Complementary transcriptomic and proteomic analyses of a chlorophyll-deficient tea plant cultivar reveal multiple metabolic pathway changes

•We identified 3131 proteins from Camellia sinensis leaves using the iTRAQ approach.•Comparative transcriptomics and proteomics of two tea cultivars were performed.•Differentially expressed proteins/genes enriched in pathways related to the phenotype.•We clarified the mechanism of chlorina through microarray and proteomic approaches.

ABSTRACTTo uncover the mechanisms that underlie the chlorina phenotype of the tea plant, this study employs morphological, biochemical, transcriptomic, and iTRAQ-based proteomic analyses to compare the green tea cultivar LJ43 and the yellow-leaf tea cultivar ZH1. ZH1 exhibited the chlorina phenotype, with significantly decreased chlorophyll content and abnormal chloroplast development compared with LJ43. ZH1 also displayed higher theanine and free amino acid content and lower carotenoid and catechin content. Microarray and iTRAQ analyses indicated that the differentially expressed genes and proteins could be mapped to the following pathways: ‘phenylpropanoid biosynthesis,’ ‘glutathione metabolism,’ ‘phenylalanine metabolism,’ ‘photosynthesis,’ and ‘flavonoid biosynthesis.’ Altered gene and protein levels in these pathways may account for the increased amino acid content and reduced chlorophyll and flavonoid content of ZH1. Altogether, this study combines transcriptomic and proteomic approaches to better understand the mechanisms responsible for the chlorina phenotype.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (318 K)Download as PowerPoint slide