Abstract:

【Objective】 To identify and characterize OsBTF3, a rice gene encoding a transcriptional factor up-regulated by Xanthomonas oryzae pv. oryzae (Xoo). 【Method】 Identification and isolation of the full length of cDNA sequence of OsBTF3 from rice (Oryza sativa L. cv. Nipponbare) was performed through bioinformatics and RT-PCR analysis. Prokaryotic expression and subcellular localization of OsBTF3 was conducted as well. Expression of OsBTF3 in rice tissues at various developmental stages and in response to Xoo infection was assayed via real-time quantitative PCR (RT-Q-PCR). 【Result】 The cloned OsBTF3 gene encodes a putative protein consisting of 175 amino acids with a nuclear localization signal (NLS) in N-terminal and a conserved NAC domain. OsBTF3 shares a high identity with the BTF3 homologues from other species (79%-88%). Prokaryotic expression analysis shows that an expressed protein (27 kD) is obtained after IPTG induction in E. coli. OsBTF3::GFP fusion protein mainly appears in the nuclear and cell membrane. RT-Q-PCR analysis indicates that OsBTF3 can express in various tissues of rice plants and be significantly induced by Xoo inoculation. 【Conclusion】 The full length cDNA sequence of OsBTF3 is successfully isolated. OsBTF3 is mainly localized in nuclear and cell membrane, and might play an important role in the regulation of susceptibility of rice.

Key words: rice')">rice, OsBTF3, gene cloning, gene expression, disease susceptibility