毛竹CCR基因家族成员生物信息学和表达模式分析

Bioinformatics and Expression Pattern Analysis of Moso Bamboo CCR Gene Family Members

肉桂酰辅酶A还原酶(CCR)是木质素生物合成的关键酶之一,对木质素生物合成途径的碳流具有重要的调控作用。研究毛竹(Phyllostachys edulis) CCR基因的分子特征和表达模式对于揭示影响竹子材性的木质素调控机制具有重要意义。采用同源序列比对的方法在毛竹基因组中获取13个CCR基因同源序列,其中9个具有完整的保守结构域,依次命名为PeCCR1～PeCCR9。PeCCRs基因的内含子数量、长度和位置均存在较大差异,如PeCCR2有5个内含子,而PeCCR5没有内含子;内含子最长的为4 090 bp,最短的仅为89 bp。PeCCRs编码的氨基酸序列长度范围为136～391 aa,推测分子量在14.97～43.05 kD之间,理论等电点介于5.60～8.31之间。PeCCRs的氨基酸序列在N-端和C-端均存在明显的差异,二级、三级结构进一步显示了其差异,但中部序列具有很高的一致性,都含有肉桂酰辅酶A还原酶家族蛋白特有的保守结构域和催化位点,表明其进化上是比较保守的。基于转录组数据的基因组织表达特异性分析表明,PeCCRs在各组织中的表达量差异明显,如PeCCR6在盛花期花序、鞭和笋中均未检测到基因表达,PeCCR9在盛花期花序中的表达是所有PeCCRs最高的,而PeCCR5在50 cm笋中则是所有检测到PeCCRs中最低的。本研究为进一步研究毛竹CCR基因家族成员的功能提供了参考,为利用基因工程调控竹子木质素提供了依据。

Cinnamoyl-CoA reductase(CCR)is one of key enzymes involved in lignin biosynthesis,which plays a vital role in the regulation of carbon flow in lignin biosynthetic pathway.Study on the molecular characteristics and expression patterns of the CCR gene in Phyllostachys edulis is of great significance to reveal the regulatory mechanism of lignin affecting bamboo properties.By using the method of homologous sequence alignment,thirteen homologous sequences of CCR gene in moso bamboo genome were obtained,among which nine had the complete conserved domain,and were named as PeCCR1~PeCCR9 respectively.There were significant differences in the number,length and location of the introns of PeCCRs,for example,PeCCR2 had five introns while PeCCR5 had no intron.The longest intron was 4 090 bp,and the shortest one was 89 bp.The length of amino acid sequences encoded by PeCCRs ranged from 136 to 391 aa,with the predicted molecular weight of 4.971~43.05 kD and the isoelectric point of 5.60~8.31.The amino acid sequences of PeCCRs were sign-ificantly different at the N-terminus and C-terminus consistent with their secondary and tertiary structures,but the central sequences were highly consistent,containing the conserved domain and catalytic sites specific to the cinnamoyl-CoA reductase family proteins,which indicated CCRs were relatively conservative in evolution.Based on transcriptome data,the tissue specific expression analysis showed that the expression levels of PeCCRs in tissues were significantly different,for example,the expression of PeCCR6 was not detected in flowering inflorescence,rhizome and shoot,the expression of PeCCR9 in flowering inflorescence was the highest of all the PeCCRs,and the expression of PeCCR5 in 50 cm shoot was the lowest of all detected PeCCRs.This study could provide a reference for the further study on the function of CCR gene family members in bamboo and lay the foundation for the regulation of bamboo lignin synthesis by genetic engineering.