S-Space College of Agriculture and Life Sciences (농업생명과학대학) Dept. of Agricultural Biotechnology (농생명공학부) Theses (Ph.D. / Sc.D._농생명공학부)
(The) type III effector XopN of Xanthomonas oryzae pv. oryzae Targets OsVOZ2 and a putative thiamine synthase in rice
벼흰잎마름병균이 분비하는 Type III Effector XopN과 벼의 단백질 OsVOZ2, Putative Thiamine Synthase의 상호작용
- 농업생명과학대학 농생명공학부
- Issue Date
- 서울대학교 대학원
- Xanthomonas oryzae pv. oryzae; xop genes; type III secretion system; yeast two-hybrid; bimolecular fluorescence complementation; pull-down assay
- 학위논문 (박사)-- 서울대학교 대학원 : 농생명공학부, 2014. 2. 황인규.
- Bacterial leaf blight on rice, one of the most serious rice diseases, is caused by Xanthomonas oryzae pv. oryzae (Xoo). To determine roles of Xanthomonas outer proteins (Xop) in Xoo, I identified seven Xop homologs from the genome information of Xoo KXO85. The xopQKXO85, xopXKXO85, xopP2KXO85, xopP1KXO85, and xopNKXO85 were generated by EZ-Tn5 mutagenesis. Among the individual mutants, the xopP2KXO85, xopP1KXO85 and xopNKXO85 mutants exhibited significantly reduced virulence compared to the wild-type in the flag leaves of Dongjin. Interestingly, I did not see reduced virulence when the xopP2KXO85, xopP1KXO85 and xopNKXO85 mutants were inoculated into young leaves of the Dongjin. This indicated that Xop-mediated virulence is dependent on leaf stages in rice. To identify target proteins of XopNKXO85 in rice, I performed yeast two-hybrid screening. Two rice proteins, OsVOZ2 and putative thiamine synthase, appeared to interact with XopNKXO85 in yeast. This interaction was further confirmed by bimolecular fluorescence complementation and in vivo pull-down assays. OsVOZ2 is a hypothetical protein, and OsXNP is a putative thiamine synthase. To investigate roles of OsVOZ2 in interactions between rice and Xoo, I evaluated virulence of the wild-type and the xopNKXO85 mutant strain in the OsVOZ2 mutant rice generated by T-DNA insertion in Dongjin. Both the wild-type and the xopNKXO85 mutant were less virulent in the mutant rice than in the wild-type rice. Therefore, XopNKXO85 is a virulence factor that it plays an important role in the Xoo and rice interactions.