Lloyd Alan, Brockman Austen, Aguirre Lyndsey, Campbell Annabelle, Bean Alex, Cantero Araceli, Gonzalez Antonio
Department of Molecular Biosciences and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2500 Speedway, Austin, TX 78712, USA.
The Freshman Research Initiative, The University of Texas at Austin, Austin, TX 78712, USA.
Plant Cell Physiol. 2017 Sep 1;58(9):1431-1441. doi: 10.1093/pcp/pcx075.
Flavonoids are secondary metabolites derived from the general phenylpropanoid pathway and are widespread throughout the plant kingdom. The functions of flavonoids are diverse, including defense against phytopathogens, protection against UV light damage and oxidative stress, regulation of auxin transport and allelopathy. One of the most conspicuous functions of flavonoids has long attracted the attention of pollinators and scientist alike: the vivid shades of red, pink, orange, blue and purple on display in the flowers of angiosperms. Thus, flavonoid pigments have perhaps been the most intensely studied phenylpropanoids. From Mendel to McClintock and up to the present, studies centered on flavonoid pigments have resulted in some of the most important scientific discoveries of the last 150 years, including the first examples of transcriptional regulation in plants. Here we focus on the highly conserved MYB-bHLH-WD repeat (MBW) transcriptional complex model for the regulation of the flavonoid pigment pathway. We will survey the history of the MBW model spanning the last three decades, highlighting the major findings that have contributed to our current understanding. In particular, recent discoveries regarding WRKY protein control of the flavonoid pigment pathway and its relationship to the MBW complex will be emphasized. In addition, we will discuss recent findings about the regulation of the beet betalain pigment pathway, and how a MYB member of the MBW complex was co-opted to regulate this chemically unrelated but functionally equivalent pathway.
黄酮类化合物是源自通用苯丙烷途径的次生代谢产物，广泛存在于植物界。黄酮类化合物的功能多样，包括抵御植物病原体、保护免受紫外线损伤和氧化应激、调节生长素运输以及化感作用。黄酮类化合物最显著的功能之一长期以来一直吸引着传粉者和科学家的关注：被子植物花朵中呈现出的鲜艳的红色、粉色、橙色、蓝色和紫色。因此，黄酮类色素可能是研究最为深入的苯丙烷类化合物。从孟德尔到麦克林托克直至现在，以黄酮类色素为中心的研究促成了过去150年中一些最重要的科学发现，包括植物转录调控的首个实例。在此，我们聚焦于调控黄酮类色素途径的高度保守的MYB-bHLH-WD重复（MBW）转录复合体模型。我们将审视MBW模型过去三十年的发展历程，突出那些促成我们当前理解的主要发现。特别强调关于WRKY蛋白对黄酮类色素途径的调控及其与MBW复合体关系的近期发现。此外，我们将讨论关于甜菜红素色素途径调控的近期发现，以及MBW复合体中的一个MYB成员是如何被征募来调控这条化学性质不同但功能等效的途径的。
