A clp gene homologue belonging to the Crp gene family globally regulates lytic enzyme production, antimicrobial activity, and biological control activity expressed by Lysobacter enzymogenes strain C3
A clp gene homologue belonging to the Crp gene family globally regulates lytic enzyme production, antimicrobial activity, and biological control activity expressed by Lysobacter enzymogenes strain C3
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DOI：
10.1128/aem.71.1.261-269.2005
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发表时间：
2005-01-01
影响因子：
4.4
通讯作者：
Yuen, GY
中科院分区：
文献类型：
--
作者：
Kobayashi, DY;Reedy, RM;Yuen, GY
产酶溶杆菌菌株C3是一种植物病害生物防治剂，产生多种胞外水解酶，并对各种真菌和卵菌物种显示出抗微生物活性。然而，很少有人知道这些酶的调节或其在抗菌活性和生物防治中的作用。对菌株C3的胞外酶产生突变体进行了鉴定，并对其生防效果进行了评价。一个L.分离出在多种表型中受到全面影响的产酶菌株C3。在这个突变体中，5E 4，几种胞外溶解酶的活性，滑行运动，和体外抗菌活性降低。5E 4的特性表明，转座子插入clp基因的同源物属于Crp基因家族的调节器。紧接着下游是第二个开放阅读框，其类似于编码属于Gcn 5相关N-乙酰转移酶超家族的乙酰转移酶的开放阅读框，逆转录-PCR证实其与clp共转录。染色体缺失突变体与突变的CLP和CLP和乙酰转移酶基因之间验证了5E 4突变表型。将clp基因染色体插入突变体5E 4中，得到互补菌株P1。所有的突变表型恢复P1，虽然滑行运动被观察到过度与野生型菌株。clp突变菌株对甜菜腐霉立枯病和高羊茅小斑病的生物防治效果受到显着影响，而补充菌株P1则部分或完全恢复了这一效果。这些结果表明，clp基因是一个全局性的调控基因，控制着L.酶基因C3。
Lysobacter enzymogenes strain C3, a biological control agent for plant diseases, produces multiple extracellular hydrolytic enzymes and displays antimicrobial activity against various fungal and oomycetous species. However, little is known about the regulation of these enzymes or their roles in antimicrobial activity and biocontrol. A study was undertaken to identify mutants of strain C3 affected in extracellular enzyme production and to evaluate their biocontrol efficacy. A single mini-Tn5-lacZ(1)-cat transposon mutant of L. enzymogenes strain C3 that was globally affected in a variety of phenotypes was isolated. In this mutant, 5E4, the activities of several extracellular lytic enzymes, gliding motility, and in vitro antimicrobial activity were reduced. Characterization of 5E4 indicated that the transposon inserted in a clp gene homologue belonging to the Crp gene family of regulators. Immediately downstream was a second open reading frame similar to that encoding acetyltransferases belonging to the Gcn5-related N-acetyltransferase superfamily, which reverse transcription-PCR confirmed was cotranscribed with clp. Chromosomal deletion mutants with mutations in clp and between clp and the acetyltransferase gene verified the 5E4 mutant phenotype. The clp gene was chromosomally inserted in mutant 5E4, resulting in complemented strain P1. All mutant phenotypes were restored in P1, although the gliding motility was observed to be excessive compared with that of the wild-type strain. clp mutant strains were significantly affected in biological control of pythium damping-off of sugar beet and bipolaris leaf spot of tall fescue, which was partially or fully restored in the complemented strain P1. These results indicate that clp is a global regulatory gene that controls biocontrol traits expressed by L. enzymogenes C3.