Abstract:

Tea tree (Camellia sinensis) blossoms every year and a lot of nutrients are consumed by itself during blooming and fruiting, resulting in decreased yield and quality of fresh tea leaf. In the present study, the flowers of Fuding Dabaicha (male parent), Foxiang 2 (female parent) and their hybrid (sterile flowers) were used to construct cDNA libraries and the gene expression profiles were analyzed by Solexa sequencing technology. A total of 1219 candidate sterility genes were identified according to their differential expression between the male/female parent and the hybrid but identical between the two parents. These sterility gene were subject to GO analysis, and metabolic process, hydrolase activity and catalytic activity were enriched. KEGG pathway analysis showed that the sterility genes were involved in biosynthesis of amino acids and carbohydrate, second any metabolism, plant hormone signal transduction, and energy metabolism. In the function group of plant hormone signal transduction, 16 annotated genes were involved in the auxin signal transduction pathway, including five up-regulated AFR genes in the hybrid and 11 down-regulated genes. Thus, we speculate that auxin signal transduction might regulate the flower sterility in tea tree. Five sterility genes were selected randomly for qRT-PCR assay and the result was consistent with that of Solexa sequencing. The candidate sterility genes found in this study are worthy of sterile mechanism research in tea plant and sterility gene screening.

Key words: Tea plant flowers, Gene expression profiles, Sterility gene, Differentially expressed genes