Characterization of rice polyphenol oxidase promoter in transgenic Arabidopsis thaliana

Authors : Wasim AKHTAR, Ejaz AZIZ, Hisashi KOIWA, Tariq MAHMOOD

Pages : 223-233

View : 15 | Download : 8

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Polyphenol oxidase insert ignore into journalissuearticles values(PPO); enzymes are ubiquitous in plant kingdom and catalyze the oxidation of phenols to highly reactive quinones. The PPO gene plays an important role in plant defense mechanisms against biotic and abiotic stresses but the regulation of PPO promoter in stresses remains unclear. Here Oryza sativa insert ignore into journalissuearticles values(OsPPO); promoter was fused to firefly Luciferase insert ignore into journalissuearticles values(LUC); and β-glucuronidase insert ignore into journalissuearticles values(GUS); reporter genes separately to test the effects of wounding, abscisic acid insert ignore into journalissuearticles values(ABA);, and methyl jasmonate insert ignore into journalissuearticles values(MeJ); applications on PPO promoter induction. To the best of our knowledge, this is the first report about rice PPO promoter induction in response to wounding and ABA characterized by RT-PCR. Transcriptional profiling of reporter genes by real-time insert ignore into journalissuearticles values(RT); PCR in transgenic Arabidopsis revealed ~2.5-fold induction under PPO promoter directed activity in response to ABA treatment. Moreover, a strong induction of 11-fold was observed in response to wounding in reporter gene transcripts under control of OsPPO promoter. Plant cis-acting regulatory DNA elements signal scanning of OsPPO promoter also showed homologies to ABA cis-regulatory element signaling complexes and wound responsive elements insert ignore into journalissuearticles values(W-boxes); residing within the 1020 bp promoter region. Wound and ABA inducibility of OsPPO promoter is a strong indicator of its role in the plant defense mechanism against abiotic and biotic stresses.
Keywords : Characterization, wound induction, PPO, elicitors, transgenic Arabidopsis