天女木兰种子天冬氨酸蛋白酶基因的克隆与分析

Cloning and analysis of aspartic acidase gene from Magnolia sieboldii

天冬氨酸蛋白酶在天女木兰种子萌发过程中发挥着重要作用。以天女木兰种子为试验材料,利用同源克隆法RACE技术,从天女木兰种子中克隆得到天冬氨酸蛋白酶基因,全长1 545 bp,可以编码514个氨基酸残基。同源性分析显示,目的序列推导的氨基酸序列与其它植物中已知的天冬氨酸蛋白酶基因的氨基酸序列的同源性都在85%以上;采用生物信息学的方法进行分析,初步预测该基因编码的蛋白属于跨膜的分泌蛋白,大部分区域属于疏水结构;结构域的预测分析显示,此类蛋白包含约100个植物组织蛋白酶所特有的区域,该区域可能在植物液泡中发挥着重要作用。本研究为下一步系统、全面地研究天女木兰种子休眠的分子机理奠定了基础。

Aspartic Protease, in the process of seed germination plays an important role. The aspartic protease gene was cloned from the seeds of Magnolia sieboldii by using the homologous cloning method RACE technology, which had a total length of 1 545 BP and can encode 514 amino acid residues. Homology analysis shows that the amino acid sequence deduced from the target sequence was more than 85% homologous to the amino acid sequence of the known aspartic protease gene in other plants. Using bioinformatics methods, it is preliminarily predicted that the protein encoded by this gene belongs to the transmembrane secreted protein, and most of the regions belong to the hydrophobic structure. Predictive analysis of domains showed that these proteins contained about 100 specific regions of plant cathepsin, which may play an important role in plant vacuoles. This study laid a foundation for further systematic and comprehensive study on the molecular mechanism of seed dormancy of M. sieboldii.