两个烟草多聚半乳糖醛酸酶抑制蛋白基因的克隆和表达分析

摘要

In order to study the biological functions of tobacco PGIP ,two full-length polygalacturonase inhibi-ting protein ( PGIP) cDNA and DNA were cloned from Nicotiana tabacum by bioinformation ,RT-PCR and SMART RACE technology ,which were named NtPGIP1 ( GenBank Number KF 317203 ) and NtPGIP2 ( GenBank Number KF317204 ) ,respectively .The full length NtPGIP1 was 1 413 bp which coding a protein for 338 amino acids .The full length NtPGIP2 was 1 185 bp which coding for 329 amino acids.Sequencing analysis showed that the identical amino acid sequence of the two genes was 54%,while the identical nucleotide sequence was 50%,and no intron se-quences were found in the two genes .The amino acid sequences of the two proteins both contained plant PGIP spe-cific conserved leucine repeat sequence LXXLXXLXXLXLXXNXLXGXIPXX .The gene expression patterns were an-alyzed by Real-time quantitative PCR .The results indicated that the expression of the two genes was detected in all tissues with the highest expression level in stems ,followed in roots ,and lowest level in leaves .%为了研究多聚半乳糖醛酸酶抑制蛋白（ PGIP）在烟草中的生物学功能，运用生物信息学方法，结合RT-PCR和SMART RACE技术，从烟草中克隆到2个多聚半乳糖醛酸酶抑制蛋白（ PGIP）基因cDNA和DNA全长序列，分别命名为NtPGIP1（GenBank登录号：KF317203）和NtPGIP2（GenBank登录号：KF317204）。 NtPGIP1基因全长为1413 bp，编码338个氨基酸；NtPGIP2基因全长为1185 bp，编码329个氨基酸；两基因均没有内含子序列，核苷酸序列有50％的一致性，编码的氨基酸序列有54％的一致性。两基因编码蛋白均含有植物PGIP蛋白特有的重复保守序列LXX-LXXLXXLXLXXNXLXGXIPXX。对PGIP基因在烟草不同组织表达量分析发现，两基因在根、茎、叶和芽中均有表达，其中均在茎中表达量最高，其次是根，叶中表达量很低。