关键词: 红肉蜜柚, 琯溪蜜柚, RING-H2 finger基因, 克隆, 基因表达

Abstract: RING（Real Interesting New Gene）finger proteins specify the substrates in the 26S ubiquitin-proteasome pathway，and play important roles in plant development and stress responses. However，the sequences，expression characteristics and physiological functions of RING finger genes in pommelo are little known. In this study，two RING finger（CgRHF1 and CgRHF2）cDNA fragments were isolated from Red-fleshed and Guanxi pommelo. The results showed that two CgRHFs were belonged to RING-H2 finger subfamilies，and there is no DNA base difference in the sequences of two cultivars. Quantitative real-time PCR results showed that gene expression of CgRHF1 is significantly higher than CgRHF2，especially in the stems，leaves and flowers of red-fleshed pommelo. The expression levels of CgRHF2 were relatively low in the tissues and fruit development of two pommelo cultivars，but dramatically increased at the fruit mature stage. This study has implied that CgRHF1 and CgRHF2 may play different roles in the tissues and fruit development of Red-fleshed and Guanxi pommelo，and can not functionally complement.

Key words: red-fleshed pommelo, Guanxi pommelo, RING-H2 finger gene, clone, gene expression