynthesis genes, and on flavonoid composition. In many cases, plant reactions to a combination of cold and UV were unique under combined stress and not predictable from the responses to the single stresses. Strikingly, all correlations between expression levels of flavonoid biosynthesis genes and flavonol levels were abolished by UV-B exposure. Similarly, correlations between transcript levels of flavonoid biosynthesis genes or flavonoid contents, and freezing tolerance were lost in the presence of UV radiation, while correlations with the expression levels of cold regulated genes largely persisted. This may indicate different molecular cold acclimation responses in the presence or absence of UV radiation.
PMID: 33544865
Ann Bot , IF:4.005 , 2021 Feb , V127 (3) : P317-326 doi: 10.1093/aob/mcaa197
Dynamic modelling of cold-hardiness in tea buds by imitating past temperature memory.
National Agriculture and Food Research Organization (NARO), Institute of Agro-Environmental Sciences, Kannondai, Tsukuba, Ibaraki, Japan.; Kyushu University, Faculty of Agriculture, Fukuoka, Japan.; Kyushu University, Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.; Kochi University, Faculty of Agriculture and Marine Science, Kochi, Japan.
BACKGROUND AND AIMS: Most perennial plants memorize cold stress for a certain period and retrieve the memories for cold acclimation and deacclimation, which leads to seasonal changes in cold-hardiness. Therefore, a model for evaluating cold stress memories is required for predicting cold-hardiness and for future frost risk assessments under warming climates. In this study we develop a new dynamic model of cold-hardiness by introducing a function imitating past temperature memory in the processes of cold acclimation and deacclimation. METHODS: We formulated the past temperature memory for plants using thermal time weighted by a forgetting function, and thereby proposed a dynamic model of cold-hardiness. We used the buds of tea plants (Camellia sinensis) from two cultivars, 'Yabukita' and 'Yutakamidori', to calibrate and validate this model based on 10 years of observed cold-hardiness data. KEY RESULTS: The model captured more than 90 % of the observed variation in cold-hardiness and predicted accurate values for both cultivars, with root mean square errors of ~1.0 degrees C. The optimized forgetting function indicated that the tea buds memorized both short-term (recent days) and long-term (previous months) temperatures. The memories can drive short-term processes such as increasing/decreasing the content of carbohydrates, proteins and antioxidants in the buds, as well as long-term processes such as determining the bud phenological stage, both of which vary with cold-hardiness. CONCLUSIONS: The use of a forgetting function is an effective means of understanding temperature memories in plants and will aid in developing reliable predictions of cold-hardiness for various plant species under global climate warming.
PMID: 33247901
Genes (Basel) , IF:3.759 , 2021 Feb , V12 (2) doi: 10.3390/genes12020219
Screening and Genetic Network Analysis of Genes Involved in Freezing and Thawing Resistance in DaMDHAR-Expressing Saccharomyces cerevisiae Using Gene Expression Profiling.
Advanced Bio-Resource Research Center, Kyungpook National University, Daegu 41566, Korea.; Korea Polar Research Institute, Incheon 21990, Korea.; Department of Polar Science, University of Science and Technology, Incheon 21990, Korea.
The cryoprotection of cell activity is a key determinant in frozen-dough technology. Although several factors that contribute to freezing tolerance have been reported, the mechanism underlying the manner in which yeast cells respond to freezing and thawing (FT) stress is not well established. Therefore, the present study demonstrated the relationship between DaMDHAR encoding monodehydroascorbate reductase from Antarctic hairgrass Deschampsia antarctica and stress tolerance to repeated FT cycles (FT2) in transgenic yeast Saccharomyces cerevisiae. DaMDHAR-expressing yeast (DM) cells identified by immunoblotting analysis showed high tolerance to FT stress conditions, thereby causing lower damage for yeast cells than wild-type (WT) cells with empty vector alone. To detect FT2 tolerance-associated genes, 3'-quant RNA sequencing was employed using mRNA isolated from DM and WT cells exposed to FT (FT2) conditions. Approximately 332 genes showed >/=2-fold changes in DM cells and were classified into various groups according to their gene expression. The expressions of the changed genes were further confirmed using western blot analysis and biochemical assay. The upregulated expression of 197 genes was associated with pentose phosphate pathway, NADP metabolic process, metal ion homeostasis, sulfate assimilation, beta-alanine metabolism, glycerol synthesis, and integral component of mitochondrial and plasma membrane (PM) in DM cells under FT2 stress, whereas the expression of the remaining 135 genes was partially related to protein processing, selenocompound metabolism, cell cycle arrest, oxidative phosphorylation, and alpha-glucoside transport under the same condition. With regard to transcription factors in DM cells, MSN4 and CIN5 were activated, but MSN2 and MGA1 were not. Regarding antioxidant systems and protein kinases in DM cells under FT stress, CTT1, GTO, GEX1, and YOL024W were upregulated, whereas AIF1, COX2, and TRX3 were not. Gene activation represented by transcription factors and enzymatic antioxidants appears to be associated with FT2-stress tolerance in transgenic yeast cells. RCK1, MET14, and SIP18, but not YPK2, have been known to be involved in the protein kinase-mediated signalling pathway and glycogen synthesis. Moreover, SPI18 and HSP12 encoding hydrophilin in the PM were detected. Therefore, it was concluded that the genetic network via the change of gene expression levels of multiple genes contributing to the stabilization and functionality of the mitochondria and PM, not of a single gene, might be the crucial determinant for FT tolerance in DaMDAHR-expressing transgenic yeast. These findings provide a foundation for elucidating the DaMDHAR-dependent molecular mechanism of the complex functional resistance in the cellular response to FT stress.
PMID: 33546197
Plant Physiol Biochem , IF:3.72 , 2021 Feb , V161 : P86-97 doi: 10.1016/j.plaphy.2021.02.005
Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase genes of winter wheat enhance the cold tolerance of transgenic Arabidopsis.
College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China.; College of Agriculture, Northeast Agricultural University, Harbin, 150030, PR China.; College of Life Science, Northeast Agricultural University, Harbin, 150030, PR China. Electronic address: 1936958667@qq.com.
In this study, winter wheat G6PDH (TaG6PDH) and 6PGDH (Ta6PGDH) were investigated. Both their expression and their activity were upregulated under cold stress, suggesting that TaG6PDH and Ta6PGDH positively respond to cold stress in winter wheat. Exogenous abscisic acid (ABA) treatment markedly increased the expression and activity levels of TaG6PDH and Ta6PGDH in winter wheat under cold stress. Subsequently, TaG6PDH-and Ta6PGDH were overexpressed in Arabidopsis, and showed stronger reactive oxygen species (ROS)-scavenging ability and higher survival rate compared with wild-type (WT) plants under cold stress. In addition, we found that TaG6PDH and Ta6PGDH overexpression can promote the oxidative pentose phosphate pathway (OPPP) in the cytoplasm and peroxisomes of Arabidopsis. In summary, Arabidopsis overexpressing TaG6PDH and Ta6PGDH showed improved cold tolerance.
PMID: 33581622
Plant Sci , IF:3.591 , 2021 Feb , V303 : P110753 doi: 10.1016/j.plantsci.2020.110753
A tomato dynein light chain gene SlLC6D is a negative regulator of chilling stress.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, No.3, Taicheng Road, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Vegetables, No. 3, Taicheng Road, Yangling, Shaanxi, 712100, China. Electronic address: htx0729@nwsuaf.edu.cn.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, No.3, Taicheng Road, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Vegetables, No. 3, Taicheng Road, Yangling, Shaanxi, 712100, China. Electronic address: sfwang0321@163.com.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, No.3, Taicheng Road, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Vegetables, No. 3, Taicheng Road, Yangling, Shaanxi, 712100, China. Electronic address: wangelaxn@163.com.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, No.3, Taicheng Road, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Vegetables, No. 3, Taicheng Road, Yangling, Shaanxi, 712100, China. Electronic address: 826586930@qq.com.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, No.3, Taicheng Road, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Vegetables, No. 3, Taicheng Road, Yangling, Shaanxi, 712100, China. Electronic address: 503554334@qq.com.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, No.3, Taicheng Road, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Vegetables, No. 3, Taicheng Road, Yangling, Shaanxi, 712100, China. Electronic address: zhanxq77@nwsuaf.edu.cn.
Dynein light chain (DLC) proteins are an important component of dynein complexes, which are widely distributed in plants and animals and involved in a variety of cellular processes. The functions of DLC genes in plant chilling stress remain unclear. In this study, we isolated a DLC gene from tomato, designated SlLC6D. Promoter analysis revealed many cis-elements involved in abiotic stress in the SlLC6D promoter. Expression of SlLC6D was induced by heat and salt stress, and inhibited by polyethylene glycol and chilling stress. Knockdown of SlLC6D in tomato exhibited low relative electrolyte leakage, malondialdehyde content, and reactive oxygen species (ROS) accumulation under chilling stress. The content of proline and activities of superoxide dismutase and peroxidase in knockdown lines were higher than in the wild type and overexpression lines during chilling stress. The high transcript abundances of three cold-responsive genes were detected in knockdown lines in response to chilling stress. Seedling growth of knockdown lines was significantly higher than that of the wild type and overexpression lines under chilling stress. These results suggest that SlLC6D is a negative regulator of chilling stress tolerance, possibly by regulating ROS contents and the ICE1-CBF-COR pathway.
PMID: 33487341
J Biotechnol , IF:3.503 , 2021 Feb , V327 : P97-105 doi: 10.1016/j.jbiotec.2021.01.003
Expression of ice recrystallization inhibition protein in transgenic potato lines associated with reduced electrolyte leakage and efficient recovery post freezing injury.
Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.; Department of Microbiology, BUITEMS, Quetta, Pakistan.; Institute of Agricultural Sciences (IAGS), University of the Punjab Lahore-Pakistan, Pakistan.; Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan; School of Biological Sciences, University of the Punjab, Pakistan. Electronic address: bushratabassum.sbs@pu.edu.pk.
Potato (Solanum tuberosum L.) is considered to be frost-susceptible as short spells of frost can reduce the tuber yield and quality. Ice recrystallization inhibition (IRI) protein helps prevent growth of ice crystals in the cell apoplast during frost and help prevent damage associated with freezing stress. In this study, we investigated the in planta potential of Lolium perenne derived IRI3 transgene in improving the tolerance of transgenic potato lines for freezing stress. The codon optimized IRI3 transgene was introduced into potato cultivar Diamant through Agrobacterium mediated transformation. Three transgenic potato lines were successfully generated which were confirmed for transgene insertion and genomic integration by polymerase chain reaction and Southern blot. It was evident that the IRI3 transcript decreased in initial 24 h of cold stress treatment while the IRI3 mRNA expression up regulated in subsequent hours of cold treatment with maximum increase to 20 folds at 96 h post stress. A similar trend was also revealed in ion-leakage assay which showed that during cold stress, the transgenic potato lines depicted reduced ion leakage of 14-22% as compared to non-transgenic control plants. Further, the generated transgenic potato lines were tolerant to the frost spell in quarantine field conditions as compared to the non-transgenic potato lines. Additionally, the transgenic lines exhibited efficient recovery post frost injury in field conditions. The biochemical profiles of chlorophyll, proline and higher levels of antioxidant enzyme (superoxide dismutase, Catalase) activity and malondialdehyde levels showed that despite the phenotypic impact of low temperature, the transgenic potato lines quickly adjusted to maintain their cellular homeostasis post freezing stress by increasing the antioxidant defenses. This study suggests that up regulation of IRI3 transcript and regulatory network of cold stress response in transgenic potato lines improve frost tolerance and help stabilize yield in cultivated potato.
PMID: 33450348
BMC Plant Biol , IF:3.497 , 2021 Feb , V21 (1) : P99 doi: 10.1186/s12870-021-02864-3
Genome-wide association of rice response to blast fungus identifies loci for robust resistance under high nitrogen.
BGPI, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France.; Centre Francais du Riz, Arles, France.; AGAP, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France.; Groupe de Valorisation des Produits Agricoles (GVAPRO), Alger, Algeria.; BGPI, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France. elsa.ballini@supagro.fr.
BACKGROUND: Nitrogen fertilization is known to increase disease susceptibility, a phenomenon called Nitrogen-Induced Susceptibility (NIS). In rice, this phenomenon has been observed in infections with the blast fungus Magnaporthe oryzae. A previous classical genetic study revealed a locus (NIS1) that enhances susceptibility to rice blast under high nitrogen fertilization. In order to further address the underlying genetics of plasticity in susceptibility to rice blast after fertilization, we analyzed NIS under greenhouse-controlled conditions in a panel of 139 temperate japonica rice strains. A genome-wide association analysis was conducted to identify loci potentially involved in NIS by comparing susceptibility loci identified under high and low nitrogen conditions, an approach allowing for the identification of loci validated across different nitrogen environments. We also used a novel NIS Index to identify loci potentially contributing to plasticity in susceptibility under different nitrogen fertilization regimes. RESULTS: A global NIS effect was observed in the population, with the density of lesions increasing by 8%, on average, under high nitrogen fertilization. Three new QTL, other than NIS1, were identified. A rare allele of the RRobN1 locus on chromosome 6 provides robust resistance in high and low nitrogen environments. A frequent allele of the NIS2 locus, on chromosome 5, exacerbates blast susceptibility under the high nitrogen condition. Finally, an allele of NIS3, on chromosome 10, buffers the increase of susceptibility arising from nitrogen fertilization but increases global levels of susceptibility. This allele is almost fixed in temperate japonicas, as a probable consequence of genetic hitchhiking with a locus involved in cold stress adaptation. CONCLUSIONS: Our results extend to an entire rice subspecies the initial finding that nitrogen increases rice blast susceptibility. We demonstrate the usefulness of estimating plasticity for the identification of novel loci involved in the response of rice to the blast fungus under different nitrogen regimes.
PMID: 33602120
BMC Plant Biol , IF:3.497 , 2021 Feb , V21 (1) : P97 doi: 10.1186/s12870-021-02868-z
MaMAPK3-MaICE1-MaPOD P7 pathway, a positive regulator of cold tolerance in banana.
Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangzhou, 510640, China.; Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.; Institute of Biotechnology, Cornell University, Ithaca, NY, 14853, USA.; Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangzhou, 510640, China. huchunhua007@126.com.; Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangzhou, 510640, China. soyang@hotmail.com.
BACKGROUND: Banana is a tropical fruit with a high economic impact worldwide. Cold stress greatly affects the development and production of banana. RESULTS: In the present study, we investigated the functions of MaMAPK3 and MaICE1 involved in cold tolerance of banana. The effect of RNAi of MaMAPK3 on Dajiao (Musa spp. 'Dajiao'; ABB Group) cold tolerance was evaluated. The leaves of the MaMAPK3 RNAi transgenic plants showed wilting and severe necrotic symptoms, while the wide-type (WT) plants remained normal after cold exposure. RNAi of MaMAPK3 significantly changed the expressions of the cold-responsive genes, and the oxidoreductase activity was significantly changed in WT plants, while no changes in transgenic plants were observed. MaICE1 interacted with MaMAPK3, and the expression level of MaICE1 was significantly decreased in MaMAPK3 RNAi transgenic plants. Over-expression of MaICE1 in Cavendish banana (Musa spp. AAA group) indicated that the cold resistance of transgenic plants was superior to that of the WT plants. The POD P7 gene was significantly up-regulated in MaICE1-overexpressing transgenic plants compared with WT plants, and the POD P7 was proved to interact with MaICE1. CONCLUSIONS: Taken together, our work provided new and solid evidence that MaMAPK3-MaICE1-MaPOD P7 pathway positively improved the cold tolerance in monocotyledon banana, shedding light on molecular breeding for the cold-tolerant banana or other agricultural species.
PMID: 33596830
BMC Plant Biol , IF:3.497 , 2021 Feb , V21 (1) : P86 doi: 10.1186/s12870-021-02862-5
Genome-wide identification of PbrbHLH family genes, and expression analysis in response to drought and cold stresses in pear (Pyrus bretschneideri).
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Centre of Pear Engineering Technology Research, Nanjing Agricultual University, Nanjing, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, Centre of Pear Engineering Technology Research, Nanjing Agricultual University, Nanjing, China. huangxs@njau.edu.cn.
BACKGROUND: The basic helix-loop-helix (bHLH) transcription factors play important roles in many processes in plant growth, metabolism and responses to abiotic stresses. Although, the sequence of Chinese white pear genome (cv. 'Dangshansuli') has already been reported, there is still a lack of clarity regarding the bHLH family genes and their evolutionary history. RESULTS: In this work, a genome-wide identification of the bHLH genes in Chinese white pear was performed, and we characterized the functional roles of these PbrbHLH genes in response to abiotic stresses. Based on the phylogenetic analysis and structural characteristics, 197 identified bHLH genes could be well classified into 21 groups. Expansion of PbrbHLH gene family was mainly driven by WGD and dispersed duplication with the purifying selection from the recent WGD. The functional annotation enrichment showed that the majority of PbrbHLHs were enriched in the GO terms and KEGG pathways involved in responds to stress conditions as TFs. Transcriptomic profiles and qRT-PCR revealed that PbrbHLH7, PbrbHLH8, PbrbHLH128, PbrbHLH160, PbrbHLH161 and PbrbHLH195 were significantly up-regulated under cold and drought treatments. In addition, PbrbHLH195-silenced pear seedlings display significant reduced cold tolerance, exhibiting reduced chlorophyll content, as well as increased electrolyte leakage and concentrations of malondialdehyde and H2O2. CONCLUSION: For the first time, a comprehensive analysis identified the bHLH genes in Chinese white pear and demonstrated that PbrbHLH195 is involved in the production of ROS in response to cold stress, suggesting that members of the PbrbHLH family play an essential role in the stress tolerance of pear.
PMID: 33563216
BMC Plant Biol , IF:3.497 , 2021 Feb , V21 (1) : P75 doi: 10.1186/s12870-021-02851-8
SiFBA5, a cold-responsive factor from Saussurea involucrata promotes cold resilience and biomass increase in transgenic tomato plants under cold stress.
Key Laboratory of Agricultural Biotechnology, College of Life Science, Shihezi University, Shihezi, Xinjiang, 832003, China.; Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.; Key Laboratory of Agricultural Biotechnology, College of Life Science, Shihezi University, Shihezi, Xinjiang, 832003, China. zhujianboSHZU@163.com.
BACKGROUND: Saussurea involucrata survives in extreme arctic conditions and is very cold-resistant. This species grows in rocky, mountainous areas with elevations of 2400-4100 m, which are snow-covered year-round and are subject to freezing temperatures. S. involucrata's ability to survive in an extreme low-temperature environment suggests that it has particularly high photosynthetic efficiency, providing a magnificent model, and rich gene pool, for the analysis of plant cold stress response. Fructose-1, 6-bisphosphate aldolase (FBA) is a key enzyme in the photosynthesis process and also mediates the conversion of fructose 1, 6-bisphosphate (FBP) into dihydroxyacetone phosphate (DHAP) and glycerol triphosphate (GAP) during glycolysis and gluconeogenesis. The molecular mechanisms underlying S. involucrata's cold tolerance are still unclear; therefore, our work aims to investigate the role of FBA in plant cold-stress response. RESULTS: In this study, we identified a cold-responsive gene, SiFBA5, based on a preliminary low-temperature, genome-wide transcriptional profiling of S. involucrata. Expression analysis indicated that cold temperatures rapidly induced transcriptional expression of SiFBA5, suggesting that SiFBA5 participates in the initial stress response. Subcellular localization analysis revealed that SiFBA5 is localized to the chloroplast. Transgenic tomato plants that overexpressed SiFBA5 were generated using a CaMV 35S promoter. Phenotypic observation suggested that the transgenic plants displayed increased cold tolerance and photosynthetic efficiency in comparison with wild-type plants. CONCLUSION: Cold stress has a detrimental impact on crop yield. Our results demonstrated that SiFBA5 positively regulates plant response to cold stress, which is of great significance for increasing crop yield under cold stress conditions.
PMID: 33541285
Planta , IF:3.39 , 2021 Feb , V253 (2) : P58 doi: 10.1007/s00425-020-03553-5
Stress-Related Changes in the Expression and Activity of Plant Carbonic Anhydrases.
Membranology and Phytochemistry Department, M.G. Kholodny Institute of Botany of NAS of Ukraine, 2 Tereshchenkivska Str, Kyiv, 01004, Ukraine. mrpolishchuk@gmail.com.
The data on stress-related changes in the expression and activity of plant carbonic anhydrases (CAs) suggest that they are generally upregulated at moderate stress severity. This indicates probable involvement of CAs in adaptation to drought, high salinity, heat, high light, Ci deficit, and excess bicarbonate. The changes in CA levels under cold stress are less studied and generally represented by the downregulation of CAs excepting betaCA2. Excess Cd(2+) and deficit of Zn(2+) specifically reduce CA activity and reduce its synthesis. Probable roles of betaCAs in stress adaptation include stomatal closure, ROS scavenging and partial compensation for decreased mesophyll CO2 conductance. betaCAs play contrasting roles in pathogen responses, interacting with phytohormone signaling networks. Their role can be either negative or positive, probably depending on the host-pathogen system, pathogen initial titer, and levels of .NO and ROS. It is still not clear why CAs are suppressed under severe stress levels. It should be noted, that the role of betaCAs in the facilitation of CO2 diffusion and their involvement in redox signaling or ROS detoxication are potentially antagonistic, as they are inactivated by oxidation or nitrosylation. Interestingly, some chloroplastic betaCAs may be relocated to the cytoplasm under stress conditions, but the physiological meaning of this effect remains to be studied.
PMID: 33532871
Planta , IF:3.39 , 2021 Feb , V253 (2) : P55 doi: 10.1007/s00425-021-03574-8
Transcriptomic analysis of grapevine Dof transcription factor gene family in response to cold stress and functional analyses of the VaDof17d gene.
Beijing Key Laboratory of Grape Science and Enology, and CAS Key Laboratory of Plant Resources, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Science, Beijing, 100093, People's Republic of China.; University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.; State Key Laboratory of the Seedling Bioengineering, Yinchuan, 750004, People's Republic of China.; China Wine Industry Technology Institute, Yinchuan, 750021, People's Republic of China.; Beijing Key Laboratory of Grape Science and Enology, and CAS Key Laboratory of Plant Resources, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Science, Beijing, 100093, People's Republic of China. shhli@ibcas.ac.cn.; University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China. shhli@ibcas.ac.cn.; Beijing Key Laboratory of Grape Science and Enology, and CAS Key Laboratory of Plant Resources, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Science, Beijing, 100093, People's Republic of China. zl249@ibcas.ac.cn.; Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, People's Republic of China. zl249@ibcas.ac.cn.
MAIN CONCLUSION: Dof genes enhance cold tolerance in grapevine and VaDof17d is tightly associated with the cold-responsive pathway and with the raffinose family oligosaccharides. DNA-binding with one finger (Dof) proteins comprise a large family that plays important roles in the regulation of abiotic stresses. No in-depth analysis of Dof genes has been performed in the grapevine. In this study, we analyzed a total of 25 putative Dof genes in grapevine at genomic and transcriptomic levels, compiled expression profiles of 11 selected VaDof genes under cold stress and studied the potential function of the VaDof17d gene in grapevine calli. The 25 Dof proteins can be classified into four phylogenetic groups. RNA-seq and qRT-PCR results demonstrated that a total of 11 VaDof genes responded to cold stress. Comparative mRNA sequencing of 35S::VaDof17d grape calli showed that VaDof17d was tightly associated with the cold-responsive pathway and with the raffinose family oligosaccharides (RFOs), as observed by the up-regulation of galactinol synthase (GolS) and raffinose synthase genes. We found that the Dof17d-ED (CRISPR/Cas9-mediated mutagenesis of Dof17d-ED) mutant had low cold tolerance with a decreased RFOs level during cold stress. These results formed the fundamental knowledge for further analysis of the biological roles of Dof genes in the grapevine's adaption to cold stresses.
PMID: 33523295
Funct Integr Genomics , IF:3.058 , 2021 Feb doi: 10.1007/s10142-021-00773-0
Genome-wide identification of Ran GTPase family genes from wheat (T. aestivum) and their expression profile during developmental stages and abiotic stress conditions.
ICAR-National Institute for Plant Biotechnology, New Delhi, India.; ICAR-Central Tuber Crops Research Institute, Thiruvananthapuram, Kerala, India.; ICAR-National Institute for Plant Biotechnology, New Delhi, India. monikadalal@hotmail.com.
Maintenance of growth is important for sustaining yield under stress conditions. Hence, identification of genes involved in cell division and growth under abiotic stress is utmost important. Ras-related nuclear protein (Ran) is a small GTPase required for nucleocytoplasmic transport, mitotic progression, and nuclear envelope assembly in plants. In the present study, two Ran GTPase genes TaRAN1 and TaRAN2 were identified though genome-wide analysis in wheat (T. aestivum). Comparative analysis of Ran GTPases from wheat, barley, rice, maize, sorghum, and Arabidopsis revealed similar gene structure within phylogenetic clades and highly conserved protein structure. Expression analysis from expVIP platform showed ubiquitous expression of TaRAN genes across tissues and developmental stages. Under biotic and abiotic stresses, TaRAN1 expression was largely unaltered, while TaRAN2 showed stress specific response. In qRT-PCR analysis, TaRAN1 showed significantly higher expression as compared to TaRAN2 in shoot and root at seedling, vegetative, and reproductive stages. During progressive drought stress, TaRAN1 and TaRAN2 expression increase during early stress and restored to control level expression at higher stress levels in shoot. The steady-state level of transcripts was maintained to that of control in roots under drought stress. Under cold stress, expression of both the TaRAN genes decreased significantly at 3 h and became similar to control at 6 h in shoots, while salt stress significantly reduced the expression of TaRAN genes in shoots. The analysis suggests differential regulation of TaRAN genes under developmental stages and abiotic stresses. Delineating the molecular functions of Ran GTPases will help unravel the mechanism of stress induced growth inhibition in wheat.
PMID: 33609188
Saudi J Biol Sci , IF:2.802 , 2021 Feb , V28 (2) : P1465-1476 doi: 10.1016/j.sjbs.2020.12.001
Arbuscular mycorrhiza in combating abiotic stresses in vegetables: An eco-friendly approach.
Punjab Agricultural University, Ludhiana, India.; CCS Haryana Agricultural University, Hisar, India.; Instituto de Conservacion y Mejora de la Agrodiversidad Valenciana, Universitat Politecnica de Valencia, 46022 Valencia, Spain.; Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.; Department of Botany, S.P. College, Srinagar, Jammu and Kashmir, 190001, India.
Vegetable production is hampered by several abiotic stresses which are very common in this era of climate change. There is a huge pressure on the plants to survive and yield better results even in the prevalence of various environmental stresses such as cold stress, drought, heat stress, salinity etc. This necessitates the need of robust plant growth which is possible with mycorrhizal association. Mycorrhiza improves plants tolerance to several abiotic stresses by various physiological, functional and biochemical changes in plants. The application of arbuscular mycorrhiza (AM) as vegetable biofertilizers doesn't only influence the plant health, but moreover discursively it lowers the demand for harmful chemical fertilizers. Overall, it may be concluded that inoculation of vegetables with arbuscular mycorrhizal fungi can be used, as it easily guards plants against undesirable abiotic stresses. In this work, information is provided based on several examples from the literature based on the application of AM to combat harmful abiotic stresses in vegetable crops. This paper reviews the impacts of AM fungi on the plant parameters, its functional activities and molecular mechanisms which makes it more adaptable and underline the future prospects of using AM fungi as a biofertilizer in the stress condition.
PMID: 33613074
Plants (Basel) , IF:2.762 , 2021 Feb , V10 (2) doi: 10.3390/plants10020293
Thermal Stresses in Maize: Effects and Management Strategies.
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; College of Life Sciences, Yan'an University, Yan'an 716000, China.; Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA.; Key Laboratory of Crop Physiology and Ecology, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China.; Department of Horticulture, College of Agriculture, University of Sargodha, Sargodha 40100, Pakistan.; Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al-Khoud 123, Oman.; Department of Agronomy, University of Agriculture, Faisalabad 38000, Pakistan.
Climate change can decrease the global maize productivity and grain quality. Maize crop requires an optimal temperature for better harvest productivity. A suboptimal temperature at any critical stage for a prolonged duration can negatively affect the growth and yield formation processes. This review discusses the negative impact of temperature extremes (high and low temperatures) on the morpho-physiological, biochemical, and nutritional traits of the maize crop. High temperature stress limits pollen viability and silks receptivity, leading to a significant reduction in seed setting and grain yield. Likewise, severe alterations in growth rate, photosynthesis, dry matter accumulation, cellular membranes, and antioxidant enzyme activities under low temperature collectively limit maize productivity. We also discussed various strategies with practical examples to cope with temperature stresses, including cultural practices, exogenous protectants, breeding climate-smart crops, and molecular genomics approaches. We reviewed that identified quantitative trait loci (QTLs) and genes controlling high- and low temperature stress tolerance in maize could be introgressed into otherwise elite cultivars to develop stress-tolerant cultivars. Genome editing has become a key tool for developing climate-resilient crops. Moreover, challenges to maize crop improvement such as lack of adequate resources for breeding in poor countries, poor communication among the scientists of developing and developed countries, problems in germplasm exchange, and high cost of advanced high-throughput phenotyping systems are discussed. In the end, future perspectives for maize improvement are discussed, which briefly include new breeding technologies such as transgene-free clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas)-mediated genome editing for thermo-stress tolerance in maize.
PMID: 33557079
PLoS One , IF:2.74 , 2021 , V16 (2) : Pe0245494 doi: 10.1371/journal.pone.0245494
Identification of differentially expressed genes involved in amino acid and lipid accumulation of winter turnip rape (Brassica rapa L.) in response to cold stress.
Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou, China.; College of Agronomy, Gansu Agricultural University, Lanzhou, China.; Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN, United States of America.; Crop Research Institute, Gansu Academy of Agricultural Sciences, Lanzhou, China.; College of Agronomy and Biotechnology, Hexi University, Zhangye, China.
Winter turnip rape (Brassica rapa L.) is an important overwintering oil crop that is widely planted in northwestern China. It considered to be a good genetic resource for cold-tolerant research because its roots can survive harsh winter conditions. Here, we performed comparative transcriptomics analysis of the roots of two winter turnip rape varieties, Longyou7 (L7, strong cold tolerance) and Tianyou2 (T2, low cold tolerance), under normal condition (CK) and cold stress (CT) condition. A total of 8,366 differentially expressed genes (DEGs) were detected between the two L7 root groups (L7CK_VS_L7CT), and 8,106 DEGs were detected for T2CK_VS_T2CT. Among the DEGs, two omega-3 fatty acid desaturase (FAD3), two delta-9 acyl-lipid desaturase 2 (ADS2), one diacylglycerol kinase (DGK), and one 3-ketoacyl-CoA synthase 2 (KCS2) were differentially expressed in the two varieties and identified to be related to fatty acid synthesis. Four glutamine synthetase cytosolic isozymes (GLN), serine acetyltransferase 1 (SAT1), and serine acetyltransferase 3 (SAT3) were down-regulated under cold stress, while S-adenosylmethionine decarboxylase proenzyme 1 (AMD1) had an up-regulation tendency in response to cold stress in the two samples. Moreover, the delta-1-pyrroline-5-carboxylate synthase (P5CS), delta-ornithine aminotransferase (delta-OAT), alanine-glyoxylate transaminase (AGXT), branched-chain-amino-acid transaminase (ilvE), alpha-aminoadipic semialdehyde synthase (AASS), Tyrosine aminotransferase (TAT) and arginine decarboxylase related to amino acid metabolism were identified in two cultivars variously expressed under cold stress. The above DEGs related to amino acid metabolism were suspected to the reason for amino acids content change. The RNA-seq data were validated by real-time quantitative RT-PCR of 19 randomly selected genes. The findings of our study provide the gene expression profile between two varieties of winter turnip rape, which lay the foundation for a deeper understanding of the highly complex regulatory mechanisms in plants during cold treatment.
PMID: 33556109
Oecologia , IF:2.654 , 2021 Feb , V195 (2) : P299-312 doi: 10.1007/s00442-020-04839-x
Carbon allocation to growth and storage depends on elevation provenance in an herbaceous alpine plant of Mediterranean climate.
ECOBIOSIS, Departamento de Botanica, Facultad de Ciencias Naturales y Oceanograficas, Universidad de Concepcion, Casilla 160-C, Concepcion, Chile. clau.m.reyes@gmail.com.; Instituto de Ecologia y Biodiversidad (IEB), Casilla 653, Santiago, Chile. clau.m.reyes@gmail.com.; Centro de Investigacion en Ecosistemas de la Patagonia (CIEP), Moraleda 16, Coyhaique, Chile.; ECOBIOSIS, Departamento de Botanica, Facultad de Ciencias Naturales y Oceanograficas, Universidad de Concepcion, Casilla 160-C, Concepcion, Chile.; Instituto de Ecologia y Biodiversidad (IEB), Casilla 653, Santiago, Chile.
It is unclear whether the frequently observed increase in non-structural carbohydrates (NSC) in plants exposed to low temperatures or drought reflects a higher sensitivity of growth than photosynthesis in such conditions (i.e. sink limitation), or a prioritization of carbon (C) allocation to storage. Alpine areas in Mediterranean-type climate regions are characterized by precipitation increases and temperature decreases with elevation. Thus, alpine plants with wide elevational ranges in Mediterranean regions may be good models to examine these alternative hypotheses. We evaluated storage and growth during experimental darkness and re-illumination in individuals of the alpine plant Phacelia secunda from three elevations in the Andes of central Chile. We hypothesized that storage is prioritized regarding growth in plants of both low- and high elevations where drought and cold stress are greatest, respectively. We expected that decreases in NSC concentrations during darkness should be minimal and, more importantly, increases in NSC after re-illumination should be higher than increases in biomass. We found that darkness caused a significant decrease in NSC concentrations of both low- and high-elevation plants, but the magnitude of the decrease was lower in the latter. Re-illumination caused higher increase in NSC concentration than in biomass in both low- and high-elevation plants (1.5- and 1.9-fold, respectively). Our study shows that C allocation in Phacelia secunda reflects ecotypic differences among elevation provenances and suggests that low temperature, but not drought, favours C allocation to storage over growth after severe C limitation.
PMID: 33459865
Oecologia , IF:2.654 , 2021 Feb doi: 10.1007/s00442-021-04870-6
Altitudinal differentiation in the leaf wax-mediated flowering bud protection against frost in a perennial Arabidopsis.
Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan.; School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.; Amrit Campus, Tribhuvan University, Lekhnath Marg, Kathmandu, 44600, Nepal.; Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan. kudoh@ecology.kyoto-u.ac.jp.
An altitudinal gradient of leaf water repellency is often observed between and within species. In a previous study of Arabidopsis halleri, cauline leaves (stem leaves that wrap flowering buds) showed higher water repellency in exposed semi-alpine plants than in understory low-elevation plants. Here, we examined altitudinal variations in the cuticular wax content of the leaf surface and experimentally evaluated the role of high water repellency of cauline leaves. Leaf cuticular wax was analysed using comprehensive two-dimensional gas chromatography (GC)-mass spectrometry and a GC-flame ionisation detector. Young flowering buds wrapped by cauline leaves were exposed to freezing temperatures with or without water, and frost damage to the flowering buds was compared between plants from semi-alpine and low-elevation habitats. Higher amounts of C29, C31, and C33 alkanes were observed in the cauline leaves of semi-alpine plants than in those of low-elevation plants. In the freezing experiment, water application increased damage to the flowering buds of low-elevation plants, and the extent of damage to the flowering buds was lower in semi-alpine plants than in low-elevation plants when water was applied to the plant surface. Genetic variations in the amounts of alkanes on the leaf surface depending on the altitude occurred specifically in cauline leaves. Our results indicate that the water repellency of cauline leaves presumably minimises frost damage to flowering buds at high altitudes.
PMID: 33611626
Mol Biol Rep , IF:1.402 , 2021 Feb doi: 10.1007/s11033-021-06235-x
35S promoter-driven transgenes are variably expressed in different organs of Arabidopsis thaliana and in response to abiotic stress.
Laboratory of Biotechnology, Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia, 690022.; Laboratory of Biotechnology, Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia, 690022. dubrovina@biosoil.ru.
The cauliflower mosaic virus (CaMV) 35S promoter is known as the most frequently used promoter in plant biotechnology. Although it is widely considered to be a strong constitutive promoter exhibiting high transcriptional activity, the transcriptional stability of CaMV 35S has not been extensively studied. Using the model plant species Arabidopsis thaliana, this study aimed for a comprehensive expression analysis of two widely used plant transgenes, neomycin phosphotransferase II (NPTII) and enhanced green fluorescent protein (EGFP), regulated by a double CaMV 35S promoter depending on the organ type, time of day, plant age, and in response to abiotic stress conditions. Quantitative real-time PCR (qRT-PCR) analysis revealed that the NPTII and EGFP transcript levels were markedly higher in the cotyledons, young leaves, and roots than in the inflorescences, stems, and adult leaves of three independent transgenic A. thaliana lines. The expression of NPTII and EGFP varied during the day and was elevated with the plant age. Drought and cold stress considerably affected the expression of the transgenes, while heat, high salinity, and wounding had no significant effect. This study shows that transgenes driven by a common constitutive promoter can exhibit marked variations in transcriptional activity depending on plant organ, physiological conditions, and in response to abiotic stress. Therefore, to ensure high and stable transgene activity, considerable attention should be given to the transgenic plant material and incubation conditions before harvesting the plant material.
PMID: 33630207