Dataset Information

Melatonin Improved Waterlogging Tolerance in Alfalfa (Medicago sativa) by Reprogramming Polyamine and Ethylene Metabolism.

ABSTRACT: Melatonin (MT), polyamines (PAs), and ethylene have been suggested to play key roles in plant growth and development in response to environmental abiotic stresses. However, the effect of melatonin on polyamine and ethylene metabolism under waterlogging stress has rarely been elucidated. The main purpose of this study was to investigate the effect of melatonin pretreatment on waterlogging stress in alfalfa. The experiment was arranged into four treatment groups control with water pretreatment (CK-MT), control with melatonin pretreatment (CK+MT), waterlogging pretreated with water (WL-MT) and waterlogging pretreated with melatonin (WL+MT), with three replications. Six-week-old alfalfa seedlings were pretreated with 100 ?M melatonin and exposed to waterlogging stress for 10 days. Plant growth rate, different physiological characteristics, and gene expression level were measured. Results showed that waterlogging induced melatonin accumulation, and melatonin pretreatment increased endogenous MT levels for the control and water-logged plants. Waterlogging stress caused a significant reduction in plant growth, chlorophyll content, photochemical efficiency (Fv/Fm) and net photosynthetic rate (Pn), while also causing increased leaf electrolyte leakage (EL) and malondialdehyde (MDA) content. Pretreatment with melatonin alleviated the waterlogging-induced damage and reduction in plant growth, chlorophyll content, Fv/Fm and Pn. Waterlogging stress significantly increased leaf polyamines (Put, Spd, Spm) and ethylene levels, and the increased PAs and ethylene levels are coupled with higher metabolic enzymes and gene expressions. While pretreatment with melatonin further increased Put, Spd and Spm levels, it also decreased ethylene levels under waterlogging, and those increased PAs levels or decreased ethylene levels are regulated by the metabolic enzymes and gene expressions. The results in this study provide more comprehensive insight into the physiological and molecular mechanisms of melatonin-improved waterlogging tolerance in alfalfa. Furthermore, they suggested that melatonin improved waterlogging tolerance in alfalfa at least partially by reprogramming ethylene and PA biosynthesis, attributable to the increased PAs and decreased ethylene levels, which leads to more enhanced membrane stability and photosynthesis as well as less leaf senescence caused by ethylene.

SUBMITTER: Zhang Q

PROVIDER: S-EPMC6367245 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Melatonin Improved Waterlogging Tolerance in Alfalfa (<i>Medicago sativa</i>) by Reprogramming Polyamine and Ethylene Metabolism.

Zhang Qiang Q Liu Xiaofei X Zhang Zhifei Z Liu Ningfang N Li Danzhu D Hu Longxing L

Frontiers in plant science 20190201

Melatonin (MT), polyamines (PAs), and ethylene have been suggested to play key roles in plant growth and development in response to environmental abiotic stresses. However, the effect of melatonin on polyamine and ethylene metabolism under waterlogging stress has rarely been elucidated. The main purpose of this study was to investigate the effect of melatonin pretreatment on waterlogging stress in alfalfa. The experiment was arranged into four treatment groups control with water pretreatment (CK ...[more]

PMID: 30774639

Similar Datasets

Project description:As a high-quality legume forage, alfalfa is restricted by various abiotic stresses during its growth and development. Melatonin is a multifunctional signaling molecule that involves in plant defense against multiple stresses. However, little is known about its downstream signaling pathway and regulatory mechanisms in salt stress of alfalfa. In this study, we investigated the protective effects and key regulatory pathways of melatonin on alfalfa under salt tolerance. The results showed that melatonin promoted the growth of alfalfa seedlings under salt stress, as demonstrated by higher plant height, leaf area, and fresh weight. Melatonin treatment resulted in an increase in the photosynthetic capacity and starch content of alfalfa. Moreover, melatonin decreased cell membrane damage and reactive oxygen species (ROS) accumulation by enhancing antioxidant defense activity under salt stress conditions. Transcriptome sequencing (RNA-seq) analysis revealed that melatonin mainly induced the transcription of genes involved in Ca2+ signaling (cyclic nucleotide gated channel, CNGCs; cam modulin/calmodulin-like protein, CAM/CMLs and calcium-dependent protein kinase, CDPKs), starch and sucrose metabolism (α-amylase, AMYs; β-amylase, BAMs; starch synthase, SSs and sucrose synthase, SUSs), plant hormone signal transduction (auxin/indole acetic acid protein, AUX/IAAs; ABA receptor, PYL4; protein phosphatase 2C, PP2Cs; scarecrow-like protein, SCLs and ethylene-responsive transcription factor 1B, ERF1B), and key transcription factors (C3Hs, MYBs, ERFs, and WRKYs). Specifically, we focused on starch and sucrose metabolism and plant hormone signal transduction pathways. The interactions between melatonin and other phytohormones occurred via regulation of the expression of genes involved in hormone signaling pathways. In addition, melatonin increased the contents of endogenous melatonin, auxin, gibberellic acid (GA3), salicylic acid, brassinosteroids, and ethylene, while decreasing the abscisic acid content under salt stress. In summary, this study established a regulatory network for melatonin-induced key signaling pathways and functional genes under salt stress and provided a theoretical basis for salt tolerance breeding in alfalfa.

Project description:Alfalfa (Medicago sativa) is the most widely grown and most important forage crop in the world. However, alfalfa is susceptible to waterlogging stress, which is the major constraint for its cultivation area and crop production. So far, the molecular mechanism of alfalfa response to the waterlogging is largely unknown. Here, comparative transcriptome combined with proteomic analyses of two cultivars (M12, tolerant; M25, sensitive) of alfalfa showing contrasting tolerance to waterlogging were performed to understand the mechanism of alfalfa in response to waterlogging stress. Totally, 748 (581 up- and 167 down-regulated) genes were differentially expressed in leaves of waterlogging-stressed alfalfa compared with the control (M12_W vs. M12_CK), whereas 1193 (740 up- and 453 down-regulated) differentially abundant transcripts (DATs) were detected in the leaves of waterlogging-stressed plants in comparison with the control plants (M25_W vs. M25_CK). Furthermore, a total of 187 (122 up- and 65 down-regulated) and 190 (105 up- and 85 down-regulated) differentially abundant proteins (DAPs) were identified via isobaric tags for relative and absolute quantification (iTRAQ) method in M12_W vs. M12_CK and M25_W vs. M25_CK comparison, respectively. Compared dataset analysis of proteomics and transcriptomics revealed that 27 and eight genes displayed jointly up-regulated or down-regulated expression profiles at both mRNA and protein levels in M12_W vs. M12_CK comparison, whereas 30 and 27 genes were found to be co-up-regulated or co-down-regulated in M25_W vs. M25_CK comparison, respectively. The strongly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for co-up-regulated genes at mRNA and protein levels in M12_W vs. M12_CK comparison were 'Amino sugar and nucleotide sugar metabolism', 'Arginine and proline metabolism' and 'Starch and sucrose metabolism', whereas co-up-regulated protein-related pathways including 'Arginine and proline metabolism' and 'Valine, leucine and isoleucine degradation' were largely enriched in M25_W vs. M25_CK comparison. Importantly, the identified genes related to beta-amylase, Ethylene response Factor (ERF), Calcineurin B-like (CBL) interacting protein kinases (CIPKs), Glutathione peroxidase (GPX), and Glutathione-S-transferase (GST) may play key roles in conferring alfalfa tolerance to waterlogging stress. The present study may contribute to our understanding the molecular mechanism underlying the responses of alfalfa to waterlogging stress, and also provide important clues for further study and in-depth characterization of waterlogging-resistance breeding candidate genes in alfalfa.

Project description:BackgroundSoil salinity is an important factor affecting growth, development, and productivity of almost all land plants, including the forage crop alfalfa (Medicago sativa). However, little is known about how alfalfa responds and adapts to salt stress, particularly among different salt-tolerant cultivars.ResultsAmong seven alfalfa cultivars, we found that Zhongmu-1 (ZM) is relatively salt-tolerant and Xingjiang Daye (XJ) is salt-sensitive. Compared to XJ, ZM showed slower growth under low-salt conditions, but exhibited stronger tolerance to salt stress. RNA-seq analysis revealed 2237 and 1125 differentially expressed genes (DEGs) between ZM and XJ in the presence and absence of salt stress, among which many genes are involved in stress-related pathways. After salt treatment, compared with the controls, the number of DEGs in XJ (19373) was about four times of that in ZM (4833). We also detected specific differential gene expression patterns: In response to salt stress, compared with XJ, ZM maintained relatively more stable expression levels of genes related to the ROS and Ca2+ pathways, phytohormone biosynthesis, and Na+/K+ transport. Notably, several salt resistance-associated genes always showed greater levels of expression in ZM than in XJ, including a transcription factor. Consistent with the suppression of plant growth resulting from salt stress, the expression of numerous photosynthesis- and growth hormone-related genes decreased more dramatically in XJ than in ZM. By contrast, the expression levels of photosynthetic genes were lower in ZM under low-salt conditions.ConclusionsCompared with XJ, ZM is a salt-tolerant alfalfa cultivar possessing specific regulatory mechanisms conferring exceptional salt tolerance, likely by maintaining high transcript levels of abiotic and biotic stress resistance-related genes. Our results suggest that maintaining this specific physiological status and/or plant adaptation to salt stress most likely arises by inhibition of plant growth in ZM through plant hormone interactions. This study identifies new candidate genes that may regulate alfalfa tolerance to salt stress and increases the understanding of the genetic basis for salt tolerance.

Project description:BackgroundSoil pollution by heavy metals increases the bioavailability of metals like hexavalent chromium (Cr (VI)), subsequently limiting plant growth and reducing the efficiency of phytoremediation. Plant growth-promoting rhizobacteria (PGPR) have substantial potential to enhance plant growth as well as plant tolerance to metal stress. The aim of this research was to investigate Cr (VI) phytoremediation enhancement by PGPR.ResultsThe results showed that the 27 rhizobacterial isolates studied were confirmed as Cr (VI)-resistant PGPR, by using classical biochemical tests (phosphate solubilization, nitrogen fixation, indole acetic acid, exopolysaccharides, hydrogen cyanide, siderophores, ammonia, cellulase, pectinase, and chitinase production) and showed variable levels of Cr (VI) resistance (300-600 mg/L). The best four selected Cr (VI)-resistant PGPR (NT15, NT19, NT20, and NT27) retained most of the PGP traits in the presence of 100-200 mg/L concentrations of Cr (VI). The inoculation of Medicago sativa with any of these four isolates improved the shoot and root dry weight. The NT27 isolate identified using 16S rDNA gene sequence analyses as a strain of Pseudomonas sp. was most effective in terms of plant growth promotion and stress level decrease. It increased shoot and root dry weights of M. sativa by 97.6 and 95.4%, respectively, in the presence of Cr (VI) when compared to non-inoculated control plants. It also greatly increased chlorophyll content and decreased the levels of stress markers, malondialdehyde, hydrogen peroxide, and proline. The results of the effect of Pseudomonas sp. on Cr content and bioaccumulation factor (BAF) of the shoots and roots of M. sativa plants showed the increase of plant biomass concomitantly with the increase of Cr root concentration in inoculated plants. This would lead to a higher potential of Cr (VI) phytostabilization.ConclusionsThis study demonstrates that the association M. sativa-Pseudomonas sp. may be an efficient biological system for the bioremediation of Cr (VI)-contaminated soils.

Dataset Information

Melatonin Improved Waterlogging Tolerance in Alfalfa (Medicago sativa) by Reprogramming Polyamine and Ethylene Metabolism.

Publications

Melatonin Improved Waterlogging Tolerance in Alfalfa (<i>Medicago sativa</i>) by Reprogramming Polyamine and Ethylene Metabolism.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets