Physiology and transcriptome analyses reveal a protective effect of the radical scavenger melatonin in aging maize seeds

Abstract

To determine the role of melatonin in aging maize seeds ( Zea mays L.), we investigated the physiological characteristics and performance analysis of the transcriptome after applying melatonin to maize seeds as a response to aging. In this study, we demonstrated that applying exogenous melatonin alleviated aging-induced oxidative damage, improved the activity of aging seeds, promoted growth of the germ and radical, enhanced antioxidant enzyme activity and reduced membrane lipid peroxidation. In addition, transcriptome sequencing revealed that various metabolic processes were induced by exogenous melatonin application in aging maize seeds, including hormone signal transduction, cellular processes, carbohydrate metabolism, secondary metabolites, and amino acid metabolism. In summary, the findings provide a more comprehensive understanding for analyzing the protective effect of melatonin in aging maize seeds.

Melatonin Priming Alleviates Aging-Induced Germination Inhibition by Regulating β-oxidation, Protein Translation, and Antioxidant Metabolism in Oat (Avena sativa L.) Seeds

“…For instance, melatonin has been demonstrated to promote seed germination under high salinity in cucumber [35], and significantly improve coleoptile length, seedling fresh weight, and dry weight in wheat under osmotic stress [36]. In this study, the results indicated that 200 µM melatonin significantly retarded the damage caused by aging to germination and seedling growth, improving GP, VI, GI, SL, SW, and SVI (Figure 1), as reported, to increase the activity of aged seeds and enhance the growth of germ and radicle in maize [27]. It has also been demonstrated that melatonin had an ameliorative effect on meristematic cells in Vigna radiata roots under chilled and rewarmed conditions [37].…”

“…Up-to-date, studies about melatonin's role in metabolic events of aged seeds have been rarely reported. Recently, research on melatonin for alleviating aging-induced oxidative damage was reported by Su et al [27] in maize seeds, which revealed that melatonin improved germination and growth characteristics, enhanced activities of antioxidases (superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)), reduced lipid peroxidation (LPO), and induced various metabolic changes (e.g., hormone signal transduction, cellular processes, metabolism of carbohydrate, secondary metabolite, and amino acid) by physiological and transcriptome analysis. However, there are still limited data to elucidate the underlying mechanisms of melatonin priming (MP) response to seed aging.…”

Dynamic Responses of Antioxidant and Glyoxalase Systems to Seed Aging Based on Full-Length Transcriptome in Oat (Avena sativa L.)

“…H 2 O 2 has been confirmed to affect seed germination and seed longevity through activating multiple MAPK cascades which are involved in responses to various biotic and abiotic stresses and developmental processes [ 15 , 65 , 66 ]. WNK is a newly discovered protein kinase of MAPKKK family that has been reported as a regulator of plant stress resistance and tissue development [ 67 , 68 ], but little is known of their roles in seed biology.…”

Melatonin-mediated development and abiotic stress tolerance in plants

“…Several reports have shown that melatonin induces higher levels of 18 metabolites (such as cellobiose, galactose, and gentiobiose), 10 amino acids, five sugars (arabinose, mannose, maltose, glucopyranose, and turanose), five polyalcohols (dulcitol, galactinol, glycerol, myo-inositol, and sorbitol), one organic acid (propanoic acid), two sugar alcohols of the carbon metabolic pathway, and more expressed genes related to carbohydrate transcripts, including glycosyl-transferases, glycosyl-hydrolases, glycosyl-phosphatases, glycosyl-invertases, and glycosyl-mutases, hexokinases, mannosidases, α- and β-amylases, α- and β-glucan related-enzymes and several dehydrogenases (3-phosphoglycerate-, UDP-glucose-, alcohol- and aldehyde-), among others ( Fan et al., 2015 ; Hernández-Ruiz et al., 2021 ). Specifically, in seeds, amid abiotic stress, plants generate important compatible solutes (such as starch and sucrose) to improve osmosis by advancing the expression of pectinesterase, malZ, sucrose-phosphate synthase, glgC, and PYG with the support of melatonin ( Su et al., 2018 ). As previously described, it has been clearly demonstrated that melatonin mediates carbohydrate, polyalcohol, and other metabolite levels in response to osmoregulatory adaptation.…”

“…Hormone signal transduction is essential for inducing biological processes and responses to environmental factors, which are known to activate gene transcription and regulate downstream metabolic processes ( Su et al., 2018 ). Typically, melatonin helps to acclimate to thermal shock not only through the differential regulation of HSPs ( HSFB3 , HSFA1a , HSFA2b , HSP23 , HSP70 , HSP80 , and HSP90 ) but also stimulates Ca 2+ and hormone signal transduction to accelerate a general response to improve resistance ( Xing et al., 2021 ).…”