Multomics Analysis of the Characteristic Changes in Polyphenol Accumulation and Cell Wall Polysaccharide Remodelling...

Background/Objectives: At present, there are only a few studies on characteristic changes in polyphenols and cell wall polysaccharides and their correlations in Z. mioga flower buds during development. Methods: Polyphenols were analysed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Content and enzyme activities of cell wall components were examined using a microplate reader. Expression of genes related to these components was detected using de novo-Seq. Results: Most polyphenols accumulated significantly, with the highest levels being found in cyanidin-3-O-glucoside and epicatechin. PCA results show that changes in polyphenols were largely dependent on the germination and ripening stage, which might represent its specific period. Additionally, the increased flavonoid and anthocyanin fractions might be due to the up-regulated expression of DFR1/2, ANS and BZl. During development, PME, PG and β-galactosidase synergistically break down protopectin to soluble pectin; PME coordinates with cellulase in cellulose degradation, while xylanase dominates hemicellulose degradation. Lac collaborated with PME, PG and cellulase to regulate lignin synthesis. Key upregulated genes driving cell wall polysaccharide alterations include PME35, PG and GAUT7 for pectin metabolism, CESA2/3 for cellulose synthesis, and Lac25, POD6/7/47/52 and CCR6 for lignin synthesis. Correlation analysis revealed that the synergistic effects of p-coumaric acid, chlorogenic acid, epicatechin, cyanidin-3-O-glucoside, peonidin-3-O-glucoside, protopectin, pectin, lignin and cellulose might be responsible for the sensory quality formation in Z. mioga. Conclusions: This study further investigates the binding mode of polyphenols and cell wall polysaccharides, providing a theoretical basis for understanding the development of sensory qualities in Z. mioga flower buds during growth and maturation.