Lim Seon-Hwa, So Byoung-Ho, Wang Ji-Chun, Song Eun-Seong, Park Young-Jin, Lee Byoung-Moo, Kang Hee-Wan
Graduate School of Biotechnology and Information Technology, Hankyong National University, Ansung 456-749, Republic of Korea.
J Microbiol. 2008 Apr;46(2):214-20. doi: 10.1007/s12275-007-0173-9. Epub 2008 Jun 11.
Bacterial blight (BB) of rice, caused by Xanthomonas oryzae pv. oryzae (Xoo), is the most devastating bacterial disease in rice. A virulence-attenuated mutant strain HNU89K9 of X. oryzae pv. oryzae (KACC10331), with a transposon insertion in the pilQ gene was used for this study. The pilQ was involved in the gene cluster pilMNOPQ of the Xoo genome. Growth rate of the pilQ mutant was similar to that of wild-type. At level of amino acids, PilQ of Xoo showed that a high sequence identities more than 94% and 70% to Xanthomonas species and to Xyllela fastidiosa, respectively but a low sequence homology less than 30% to other bacterial species. The twitching motility forming a marginal fringe on PSA media was observed on colony of the wild-type strain KACC10331, but not in mutant HNU89K9. Wild-type Xoo cells formed a biofilm on the surface of the PVC plastic test tube, while the mutant strain HNU89K9 did not form a biofilm. The results suggest that the pilQ gene of X. oryzae pv. oryzae plays a critical role in pathogenicity, twitching motility, and biofilm formation.
由水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，简称Xoo）引起的水稻白叶枯病是水稻中最具毁灭性的细菌性病害。本研究使用了水稻白叶枯病菌（KACC10331）的一个毒力减弱突变菌株HNU89K9，其pilQ基因中有转座子插入。pilQ基因参与了水稻白叶枯病菌基因组中的pilMNOPQ基因簇。pilQ突变体的生长速率与野生型相似。在氨基酸水平上，水稻白叶枯病菌的PilQ与黄单胞菌属物种的序列同一性高于94%，与杏黄单胞菌（Xyllela fastidiosa）的序列同一性为70%，但与其他细菌物种的序列同源性低于30%。在野生型菌株KACC10331的菌落上观察到在PSA培养基上形成边缘流苏的颤动运动，但在突变体HNU89K9中未观察到。野生型水稻白叶枯病菌细胞在PVC塑料试管表面形成生物膜，而突变菌株HNU89K9不形成生物膜。结果表明，水稻白叶枯病菌的pilQ基因在致病性、颤动运动和生物膜形成中起关键作用。
