ANAC012, a member of the plant-specific NAC transcription factor family, negatively regulates xylary fiber development in Arabidopsis thaliana
ANAC012, a member of the plant-specific NAC transcription factor family, negatively regulates xylary fiber development in Arabidopsis thaliana
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DOI：
10.1111/j.1365-313x.2007.03109.x
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发表时间：
2007-06-01
期刊：
影响因子：
7.2
通讯作者：
Han, Kyung-Hwan
中科院分区：
文献类型：
--
作者：
Ko, Jae-Heung;Yang, Seung Hwan;Han, Kyung-Hwan
维管束植物进化成木质部，为其生长的身体提供物质支持，并作为水分和养分运输的管道。在之前的一项研究中，我们使用比较转录组分析来选择一组在经历二次生长的拟南芥植物木质部中上调的基因。随后的分析发现，一个植物特有的NAC结构域转录因子基因(ANAC012)是木质部形成的遗传调控候选基因。启动子-GUS分析表明，ANAC012优先定位于花序茎和根的(原)形成层区域。通过酵母反式激活分析，我们证实了ANAC012作为转录激活因子的功能，并在C末端确定了一个激活结构域。在拟南芥(35S：：ANAC012植物)中异位过表达ANAC012显著抑制了木质纤维中次生壁的沉积，并略微增加了木质部导管中的细胞壁厚度。在35S：：ANAC012植株的花序茎和根中，细胞壁的纤维素组成减少，可能是由于木质纤维形成的缺陷所致。我们的数据表明，ANAC012可能是木质纤维次生壁增厚的负调控因子。
Vascular plants evolved to have xylem that provides physical support for their growing body and serves as a conduit for water and nutrient transport. In a previous study, we used comparative-transcriptome analyses to select a group of genes that were upregulated in xylem of Arabidopsis plants undergoing secondary growth. Subsequent analyses identified a plant-specific NAC-domain transcription factor gene (ANAC012) as a candidate for genetic regulation of xylem formation. Promoter-GUS analyses showed that ANAC012 expression was preferentially localized in the (pro)cambium region of inflorescence stem and root. Using yeast transactivation analyses, we confirmed the function of ANAC012 as a transcriptional activator, and identified an activation domain in the C terminus. Ectopic overexpression of ANAC012 in Arabidopsis (35S::ANAC012 plants) dramatically suppressed secondary wall deposition in the xylary fiber and slightly increased cell-wall thickness in the xylem vessels. Cellulose compositions of the cell wall were decreased in the inflorescent stems and roots of 35S::ANAC012 plants, probably resulting from defects in xylary fiber formation. Our data suggest that ANAC012 may act as a negative regulator of secondary wall thickening in xylary fibers.