Project description:Limonium bicolor, a typical recretohalophyte living in saline land, excretes excessive salt to the environment through salt glands in the epidermis for avoiding salt stress. The aim of this study was to screen genes involved in salt secretion by high-throughput RNA sequencing. A model was established to illustrate the candidate genes regulating salt secretion of salt gland. These genes will shed light on molecular mechanism of salt secretion of salt gland in plant.Normalized cDNA libraries of L. bicolor were constructed using mature leaves treated with 200 mM NaCl (with the highest salt secretion) and the control. Illumina paired-end platform was utilized to yield 2×100 bp independent reads. After de novo assembly, unigenes were aligned to the non-redundant (Nr) protein database and differentially expressed genes were enriched by GO annotations. Candidate genes were further verified by L. bicolor mutants with abnormal salt secretion.19,498 genes were targeted in Nr database and 5,768 were differentially expressed mapping to Arabidopsis, 2,269 up-regulated and 3,519 down-regulated under NaCl treatment compared with the control. Genes related to ion transport, vesicle, reactive oxygengen species scavenging, abscisic acid-dependent signal pathway and transcription factors were found high expression under NaCl treatment, of which 55 genes were likely involved in salt secretion and also confirmed by salt-secretion mutants.The present report identified candidate genes which are highly associated with salt secretion of L. bicolor salt gland. A salt transporting pathway was illustrated to explain how Na+ excreted outside by salt gland in L. bicolor. This data provides a useful reference source for salt secretion study of recretohalophytes.
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:The salt glands in the epidermis of recretohalophytes play a pivotal role in salt tolerance by secreting excess salts from tissues. Irrespective of the importance of understanding the secretion process, nothing is known about the molecular mechanisms of salt gland development. Limonium bicolor possesses multi-cellular salt glands in the epidermis and provides a model to study salt gland development. We applied next-generation sequencing to profile early leaf development using five distinctly different developmental stages, which were quantified by successive collections of the first true leaf of L. bicolor with precise spatial and temporal resolution. Twenty-two percent of the genes were differentially expressed along the developmental gradient. Cluster analysis revealed specific expression patterns at one stage, and identified enriched functions specific for each developmental stage. Seventy-two genes were identified as highly involved in salt gland differentiation. Salt glands have high homology with trichomes, which was also confirmed by mutants with increased salt gland densities. A model is proposed to illustrate genes participating in salt gland differentiation. This unique dataset lays the foundation for identifying key genes involved in salt gland development and salt secretion, which is a requisite for understanding mechanisms that could make agriculture possible in saline areas worldwide.
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.
Project description:To investigate the role of melatonin in salt tolerance of maize, we determine the seed germinated rate of maize under CK, NaCl and NaCl+melatonin. We then performed miRNA profiling analysis using data obtained from miRNA-seq of the seeds of three different treatments.
Project description:Rhododendron is well known woody plant, as having high ornamental and economic values. Heat stress is one of the important environmental stresses that effects Rhododendron growth. Recently, melatonin was reported to alleviate abiotic stress in plants. However, the role of melatonin in Rhododendron is still unknown. In the present study, the effect of melatonin on Rhododendron under heat stress and the potential mechanism was investigated. Through morphological characterization and chlorophyll a fluorescence analysis, 200µM was selected for the best melatonin concentration to mitigate heat stress in Rhododendron. To reveal the mechanism of melatonin priming alleviating the heat stress, the photosynthesis indexes, Rubisco activity and ATP content were detected in 25 ℃, 35 ℃ and 40 ℃. The results showed that melatonin improves electron transport rate (ETR), PSII and PSI activity, Rubisco activity and ATP content under high temperature stress. Furthermore, transcriptome analysis showed that a significant enrichment of differentially expressed genes in the photosynthesis pathway, and most of genes in photosynthesis pathway displayed a more significantly slight down-regulation under high temperature stress in melatonin-treatment plants, compared with melatonin-free plants. We identified PGR5……Together, these results demonstrate that melatonin could promote the photosynthetic electron transport, improve the enzymes activities in Calvin cycle and the production of ATP, and thereby increase photosynthetic efficiency and CO2 assimilation capacity under heat stress, through regulating the expression of some key genes, such as PGR5…Therefore, melatonin application displayed great potential to cope with the heat stress in Rhododendron.
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 melatonin’s function in soybeans and other crops.
2014-08-31 | GSE57960 | GEO
Project description:Mitigation effect of exogenous melatonin on germination of common beans under salt stress