Biochemical and Proteome Analysis Reveal Different Nutritional Compound Compositions and Chloroplast Development Situations between Purple-Red and White-Yellow Tea Plant Cultivars

Abstract

Across the world, most of the main tea plant cultivars are green-leaf cultivars, but colored-leaf cultivars have become increasingly popular in recent years. In this research, the differences between purple-red and white-yellow tea plant cultivars were compared on biochemical and proteome levels. White-yellow cultivars had significantly high amino acid (AA) content and low polyphenols/amino acid (PP/AA), while purple-red cultivars showed high PP/AA. Comprehensive analysis of all nutritional compounds revealed that most of them showed significant positive correlations, except AA, and that there were significant negative correlations between AA and other compounds. The nutritional compounds of some individual cultivars differed from the average trend of the classification, using color as a criterion. Twenty-one differential proteins were detected in the purple-red and yellow-white cultivars. Among these proteins, there were 16 upregulated proteins and 5 downregulated proteins in purple-red cultivars. Most of these proteins act in the photosynthetic system. This indicated that tea plants with purple-red leaves performed better in photosynthesis than yellow-white tea plant cultivars. The chloroplast development of white-yellow tea plant cultivars was obstructed and may introduce AA accumulation.