Comprehensive Dissection of Metabolic Changes in Albino and Green Tea Cultivars

Albino tea cultivars are special mutants of tea plants with white or yellow leaf color. In this study, three albino tea cultivars, including 'Anji Baicha', 'Huangjinya', and 'Baijiguan', and two green tea cultivars, 'Longjing 43' and 'Fuding Dabaicha', were applied to metabolite profiling by gas chromatography-mass spectrometry and ultraperformance liquid chromatography-mass spectrometry. Multivariate analyses revealed significantly different metabolite phenotypes in leaves among albino cultivars and green cultivars. The differential metabolite-related pathways included galactose metabolism, tryptophan metabolism, phenylpropanoid biosynthesis, and flavonoid biosynthesis. For the young leaves of albino cultivars, the sugar (sorbitol and erythrose) and amino acid (mainly proline, isoleucine, ornithine, aspartic acid, threonine, and valine) concentrations increased, whereas gallocatechin and epigallocatechin gallate concentrations decreased. These results reveal the divergence in metabolic profiling between tea plant cultivars with different leaf colors. With the development of leaves, the concentrations of flavonoids increased largely in the older leaves of albino cultivars.