Isolation and primary analysis of protein structures and expression patterns responding to different light treatments of two phytochrome A genes in maize (Zea mays L.).

【Objective】 The protein structures and domain functions of two phytochrome genes of maize (Zea mays L.) (ZmPhyA1 and ZmPhyA2) were analyzed. The expression patterns of ZmPhyA1 and ZmPhyA2 responding to different light treatments were detected. 【Method】 The full cDNA of ZmPhyA1 and ZmPhyA2 were cloned through RT-PCR from maize inbred line of B73. The putative domains of ZmPHYA1 and ZmPHYA2 proteins were predicted via the NCBI Protein BLAST. The physical interactions between different functional domains of ZmPHYA1 and ZmPHYA2 were confirmed using yeast two hybrid system. Their expression levels were detected using semi-quantitative RT-PCR assay. 【Result】 Phylogenetic tree analysis indicated that ZmPHYA2 was more close with SbPHYA (Sorghum bicolor) than with ZmPHYA1. Both of ZmPHYA1 and ZmPHYA2 were composed of a GAF domain,a phytochrome domain,two PAS domains,a His Kinase A domain and a Histidine kinase-like ATPase domain. ZmPHYA1 and ZmPHYA2 were physically able to interact with themselves and each other through the 539-amino acids in their C terminal domains. Both of ZmPhyA1 and ZmPhyA2 showed higher expression lelvels in darkness,far-red and blue light conditions,but lower in red and white light conditions. 【Conclusion】 The ZmPHYA1and ZmPHYA2 proteins belong to active photo-receptor in maize as PHYA does in model plant Arabidopsis. The expression of ZmPhyA1 and ZmPhyA2 rapidly corresponded to dark,far-red,red and blue light treatments.