Multi-omics integration reveals pH-responsive regulatory networks underlying tea plant growth and quality formation

Abstract

Tea plant growth, development and quality formation are strongly influenced by pH, which acts as a critical environmental factor. To systematically elucidate its regulatory mechanisms, this study employed a combined approach of physiology, transcriptomics and metabolomics to analyse the phenotypic responses, gene expression and metabolite accumulation dynamics of tea plants under different pH treatments. Results indicated that moderately elevated pH significantly enhanced the photosynthetic capacity of tea plant, promoted biomass accumulation and effectively elevated levels of key quality components including tea polyphenols and free amino acids in tea leaves. Omics analysis further revealed that pH elevation induced extensive transcriptional reprogramming and metabolic remodelling. For instance, genes associated with photosynthesis and carbon fixation pathways were specifically activated, while protein synthesis pathways such as ribosome assembly were suppressed. Correspondingly, the accumulation of quality-related metabolites, including amino acids, alkaloids and carbohydrates was significantly increased. Through integrated analysis using partial least squares structural equation modelling (PLS-SEM), this study constructed a multi-level regulatory network spanning molecular to phenotype and confirmed that pH synergistically drives tea plant growth and quality enhancement by coordinating photosynthetic gene expression and metabolic resource allocation. This research provides systematic experimental evidence for elucidating tea plants' adaptive mechanisms to pH, laying a theoretical foundation for precision management of tea plantation soils and targeted regulation of tea leaf quality.