Rabibhadana S, Chamnongpol S, Sukchawalit R, Ambulos N P, Trempy J E, Mongkolsuk S
Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok, Thailand.
FEMS Microbiol Lett. 1998 Jan 15;158(2):195-200. doi: 10.1111/j.1574-6968.1998.tb12820.x.
Nucleotide sequence of Xanthomonas oryzae pv. oryzae (Xoo) DNA from pSM-A1 was determined and sequence analysis revealed an ORF with high homology to RecA proteins. Expression analysis using an anti-RecA antibody demonstrates that MMS treatment induces recA in Xanthomonas strains but not in an Escherichia coli harbouring cloned Xoo recA. This indicates the existence of a recA regulatory mechanism in Xanthomonas that is not function in E. coli. In Xoo, recA was highly induced by treatments with chemical mutagens, UV and peroxides, while superoxides, a thiol agent, a heavy metal and heat shock were not inducers. The increased amount of RecA induced by H2O2 or MMS treatments were due to increased transcription of recA. recA showed no growth phase or starvation regulation. The pattern of recA regulation in Xoo could play important roles in stress survival in the environment and during plant-microbe interactions.
测定了来自pSM - A1的水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，Xoo）DNA的核苷酸序列，序列分析揭示了一个与RecA蛋白具有高度同源性的开放阅读框（ORF）。使用抗RecA抗体进行的表达分析表明，甲磺酸甲酯（MMS）处理可诱导Xanthomonas菌株中的recA表达，但在携带克隆的Xoo recA的大肠杆菌中则不会。这表明Xanthomonas中存在一种recA调控机制，而该机制在大肠杆菌中不起作用。在Xoo中，化学诱变剂、紫外线和过氧化物处理可高度诱导recA表达，而超氧化物、一种硫醇试剂、一种重金属和热休克则不是诱导剂。H2O2或MMS处理诱导的RecA量增加是由于recA转录增加所致。recA未表现出生长期或饥饿调控。Xoo中recA的调控模式可能在环境应激存活以及植物 - 微生物相互作用过程中发挥重要作用。
