转几丁质酶基因毛壳菌的抗病原真菌作用

Antifungal activity of Chaetomium globosum transformated with an endochitinase gene, chbi, from Trichoderma viride

含有来自绿色木霉Trichoderma viride的内切几丁质酶基因chbi的真菌表达载体pECHBI,通过原生质体转化将该基因导入球毛壳菌Chaetomium globosumCG12菌株,内切几丁质酶活性的测定结果表明,1/5的CG12转化子的内切几丁质酶活性得到了明显提高,PDA平板测定证实毛壳菌转化子对9种病原真菌具有拮抗能力,其中4株转化子的拮抗能力被显著提高.

In order to find out the roles of endochitinase during biocontrol process in Chaetomiurn globosum, a 42 kDa endochitinase gene （chbi） cloned from the genomic DNA of Trichoderma viride was transferred to C. globosurn isolates CG10 and CG12 separately by fungal transformation vector pECHBI. The endochitinase activities of one-fifth transformants with a foreign endochitinase gene （chbi） were enhanced significantly. The antagonism effectiveness of C. globosum transforrnants against nine pathogen fungi （Pythium aphaniderrnaturn, Rhizoctonia solani, Fusarium oxysporum f. sp. Cumumerinum, Alternaria alternata, Sclerotiurn rolfsii, Pestalotia diospyri, Pythiurn ultimurn and Colletotrichum piperaturn） was assessed in PDA culture medium. The transformant CG10-26 exbihited higher inhibition on the growth of F. oxysporurn than the wild type CG12 in the confrontation culture on PDA plate. The antifungual activities of the organic substances secreted by the transformant CG12-14 and CG12-25 cultured on the cellophane paper in the PDA culture medium exhibited higher inhibition on the growth of A. alternata than the wild type CG12. The antifungual activities of transformants CG12-18 and CG12-21 against P. diospyri, transformant CG12-14 against S. rolfsii, and transformant CG12-21 against P. ultimum were increased as those of CG12-14 and CG12-25 on the cellophane paper against A. alternata. There are no obvious relationships between the antifungual activities and the endochitinase activities in C. globosum transformants. For particular antagonism mechanism and pathogen fungus, the way to reach the great biocontrol effectiveness of transformants is to use the pertinent resistance-related gene.