拟康宁木霉T 51几丁质酶活性及内切几丁质酶基因克隆与分析

木霉是一类重要的生防真菌,木霉产生的几丁质酶在其生物防治的重寄生过程中起着重要作用。拟康宁木霉Trichoderma koningiopsis T-51是一株对番茄灰霉病有生防潜力的木霉菌株,本文测定了T-51菌株产生几丁质酶的活性,结果表明T-51在PDB中液体培养以及与灰霉病菌在PDA上对峙培养时产生的几丁质酶活性显著受到灰霉病菌的诱导。采用RACE技术首次克隆了拟康宁木霉T-51中一个几丁质酶基因Tkchit42,全长为1 817bp,包含4个外显子和3个内含子。预测该基因有一个1 275bp的开放阅读框,编码424个氨基酸,预测的蛋白总分子量为46.378kDa,预测的等电点(pI)为5.16,与T.koningii中42kDa内切几丁质酶的氨基酸序列相似性达到99%。

Chitinase activity and endo chitinase gene cloning and sequence analysis of Trichoderma koningiopsis T 51

Trichoderma koningiopsis T 51 is a potential biological control agent against Botrytis cinerea. In this study, chitinase activity of T 51 was significantly induced by B. cinerea in both liquid PDB medium and the interacting area with B.cinerea colony on PDA medium. An endo chitinase gene Tkchit42 was cloned from T.koningiopsis T 51. The full length of Tkchit42 was 1 817 bp, encoding an endo chitinase protein containing 424 amino acid residues. The predicted protein molecular weight was 46.378 kDa. The Tkchit42 amino acid sequence BLAST showed 99% similarity with that of a 42 kDa endo chitinase of T. koningii. For our knowledge, this is the first report of chitinase gene cloned from T. koningiopsis