Integrated Transcriptome and Metabolome Analysis Reveal That Exogenous Gibberellin Application Regulates Lignin Synthesis in Ramie

Abstract

Gibberellin regulates plant growth, development, and metabolic processes. However, the underlying mechanism of the substantial effect of gibberellin on stem height and secondary metabolites in forage ramie is unclear. Therefore, this study combined transcriptomic and metabolomics analyses to identify the mechanisms regulating growth and secondary metabolite contents in forage ramie following exogenous gibberellin application. Exogenous gibberellin application significantly reduced the lignin content in the leaves but not in the stems. At the same time, gibberellin significantly increased the total flavonoid and chlorogenic acid contents in both the stems and leaves. In addition, 293 differentially expressed genes (DEGs) and 68 differentially expressed metabolites (DEMs) were identified in the leaves. In the stems, 128 DEGs and 41 DEMs were identified. The DEGs PER42, FLS, CYP75A, and PNC1 were up-regulated in the leaves, affecting phenylpropane metabolism. The joint analysis of the DEMs and DEGs revealed that the changes in the DEGs and DEMs in the leaves and stems improved the substrate efficiency in the phenol propane pathway and inhibited lignin synthesis in plants, thus shifting to flavonoid pathway synthesis. In conclusion, gibberellin treatment effectively reduces the lignin content in forage ramie while increasing the flavonoid and chlorogenic acid contents. These findings provide empirical and practical guidance for breeding for forage quality in ramie and the improvement and cultivation control of forage ramie.

Integrated Transcriptomic and Metabolomic Analysis Reveals the Mechanism of Gibberellic Acid Regulates the Growth and Flavonoid Synthesis in Phellodendron chinense Schneid Seedlings

“…Meanwhile, the cluster and class heatmaps showed the similarity of components among biological repeats and the difference of components among the two treatment groups, suggesting that GA3 strongly influenced the metabolite profiles in the stem bark of P. chinense Schneid seedlings (Figure S4b). In this present study, a total of 443 metabolites in stem bark samples from CK and GA3 treatment groups were identified and divided into 11 categories, which mainly included flavonoid (90), phenolic acid (62), lipid (59), amino acid and derivative (46), alkaloid (45), organic acid (31), nucleotide and derivative (30), and lignan and coumarin (20) (Figure S4c).…”

“…Secondary metabolites comprise a diverse group of compounds, including flavonoids, alkaloids, and terpenoids, where flavonoids play a protective role against biotic and abiotic stresses. The biosynthesis of these compounds is regulated by exogenous GA 3 in plants [19,20]. Previous studies have validated that exogenous GA 3 inhibited the biosynthesis of flavonoid and isoflavonoid through negatively regulating GA-mediated signal pathway and promoted the growth by improving nitrogen metabolism in Medicago truncatula [21].…”

A Systematic Review on the Improvement of Cd Stress Tolerance in Ramie Crop, Limitations and Future Prospective

“…The priming of barley seed with GB3 reduces the toxic effects of Cd stress on coleoptile growth [85]. Gibberellin improves ramie growth, development, and metabolic processes [86,87]. The study indicated that brassinosteroids (BR) and gibberellin (GA) have different effects on the enrichment and transport of Cd in ramie.…”

Ascorbic acid releases dormancy and promotes germination by an integrated regulation of abscisic acid and gibberellin in Pyrus betulifolia seeds

“…Furthermore, GA regulates growth by controlling the size of the meristem, thereby controlling the cell production rate (Kiradjiev and Band 2023). Even the integrated analysis of transcriptome and metabolome reveals that exogenous GA has a substantial effect on stem height and secondary metabolites in forage ramie (Jie et al 2023). Jang et al (2023) illustrated that the ABA and GA balance is not an absolute factor in determining dormancy.…”