Transcriptomic and metabolomic profiling of melatonin treated soybean (Glycine max L.) under drought stress during grain filling period through regulation of secondary metabolite biosynthesis pathways

Abstract

There is a growing need to enhance the productivity of soybean ( Glycine max L.) under severe drought conditions in order to improve global food security status. Melatonin, a ubiquitous hormone, could alleviate drought stress in various plants. Earlier, we demonstrated that exogenous melatonin treatment could enhance the tolerance of drought-treated soybean. However, the underlying mechanisms by which this hormone exerts drought resistance is still unclear. The present study used transcriptomic and metabolomic techniques to determine some critical genes and pathways regulating melatonin response to drought conditions. Results showed that exogenous melatonin treatment could increase relative water content and decrease electrolyte leakage in the leaves and increase seed yield under drought stress. Transcriptomic analysis showed that there were 852 core differentially expressed genes (DEGs) that were regulated by drought stress and melatonin in soybean leaves. The most enriched drought-responsive genes are mainly involved in the ‘biosynthesis of secondary metabolites’. Metabolomic profiling under drought stress showed higher accumulation levels of secondary metabolites related to drought tolerance after exogenous melatonin treatment. Also, we highlighted the vital role of the pathways including phenylpropanoid, flavonoid, isoflavonoid, and steroid biosynthesis pathways for improvement of drought tolerance in soybean by exogenous melatonin treatment. In all, findings from this study give detailed molecular basis for the application of melatonin as a drought-resistant agent in soybean cultivation.

iTRAQ-based proteomic and physiological analyses of broccoli sprouts in response to exogenous melatonin with ZnSO4 stress

“…16,17 Moreover, in the secondary metabolism of the plant, melatonin induces the biosynthesis of avonoids, 18,19 anthocyanins 20,21 and carotenoids, 22 among other molecules. 23 Similarly, according to our previous study, exogenous melatonin (10 mM) counters the harmful effects of ZnSO 4 stress (4 mM) and enhances sulforaphane content in broccoli sprouts during germination. Studies indicate that exogenous melatonin may be an ideal biotechnological target for improving ITC-enriched broccoli sprouts grown under stressful conditions.…”

Approaches for the amelioration of adverse effects of drought stress on crop plants

“…This study revealed metabolites that are needed for various cellular processes, like the tricarboxylic acid (TCA) cycle, glycolysis, starch biosynthesis, and pentose phosphate pathway for regulating amino acid metabolism, peptide metabolism, carbohydrate metabolism, biosynthesis of purine and pyrimidine, were affected under heat and drought stress condition [204]. Another study conducted on soybean by Cao et al [205] studied the metabolomic and transcriptomic profiling of soybean treated with melatonin under drought stress conditions during the grain-filling period through secondary metabolite biosynthesis pathways regulation.…”

Exogenous application of melatonin may contribute to enhancement of soybean drought tolerance via its effects on glucose metabolism

“…The relative soil water content (RSWC) of the control group was maintained at 80%, whereas that of the drought group was maintained at 45%. Half of the plants in the drought stress group were sprayed with 45 mL of a 100 µmol•L −1 melatonin solution for three consecutive days [1], whereas the remaining plants in the treatment group were sprayed with distilled water. The weight of each basin was measured daily to ensure that the set RSWC limit was maintained, and samples were collected on the third day after spraying.…”

“…The content of malondialdehyde (MDA) in plants was determined using the thiobarbituric acid method [14], and the method described by Cao et al [1]. was used to determine relative electrolyte leakage.…”

“…Soybean (Glycine max) is an important source of edible oil and protein worldwide [1]. As in most plant species, glucose metabolism plays important roles during the entire life of soybean plants, since glucose functions as both a nutrient and a regulatory molecule.…”