Comparative profiling of gene expression in Camellia sinensis L. cultivar AnJiBaiCha leaves during periodic albinism.

The AnJiBaiCha albino mutant tea cultivar has a reversible albino phenotype at low temperatures. Albino AnJiBaiCha leaves contain high levels of amino acids, which are important components affecting the quality of tea as a beverage. To examine the molecular mechanism of albinism and amino acid enrichment in AnJiBaiCha, we used the amplified fragment length polymorphism (cDNA-AFLP) technique to isolate genes that are differentially expressed during periodic albinism in AnJiBaiCha. A total of 127 transcript-derived fragments (TDFs) were successfully sequenced; among those, 60 TDFs showed high similarity to sequences with known functions, but 67 TDFs were not similar to any known genes. The identified transcripts include transcription factors, ubiquitination-related genes, chloroplast biogenesis genes, signal transduction genes, stress-related genes, cell cycle genes, and carbohydrate and energy metabolism genes. To validate the cDNA-AFLP results, quantitative real-time PCR was used to confirm the differential expression of six of the identified genes. The cDNA-AFLP and quantitative real-time PCR results correlated well, indicating that the cDNA-AFLP results are reliable. This study provides insights into the molecular mechanisms by which periodic albinism and amino acid accumulation take place in AnJiBaiCha.