Differential gene expression in pepper (Capsicum annuum) exposed to UV-B.

In the present paper, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) was used to examine and identify differentially expressed genes in Capsicum annuum exposed to UV-B irradiation. Around 4000 transcript derived fragments (TDFs) were visualized and in total 183 TDFs were isolated, sequenced and analyzed by Blast 2 go. Among these TDFs, 84 of them showed homology to known genes. There were 43 TDFs showing up-regulated expression, 24 TDFs showing down-regulated expression and 27 TDFs showing both up-regulated and down-regulated expression, respectively. Some of these TDFs were found to be in response/related to UV-B stress, including carbonic anhydrase, calcium-dependent protein, thionin-like protein, bzip protein and so on. In particular, chlorophyll a/b binding protein (Capcab) responding to UV-B stress was cloned. It was concluded that Capcab could play a protective role in plant anti-UV-B and maintaining photosynthetic rate under UV-B stress.