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

Abstract

Sugar metabolism is among the most important metabolic processes in soybean; it not only affects growth and development, but also plays a role in drought resistance. As a plant biological regulator, exogenous melatonin is assumed to regulate sugar metabolism. Here, physiological and transcriptomic approaches were used to determine the effects of melatonin on physiological indices and key genes and pathways associated with soybean sugar metabolism under drought stress. In plants subjected to drought stress, melatonin treatment increased dry matter accumulation, reduced malondialdehyde content, and increased the content of metabolized sugars in leaves, thereby enhancing soybean yield. Transcriptome analysis revealed that the genes differentially expressed in plants subjected to melatonin treatment and drought stress were enriched in the KEGG "sucrose and starch metabolism" pathway related to glucose metabolism. Among the differentially expressed genes, we identified 12 significantly altered genes associated with glucose metabolism that played roles in regulating the activities of glucose metabolism-related enzymes. Collectively, our results indicated that melatonin can enhance the output of glucose metabolites and tolerance of soybean subjected to drought stress by regulating the genes associated with glucose metabolism and activation of the related enzymes. Our findings provide a detailed theoretical basis for analyzing the regulatory effects of melatonin on soybean sugar metabolism under conditions of drought stress.

Melatonin as a key regulator in seed germination under abiotic stress

“…Aquaporins belong to the class of major intrinsic proteins and a fine regulation of their activities is required during imbibition and embryo growth 110 . Under DS, MEL also regulates SG and improves seedling growth by inducing the higher expression of VrPIP2 and PIP7 111 (plasma membrane intrinsic proteins [PIPs]2 and 7) and activation of starch metabolism, 112 higher accumulation of proline both at gene expression level and at enzymatic level 113 …”

Enhancement of osmotic stress tolerance in soybean seed germination by bacterial bioactive extracts

“…Therefore, to prevent infection by plant pathogens and insects after planting, soybeans require regular disease and insect management, which can be achieved through a variety of fungicides and pesticides, mechanical cultivation, the use of cover crops, and disease-resistant cultivars [6,7]. Moreover, previous studies have investigated physiological, biochemical, and molecular aspects [8][9][10][11] in an attempt to comprehend mechanisms of abiotic stress tolerance and identify potential applications in soybean [12,13].…”

“…If drought stress persists, this can negatively impact flower and pod production as well as seed quality, which may be seen in the reduced seed size and weight, and the dropping of premature pods [26,27]. To alleviate drought stress, a range of soybean crop management strategies have been developed, including planting drought-tolerant cultivars, managing irrigation, and employing alternatives such as trehalose, and biostimulants using microorganisms [12,13,[28][29][30].…”

Involvement of ethylene in melatonin‐modified photosynthetic‐N use efficiency and antioxidant activity to improve photosynthesis of salt grown wheat

“…Ethylene is also a positive mediator of adaptive responses under salt stress by upregulating antioxidant metabolism, synthesis of compatible osmolytes, and maintaining N‐use efficiency under N‐deficiency (Sehar et al, 2021). Glucose metabolism is regulated by melatonin (Cao et al, 2021), and ethylene decreases glucose‐mediated photosynthetic repression (Iqbal et al, 2011; Sehar et al, 2021).…”