Pseudomonas syringae pv. syringae B728a hydrolyses indole-3-acetonitrile to the plant hormone indole-3-acetic acid.
Pseudomonas syringae pv. syringae B728a hydrolyses indole-3-acetonitrile to the plant hormone indole-3-acetic acid.
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DOI：
10.1111/j.1364-3703.2009.00595.x
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发表时间：
2009-11
影响因子：
4.9
通讯作者：
Andrew J. M. Howden;A. Rico;Thomas A. Mentlak;L. Miguet;G. Preston
中科院分区：
文献类型：
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作者：
Andrew J. M. Howden;A. Rico;Thomas A. Mentlak;L. Miguet;G. Preston
腈水解酶催化腈化合物水解成相应的羧酸和氨，并已在植物、细菌和真菌中得到鉴定。越来越多的证据支持腈水解酶在植物-微生物相互作用中的作用，但这些酶在植物病原细菌中的活性仍未被探索。植物病原菌丁香假单胞菌 pv. 的基因组。丁香菌 B728a 和丁香假单胞菌 pv.番茄 DC3000 含有与已表征的细菌芳基乙腈酶高度相似的腈水解酶基因。在这项研究中，我们发现丁香假单胞菌 pv. 的腈水解酶。丁香假单胞菌 B728a 是一种芳基乙腈酶，能够将吲哚-3-乙腈水解为植物激素吲哚-3-乙酸，并允许丁香假单胞菌 pv.丁香菌 B728a 使用吲哚-3-乙腈作为氮源。该酶可能代表丁香假单胞菌生物合成吲哚-3-乙酸的另一种机制。丁香菌B728a，或可用于降解和同化植物次生代谢过程中产生的醛肟和腈。在丁香假单胞菌 pv. 中未检测到腈水解酶活性。番茄 DC3000，尽管存在同源腈水解酶基因。这就提出了一个有趣的问题：为什么丁香假单胞菌中保留了腈水解酶活性。丁香假单胞菌 B728a，而不是丁香假单胞菌 pv. 丁香假单胞菌。番茄DC3000。
Nitrilase enzymes catalyse the hydrolysis of nitrile compounds to the corresponding carboxylic acid and ammonia, and have been identified in plants, bacteria and fungi. There is mounting evidence to support a role for nitrilases in plant-microbe interactions, but the activity of these enzymes in plant pathogenic bacteria remains unexplored. The genomes of the plant pathogenic bacteria Pseudomonas syringae pv. syringae B728a and Pseudomonas syringae pv. tomato DC3000 contain nitrilase genes with high similarity to characterized bacterial arylacetonitrilases. In this study, we show that the nitrilase of P. syringae pv. syringae B728a is an arylacetonitrilase, which is capable of hydrolysing indole-3-acetonitrile to the plant hormone indole-3-acetic acid, and allows P. syringae pv. syringae B728a to use indole-3-acetonitrile as a nitrogen source. This enzyme may represent an additional mechanism for indole-3-acetic acid biosynthesis by P. syringae pv. syringae B728a, or may be used to degrade and assimilate aldoximes and nitriles produced during plant secondary metabolism. Nitrilase activity was not detected in P. syringae pv. tomato DC3000, despite the presence of a homologous nitrilase gene. This raises the interesting question of why nitrilase activity has been retained in P. syringae pv. syringae B728a and not in P. syringae pv. tomato DC3000.