摘要
利用桑树(MorusL.)表达序列标签(EST),采用RT-PCR方法克隆了桑树光合系统Ⅰ(PSⅠ)psaE基因的全长cDNA序列,命名为MpsaE(GenBank登录号:GU645972)。序列分析表明,该基因序列全长705bp,存在97bp的5′端非翻译区和170bp的3′端非翻译区,其开放阅读框(ORF)长438bp,编码含有146个氨基酸的蛋白,预测蛋白分子质量为15.38kD,等电点为8.08。同源性分析表明,MpsaE编码蛋白与柑桔(Citrus sinensis)、毛果杨甙(Populus trichocarpa)和欧美杨(Populus eu-ramericana)psaE基因编码的蛋白具有较高的同源性,相似性达到98%。基于MpsaE与其它18个物种的psaE基因编码氨基酸序列构建的系统进化树显示,桑树与柑桔、蓖麻(Ricinus)、毛果杨甙和欧美杨的亲缘关系较近。半定量RT-PCR分析表明,MpsaE基因mRNA在桑树不同组织及部位的转录水平有明显差异:在叶片中的转录水平较高,其中幼叶(刚展开的第1片叶)和中部叶片(8-10位叶)的转录水平最高,其次为上部叶片(2-3位叶)、顶芽和下部叶片;在根部的转录水平最低。初步推测MpsaE基因是桑树PSⅠ参与某些光合生理反应的一个亚基。
Conversion of light into chemical free energy is fundamental for life. Photosystems are protein complexes involved in photosynthesis and play a major role in this process. Based on the ESTs from Morus L., the full-length cDNA sequence of mulberry photosystem Ⅰ psaE gene, which was designated as MpsaE （GenBank No. GU645972）, was cloned by means of RT-PCR. Sequence analysis showed that MpsaE gene is 705 bp in length. It contains a 97 bp 5＇-UTR and a 170 bp 3＇-UTR. The open reading frame is 438 bp tong, encoding a 146 amino acid protein with a predicted molecular weight of 15.38 kD and a pl of 8.08. The amino acid sequence of MpsaE has 98% sequence identity with that of Citrus sinensis, Populus trichocarpa and Populus euramericana. Phylogenetic analysis based on amino acid sequences encoded by MpsaE and psaE of 18 other species suggested that Morus L. has close genetic relationship with Citrus sinensis, Ricinus, Populus trichocarpa and Populus euramericana. The results of semi-quantitative RT-PCR analysis showed that the transcriptional level of MpsaE mRNA was obviously different in various tissues and organs. The transcriptional levels were relatively high in mulberry leaves, among which the young leaf （the first opening leaf） and middle leaves （with leaf orders of 8 to 10） had the highest transcriptional level, while the upper leaves （with leaf orders of 2 to 3）, top bud and lower leaves had relatively low transcriptional levels. The transcriptional level in roots was the lowest. It is suggested that MpsaE is a subunit of mulberry photosystem Ⅰ that participates certain photosynthetic physiological reactions.
出处
《蚕业科学》
CAS
CSCD
北大核心
2010年第3期377-382,共6页
ACTA SERICOLOGICA SINICA
基金
广西2009年"西部之光"访问学者专项
现代农业产业技术体系建设专项(蚕桑)
博士后科学基金项目(No.2006-0400926
0602004C)
公益性行业(农业)科研专项(No.nyhyzx07-020-02)
广西重点科技项目(No.桂科转0629001
桂科攻0718004-1A)
