根据GenBank中登录的植物肌动蛋白保守序列设计1对引物,对三叶青的块根进行RT-PCR,在1次扩增中得到2个不同的肌动蛋白基因片段,分别命名为ThAct1和ThAct2.测序结果显示:ThAct1基因片段长度为867bp,编码252个氨基酸;ThAct2基因片段长度为1 079bp,编码152个氨基酸.经Blast分析,ThAct1和ThAct2基因均属于NBD_sugar-kinase_HSP70_actin superfamily家族,与其它物种Actin基因序列和编码的蛋白质均具有同源性.RT-PCR结果初步表明:在茎、普通根和块根中ThAct1和ThAct2基因的表达未见差异;但在叶中,ThAct1的表达稍强,而ThAct2的表达稍弱.另外,在茎、普通根和块根中,ThAct1表达比ThAct2强;但在叶中ThAct1表达比ThAct2弱.结果为分析肌动蛋白基因在三叶青块根发育中的功能奠定了基础;获得的肌动蛋白也可以作为内参基因,在三叶青功能基因组的研究中用于其它基因的定量表达分析.
According to the conserved sequence of plant actin genes in GenBank database,one pairs of primers are designed.Two different actin gene fragments,named as ThAct1 and ThAct2,are amplified in one RT-PCR reaction from calabash-shaped root of Tetrastigma hemsleyanum Diels et Gilg.The results indicate that the length of ThAct1 is 867 bp encoding 252 amino acids,and the length of ThAct2 is 1 079 bp encoding 152 amino acids.By Blast analysis,both ThAct1 and ThAct2 genes belong to the NBD_sugar-kinase_HSP70_actin superfamily,and are homology with other species in Action gene sequence and the protein of code.The RT-PCR analysis shows that the expression of ThAct1 and ThAct2 has no difference in the stem,ordinary root and calabash-shaped root,ThAct1 in the leaf is slightly stronger than ThAct2,while ThAct1 in the stem,ordinary root and calabash-shaped root is slightly high but weak in the leaf.The actin gene obtained can be used as a reference gene for the quantitative expression analysis of other genes in the genome of Tetrastigma hemsleyanum Diels et Gilg.