白桦BpCesA基因的生物信息学及表达分析

Bioinformatics and Expression Analysis of BpCesA Genes of Betula platyphylla

从白桦45个转录组数据中分析获得6条白桦纤维素合成酶基因,其中2条为该家族的新基因,通过生物信息学及实时定量PCR技术探讨白桦Bp Ces A在不同材性白桦中的表达量情况。结果表明,6条白桦Bp Ces A基因的ORF长度在2 958~3 312 bp,编码的氨基酸数目在985~1 103 aa,相对分子量在110.40~124.29 k D,理论等电点为5.90~7.43;6条Bp Ces A均含有D,D,D,QXXRW保守结构域和8个跨膜螺旋,其中2个位于N端,6个位于C端。对来自6个双子叶植物,4个单子叶植物和1个裸子植物的52条Ces A进行了聚类分析发现:白桦Bp Ces A与同为木本的杨树Ptr Ces A具有较高的同源性,其中Bp Ces A2与Ptr Ces A3同源性达到92%、另外Bp Ces A5与Ptr Ces A6、Bp Ces A1与Ptr Ces A8也具有较高的同源性,分别为89%和82%。Bp Ces A1、Bp Ces A2、Bp Ces A3、Bp Ces A5基因随纤维素含量的增加,表达量也呈现增加趋势,推测这些基因在白桦的纤维素合成中起到促进的作用。本研究为揭示纤维素合成酶基因的功能分析提供了基础。

Six cellulose synthase genes of Betula platyphylla from 45 transcriptome data sets were obtained,in which two genes were new genes of cellulose synthase gene family. The sequence characteristic and expression levels in Birch xylem of Bp Ces A were analyzed using bioinformatics and quantitative real-time PCR. The ORF length of 6 Bp Ces A genes varied from 2 958- 3 312 bp; Number of amino acids encoded varied from 985^（-1） 103 aa,and relative molecular weight varied from 110. 40^（-1）24. 29 k D; Theoretical isoelectric point was from5. 90- 7. 43. Six Bp Ces A genes all contained D,D,D,QXXRW conservative structure domain and eight transmembrane helices,in which two were located at the end of the N,and the others were at the end of the C.52 Ces As from six dicotyledonous plants,four monocotyledons,and one gymnosperms were analyzed by cluster analysis,and Bp Ces As had higher homology with Ptr Ces A. The homology between Bp Ces A2 and Ptr Ces A3 reached 92%. Bp Ces A5 and Ptr Ces A6,Bp Ces A1 and Ptr Ces A8 also had high homology of 89% and 82%,respectively. The RNA level of Bp Ces A1,Bp Ces A2,Bp Ces A3 and Bp Ces A5 was increased with the increase of cellulose content. This results suggested that these genes play a positive role in cellulose synthesis in birch. This study provides a basis for the functional analysis of cellulose synthase gene.