Effect of gravity-induced pressure treatment on the growth and development of mung bean sprouts: Integrated analysis of widely targeted metabolomics and transcriptomics

Gravity-induced pressure (GIP) has been demonstrated to enhance the phenotypic appearance of mung bean sprouts; however, the mechanism underlying the growth behaviors of mung bean sprouts in response to GIP remains unclear. The objective of this study was to investigate the association between physiological and biochemical indicators of mung bean sprouts and GIP treatment using multi-omics approaches. In combination with increased hypocotyl thickness, GIP improved the antioxidant capacity of mung bean sprouts by elevating levels of ascorbic acid and 2,2 '-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging rate, as well as enhancing catalase and peroxidase activities. Of the 9 hormones changed following GIP treatment, indole-3acetic acid, abscisic acid (ABA), 3-indolepropionic acid, gibberellic acid 4, and brassinosteroids showed GIPdependent increases, reaching their highest levels under the 350 Pa. Metabolomics and transcriptomics analyses revealed a significant enrichment of the polyphenol biosynthetic pathway in response to 350 Pa. Despite no significant changes in the content of polyphenols, they comprised over 50 % of the identified differential metabolites, indicating a shift in their composition and resulting in a remarkable increase in ABTS scavenging rate. The increased ABA level suggested an enriched ABA signalling pathway associated with enhanced stress resistance induced by GIP in mung bean sprouts. Moreover, both the activity and expression levels of ascorbate oxidase and ascorbate peroxidase were decreased, which may be responsible for a 47.06 % increase in ascorbic acid content. The utilization of GIP at 350 Pa is highly recommended for improving quality during mung bean sprout production. This study may serve as a valuable reference for practical production techniques related to mung bean sprouts and further exploration into GIP-induced plant stress resistance.