REDUCED PATHOGEN FITNESS OF PSEUDOMONAS-SYRINGAE PV TOMATO TN5 MUTANTS DEFECTIVE IN CORONATINE PRODUCTION
REDUCED PATHOGEN FITNESS OF PSEUDOMONAS-SYRINGAE PV TOMATO TN5 MUTANTS DEFECTIVE IN CORONATINE PRODUCTION
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DOI：
10.1016/0885-5765(87)90040-3
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发表时间：
1987-03-01
影响因子：
2.7
通讯作者：
COOKSEY, DA
中科院分区：
文献类型：
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作者：
BENDER, CL;STONE, HE;COOKSEY, DA
丁香假单胞菌番茄菌株PT 23在番茄上产生坏死性病变，其周围是弥漫性黄化病。Mitchell等人（Physiological Plant Pathology 23，315-322）先前发现，一些P.番茄产生诱导萎黄病的植物毒素冠菌素。在本研究中，Tn 5诱变用于分离PT 23的非致突变突变体。筛选PT 23的一千个Tn 5突变体在番茄叶片上失绿诱导;回收了10个产生很少或不产生失绿的突变体。从两个突变体中提取有机酸，并通过高效液相色谱法和豆叶生物测定法进行分析，这两个突变体被发现是有缺陷的冠菌素生产。两种突变体诱导的坏死病变接种后4天达到最大直径（0.2 mm），但野生型菌株诱导的病变继续扩大到最大直径0.62 mm。细菌种群的增加与病变大小的增加相关。因此，冠菌素的合成似乎发挥了重要的作用，在病变的扩大和增殖的P.番茄叶里的番茄。
Pseudomonas syringae pv. tomato strain PT23 produces necrotic lesions on tomato which are surrounded by a diffuse yellow chlorosis. Mitchell et al. (Physiological Plant Pathology 23, 315-322) previously found that some strains of P. syringae pv. tomato produce the chlorosis-inducing phytotoxin, coronatine. In the present study, Tn5 mutagenesis was used to isolate nontoxigenic mutants of PT23. One thousand Tn5 mutants of PT23 were screened for loss of chlorosis induction on tomato leaves; 10 mutants were recovered which produced little or no chlorosis. Organic acids were extracted from two for the mutants and analysed by high performance liquid chromatography and a bean leaf bioassay; the two mutants were found to be defective in coronatine production. The necrotic lesions induced by the two mutants reached a maximum diameter (0.2 mm) 4 days after inoculation, but lesions induced by the wild-type strain continued to expand to a maximum diameter of 0.62 mm. An increase in bacterial population was correlated with the increase in lesion size. Therefore, coronatine synthesis appears to play an important role in lesion expansion and multiplication of P. syringae pv. tomato in tomato leaves.