Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms
Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms
复制标题
DOI：
10.1111/tpj.14684
复制
发表时间：
2020-02-13
期刊：
影响因子：
7.2
通讯作者：
Perez-Amador, Miguel A.
中科院分区：
文献类型：
--
作者：
Barro-Trastoy, Daniela;Carrera, Esther;Perez-Amador, Miguel A.
胚珠原基的形成是一个复杂的发育过程，对种子的产生有很大的影响。在拟南芥中，这一过程由基因网络控制，包括生长素、油菜素类固醇(BRs)和细胞分裂素等信号通路的组成部分。最近，我们发现赤霉素(GAs)在拟南芥和番茄的胚珠原基形成中也起着重要的作用，抑制胚珠的形成。在这里，我们揭示了BRs还通过促进胚珠原基的形成而参与了番茄胚珠起始的控制。此外，对GAs和BRs共同调控胚珠起始的分子和遗传分析表明，番茄和拟南芥存在两种不同的机制。在番茄中，气体作用于BRs的下游。BRs通过下调GA的生物合成来调节胚珠数量，从而稳定Della蛋白，最终促进胚珠原基的形成。相反，在拟南芥中，GAs和BRs都独立于另一种激素的活动水平来调节胚珠数量。综上所述，我们的数据有力地表明，不同的植物物种可能有不同的分子机制来调节相同的发育过程，即使对于胚珠原基的启动，如果相同的一套激素引发类似的反应，增加了新的复杂性。
Ovule primordia formation is a complex developmental process with a strong impact on the production of seeds. In Arabidopsis this process is controlled by a gene network, including components of the signalling pathways of auxin, brassinosteroids (BRs) and cytokinins. Recently, we have shown that gibberellins (GAs) also play an important role in ovule primordia initiation, inhibiting ovule formation in both Arabidopsis and tomato. Here we reveal that BRs also participate in the control of ovule initiation in tomato, by promoting an increase on ovule primordia formation. Moreover, molecular and genetic analyses of the co-regulation by GAs and BRs of the control of ovule initiation indicate that two different mechanisms occur in tomato and Arabidopsis. In tomato, GAs act downstream of BRs. BRs regulate ovule number through the downregulation of GA biosynthesis, which provokes stabilization of DELLA proteins that will finally promote ovule primordia initiation. In contrast, in Arabidopsis both GAs and BRs regulate ovule number independently of the activity levels of the other hormone. Taken together, our data strongly suggest that different molecular mechanisms could operate in different plant species to regulate identical developmental processes even, as for ovule primordia initiation, if the same set of hormones trigger similar responses, adding a new level of complexity.