Plant Physiol , IF:6.902 , 2019 May , V180 (1) : P404-419 doi: 10.1104/pp.18.01448
Evolution of Cold Acclimation and Its Role in Niche Transition in the Temperate Grass Subfamily Pooideae.
Department of Plant Sciences, Norwegian University of Life Sciences, NO-1432 As, Norway.; Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, NO-1432 As, Norway.; Centre for Integrative Genetics, Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 As, Norway.; Umea Plant Science Centre, Department of Plant Physiology, Umea University, SE-90187 Umea, Sweden.; Department of Plant Sciences, Norwegian University of Life Sciences, NO-1432 As, Norway siri.fjellheim@nmbu.no.
The grass subfamily Pooideae dominates the grass floras in cold temperate regions and has evolved complex physiological adaptations to cope with extreme environmental conditions like frost, winter, and seasonality. One such adaptation is cold acclimation, wherein plants increase their frost tolerance in response to gradually falling temperatures and shorter days in the autumn. However, understanding how complex traits like cold acclimation evolve remains a major challenge in evolutionary biology. Here, we investigated the evolution of cold acclimation in Pooideae and found that a phylogenetically diverse set of Pooideae species displayed cold acclimation capacity. However, comparing differential gene expression after cold treatment in transcriptomes of five phylogenetically diverse species revealed widespread species-specific responses of genes with conserved sequences. Furthermore, we studied the correlation between gene family size and number of cold-responsive genes as well as between selection pressure on coding sequences of genes and their cold responsiveness. We saw evidence of protein-coding and regulatory sequence evolution as well as the origin of novel genes and functions contributing toward evolution of a cold response in Pooideae. Our results reflect that selection pressure resulting from global cooling must have acted on already diverged lineages. Nevertheless, conservation of cold-induced gene expression of certain genes indicates that the Pooideae ancestor may have possessed some molecular machinery to mitigate cold stress. Evolution of adaptations to seasonally cold climates is regarded as particularly difficult. How Pooideae evolved to transition from tropical to temperate biomes sheds light on how complex traits evolve in the light of climate changes.
PMID: 30850470
Int J Mol Sci , IF:4.556 , 2019 May , V20 (9) doi: 10.3390/ijms20092286
Role of the INDETERMINATE DOMAIN Genes in Plants.
Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul 05006, Korea. manukumar@sejong.ac.kr.; Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul 05006, Korea. dungcnshk55a@gmail.com.; Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul 05006, Korea. sbhwang@sejong.ac.kr.; Department of Chemistry, Seoul National University, Seoul 08826, Korea. pjseo1@snu.ac.kr.; Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul 05006, Korea. hukim64@sejong.ac.kr.
The INDETERMINATE DOMAIN (IDD) genes comprise a conserved transcription factor family that regulates a variety of developmental and physiological processes in plants. Many recent studies have focused on the genetic characterization of IDD family members and revealed various biological functions, including modulation of sugar metabolism and floral transition, cold stress response, seed development, plant architecture, regulation of hormone signaling, and ammonium metabolism. In this review, we summarize the functions and working mechanisms of the IDD gene family in the regulatory network of metabolism and developmental processes.
PMID: 31075826
Biomolecules , IF:4.082 , 2019 May , V9 (5) doi: 10.3390/biom9050188
Expansion and Evolutionary Patterns of Glycosyltransferase Family 8 in Gramineae Crop Genomes and Their Expression under Salt and Cold Stresses in Oryza sativa ssp. japonica.
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. Weilong.Kong@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. Gziyun@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. zhonghua0103@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. Yue.Zhang-@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. zhaogangqing@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. mayankgautam@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. 2017102040003@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. lchang@whu.edu.cn.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. zch_nx@126.com.; State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. lysh2001@whu.edu.cn.
Plant cell walls play a fundamental role in several ways, providing structural support for cells, resistance against pathogens and facilitating the communication between cells. The glycosyltransferase family 8 (GT8) is involved in the formation of the plant cell wall. However, the evolutionary relationship and the functional differentiation of this important gene family remain obscure in Gramineae crop genomes. In the present investigation, we identified 269 GT8 genes in the seven Gramineae representative crop genomes, namely, 33 in Hordeum vulgare, 37 in Brachypodium distachyon, 40 in Oryza sativa ssp. japonica, 41 in Oryza rufipogon, 36 in Setaria italica, 37 in Sorghum bicolor, and 45 in Zea mays. Phylogenetic analysis suggested that all identified GT8 proteins belonged to seven subfamilies: galacturonosyltransferase (GAUT), galacturonosyltransferase-like (GATL), GATL-related (GATR), galactinol synthase (GolS), and plant glycogenin-like starch initiation proteins A (PGSIP-A), PGSIP-B, and PGSIP-C. We estimated that the GAUT subfamily might be further divided into four subgroups (I-IV) due to differentiation of gene structures and expression patterns. Our orthogroup analysis identified 22 orthogroups with different sizes. Of these orthogroups, several orthogroups were lost in some species, such as S. italica and Z. mays. Moreover, lots of duplicate pairs and collinear pairs were discovered among these species. These results indicated that multiple duplication modes led to the expansion of this important gene family and unequal loss of orthogroups and subfamilies might have happened during the evolutionary process. RNA-seq, microarray analysis, and qRT-PCR analyses indicated that GT8 genes are critical for plant growth and development, and for stresses responses. We found that OsGolS1 was significantly up-regulated under salt stress, while OsGAUT21, OsGATL2, and OsGATL5 had remarkable up-regulation under cold stress. The current study highlighted the expansion and evolutionary patterns of the GT8 gene family in these seven Gramineae crop genomes and provided potential candidate genes for future salt- and cold- resistant molecular breeding studies in O. sativa.
PMID: 31096659
Biomolecules , IF:4.082 , 2019 May , V9 (5) doi: 10.3390/biom9050182
Identification of miRNAs and Their Response to Cold Stress in Astragalus Membranaceus.
College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China. merhaba@muc.edu.cn.; School of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, China. sunhuigai66@163.com.; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China. 15055031@muc.edu.cn.; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China. chunxiangwei2010@163.com.; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China. gaofei@muc.edu.cn.; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China. zhouyijun@muc.edu.cn.; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China. jchfeng@263.net.
Astragalus membranaceus is an important medicinal plant widely cultivated in East Asia. MicroRNAs (miRNAs) are endogenous regulatory molecules that play essential roles in plant growth, development, and the response to environmental stresses. Cold is one of the key environmental factors affecting the yield and quality of A. membranaceus, and miRNAs may mediate the gene regulation network under cold stress in A. membranaceus. To identify miRNAs and reveal their functions in cold stress response in A. membranaceus, small RNA sequencing was conducted followed by bioinformatics analysis, and quantitative real time PCR (qRT-PCR) analysis was performed to profile the expression of miRNAs under cold stress. A total of 168 conserved miRNAs belonging to 34 families and 14 putative non-conserved miRNAs were identified. Many miRNA targets were predicted and these targets were involved in diversified regulatory and metabolic pathways. By using qRT-PCR, 27 miRNAs were found to be responsive to cold stress, including 4 cold stress-induced and 17 cold-repressed conserved miRNAs, and 6 cold-induced non-conserved miRNAs. These cold-responsive miRNAs probably mediate the response to cold stress by regulating development, hormone signaling, defense, redox homeostasis, and secondary metabolism in A. membranaceus. These cold-corresponsive miRNAs may be used as the candidate genes in further molecular breeding for improving cold tolerance of A. membranaceus.
PMID: 31083391
Plant Cell Physiol , IF:4.062 , 2019 May , V60 (5) : P1025-1040 doi: 10.1093/pcp/pcz017
Tissue Distribution and Specific Contribution of Arabidopsis FAD7 and FAD8 Plastid Desaturases to the JA- and ABA-Mediated Cold Stress or Defense Responses.
Department of Plant Nutrition, Estacii inverted question mark(1/2)n Experimental Aula Dei (EEAD-CSIC), Avda. Montai inverted question mark(1/2)ana 1005, Zaragoza, Spain.; School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, UK.; Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, UK.
To overcome the difficulties to analyze membrane desaturases at the protein level, transgenic Arabidopsis plants expressing the plastidial AtFAD7 and AtFAD8 omega-3 desaturases fused to green fluorescent protein, under the control of their endogenous promoters, were generated and their tissue relative abundance was studied. Gene expression, glucuronidase promoter activity, immunoblot and confocal microscopy analyses indicated that AtFAD7 is the major omega-3 desaturase in leaves when compared to AtFAD8. This higher abundance of AtFAD7 was consistent with its higher promoter activity and could be related with its specificity for the abundant leaf galactolipids. AtFAD7 was also present in roots but at much lower level than leaves. AtFAD8 expression and protein abundance in leaves was consistent with its lower promoter activity, suggesting that transcriptional control modulates the abundance of both desaturases in leaves. AtFAD7 protein levels increased in response to wounding but not to jasmonate (JA), and decreased upon abscisic acid (ABA) treatment. Conversely, AtFAD8 protein levels increased upon cold or JA exposure and decreased at high temperatures, but did not respond to ABA or wounding. These results indicated specific and non-redundant roles for the plastidial omega-3 desaturases in defense, temperature stress or phytohormone mediated responses and a tight coordination of their activities between biotic and abiotic stress signaling pathways. Our data suggested that transcriptional regulation was crucial for this coordination. Finally, bimolecular fluorescence complementation analysis showed that both AtFAD7 and AtFAD8 interact with the AtFAD6 omega-6 desaturase in vivo, suggesting that quaternary complexes are involved in trienoic fatty acid production within the plastid membranes.
PMID: 30690505
Plant Cell Rep , IF:3.825 , 2019 May , V38 (5) : P673-680 doi: 10.1007/s00299-019-02399-w
Cold-inducible MaC2H2s are associated with cold stress response of banana fruit via regulating MaICE1.
Institute of Food Science, Zhejiang Academy of Agricultural Science, Key Laboratory of Post-Harvest Handing of Fruits, Ministry of Agriculture, Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province, Key Laboratory of China Light Industry, Hangzhou, 310021, People's Republic of China.; College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310015, People's Republic of China. 17816184576@163.com.
KEY MESSAGE: MaC2H2s are involved in cold stress response of banana fruit via repressing the transcription of MaICE1. Although C2H2 zinc finger proteins have been found to be involved in banana fruit ripening through transcriptional controlling of ethylene biosynthetic genes, their involvement in cold stress of banana remains elusive. In this study, another C2H2-ZFP gene from banana fruit was identified, which was named as MaC2H2-3. Gene expression analysis revealed that MaC2H2-1, MaC2H2-2 and MaC2H2-3 were cold inducible in the peel of banana during low temperature storage. MaC2H2-3 functions as a transcriptional repressor and localizes predominantly in nucleus. Particularly, promoters of MaC2H2-2 and MaC2H2-3 were noticeably activated by cold as well, further indicating the potential roles of C2H2 in cold stress of banana. Moreover, MaC2H2-2 and MaC2H2-3 significantly repressed the transcription of MaICE1, a key component in cold signaling pathway. Overall, these findings suggest that MaC2H2s may take part in controlling cold stress of banana through suppressing the transcription of MaICE1, providing new insight of the regulatory basis of C2H2 in cold stress.
PMID: 30826844
Plant Cell Rep , IF:3.825 , 2019 May , V38 (5) : P511-519 doi: 10.1007/s00299-019-02376-3
Cold acclimation by the CBF-COR pathway in a changing climate: Lessons from Arabidopsis thaliana.
Key Laboratory of Forest Resources Conservation and Utilization in the Southwest Mountains of China (Southwest Forestry University), Ministry of Education, College of Forestry, Southwest Forestry University, 300 Bailong Si, Kunming, 650224, Yunnan, People's Republic of China. ykliu@swfu.edu.cn.; Key Laboratory of Forest Resources Conservation and Utilization in the Southwest Mountains of China (Southwest Forestry University), Ministry of Education, College of Forestry, Southwest Forestry University, 300 Bailong Si, Kunming, 650224, Yunnan, People's Republic of China.; School of Ecology and Landscape Architecture, Dezhou University, 566 West University Road, Dezhou, 253023, Shandong, People's Republic of China.; Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, School of Life Sciences, Southwest Forestry University, 300 Bailong Si, Kunming, 650224, Yunnan, People's Republic of China. hcz70@163.com.
Cold acclimation is a process used by most temperate plants to cope with freezing stress. In this process, the expression of cold-responsive (COR) genes is activated and the genes undergo physiological changes in response to the exposure to low, non-freezing temperatures and other environmental signals. The C-repeat-binding factors (CBFs) have been demonstrated to regulate the expression of many COR genes. Recent studies have elucidated the molecular mechanisms of how plants transmit cold signals from the plasma membrane to the CBFs and the results have indicated that COR genes are also regulated through CBF-independent pathways. Climate change is expected to have a major impact on cold acclimation and freezing tolerance of plants. However, how climate change affects plant cold acclimation at the molecular level remains unclear. This mini-review focuses on recent advances in cold acclimation in Arabidopsis thaliana and discusses how signaling can be potentially impacted by climate change. Understanding how plants acquire cold acclimation is valuable for the improvement of the freezing tolerance in plants and for predicting the effects of climate change on plant distribution and agricultural yield.
PMID: 30652229
Plant Physiol Biochem , IF:3.72 , 2019 May , V138 : P9-16 doi: 10.1016/j.plaphy.2019.02.015
The regulatory effects of MeTCP4 on cold stress tolerance in Arabidopsis thaliana: A transcriptome analysis.
Haikou Experimental Station, Chinese Academy of Tropical Agricultural Sciences, Haikou, 570102, China.; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China.; Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China. Electronic address: lishuxia@itbb.org.cn.; Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China.; Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China. Electronic address: pengming@itbb.org.cn.
Cassava (Manihot esculenta), an important food crop in tropical areas, is well-adapted to drought conditions, but is sensitive to cold. The expression of MeTCP4, a transcription factor involved in the regulation of plant development and abiotic stresses responses, was altered under cold stress. However, its biological function under abiotic stress responses is still unclear. Here, we show that increased MeTCP4 expression enhances cold stress tolerance in Arabidopsis (Arabidopsis thaliana). To better understand the biological role of MeTCP4, the mRNA from overexpression and wild-type (WT) plants was isolated for whole genome sequencing to identify MeTCP4-mediated cold-responsive genes. Our results identify 1341 and 797 differentially expressed genes (DEGs) affected by MeTCP4 overexpression under normal and cold conditions, respectively. Gene ontology analysis revealed that a portion of the DEGs were involved in reactive oxygen species (ROS) metabolism process after cold treatment. qRT-PCR analysis revealed that the expression of cold-responsive genes and ROS-scavenging-related genes were increased in MeTCP4 overexpression plant, which could be responsible for the reduced ROS levels and enhanced cold resistance observed in transgenic plant. The findings provide insight into mechanisms of MeTCP4-mediated cold stress response, and provide clues for development of low temperature-tolerant cassava cultivars.
PMID: 30825725
BMC Plant Biol , IF:3.497 , 2019 May , V19 (1) : P223 doi: 10.1186/s12870-019-1836-5
Genome-wide identification and classification of MIKC-type MADS-box genes in Streptophyte lineages and expression analyses to reveal their role in seed germination of orchid.
Key Laboratory of South China Agricultural Plant Molecular Analysis and Gene Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.; University of the Chinese Academy of Sciences, Beijing, 100049, China.; Independent, Miki-Cho, Japan.; Genepioneer Biotechnologies Co. Ltd, Nanjing, 210014, China.; Key Laboratory of South China Agricultural Plant Molecular Analysis and Gene Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China. duanj@scib.ac.cn.
BACKGROUND: MADS-box genes play crucial roles in plant floral organ formation and plant reproductive development. However, there is still no information on genome-wide identification and classification of MADS-box genes in some representative plant species. A comprehensive investigation of MIKC-type genes in the orchid Dendrobium officinale is still lacking. RESULTS: Here we conducted a genome-wide analysis of MADS-box proteins from 29 species. In total, 1689 MADS-box proteins were identified. Two types of MADS-box genes, termed type I and II, were found in land plants, but not in liverwort. The SQUA, DEF/GLO, AG and SEP subfamilies existed in all the tested flowering plants, while SQUA was absent in the gymnosperm Ginkgo biloba, and no genes of the four subfamilies were found in a charophyte, liverwort, mosses, or lycophyte. This strongly corroborates the notion that clades of floral organ identity genes led to the evolution of flower development in flowering plants. Nine subfamilies of MIKC(C) genes were present in two orchids, D. officinale and Phalaenopsis equestris, while the TM8, FLC, AGL15 and AGL12 subfamilies may be lost. In addition, the four clades of floral organ identity genes in both orchids displayed a conservative and divergent expression pattern. Only three MIKC-type genes were induced by cold stress in D. officinale while 15 MIKC-type genes showed different levels of expression during seed germination. CONCLUSIONS: MIKC-type genes were identified from streptophyte lineages, revealing new insights into their evolution and development relationships. Our results show a novel role of MIKC-type genes in seed germination and provide a useful clue for future research on seed germination in orchids.
PMID: 31138149
BMC Plant Biol , IF:3.497 , 2019 May , V19 (1) : P218 doi: 10.1186/s12870-019-1826-7
An eukaryotic elongation factor 2 from Medicago falcata (MfEF2) confers cold tolerance.
College of Grassland Science, Nanjing Agricultural University, Nanjing, 210095, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, Guangdong Engineering Research Center for Grassland Science, South China Agricultural University, Guangzhou, 510642, China.; College of Grassland Science, Nanjing Agricultural University, Nanjing, 210095, China. zfguo@njau.edu.cn.
BACKGROUND: An eukaryotic translation elongation factor-2 (eEF-2) plays an important role in protein synthesis, however, investigation on its role in abiotic stress responses is limited. A cold responsive eEF2 named as MfEF2 was isolated from yellow-flowered alfalfa [Medicago sativa subsp. falcata (L.) Arcang, thereafter M. falcata], a forage legume with great cold tolerance, and transgenic tobacco (Nicotiana tabacum L.) plants overexpressing MfEF2 were analyzed in cold tolerance and proteomic profiling was conducted under low temperature in this study. RESULTS: MfEF2 transcript was induced and peaked at 24 h and remained at the high level during cold treatment up to 96 h. Overexpression of MfEF2 in trasngenic tobacco plants resulted in enhanced cold tolerance. Compared to the wild type, transgenic plants showed higher survival rate after freezing treatment, higher levels of net photosynthetic rate (A), maximum photochemical efciency of photosystem (PS) II (Fv/Fm) and nonphotochemical quenching (NPQ) and lower levels of ion leakage and reactive oxygen species (ROS) production after chilling treatment. iTRAQ-based quantitative proteomic analysis identified 336 differentially expressed proteins (DEPs) from leaves of one transgenic line versus the wild type after chilling treatment for 48 h. GO and KEGG enrichment were conducted for analysis of the major biological process, cellular component, molecular function, and pathways of the DEPs involving in. It is interesting that many down-regulated DEPs were grouped into "photosynthesis" and "photosynthesis-antenna", such as subunits of PSI and PSII as well as light harvesting chlorophyll protein complex (LHC), while many up-regulated DEPs were grouped into "spliceosome". CONCLUSIONS: The results suggest that MfEF2 confers cold tolerance through regulating hundreds of proteins synthesis under low temperature conditions. The elevated cold tolerance in MfEF2 transgenic plants was associated with downregulation of the subunits of PSI and PSII as well as LHC, which leads to reduced capacity for capturing sunlight and ROS production for protection of plants, and upregulation of proteins involving in splicesome, which promotes alternative splicing of pre-mRNA under low temperature.
PMID: 31133003
BMC Plant Biol , IF:3.497 , 2019 May , V19 (1) : P214 doi: 10.1186/s12870-019-1823-x
Overexpression of Solanum habrochaites microRNA319d (sha-miR319d) confers chilling and heat stress tolerance in tomato (S. lycopersicum).
College of Horticulture, Nanjing Agricultural University, Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in East China, Ministry of Agriculture, Nanjing, 210095, People's Republic of China.; College of Horticulture, Nanjing Agricultural University, Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in East China, Ministry of Agriculture, Nanjing, 210095, People's Republic of China. wzh@njau.edu.cn.
BACKGROUND: MicroRNA319 (miR319) acts as an essential regulator of gene expression during plant development and under stress conditions. Although the role of miR319a in regulating leaf development has been well studied in tomato (Solanum lycopersicum), the function of the recently discovered wild tomato Solanum habrochaites miRNA319d (sha-miR319d) remains poorly understood. In this study, we overexpressed sha-miR319d in cultivated tomato 'Micro-Tom' to further investigate its role in tomato temperature stress responses. RESULTS: Under chilling or heat stress, sha-miR319d-overexpressing plants showed enhanced stress tolerance, including lower relative electrolyte leakage (REL), malondialdehyde (MDA) concentration, O2(-) generation and H2O2 concentration and higher chlorophyll contents and Fv/Fm values than wild-type (WT) plants. Overexpression of sha-miR319d enhanced the activities of superoxide dismutase (SOD) and catalase (CAT), with possible correlation with elevated expression levels of the genes FeSOD, CuZnSOD and CAT. Moreover, different expression levels of key genes involved in chilling (MYB83 and CBF1), heat (HsfA1a, HsfA1b and Hsp90), and reactive oxygen species (ROS) (ZAT12 and ZAT10) signaling in transgenic plants and WT were determined, suggesting a role for sha-miR319d in regulating tomato temperature stress via chilling, heat and ROS signaling. Silencing GAMYB-like1 increased tomato chilling tolerance as well as the expression levels of CBF1, CuZnSOD, CAT, APX1, APX2, ZAT12 and ZAT10. Additionally, overexpression of sha-miR319d in tomato caused plant leaf crinkling and reduced height. CONCLUSIONS: Overexpression of sha-miR319d confers chilling and heat stress tolerance in tomato. Sha-miR319d regulates tomato chilling tolerance, possibly by inhibiting expression of GAMYB-like1 and further alters chilling, heat and ROS signal transduction. Our research provides insight for further study of the role of sha-miR319d in tomato growth and stress regulation and lays a foundation for the genetic improvement of tomato.
PMID: 31122194
BMC Plant Biol , IF:3.497 , 2019 May , V19 (1) : P205 doi: 10.1186/s12870-019-1773-3
How fall dormancy benefits alfalfa winter-survival? Physiologic and transcriptomic analyses of dormancy process.
Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China.; Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China. bytgtnm@126.com.; Key Laboratory of Grassland Ecology and Restoration of Ministry of Agriculture, National Forage Improvement Center, Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot, China.; China Animal Health and Epidemiology Center, Qingdao, China.
BACKGROUND: Fall dormancy and freezing tolerance characterized as two important phenotypic traits, have great effects on productivity and persistence of alfalfa (Medicago sativa L.). Despite the fact that one of the most limiting traits for alfalfa freezing tolerance in winter is fall dormancy, the interplay between fall dormancy and cold acclimation processes of alfalfa remains largely unknown. We compared the plant regrowth, winter survival, raffinose and amino acids accumulation, and genome-wide differentially expressed genes of fall-dormant cultivar with non-dormant cultivar under cold acclimation. RESULTS: Averaged over both years, the non-dormant alfalfa exhibited largely rapid regrowth compared with fall dormant alfalfa after last cutting in autumn, but the winter survival rate of fall dormant alfalfa was about 34-fold higher than that of non-dormant alfalfa. The accumulation of raffinose and amino acids were significantly increased in fall dormant alfalfa, whereas were decreased in non-dormant alfalfa under cold acclimation. Expressions of candidate genes encoding raffinose biosynthesis genes were highly up-regulated in fall dormant alfalfa, but down-regulated in non-dormant alfalfa under cold acclimation. In fall dormant alfalfa, there was a significantly down-regulated expression of candidate genes encoding the glutamine synthase, which is indirectly involved in the proline metabolism. A total of eight significantly differentially expressed transcription factors (TFs) related to CBF and ABRE-BFs were identified. The most up-regulated TFs in fall dormant alfalfa cultivar were ABF4 and DREB1C. CONCLUSIONS: Fall dormant alfalfa drastically increased raffinose and amino acids accumulation under cold acclimation. Raffinose-associated and amino acid-associated genes involved in metabolic pathways were more highly expressed in fall dormant alfalfa than non-dormant alfalfa under cold acclimation. This global survey of transcriptome profiles provides new insights into the interplay between fall dormancy and cold acclimation in alfalfa.
PMID: 31109303
Plant Mol Biol , IF:3.302 , 2019 May , V100 (1-2) : P95-110 doi: 10.1007/s11103-019-00846-6
Overexpression of VaWRKY12, a transcription factor from Vitis amurensis with increased nuclear localization under low temperature, enhances cold tolerance of plants.
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, People's Republic of China.; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.; Beijing Key Laboratory of Grape Sciences and Enology, CAS Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China.; Beijing Key Laboratory of Grape Sciences and Enology, CAS Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China. shhli@ibcas.ac.cn.; Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, People's Republic of China. xinhaiping215@hotmail.com.
KEY MESSAGE: Overexpression of VaWRKY12, whose nuclear translocation increased under low temperature, enhanced the cold tolerance of Arabidopsis and grapevine calli and significantly increased the expression of antioxidant-related genes. Low temperature causes injuries to buds during winter and to young shoots during early spring, thereby affecting grapevine quality and yield. Understanding the regulatory mechanisms of cold stress responses is essential for the breeding of new grapevine cultivars with excellent cold tolerance. Previous studies indicated that WRKY family genes are induced by low temperature in grapevine, but their function in cold stress responses was not clear. Here, a cold-induced WRKY gene, named VaWRKY12, was cloned from Vitis amurensis, which displays remarkable cold tolerance. An atypical transmembrane (TM) region was found in its C-terminal region. Transient expression assays showed that VaWRKY12 was localized in the nucleus and cytoplasm at normal temperature but only in the nucleus after cold treatment. By contrast, a truncated version of VaWRKY12 without the TM region was found specifically in the nucleus at normal temperature, and its binding activity to tandem W-box elements in yeast was stronger than that of VaWRKY12, indicating that the TM region might affect the location and function of VaWRKY12. Overexpression of VaWRKY12 enhanced the cold tolerance of transformed Arabidopsis and grapevine calli. Transcriptome data revealed that the expression of genes encoding antioxidant enzymes, including peroxidases and glutathione S-transferases, was upregulated after cold treatment in VaWRKY12-overexpressing grapevine calli compared to the control calli. This study identifies candidate target genes as a basis for further studies on the roles of VaWRKY12 in cold stress responses in grapevine.
PMID: 31011887
Molecules , IF:3.267 , 2019 May , V24 (9) doi: 10.3390/molecules24091826
Exogenous Melatonin Enhances Cold, Salt and Drought Stress Tolerance by Improving Antioxidant Defense in Tea Plant (Camellia sinensis (L.) O. Kuntze).
Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China. 2016104091@njau.edu.cn.; Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China. 14216111@njau.edu.cn.; Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China. sunkang@njau.edu.cn.; Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China. 2017804134@njau.edu.cn.; Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China. chenxuan@njau.edu.cn.; Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China. lxh@njau.edu.cn.
Melatonin is a biological hormone that plays crucial roles in stress tolerance. In this study, we investigated the effect of exogenous melatonin on abiotic stress in the tea plant. Under cold, salt and drought stress, increasing malondialdehyde levels and decreasing maximum photochemical efficiency of PSII were observed in tea leaves. Meanwhile, the levels of reactive oxygen species (ROS) increased significantly under abiotic stress. Interestingly, pretreatment with melatonin on leaves alleviated ROS burst, decreased malondialdehyde levels and maintain high photosynthetic efficiency. Moreover, 100 muM melatonin-pretreated tea plants showed high levels of glutathione and ascorbic acid and increased the activities of superoxide dismutase, peroxidase, catalase and ascorbate peroxidase under abiotic stress. Notably, melatonin treatments can positively up-regulate the genes (CsSOD, CsPOD, CsCAT and CsAPX) expression of antioxidant enzyme biosynthesis. Taken together, our results confirmed that melatonin protects tea plants against abiotic stress-induced damages through detoxifying ROS and regulating antioxidant systems.
PMID: 31083611
Amino Acids , IF:3.063 , 2019 May , V51 (5) : P839-853 doi: 10.1007/s00726-019-02727-0
Computational characterization of structural and functional roles of DREB1A, DREB1B and DREB1C in enhancing cold tolerance in rice plant.
ICAR-National Rice Research Institute, Cuttack, Odisha, 753 006, India.; Department of Biotechnology and Bioinformatics, Yogi Vemana University, Kadapa, Andhra Pradesh, 516003, India.; Department of Biotechnology, Ravenshaw University, Cuttack, Odisha, 753003, India.; ICAR-National Rice Research Institute, Cuttack, Odisha, 753 006, India. lambodarjamujhadi@gmail.com.
Rice serves as the major food for almost half of the world population. Because of its origin in the tropical and subtropical area, rice is more sensitive towards cold stress. Three homologs of DREB1, namely DREB1A, DREB1B and DREB1C are induced Queryduring cold stress and after binding with GCC-box in the promoter region of the target gene, they enhance cold tolerance in rice plants. Though the majority of DREBs bind GCC-box, the degree of activation varies among DREBs. The protein encoded via these three transcription factors contains a common domain, namely AP2/ERF. In silico method was utilised to predict 3D structure of each AP2/ERF domain. The molecular dynamic analysis suggests, under the normal environmental condition, in each AP2/ERF domain, a positive correlation exists between beta-strands and the movement of C-alpha is constrained. However, during cold stress, when AP2/ERF domain binds with GCC-box present in the promoter region of the target gene, mean pressure of each three AP2/ERF domain gets lowered and final potential energy increases. A positive correlation between beta-strands gets disrupted and C-alpha experiences random movement suggesting enhanced activity of DREB1A, DREB1B and DREB1C during cold stress and enhancement of cold tolerance in plants. Further, MM/PBSA calculations for protein-DNA affinities reveal that, due to lack of alpha2 in DREB1C, the binding affinity of GCC-box with AP2/ERF domain of DREB1A > DREB1B > DREB1C. Thus, due to a better binding affinity with GCC-box, DREB1A and DREB1B can be utilised in near future for increasing cold tolerance of rice plant and increasing yield.
PMID: 30900088
Funct Integr Genomics , IF:3.058 , 2019 May , V19 (3) : P497-513 doi: 10.1007/s10142-019-00666-3
Functional characterization of HSFs from wheat in response to heat and other abiotic stress conditions.
Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, 110021, India.; Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, 110021, India. param@genomeindia.org.
High temperature stress is known to be one of the major limiting factors for wheat productivity worldwide. HSFs are known to play a central role in heat stress response in plants. Hence, the current study is an attempt to explore an in-depth involvement of TaHSFs in stress responses mainly in heat and other abiotic responses like salinity, drought, and cold stress. Effort was made to understand as how the expression of HSF is able to define the differential robustness of wheat varieties. Subsequent studies were done to establish the involvement of any temporal or spatial cue on the behavior of these TaHSFs under heat stress conditions. A total of 53 HSFs have been reported until date and out of these, few TaHSFs including one identified in our library, i.e., TaHsfA2d (Traes_4AS_52EB860E7.2), were selected for the expression analysis studies. The expressions of these HSFs were found to differ in both magnitude and sensitivity to the heat as well as other abiotic stresses. Moreover, these TaHSFs displayed wide range of expression in different tissues like anther, ovary, lemma, palea, awn, glume, and different stages of seed development. Thus, TaHSFs appear to be under dynamic expression as they respond in a unique manner to spatial, temporal, and environmental cues. Therefore, these HSFs can be used as candidate genes for understanding the molecular mechanism under heat stress and can be utilized for improving crop yield by enhancing the tolerance and survival of the crop plants under adverse environment conditions.
PMID: 30868385
Gene , IF:2.984 , 2019 May , V695 : P32-41 doi: 10.1016/j.gene.2019.02.005
Two ICE isoforms showing differential transcriptional regulation by cold and hormones participate in Brassica juncea cold stress signaling.
Molecular Plant Physiology and Proteomics Laboratory, Department of Botany, University of Delhi, India.; Molecular Plant Physiology and Proteomics Laboratory, Department of Botany, University of Delhi, India. Electronic address: rdeswal@botany.du.ac.in.
C-repeat binding factor (CBF) dependent cold stress signaling cascade is well studied in the model plant arabidopsis but is relatively lesser studied in the crop plants. In the present study, two novel isoforms of an upstream regulator of CBF, Inducer of CBF expression (ICE), BjICE46 (1314bp, accession number HQ446510) and BjICE53 (1494bp, accession number HQ857208) were isolated from Brassica juncea seedlings. Genomic clones of both the isoforms (accession numbers HQ433510 and JX571043) showed three introns, out of which one intron was spanning the bHLH (basic helix-loop-helix) domain. Interestingly, the constitutive expression of BjICE53 was 21 fold higher than BjICE46. Real time quantitative expression (RT-qPCR) showed BjICE53 to be cold induced but non-responsive to phytohormones. Interestingly, BjICE46 was salinity stress induced and showed upregulation with methyl jasmonate (MeJa) and abscisic acid (ABA). This was supported by the presence of ABA, MeJa and defense related cis- acting regulatory elements in the promoter region of BjICE46. The downstream transcription factor BjCBF (645bp) was also isolated. The promoter region of BjCBF showed three E-boxes, the binding site for ICE. BjCBF was expressed and purified from E. coli and binding of purified BjCBF with the DRE/CRT elements (present in the promoter of cold responsive genes) was EMSA confirmed. Overall, this study shows that ICE-CBF pathway is conserved in Brassica juncea along with the differential regulation of the ICE isoforms indicating cross-talk between cold and defense signaling.
PMID: 30738965
J Sci Food Agric , IF:2.614 , 2019 May , V99 (7) : P3367-3380 doi: 10.1002/jsfa.9554
Interactive effects of abscisic acid and nitric oxide on chilling resistance and active oxygen metabolism in peach fruit during cold storage.
Department of Horticulture, College of Agriculture, Shihezi University, Shihezi, PR China.; College of Chemistry and Material Science, Shandong Agriculture University, Taian, PR China.
BACKGROUND: Cold conditions can accelerate the production of reactive oxygen species (ROS), and excessive ROS may attack biological macromolecules, disrupt related signal pathways, induce oxidative stress and influence plant metabolism. The cross-talk between nitric oxide (NO) and abscisic acid (ABA) and the inhibitions by NO or ABA on oxidative damage have been reported in fruits. However, there are few reports about the roles of NO-ABA interactions in chilling stress and antioxidant defense in fruits during cold storage. This study was conducted to investigate the roles of NO, ABA and interactions between NO and ABA in response to chilling stress on peach fruit (Prunus persica (L.) Batsch, cv. 'Xintaihong'). RESULTS: Treatments with 15 micromol L(-1) NO, 100 micromol L(-1) ABA and 15 micromol L(-1) NO + 5 mmol L(-1) sodium tungstate solution could reduce ROS content, alleviate lipid peroxidation and enhance antioxidant enzyme activities and antioxidant capacities. However, treatments with 5 micromol L(-1) potassium 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO), 5 mmol L(-1) sodium tungstate and 100 micromol L(-1) ABA + 5 micromol L(-1) c-PTIO differentially blocked these protective effects and significantly increased ROS content and lipid peroxidation of peaches under low-temperature conditions. CONCLUSIONS: Application of exogenous ABA could increase the resistance to cold-induced oxidative stress by enhancing the efficiency of enzymatic and non-enzymatic systems, which were partially mediated by NO. (c) 2018 Society of Chemical Industry.
PMID: 30584803
J Plant Res , IF:2.185 , 2019 May , V132 (3) : P395-403 doi: 10.1007/s10265-019-01096-9
Heat and chilling stress induce nucleolus morphological changes.
Department of Applied Biological Science Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.; Department of Applied Biological Science Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan. sachi@rs.tus.ac.jp.
The nucleolus, where components of the ribosome are constructed, is known to play an important role in various stress responses in animals. However, little is known about the role of the plant nucleolus under environmental stresses such as heat and chilling stress. In this study, we analyzed nucleolus morphology by determining the distribution of newly synthesized rRNAs with an analog of uridine, 5-ethynyl uridine (EU). When EU was incorporated into the root of the Arabidopsis thaliana, EU signals were strongly localized in the nucleolus. The results of the short-term incorporation of EU implied that there is no compartmentation among the processes of transcription, processing, and construction of rRNAs. Nevertheless, under heat and chilling stress, EU was not incorporated into the center of the nucleolus. Morphological analyses using whole rRNA staining and differential interference contrast observations revealed speckled and round structures in the center of the nucleolus under heat and chilling stress, respectively.
PMID: 30847615
Physiol Mol Biol Plants , IF:2.005 , 2019 May , V25 (3) : P649-665 doi: 10.1007/s12298-019-00656-6
Redox-regulation of germination during imbibitional oxidative and chilling stress in an indica rice cultivar (Oryza sativa L., Cultivar Ratna).
UGC Centre for Advanced Study, Plant Physiology and Biochemistry Research Laboratory, Department of Botany, The University of Burdwan, Burdwan, West Bengal India.0000 0001 0559 4125grid.411826.8
Imbibitional oxidative stress of different magnitude, imposed by treatment with different titer of H2O2 (both elevated, 20 mM and low, 500 microM) to an indica rice cultivar (Oryza sativa L., Cultivar Ratna) caused formation of differential redox cues at the metabolic interface, as evident from significant alteration of ROS/antioxidant ratio, efficacy of ascorbate-glutathione cycle, radical scavenging property, modulation of total thiol content and expression of oxidative membrane protein and lipid damages as biomarkers of oxidative stress. All the redox parameters examined, substantiate the experimental outcome that treatment with elevated concentration of H2O2 caused serious loss of redox homeostasis and germination impairment, whereas low titre H2O2 treatment not only restored redox homeostasis but also improve germination and post-germinative growth. The inductive pulse of H2O2 (500 microM) exhibited significantly better performance of ascorbate-glutathione pathway, which was otherwise down-regulated significantly in 20 mM H2O2 treatment-raised seedlings. A comparison between imbibitional chilling stress-raised experimental rice seedlings with 20 mM H2O2 treated rice seedling revealed similar kind of generation of redox cues and oxidative stress response. Further, imbibitional H2O2 treatments in rice also revealed a dose-dependent regulation of expression of genes of Halliwell-Asada pathway enzymes, which is in consonance with the redox metabolic response of germinating rice seeds. In conclusion, a dose-dependent regulation of H2O2 mediated redox cues and redox regulatory properties during germination in rice are suggested, the knowledge of which may be exploited as a promising seed priming technology.
PMID: 31168230