PtoMYB92 is a Transcriptional Activator of the Lignin Biosynthetic Pathway During Secondary Cell Wall Formation in Populus tomentosa
PtoMYB92 is a Transcriptional Activator of the Lignin Biosynthetic Pathway During Secondary Cell Wall Formation in Populus tomentosa
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PtoMYB92 是毛白杨次生细胞壁形成过程中木质素生物合成途径的转录激活剂。
DOI：
10.1093/pcp/pcv157
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发表时间：
2015-12-01
影响因子：
4.9
通讯作者：
Luo, Keming
中科院分区：
文献类型：
--
作者：
Li, Chaofeng;Wang, Xianqiang;Luo, Keming
木材是多年生木本植物中最丰富的生物量，主要由次生细胞壁组成。R2R3-MYB转录因子是植物次生壁生物合成的重要调控因子。在本研究中，我们对杨树MYB转录因子PtoMYB92进行了鉴定和鉴定，PtoMYB92是拟南芥MYB42和MYB85的同源基因，参与了次生细胞壁生物合成的调控。PtoMYB92在杨树木质部组织中特异表达。亚细胞定位和转录激活分析表明，PtoMYB92是一种核定位的转录激活因子。PtoMYB92基因在杨树中的过表达导致了茎中次生细胞壁厚度的增加和叶片中木质素的异位沉积。实时荧光定量聚合酶链式反应显示，PtoMYB92特异性激活了木质素生物合成基因的表达。此外，利用β-葡萄糖醛酸酶(GUS)报告基因进行的瞬时表达分析表明，PtoMYB92是次生细胞壁形成过程中木质素生物合成途径的激活剂。综上所述，我们的结果表明，PtoMYB92通过控制单酚的生物合成参与了杨树次生细胞壁形成的调控。
Wood is the most abundant biomass in perennial woody plants and is mainly made up of secondary cell wall. R2R3-MYB transcription factors are important regulators of secondary wall biosynthesis in plants. In this study, we describe the identification and characterization of a poplar MYB transcription factor PtoMYB92, a homolog of Arabidopsis MYB42 and MYB85, which is involved in the regulation of secondary cell wall biosynthesis. PtoMYB92 is specifically expressed in xylem tissue in poplar. Subcellular localization and transcriptional activation analysis suggest that PtoMYB92 is a nuclear-localized transcriptional activator. Overexpression of PtoMYB92 in poplar resulted in an increase in secondary cell wall thickness in stems and ectopic deposition of lignin in leaves. Quantitative real-time PCR showed that PtoMYB92 specifically activated the expression of lignin biosynthetic genes. Furthermore, transient expression assays using a β-glucuronidase (GUS) reporter gene revealed that PtoMYB92 is an activator in the lignin biosynthetic pathway during secondary cell wall formation. Taken together, our results suggest that PtoMYB92 is involved in the regulation of secondary cell wall formation in poplar by controlling the biosynthesis of monolignols.