摘要
玉米茎腐病菌 Pythium aphanidermatum、Fusarium graminearum能够产生一系列细胞壁降解酶 ,即果胶甲基酯酶 ( PE)、多聚半乳糖醛酸酶 ( PG)、果胶甲基半乳糖醛酸酶 ( PMG)、多聚半乳糖醛酸反式消除酶 ( PGTE)、果胶甲基反式消除酶 ( PMTE)和纤维素酶 ( Cx)。Fusarium graminearum产生的细胞壁降解酶活性明显高于 Pythium aphanidermatum。病菌在活体内和活体外产生的细胞壁降解酶活性明显不同。酶动力学研究表明 :Fusarium graminearum产生的各种细胞壁降解酶均有特定的最适反应条件。水解酶类的 PG、PMG、Cx最大酶活的 p H分别为 6.0、5.0、6.0 ,温度分别为 50、4 0、50℃ ;裂解酶类的 PGTE和 PMTE最大酶活的 p H均为 9.0 ,温度分别为 30、2 0℃ ,与其它病菌产生的细胞壁降解酶的特性基本相同。
A series of cell wall degrading enzymes (CWDEs) including pectin methylesterase(PE),polygalacturonase(PG), polymethylgalacturonase (PMG), polygalacturonic acid trans-eliminase(PGTE),pectin methyl trans-eliminase(PMTE)and Cx were found in corn stalk pathogens,Pythium aphanidermatum and Fusarium graminearum.CWDEs produced from F.graminearum showed higher activities as compared with those from P.aphanidermatum.There were much difference of enzyme activities between in vitro and in vivo CWDEs.Results from enzyme dynamics analysis showed that different kinds of CWDEs had special optimum temperature,pH and reaction time of their maximum activities.For example,PG,PMG and Cx as a hydrolytic enzymes showed maximum activities at pH 6.0,5.0,6.0 and 50℃,40℃,50℃;PGTE and PMTE as a lytic enzymes at pH 9.0,9.0 and 30℃,20℃,respectively.
出处
《植物病理学报》
CAS
CSCD
北大核心
2000年第2期148-152,共5页
Acta Phytopathologica Sinica
基金
国家"九五"攻关课题! (96 - 0 0 5 - 0 1- 0 3- 0 3)
国家自然科学基金资助课题! (39170 5 15 )
关键词
茎腐病
细胞壁降解酶
酶动力学
玉米
stalk rot
cell wall degrading enzymes
pectinase
enzyme dynamics
