Cloning and Molecular Characterization of the Major Light Harvesting Antenna Protein Genes of PSⅡ in Phyllostachys edulis

Three light harvesting chlorophyll a/b-binding protein genes (cab-PhE2,cab-PhE3 and cab-PhE6) were isolated from fresh leaves of Phyllostachys edulis by RT-PCR and RACE methods.The GenBank accession numbers were EF207230, EF405877 and EF628209,respectively.They shared high identities,with lhcb2,lhcb1,and lhcb3 genes encoding the major antenna proteins of PSⅡ from other plants such as Oryza sativa,Zea mays,and Hordeum vulgare.Secondary structure analysis showed that all the deduced proteins consisted of signal peptide and mature protein containing four α helices,three carotenoid binding sites and chlorophyll a/b-binding sites.The expression of these genes was detected in leaf (highest),sheath,and stem,but was undetectable in root.The genes were all down-regulated in leaf treated with strong light (1500 μmol·m^-2·s^-1),although they showed differences during treatment.The expression of cab-PhE3 and cab-PhE2 decreased rapidly during the first four hours,and cab-PhE2 dropped nearly to zero after six hours’ treatment.However,the expression level of cab-PhE6 was more than 70% that of the control after four hours,after which it reduced to less than 5% during the following two hours.