Kim Hong-Il, Noh Tae-Hwan, Lee Chang-Soo, Park Young-Jin
Department of Biomedical Chemistry, Konkuk University, Chung-Ju 380-701, Republic of Korea.
Department of Rice and Winter Cereal Crop, National Institute of Crop Science, Iksan 570-080, Republic of Korea.
Microbiol Res. 2015 Jan;170:124-30. doi: 10.1016/j.micres.2014.08.006. Epub 2014 Aug 29.
Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB) in rice. To study its function, a random insertion mutation library of Xoo was constructed using the Tn5 transposon. A mutant strain with decreased virulence against the susceptible rice cultivar IR24 was isolated from the library (aroE mutant), which also had extremely low pigment production. Thermal asymmetric interlaced-polymerase chain reaction (TAIL-PCR) and sequence analysis of the mutant revealed that the transposon was inserted into the aroE gene (encoding shikimate dehydrogenase). To investigate gene expression changes in the pigment- and virulence-deficient mutant, DNA microarray analysis was performed, which showed downregulation of 20 genes involved in the chemotaxis of Xoo. Our findings reveal that mutation of the aroE gene affects virulence and pigment production, as well as expression of genes involved in Xoo chemotaxis.
水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，Xoo）可引发水稻白叶枯病（BB）。为研究其功能，利用Tn5转座子构建了Xoo的随机插入突变文库。从该文库中分离出一株对感病水稻品种IR24致病力下降的突变菌株（aroE突变体），其色素产生量也极低。对该突变体进行热不对称交错聚合酶链反应（TAIL-PCR）和序列分析，结果显示转座子插入到aroE基因（编码莽草酸脱氢酶）中。为研究色素和致病力缺陷型突变体中的基因表达变化情况，进行了DNA微阵列分析，结果表明20个参与Xoo趋化性的基因表达下调。我们的研究结果表明，aroE基因突变会影响致病力、色素产生以及参与Xoo趋化性的基因表达。
