法国里昂大学Teva Vernoux课题组取得一项新突破。他们发现转录阻遏物网络调节生长素应答。这一研究成果于2020年11月18日发表在《自然》杂志上。
他们通过研究染色质修饰和可及性表明，编码这些蛋白质的基因座组成性地开放转录。通过酵母单杂交筛选，他们确定了拟南芥A类生长素响应因子（ARF）编码基因的转录调节子，并证明每个基因受特定的转录调节亚群控制。突变体中的瞬时转化测定和表达分析表明，在植物中，大多数这些调节子抑制编码A类ARF的基因转录。
这些观察结果支持以下情况：开放染色质的默认配置使转录阻遏物网络能够调节A类ARF蛋白的表达水平并在整个发育过程中调节植物生长素信号输出。
据了解，信号传递能力的调节与发育信号本身的时空分布相结合，对于确定动植物的发育响应至关重要。生长素激素是植物生长发育的关键信号，其通过ARF转录因子起作用。其中的一个亚群，即保守的A类ARFs，是植物生长素应答性靶基因的转录激活因子，在整个植物生命周期中对调节植物生长素信号传导至关重要。尽管A类ARF具有组织特异性表达模式，但如何调节其表达尚不清楚。
附：英文原文
Title: A network of transcriptional repressors modulates auxin responses
Author: Jekaterina Truskina, Jingyi Han, Elina Chrysanthou, Carlos S. Galvan-Ampudia, Stphanie Lain, Graldine Brunoud, Julien Mac, Simon Bellows, Jonathan Legrand, Anne-Maarit Bgman, Margot E. Smit, Ondej Smetana, Arnaud Stigliani, Silvana Porco, Malcolm J. Bennett, Ari Pekka Mhnen, Franois Parcy, Etienne Farcot, Francois Roudier, Siobhan M. Brady, Anthony Bishopp, Teva Vernoux
Issue&Volume: 2020-11-18
Abstract: The regulation of signalling capacity, combined with the spatiotemporal distribution of developmental signals themselves, is pivotal in setting developmental responses in both plants and animals1. The hormone auxin is a key signal for plant growth and development that acts through the AUXIN RESPONSE FACTOR (ARF) transcription factors2,3,4. A subset of these, the conserved class A ARFs5, are transcriptional activators of auxin-responsive target genes that are essential for regulating auxin signalling throughout the plant lifecycle2,3. Although class A ARFs have tissue-specific expression patterns, how their expression is regulated is unknown. Here we show, by investigating chromatin modifications and accessibility, that loci encoding these proteins are constitutively open for transcription. Through yeast one-hybrid screening, we identify the transcriptional regulators of the genes encoding class A ARFs from Arabidopsis thaliana and demonstrate that each gene is controlled by specific sets of transcriptional regulators. Transient transformation assays and expression analyses in mutants reveal that, in planta, the majority of these regulators repress the transcription of genes encoding class A ARFs. These observations support a scenario in which the default configuration of open chromatin enables a network of transcriptional repressors to regulate expression levels of class A ARF proteins and modulate auxin signalling output throughout development.
DOI: 10.1038/s41586-020-2940-2
Source: https://www.nature.com/articles/s41586-020-2940-2
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
