Widely Targeted Metabolomic and Transcriptomic Analyses of a Novel Albino Tea Mutant of Rougui

Albino tea mutants with specific shoot colors (white or yellow) have received increasing attention from researchers due to their unique phenotypes, beneficial metabolites, and special flavor. In this study, novel natural yellow leaf mutants of the same genetic background of Rougui were obtained, and the transcriptome and metabolite profiles of the yellow leaf mutant (YR) and original green cultivar (GR) were investigated. A total of 130 significantly changed metabolites (SCMs) and 55 differentially expressed genes (DEGs) were identified in YR compared to GR. The leaf coloration of YR was primarily affected by pigment metabolism including of chlorophyll, carotenoids, and flavonoids, and the co-expression of three heat shock proteins (HSPs) and four heat shock transcription factors (HSFs) may also regulate leaf coloration by affecting chloroplast biogenesis. Of the 130 SCMs, 103 showed clearly increased abundance in YR, especially nucleotides and amino acids and their derivatives and flavonoids, suggesting that YR may be an ideal albino tea germplasm for planting and breeding. Our results may help to characterize the leaf coloration and metabolic mechanism of albino tea germplasm.