The pea branching RMS2 gene encodes the PsAFB4/5 auxin receptor and is involved in an auxin-strigolactone regulation loop.
The pea branching RMS2 gene encodes the PsAFB4/5 auxin receptor and is involved in an auxin-strigolactone regulation loop.
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DOI：
10.1371/journal.pgen.1007089
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发表时间：
2017-12
期刊：
影响因子：
4.5
通讯作者：
Rameau C
中科院分区：
文献类型：
--
作者：
Ligerot Y;de Saint Germain A;Waldie T;Troadec C;Citerne S;Kadakia N;Pillot JP;Prigge M;Aubert G;Bendahmane A;Leyser O;Estelle M;Debellé F;Rameau C
己金内酯（SLs）因其抑制茎枝分支的作用而闻名。在豌豆中，高分支SL缺陷（ramosus1 （rms1）和rms5）和SL响应（rms3和rms4）突变体的茎中观察到SL生物合成基因转录水平升高，表明负反馈控制。相反，高度分支的rms2突变体降低了SL生物合成基因的转录水平。嫁接研究和激素量化得出RMS2介导茎到根反馈信号的模型，该信号调节SL生物合成基因转录水平和从根输出的细胞分裂素的木质部汁液水平。在这里，我们利用与Medicago truncatula的合成克隆了RMS2，并证明它编码AFB4/5分支的一个假定的生长素受体。在拟南芥afb4/5突变体中发现了与rms2相似的表型，包括茎部分枝增加、SL生物合成基因低表达和茎部生长素水平高。此外，afb4/5和rms2对除草剂picloram具有特异性抗性。酵母双杂交实验支持了RMS2蛋白作为生长素受体的假设。水培SL根饲在1小时内抑制茎部生长素水平，下调生长素生物合成基因转录水平。在极性生长素运输抑制剂NPA处理的植物中也观察到这种生长素下调。综上所述，这些数据表明生长素以依赖rms2的方式上调SL合成，而SL以依赖RMS3和rms4的方式下调生长素合成，这是一个稳态反馈回路。植物芽的分枝是芽生长与休眠的精确调控的结果。正反馈和负反馈机制可能参与了这种高度可塑性特征的动态控制。独角孤内酯是最近发现的一类植物激素，在控制茎枝分枝中起关键作用。在一些物种中已经观察到独脚金内酯生物合成的负反馈控制，并且在豌豆中被证明是由一个依赖于RAMOSUS2 （RMS2）的茎到根信号介导的。这种反馈信号的化学性质已经被广泛讨论过。在这里，我们证明了RMS2蛋白属于生长素受体的小家族，并证实了它作为生长素受体的行为。独脚金内酯通过快速抑制生长素生物合成基因的转录水平来降低茎部生长素水平，从而在植物生长素和独脚金内酯之间形成一个远程反馈回路，精确调控植物茎部分支。
Strigolactones (SLs) are well known for their role in repressing shoot branching. In pea, increased transcript levels of SL biosynthesis genes are observed in stems of highly branched SL deficient (ramosus1 (rms1) and rms5) and SL response (rms3 and rms4) mutants indicative of negative feedback control. In contrast, the highly branched rms2 mutant has reduced transcript levels of SL biosynthesis genes. Grafting studies and hormone quantification led to a model where RMS2 mediates a shoot-to-root feedback signal that regulates both SL biosynthesis gene transcript levels and xylem sap levels of cytokinin exported from roots. Here we cloned RMS2 using synteny with Medicago truncatula and demonstrated that it encodes a putative auxin receptor of the AFB4/5 clade. Phenotypes similar to rms2 were found in Arabidopsis afb4/5 mutants, including increased shoot branching, low expression of SL biosynthesis genes and high auxin levels in stems. Moreover, afb4/5 and rms2 display a specific resistance to the herbicide picloram. Yeast-two-hybrid experiments supported the hypothesis that the RMS2 protein functions as an auxin receptor. SL root feeding using hydroponics repressed auxin levels in stems and down-regulated transcript levels of auxin biosynthesis genes within one hour. This auxin down-regulation was also observed in plants treated with the polar auxin transport inhibitor NPA. Together these data suggest a homeostatic feedback loop in which auxin up-regulates SL synthesis in an RMS2-dependent manner and SL down-regulates auxin synthesis in an RMS3 and RMS4-dependent manner. Plant shoot branching results from the precise regulation of bud growth versus dormancy. Positive and negative feedback mechanisms are likely involved in the dynamic control of this highly plastic trait. Strigolactones, the most recently discovered class of plant hormones, play a key role in controlling shoot branching. Negative feedback control of strigolactone biosynthesis has been observed in several species and was shown in pea to be mediated by a shoot-to-root signal that is RAMOSUS2 (RMS2)-dependent. The chemical nature of this feedback signal has been extensively discussed. Here, we demonstrate that the RMS2 protein belongs to the small family of auxin receptors and confirm that it behaves as an auxin receptor. Strigolactones decrease stem auxin levels by rapidly repressing transcript levels of auxin biosynthesis genes, thereby forming a long-distance feedback loop between auxin and strigolactones for the precise regulation of shoot branching in plants.
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影响因子：
5.1
作者：
Bennett, Tom;Leyser, Ottoline
通讯作者：
Leyser, Ottoline
影响因子：
2.4
作者：
Bennett T;Liang Y;Seale M;Ward S;Müller D;Leyser O
通讯作者：
Leyser O
豆类中的转化基因组学允许将硅溶液图上的硅5460个单基因放置在Pisum sativum L.中的候选基因上。
DOI：
10.1534/g3.111.000349
发表时间：
2011-07
期刊：
G3 (Bethesda, Md.)
影响因子：
--
作者：
Bordat A;Savois V;Nicolas M;Salse J;Chauveau A;Bourgeois M;Potier J;Houtin H;Rond C;Murat F;Marget P;Aubert G;Burstin J
通讯作者：
Burstin J
影响因子：
7.4
作者：
BEVERIDGE, CA;ROSS, JJ;MURFET, IC
通讯作者：
MURFET, IC
影响因子：
7.2
作者：
Beveridge, CA;Murfet, IC;Rameau, C
通讯作者：
Rameau, C