Genome-wide analysis of the lignin toolbox of Eucalyptus grandis
Genome-wide analysis of the lignin toolbox of Eucalyptus grandis
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DOI：
10.1111/nph.13313
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发表时间：
2015-06-01
期刊：
影响因子：
9.4
通讯作者：
Grima-Pettenati, Jacqueline
中科院分区：
文献类型：
--
作者：
Carocha, Victor;Soler, Marcal;Grima-Pettenati, Jacqueline
木质素是次生细胞壁的主要成分，阻碍了工业用途木材的最佳加工。最近获得的巨桉基因组序列允许全面分析的基因编码的11个蛋白质家族的木质素分支的苯丙烷途径和鉴定那些主要参与木质部发育木质化。我们进行了全基因组的木质素基因家族的推定成员的鉴定，然后比较系统发育研究，重点是真正的分支推断在其他物种的功能特征的基因。RNA-seq和微流体实时定量PCR（RT-qPCR）表达数据被用来研究基因的发育和环境响应表达模式。系统发育分析表明，38个巨桉基因位于真正的木质化分支中。通过串联基因重复，与其它植物相比，扩展了4个多基因家族（莽草酸O-羟基肉桂酰转移酶（HCT）、对香豆酸3-羟化酶（C3 H）、咖啡酸/5-羟基阿魏酸O-甲基转移酶（COMT）和苯丙氨酸解氨酶（PAL））。38个基因中有17个在高度木质化组织中表现出强烈的优先表达，这可能代表了巨桉核心木质化工具箱。对E. grandis是全世界种植最广泛的硬木作物，它为开发生物技术方法提供了基础，以开发具有更高加工质量的树木品种。
Lignin, a major component of secondary cell walls, hinders the optimal processing of wood for industrial uses. The recent availability of the Eucalyptus grandis genome sequence allows comprehensive analysis of the genes encoding the 11 protein families specific to the lignin branch of the phenylpropanoid pathway and identification of those mainly involved in xylem developmental lignification. We performed genome-wide identification of putative members of the lignin gene families, followed by comparative phylogenetic studies focusing on bona fide clades inferred from genes functionally characterized in other species. RNA-seq and microfluid real-time quantitative PCR (RT-qPCR) expression data were used to investigate the developmental and environmental responsive expression patterns of the genes. The phylogenetic analysis revealed that 38 E.grandis genes are located in bona fide lignification clades. Four multigene families (shikimate O-hydroxycinnamoyltransferase (HCT), p-coumarate 3-hydroxylase (C3H), caffeate/5-hydroxyferulate O-methyltransferase (COMT) and phenylalanine ammonia-lyase (PAL)) are expanded by tandem gene duplication compared with other plant species. Seventeen of the 38 genes exhibited strong, preferential expression in highly lignified tissues, probably representing the E.grandis core lignification toolbox. The identification of major genes involved in lignin biosynthesis in E. grandis, the most widely planted hardwood crop world-wide, provides the foundation for the development of biotechnology approaches to develop tree varieties with enhanced processing qualities.