Comparative physiological, metabolomic, and transcriptomic analyses reveal mechanisms of improved abiotic stress resistance in bermudagrass [Cynodon dactylon (L). Pers.] by exogenous melatonin

Abstract

SummaryExogenous melatonin application confers abiotic stress resistance in bermudagrass through modulation of antioxidants and metabolic homeostasis, and extensive transcriptional reprogramming such as the reorientation of photorespiratory, carbohydrate, and nitrogen metabolism.

A new balancing act: The many roles of melatonin and serotonin in plant growth and development

“…MEL has been shown to differentially regulate expression of genes associated with the antioxidant enzymes including ascorbate-glutathione, auxin-related genes, development-associated genes and senescence-associated genes in plant cells 106,107,127,132 . Recent differential expression analyses of transcriptomes of plants exposed to MEL have found that the expression of more than 1300 genes are modified by MEL in A. thaliana and over 300 in cucumber.…”

“…This adds a further level of complexity to the signaling networks influenced by MEL 59,127,156 . Furthermore specific research has started to uncover the mechanisms behind this regulation with a Crepeat-binding factors (CBFs)/drought response element binding 1 factors (DREB1s) as well as WRKY, MYB and bHLH transcription factors being implicated in mediation of these responses 48,132,157 . Though large-scale transcriptomics analysis has not been …”

Improved abiotic stress tolerance of bermudagrass by exogenous small molecules

“…[1][2][3] Exogenous application of small molecules could effectively alleviate damages caused by multiple abiotic stresses, including drought, salt and cold. [4][5][6][7][8] Exogenous ABA treatment improved drought stress tolerance in 'TifEagle' cultivar through induction of H 2 O 2 and NO, which, in turn, enhanced antioxidant enzyme activities. 4 Our studies indicated that exogenous CaCl 2 , polyamines, H 2 S, and NO treatments were effective to induce bermudagrass tolerance to drought, salt, and cold stresses.…”

“…17 More recently, high throughput RNA seq analysis showed that exogenous melatonin treatment conferred improved salt, drought, and cold stress tolerances in bermudagrass through modulation of 3933 genes (2361 up-regulated and 1572 downregulated). 7 Melatonin (N-acetyl-5-methoxytryptamine) is a well-known animal hormone which is also found to play important roles in plant development and abiotic stress responses. [18][19] Exogenous melatonin treatment alleviated ROS burst and cell damage induced by abiotic stress in bermudagrass.…”

“…This was consistent with transcriptomic data which showed that redox-related genes were enriched. 7 Moreover, pathway and GO term enrichment analyses indicated that 8 pathways were over-represented after melatonin pre-treatment, including nitrogen metabolism, major carbohydrate metabolism, TCA/org transformation, transport, hormone metabolism, metal handling, redox, and secondary metabolism. Interestingly, several key genes involved in ABA (RCAR/PYR/PYL, SnRK2, and NCED3) and JA (JAZs) signaling were significantly changed after melatonin pre-treatment, which might be contributed to increased abiotic stress tolerance in bermudagrass.…”