Hd3a, RFT1 and Ehd1 integrate photoperiodic and drought stress signals to delay the floral transition in rice
Hd3a, RFT1 and Ehd1 integrate photoperiodic and drought stress signals to delay the floral transition in rice
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DOI：
10.1111/pce.12760
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发表时间：
2016-09-01
影响因子：
7.3
通讯作者：
Fornara, Fabio
中科院分区：
文献类型：
--
作者：
Galbiati, Francesca;Chiozzotto, Remo;Fornara, Fabio
植物对外界因素（包括日照长度和环境胁迫）的反应表现出高度的发育可塑性。特别是缺水会干扰光周期开花，导致若干物种加速转向生殖生长，这一过程被称为干旱逃逸。然而，其他策略是可能的，干旱胁迫也可以延迟开花，尽管其潜在机制从未在分子水平上得到解决。我们研究了这些相互作用在水稻，一个短日照的物种，干旱胁迫延迟开花。一个协议，允许同步干旱与花的过渡被设置为配置文件的转录组的叶片受到压力下不同的光周期。我们确定了对干旱有不同反应的基因簇，这取决于白天的长度。暴露于干旱胁迫下的花诱导光周期强烈减少转录的早抽穗日期1（Ehd1），抽穗日期3a（Hd3a）和水稻开花位点T1（RFT1），日长信号的主要集成商，提供胁迫和光周期途径之间的分子连接。然而，表型和转录分析表明OsGIGANTEA（OsGI）不像拟南芥那样整合干旱和光周期信号，突出了长日和短日模式物种之间的分子差异。干旱信号如何影响发育转换，包括从营养生长到生殖生长的过渡，从未得到过彻底的评估。我们建立了一个协议，允许监测干旱胁迫的影响，而植物正在经历生殖阶段的变化，并使用全基因组转录组的方法，我们确定了集群的基因差异响应干旱的条件下，无论是促进或抑制花的过渡。新出现的图片表明，经历干旱的水稻植物采用了一种独特的策略，与拟南芥相比，调节植物繁殖，开花网络中的特定基因作为枢纽，非生物和发育信号汇聚。
Plants show a high degree of developmental plasticity in response to external cues, including day length and environmental stress. Water scarcity in particular can interfere with photoperiodic flowering, resulting in the acceleration of the switch to reproductive growth in several species, a process called drought escape. However, other strategies are possible and drought stress can also delay flowering, albeit the underlying mechanisms have never been addressed at the molecular level. We investigated these interactions in rice, a short day species in which drought stress delays flowering. A protocol that allows the synchronization of drought with the floral transition was set up to profile the transcriptome of leaves subjected to stress under distinct photoperiods. We identified clusters of genes that responded to drought differently depending on day length. Exposure to drought stress under floral-inductive photoperiods strongly reduced transcription of EARLY HEADING DATE 1 (Ehd1), HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1), primary integrators of day length signals, providing a molecular connection between stress and the photoperiodic pathway. However, phenotypic and transcriptional analyses suggested that OsGIGANTEA (OsGI) does not integrate drought and photoperiodic signals as in Arabidopsis, highlighting molecular differences between long and short day model species.Rice plants grown in rainfed areas can experience periods of water scarcity, culminating in drought stress. How drought signals impact on developmental switches, including the transition from vegetative to reproductive growth, has never been thoroughly assessed. We set up a protocol that allows monitoring the effects of drought stress while plants are undergoing reproductive phase change, and using a genome-wide transcriptomic approach we identified clusters of genes differentially responding to drought under conditions that either promote or repress the floral transition. The emerging picture suggests that rice plants experiencing drought adopt a distinct strategy, compared to Arabidopsis, to regulate plant reproduction, and that specific genes in the flowering network act as hubs where abiotic and developmental signals converge.