CHARACTERIZATION OF ECH-42, A TRICHODERMA-HARZIANUM ENDOCHITINASE GENE EXPRESSED DURING MYCOPARASITISM
CHARACTERIZATION OF ECH-42, A TRICHODERMA-HARZIANUM ENDOCHITINASE GENE EXPRESSED DURING MYCOPARASITISM
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DOI：
10.1073/pnas.91.23.10903
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发表时间：
1994-11-08
影响因子：
11.1
通讯作者：
HERRERAESTRELLA, A
中科院分区：
文献类型：
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作者：
CARSOLIO, C;GUTIERREZ, A;HERRERAESTRELLA, A
克隆了由生防菌哈茨木霉IMI206040产生的一种内切几丁质酶基因(ECH-42；以前命名为ECH-42)，并对其进行了鉴定。将该克隆在大肠杆菌中表达，获得了具有几丁质酶活性的细菌。这种几丁质酶在体外对灰霉病菌细胞壁具有裂解活性。经电泳分离和Southern分析，将ECH-42基因归属于双染色体带(染色体V或VI)。引物延伸分析表明，该基因的转录开始于翻译起始密码子上游109个碱基对。当真菌寄生虫与植物病原真菌在体外直接相互作用时，通过在含有甲壳素作为唯一碳源的最低限度的培养基中培养，ECH-42的表达被强烈地增强。类似地，光诱导的孢子形成导致高水平的转录，这表明该基因的发育调节。对这些发现的意义进行了讨论。
A gene (ech-42; previously named ThEn-42) coding for one of the endochitinases produced by the biocontrol agent Trichoderma harzianum IMI206040 was cloned and characterized. Expression of the cDNA clone in Escherichia coli resulted in bacteria with chitinase activity. This chitinase has bees shown to have lytic activity on Botrytis cinerea cell walls in vitro. The ech-42 gene was assigned to a double chromosomal band (chromosome V or VI) upon electrophoretic separation and Southern analysis of the chromosomes. Primer extension analysis indicated that transcription of the gene begins preferentially 109 bp upstream of the translation initiation codon. Expression of ech-42 was strongly enhanced during direct interaction of the mycoparasite with a phytopathogenic fungus when confronted in vitro and by growing it in minimal medium containing chitin as sole carbon source. Similarly, light-induced sporulation resulted in high levels of transcript, suggesting developmental regulation of the gene. The implications of these findings are discussed.