Molecular Cloning and Characterization of Photosystem II gene (BcppsbO) from Brassica Campestris ssp . Pekinensis

摘要

Photosystem II ( PSII) is the primary charge separation reaction, including the transfer of an electron in green plant and harness of light energy to split H_2O into O_2, protons and electrons. The photosystem II complex of chloroplasts plays a vital role in the sustenance of life on earth and is a key component of photosynthesis. In the present study, we report on the cloning and characterization of photosystem II gene from Chinese cabbage ( designated BcppsbO , GenBank accession number; AY364014) using Rapid Amplification of cDNA Ends( RACE). The full-length cDNA of BcppsbO consisted of 1156 bp and contained a 699 bp open reading frame (ORF) encoding a 233-amino acid protein. The sequence similarity and comparative analysis showed that BcppsbO had high homology with other photosystem II oxygen-evolving proteins, such as Brassica napus 33 oxygen evolving protein of photosystem II ( Psbo) (AAD38521) and Arabidopsis thaliana photosystem II oxygen-evolving complex 33 (AROEC33) (NP_201458). Southern blot analysis indicated that the BcppsbO gene belonged to a low-copy gene family. Northern blot analysis revealed that the BcppsbO expressed in Chinese cabbage in a tissue-specific manner, and expressed higher in leaves than in roots and stems. BcppsbO transcript level was obviously reduced in leaves after dark treatment. Our study suggested that the BcppsbO gene was related with the light reaction.