Arabidopsis Cuticular Wax Biosynthesis Is Negatively Regulated by the DEWAX Gene Encoding an AP2/ERF-Type Transcription Factor
Arabidopsis Cuticular Wax Biosynthesis Is Negatively Regulated by the DEWAX Gene Encoding an AP2/ERF-Type Transcription Factor
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DOI：
10.1105/tpc.114.123307
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发表时间：
2014-04-01
期刊：
影响因子：
11.6
通讯作者：
Suh, Mi Chung
中科院分区：
文献类型：
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作者：
Go, Young Sam;Kim, Hyojin;Suh, Mi Chung
植物的地上部分被表面的角质层蜡保护，免受干燥和其他胁迫。在黑暗条件下，拟南芥的角质层蜡质总负荷量和蜡质生物合成基因的表达显著下调。我们分离到了蜡质生物合成减少(脱蜡)，它编码一种AP2/ERF类型的转录因子，该转录因子优先在表皮中表达，并在黑暗中诱导。脱蜡的破坏导致叶片和茎的总蜡量增加，在互补系中脱蜡的过剩蜡型恢复到野生型水平。此外，与野生型相比，过表达脱蜡导致叶和茎的总蜡质负载量减少，并改变了角质层的超微结构。脱蜡对烷烃形成酶、长链酰辅酶A合成酶、三磷酸腺苷柠檬酸裂解酶A亚单位、enoyl-CoA还原酶和脂肪酰辅酶A还原酶的表达具有负性调节作用，染色质免疫沉淀分析表明脱蜡与蜡生物合成基因的启动子直接相互作用。角质层蜡质的生物合成一天两次受到脱蜡表达的负调控，整个夜间和气孔关闭时。叶中的脱蜡转录本水平显著高于茎中(10-100倍)，这表明脱蜡介导的转录抑制可能是导致叶和茎中总蜡量不同的另一种机制。
The aerial parts of plants are protected from desiccation and other stress by surface cuticular waxes. The total cuticular wax loads and the expression of wax biosynthetic genes are significantly downregulated in Arabidopsis thaliana under dark conditions. We isolated Decrease Wax Biosynthesis (DEWAX), which encodes an AP2/ERF-type transcription factor that is preferentially expressed in the epidermis and induced by darkness. Disruption of DEWAX leads to an increase in total leaf and stem wax loads, and the excess wax phenotype of dewax was restored to wild type levels in complementation lines. Moreover, overexpression of DEWAX resulted in a reduction in total wax loads in leaves and stems compared with the wild type and altered the ultrastructure of cuticular layers. DEWAX negatively regulates the expression of alkane-forming enzyme, long-chain acyl-CoA synthetase, ATP citrate lyase A subunit, enoyl-CoA reductase, and fatty acyl-CoA reductase, and chromatin immunoprecipitation analysis suggested that DEWAX directly interacts with the promoters of wax biosynthesis genes. Cuticular wax biosynthesis is negatively regulated twice a day by the expression of DEWAX, throughout the night and at stomata closing. Significantly higher levels (10-to 100-fold) of DEWAX transcripts were found in leaves than in stems, suggesting that DEWAX-mediated transcriptional repression may be an additional mechanism contributing to the different total wax loads in leaves and stems.