Differential expression analysis of different albescent stages of ‘Anji Baicha’ (Camellia sinensis (L.) O. Kuntze) using cDNA microarray

Tea cultivar ‘Anji Baicha’ is a special green-revertible albino mutant and is widely cultivated in China for producing high price, high quality green tea with jade color, high aroma and nice taste. However, the molecular mechanism of the albino mutation is still unclear until now. The first tea plant cDNA microarray with 4866 clones was developed to analyze gene expression profiling of different albescent stages. A total of 671 differentially expressed genes at different albescent stages were found via the microarray analysis, which could be grouped into five clusters. The corresponding genes were involved in energy metabolism, carbon fixation, cell expansion, secondary metabolism, plant growth and defence, and other physiological processes including protein, nucleotide synthesis, etc. Particularly, some differentially expressed genes encoding important catalyzing enzymes or regulatory proteins which took part in chlorophyll biosynthesis or chloroplast development were identified. Some candidate genes possibly related to the albino process were further analyzed by using real-time PCR. The present study gave some useful clues for genes worthy of further understanding the albino phenotype of ‘Anji Baicha’ and also provided a model for utilization of the microarray technology in the tea plant.

► The first medium density cDNA microarray of the tea plant was constructed and developed.
► The gene expression profiling of a green-revertible albino tea cultivar was analyzed.
► A total of 671 differentially expressed genes were identified.
► Fourteen candidate genes possibly related to the albino process were validated.