A Conserved Network of Transcriptional Activators and Repressors Regulates Anthocyanin Pigmentation in Eudicots
A Conserved Network of Transcriptional Activators and Repressors Regulates Anthocyanin Pigmentation in Eudicots
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DOI：
10.1105/tpc.113.122069
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发表时间：
2014-03-01
期刊：
影响因子：
11.6
通讯作者：
Schwinn, Kathy E.
中科院分区：
文献类型：
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作者：
Albert, Nick W.;Davies, Kevin M.;Schwinn, Kathy E.
植物需要复杂的调节机制来确保花青素的色素沉着程度与无数的发育和环境信号相适应。这一过程的核心是MYB-bHLH-WD重复序列（MBW）复合物的活性，该复合物调节花青素苷基因的转录。在这项研究中，基因调控网络调控花青苷合成矮牵牛（矮牵牛）的特点。遗传和分子证据表明，R2 R3-MYB，MYB 27，是一种花青素阻遏物，作为MBW复合物的一部分发挥作用，并通过其C-末端的抑制基序抑制转录。MYB 27靶向花青素途径基因和碱性螺旋环螺旋（bHLH）花青素1（AN 1），AN 1本身是MBW激活复合物的重要组成部分。所鉴定的调控网络的其他特征包括通过竞争性R3-MYB阻遏物MYBx抑制AN 1活性，以及通过MBW活化复合物活化AN 1、MYB 27和MYBx，从而提供强化和反馈调控。我们还证明了WDR蛋白（AN 11）和R3-阻遏物（MYBx）的细胞间运动，这可能有助于花青素色素图案的形成。在矮牵牛的Asterid模型中，这种调控网络的基本特征与拟南芥的Rosid模型中的那些相似，因此可能在真双子叶植物中广泛存在。
Plants require sophisticated regulatory mechanisms to ensure the degree of anthocyanin pigmentation is appropriate to myriad developmental and environmental signals. Central to this process are the activity of MYB-bHLH-WD repeat (MBW) complexes that regulate the transcription of anthocyanin genes. In this study, the gene regulatory network that regulates anthocyanin synthesis in petunia (Petunia hybrida) has been characterized. Genetic and molecular evidence show that the R2R3-MYB, MYB27, is an anthocyanin repressor that functions as part of the MBW complex and represses transcription through its C-terminal EAR motif. MYB27 targets both the anthocyanin pathway genes and basic-helix-loop-helix (bHLH) ANTHOCYANIN1 (AN1), itself an essential component of the MBW activation complex for pigmentation. Other features of the regulatory network identified include inhibition of AN1 activity by the competitive R3-MYB repressor MYBx and the activation of AN1, MYB27, and MYBx by the MBW activation complex, providing for both reinforcement and feedback regulation. We also demonstrate the intercellular movement of the WDR protein (AN11) and R3-repressor (MYBx), which may facilitate anthocyanin pigment pattern formation. The fundamental features of this regulatory network in the Asterid model of petunia are similar to those in the Rosid model of Arabidopsis thaliana and are thus likely to be widespread in the Eudicots.