Project description:Melatonin plays a potential role in multiple plant developmental processes and stress response. However, there are no reports regarding exogenous melatonin promoting rice seed germination under salinity and nor about the underlying molecular mechanisms at genome-wide. Here, we revealed that exogenous application of melatonin conferred roles in promoting rice seed germination under salinity. The putative molecular mechanisms of exogenous melatonin in promoting rice seed germination under high salinity were further investigated through metabolomic and transcriptomic analyses. The results state clearly that the phytohormone contents were reprogrammed, the activities of SOD, CAT, POD were enhanced, and the total antioxidant capacity was activated under salinity by exogenous melatonin. Additionally, melatonin-pre-treated seeds exhibited higher concentrations of glycosides than non-treated seeds under salinity. Furthermore, exogenous melatonin alleviated the accumulation of fatty acids induced by salinity. Genome-wide transcriptomic profiling identified 7160 transcripts that were differentially expressed in NaCl, MT100 and control. Pathway and GO term enrichment analysis revealed that genes involved in the response to oxidative stress, hormone metabolism, heme building, mitochondrion, tricarboxylic acid transformation were altered after melatonin pre-treatment under salinity. This study provides the first evidence of the protective roles of exogenous melatonin in increasing rice seed germination under salt stress, mainly via activation of antioxidants and modulation of metabolic homeostasis.
2020-01-20 | GSE143922 | GEO
Project description:Effect of exogenous melatonin on salt tolerance of common vegetables and beans in sprouting stage
Project description:Melatonin is a well-known agent that plays multiple roles in animals. Its possible function in plants is less clear. In the present study, we tested the effect of melatonin (N-acetyl-5-methoxytryptamine) on soybean growth and development. Both spraying of leaves and seed-coating with melatonin significantly promoted soybean growth as judged from leaf size and plant height. This enhancement was also observed in soybean production and their fatty acid content. Melatonin increased pod number, seed number and seed weight. However, the 100-seed weight was not influenced by melatonin application. Melatonin also improved soybean tolerance to salt and drought stresses. Transcriptome analysis revealed that melatonin up-regulated the expression of many genes and alleviated the inhibitory effects of salt stress on gene expressions. Further detailed analysis of the affected pathways documents that melatonin likely achieved its promotional roles in soybean through enhancement of genes involved in cell division, photosynthesis, carbohydrate metabolism, fatty acid biosynthesis and ascorbate metabolism. Our results demonstrate that melatonin has significant potential for improving of soybean growth and seed production. Further study should uncover more about the molecular mechanisms of melatoninM-bM-^@M-^Ys function in soybeans and other crops. Four different treatments were chosen, water, salt, 100M-BM-5M melatonin and salt plus 100M-BM-5M melatonin. The comparison of salt/melatonin-treated sample versus water-treated sample reveals salt or melatonin induced transcriptome changes. The comparison of melatonin plus salt treated sample versus salt-treated sample reveals melatonin induced changes when salt exists.
Project description:Salinity is a major abiotic stress at critical stages of seed germination and seedling establishment. Germination rate (GR) and field emergence rate (FER) are the key traits that determine the basic number of plants stand under field conditions. To explore molecular mechanisms in upland cotton under salt stress, a population of 177 recombinant inbred lines (RILs) and their parents were evaluated for seed germination traits (GP, germination potential; GR; FW, fresh weight; DW, dry weight; GL, germinal length) and seedling traits (FER; SH, seedling height; NL, Number of main stem leaves) in 2016-2018. Based on the linkage map contained 2,859 single nucleotide polymorphism (SNP) and simple sequence repeats (SSR) markers, traits under salt stress (E1) and normal condition, (E2) and the converted relative index (R-value) of three years’ trials were used to map quantitative trait loci (QTL). A total of three QTL and two clusters were detected as salt-tolerant QTL. Three QTL (qGR-Chr4-3, qFER-Chr12-3, qFER-Chr15-1) were detected under salt stress and R-value, which explained phenotypic variance of 9.62%-13.67%, and 4.2%-4.72%, 4.75%-8.96%, respectively. Two clusters (Loci-Chr4-2 and Loci-Chr5-4) harboring the QTL for four germination traits (GR, FER, GL, NL) and six seedling traits (GR, FER, DW, FW, SH, NL) were detected related under salt stress. A total of 691 genes were found in the candidate QTL or clusters. Among them, four genes (Gh_A04G1106, Gh_A05G3246, Gh_A05G3177, Gh_A05G3266) showed expression changes between sensitive and tolerant lines under salt stress, and were assigned as candidate genes in response to salt stress. The consistent salt-tolerance QTL identified in both germination and seedling stages will facilitate new information for cotton breeding.
Project description:Salt stress is a critical factor of abiotic stress in agricultural production that significantly affects seed germination and early seedling development. In this study, we characterized the function of the Arabidopsis Long Hypocotyl 2(HY2) gene in NaCl signaling. The hy2 mutant was NaCl-insensitive, whereas HY2-overexpressing lines shows NaCl-hypersensitive phenotypes during seed germination. Induced by exogenous NaCl, the transcription and the protein level of HY2 were up regulated, and HY2 positively mediated the expression of downstream stress-related genes of RD29A, RD29B and DREB2A. With further quantitative proteomics, we got the patterns of 7,391 proteins under salt stress, and identified 215 differentially regulated proteins (DRPs) specifically regulated by HY2. According to GO enrichment analysis, these proteins are mainly involved in ion homeostasis, hormone response, reactive oxygen species(ROS) metabolic, photosynthesis and detoxification pathway to response salt stress . These results direct the pathway of HY2 participating salt stress, and provide new insights for the plant to resist salt stress.
Project description:Increase soil salinization is affecting hull-less barley cultivation in the Qinghai-Tibet Plateau of China. Under saline conditions wild hull-less barley seeds showed high melatonin (MEL) accumulation during germination with improve salt tolerance. Hence, the present study aimed to understand the proteome level changes that result in high melatonin content in the germinating hull-less barley seed after treatment with 240mM-NaCl concentrations compared to control. Our results indicate that salt stress induced global changes in the proteome of germinating barley seeds. The NaCl treatment altered the expression and abundance of several proteins related to carbohydrate and energy metabolism, amino acid transport and metabolism which contributed to the high melatonin content in the seeds under salt stress. Further, proteins associated with cellular redox homeostasis, osmotic stress response and secondary metabolites derived from amino acid metabolism, including purine degradation, and shikimate pathways were induced in seeds with high melatonin content. Consequently, triggering a robust response to the oxidative stress occasioned by the NaCl-induced salt stress and lead to improved germination rate and salt stress adaptation in hull-less barley seeds. Overall our finding contribute to our understanding of the mechanism of melatonin mediated salt stress tolerance in barley at the protein level.
Project description:Proteomics was used to analyze the effect of 100μM exogenous melatonin on protein expression of tomato leaves under low night temperature stress.
Project description:Loss of the seed-specific WRKY transcription factor WRKY43 confers enhanced tolerance towards high salt, high osmolarity and low temperature with respect to seed germination. wrky43 loss of function lines display increased inhibition of seed germination in response to exogenous ABA, while WRKY43 overexpression lines are more tolerant towards exogenous ABA. The opposing effect of the wrky43 mutant on salt and ABA tolerance is reminiscent of fatty acid desaturase mutants. Loss of WRKY43 enhances polyunsaturated fatty acid content, particularly 18:2 and 18:3 in TAGs and Phospholipids. Gene chip arrays show that ABA-induced regulation of FUSCA3, ZAT10 and seed storage proteins are absent in the wrky43 mutant. Promoter-Luciferase studies confirm direct regulation of ZAT10 by WRKY43 and suggest indirect regulation of FUS3 and SSPs. In summary WRKY43 acts as a positive regulator of ABA-dependent gene regulation and of fatty acid desaturation that finally results in enhanced tolerance to abiotic stress.