棘孢木霉天冬氨酸蛋白酶家族基因特性研究

Properties Analysis of Aspartic Protease Genes in Trichoderma asperellum Genome

本研究旨对棘孢木霉基因组20个天冬氨酸蛋白酶家族基因(Asp)特性进行分析。分别进行了保守区及家族预测、氨基酸多序列比较及功能区预测、进化关系分析及其在不同培养条件下棘孢木霉中的差异表达分析。20个Asp均属Asp蛋白酶家族(PF00026),均为酸性(p I<7)。有18个Asps含有信号肽。多序列比对发现Asps含有2个特征性催化指纹"DTGS/A"和"DT/SGS/Y/T/A/N",根据第二个"DTGT"、"DSGT"、"DTGA/N"和"DSGY/T/S"特征性催化指纹,将20个Asps分为4个分支。进一步在C-hungry胁迫下,10个Asps基因上调,Asp54.2上调最高为3222。在N-hungry胁迫下,8个Asps基因上调,Asp50.9上调最高为33100。山新杨(Tas-Pd Pap)叶粉诱导后,13个Asps基因上调,Asp50.9上调最高为21078。说明棘孢木霉促杨树生长及与病原菌拮抗过程中,Asp起了非常重要的作用。

The study aims at analyzing the characteristics of 20 aspartic protease family genes（ASP） in Trichoderma asperellum genome. Their conserved domains and family, the amino acid sequences alignment,functional domains are predicted, and the evolutionary relationship and the differential expression of Asp genesof T. asperellum under different culture conditions are analyzed. All 20 ASPs belong to the Asp family（PF00026） and are all acidic protease（pI〈7）. 18 of 20 Asps have signal peptides. The alignment analysis findsthat they contain two special catalytic characteristic fingerprints＂DTGS/A＂and＂DT/SGS/Y/T/A/N＂and the20 Asps are divided into 4 branches according to the second catalytic fingerprints＂DTGT＂,＂DSGT＂,＂DTGA/N＂, and＂DSGY/T/S＂respectively. Further, under C-hungry stress, the expression of 10 Asps is up-regulated,and the Asp54.2 is up-regulated to the highest value of 3222. Under N-hungry stress, the expression of 8 Aspsare up-regulated, particularly the Asp50.9 is up-regulated to the highest value of 33100. After induced withleaf powder of Poplar（Tas ＋ Pd Pap）, the expression of 13 Asp genes of T. asprellum are up-regulated,especially the Asp50.9 is up-regulated to the highest value of 21078. It indicates that the aspartic proteasegenes play important roles in the process of T. asperellum promoting poplar growth and interacting with the pathogen.