External pH:: an environmental signal that helps to rationalize pel gene duplication in Erwinia chrysanthemi
External pH:: an environmental signal that helps to rationalize pel gene duplication in Erwinia chrysanthemi
复制标题
DOI：
10.1094/mpmi.2000.13.8.882
复制
发表时间：
2000-08-01
影响因子：
3.5
通讯作者：
Barras, F
中科院分区：
文献类型：
--
作者：
Nachin, L;Barras, F
植物病原菌欧文氏菊花欧文氏菌产生五种主要的果胶裂解酶，这五种酶是软腐病发展的关键毒力因子。利用转录融合技术，我们研究了PELA、PelD和Pelf基因的表达随外界pH的变化而变化的规律。当细菌在酸性介质中生长时，PELA和PelD表达，而Pelf仅在碱性介质中转录。利用酚红，我们观察到，在菊苣叶片中，侵染组织的pH值从酸性到碱性变化。综上所述，这些发现是在一个模型的背景下讨论的，该模型统一了催化和调节，以解释Pel基因的进化。特别是，我们认为这三种同工酶是在感染过程中顺序产生的。
The phytopathogenic bacterium Erwinia chrysanthemi produces five major pectate lyases that are key virulence factors in soft-rot disease development. Using transcriptional fusions, we studied the regulation of pelA, pelD, and pelf gene expression as a function of variation of the external pH pelA and pelD were expressed when bacteria were grown in an acidic medium while pelf was transcribed only in basic medium. Using phenol red, we observed that, in chicory leaves, pH value of infected tissue varies from acidic to basic. Taken together, these findings are discussed in the context of a model unifying both catalysis and regulation to account for pel gene evolution. In particular, we propose that the three isoenzymes are produced sequentially during the infection process.