SND1, a NAC Domain Transcription Factor, Is a Key Regulator of Secondary Wall Synthesis in Fibers of Arabidopsis[W]
SND1, a NAC Domain Transcription Factor, Is a Key Regulator of Secondary Wall Synthesis in Fibers of Arabidopsis[W]
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DOI：
10.1105/tpc.106.047399
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发表时间：
2006-11
期刊：
影响因子：
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通讯作者：
R. Zhong;T. Demura;Z. Ye
中科院分区：
文献类型：
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作者：
R. Zhong;T. Demura;Z. Ye
次生壁中的纤维和管状分子构成了植物产生的最丰富的生物量。虽然一些参与次生壁成分生物合成的基因已经被鉴定，但对这些基因协调表达的分子机制知之甚少。在这里，我们证明了拟南芥NAC(针对NAM，ATAF1/2和CUC2)结构域转录因子SND1(针对次生壁相关的NAC结构域蛋白)是调节纤维次生壁合成的关键转录开关。我们发现，SND1在茎中的束间纤维和木质纤维中特异表达，并且SND1的显性抑制导致纤维次生壁增厚的急剧减少。异位过表达SND1导致次生壁生物合成基因的表达激活，导致正常非厚壁细胞中次生壁的大量沉积。此外，我们还发现，在次生壁合成过程中，SND1上调了几种转录因子的表达，这些转录因子在纤维中高表达。综上所述，我们的结果表明SND1是参与纤维次生壁生物合成的关键转录激活因子。
Secondary walls in fibers and tracheary elements constitute the most abundant biomass produced by plants. Although a number of genes involved in the biosynthesis of secondary wall components have been characterized, little is known about the molecular mechanisms underlying the coordinated expression of these genes. Here, we demonstrate that the Arabidopsis thaliana NAC (for NAM, ATAF1/2, and CUC2) domain transcription factor, SND1 (for secondary wall–associated NAC domain protein), is a key transcriptional switch regulating secondary wall synthesis in fibers. We show that SND1 is expressed specifically in interfascicular fibers and xylary fibers in stems and that dominant repression of SND1 causes a drastic reduction in the secondary wall thickening of fibers. Ectopic overexpression of SND1 results in activation of the expression of secondary wall biosynthetic genes, leading to massive deposition of secondary walls in cells that are normally nonsclerenchymatous. In addition, we have found that SND1 upregulates the expression of several transcription factors that are highly expressed in fibers during secondary wall synthesis. Together, our results reveal that SND1 is a key transcriptional activator involved in secondary wall biosynthesis in fibers.