大白菜雄性不育系RC_7育性相关基因克隆与特性分析

Cloning and Molecular Identification of Gene Associated with CMS RC_7 in Chinese Cabbage(Brassica campestris L.ssp.pekinensis)

根据orf138的保守序列设计引物,以大白菜萝卜胞质雄性不育系RC7的mtDNA为模板进行PCR扩增,扩增出大小为588 bp的特异条带,该片段在叶片和花蕾中均有表达,没有转录后加工,可编码75个氨基酸,定名为orf75。同源性分析结果表明:orf75推导的氨基酸序列N末端与萝卜Ogu CMS所具有的ORF138一致性为100%,有28个氨基酸完全相同,C末端与钾依赖钠钙交换蛋白-1一致性为54%。初步认为,orf75可能是orf138与钾依赖钠钙交换蛋白-1的编码基因发生重排产生的新的开放阅读框。RC7的不育性与Ogu CMS具有相似性。该588 bp片段还可编码1个含有1个疏水基团和1个跨膜区的67aa的蛋白片段,定名为orf67,属可溶性蛋白。

We designed the primers according to the conserved sequence of orf138 and amplified a 588 bp fragment from mtDNA of CMS RCr （the Chinese cabbage CMS）. The fragment can code a protein of 75 a- mino acids. The coding sequence is named off75. The N terminal of deduced amino acid sequence from orf75 has 28 same amino acids with ORF138 and the C terminal has 54% homology with solute carrier family 24 （sodium/potassium/calcium exchanger） member 1. We conclude that or f75 maybe an new open reading frame （off） which originates from rearrangement of orf138 and gene of solute carrier family 24 （sodium/potassium/calcium exchanger） member 1. The sterility of RCr is similar to Ogura CMS. This 588 bp specific fragment can also code a protein of 67 amino acids. The coding sequence is named or f67. This feasible amino acid is soluble protein with a transmembrane helical regions and hydrophobic group. RTPCR analysis indicates that the 588 bp specific fragment is expressed in both leaf and bud,and has no posttranscriptional modification.