Suppr超能文献

来自墨西哥根瘤菌的酪氨酸酶参与结瘤效率和共生相关的胁迫抗性。

Tyrosinase from Rhizobium etli is involved in nodulation efficiency and symbiosis-associated stress resistance.

作者信息

Piñero Silvia, Rivera Javier, Romero David, Cevallos Miguel Angel, Martínez Alfredo, Bolívar Francisco, Gosset Guillermo

机构信息

Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología/UNAM, Cuernavaca, Mexico.

出版信息

J Mol Microbiol Biotechnol. 2007;13(1-3):35-44. doi: 10.1159/000103595.

Abstract

Tyrosinase (EC 1.14.18.1) is a monophenol oxidase responsible for the synthesis of the black pigment known as melanin. The tyrosinase gene (melA) is plasmid-encoded in many rhizobial species. In Rhizobium etli CFN42, the genetic location of melA in the symbiotic plasmid (p42d) and its RpoN-NifA regulation suggest an involvement in symbiosis. In this work, we analyzed the symbiotic phenotype of a streptomycin-resistant derivative of CFN42 (CE3), a melA mutant (SP2) and a complemented strain (SP66), demonstrating that melA inactivation reduced nodule formation rate and diminished total nodule number by 27% when compared to the CE3 strain. The nitrogen fixation capacity of the mutant strain was not affected. Also, in vitro assays were performed where the resistance of CE3, SP2 and SP66 strains to H(2)O(2) was evaluated; the melA mutant strain was consistently less resistant to peroxide. In another series of experiments, Escherichia coli W3110 strain expressing R. etli melA displayed enhanced resistance to p-hydroxybenzoic, vanillinic and syringic acids, which are phenolic compounds frequently found in the soil. Our results are the first to demonstrate a specific role for tyrosinase in R. etli: this enzyme is required during early symbiosis, apparently providing resistance against reactive oxygen species and phenolic compounds generated as part of the plant protective responses.

摘要

酪氨酸酶(EC 1.14.18.1)是一种单酚氧化酶,负责合成名为黑色素的黑色色素。酪氨酸酶基因(melA)在许多根瘤菌物种中由质粒编码。在根瘤菌CFN42中,melA在共生质粒(p42d)中的基因定位及其RpoN-NifA调控表明其参与共生作用。在本研究中,我们分析了CFN42的链霉素抗性衍生物(CE3)、melA突变体(SP2)和互补菌株(SP66)的共生表型,结果表明与CE3菌株相比,melA失活降低了根瘤形成率,使根瘤总数减少了27%。突变菌株的固氮能力未受影响。此外,还进行了体外试验,评估了CE3、SP2和SP66菌株对H₂O₂的抗性;melA突变菌株对过氧化物的抗性始终较低。在另一系列实验中,表达根瘤菌melA的大肠杆菌W3110菌株对对羟基苯甲酸、香草酸和丁香酸的抗性增强,这些都是土壤中常见的酚类化合物。我们的结果首次证明了酪氨酸酶在根瘤菌中的特定作用:这种酶在共生早期是必需的,显然能提供对作为植物保护反应一部分产生的活性氧和酚类化合物的抗性。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验