Temperature-dependent control of flowering by the gibberellin pathway and interactions between DELLA proteins and APETALA1/VRN1 MADS-box factors.

温度是控制花期的重要环境因子。在拟南芥中，低温的经历延迟了生长和开花，并且在分子水平上，低温导致DELLA蛋白的积累，DELLA蛋白是赤霉素（GA）信号传导途径的主要植物生长和开花时间阻遏物。DELLA丰度对温度变化的响应相当迅速，并且DELLA积累的影响可以通过GA（处理）来抑制。我们以前已经表明，拟南芥MADS盒转录因子APETALA 1（AP 1）被直接与DELLA相互作用抑制。此外，我们有证据表明，增加AP 1的表达可能是原因的两个拟南芥加入在寒冷的温度下提前开花。在这里，我们想测试的假设，增加AP 1水平在这些加入竞争的生长抑制作用的DELLA在寒冷。第二，我们想测试这个AP 1-DELLA调节模块是否在谷类物种中是保守的。在大麦和小麦中，VERNALIZATION 1（VRN 1）蛋白是与拟南芥AP 1最接近的同源物，是主要的开花时间调节因子。因此，我们想研究大麦和小麦VRN 1是否也可以与各自的DELLA相互作用，以及开花时间控制是否响应于温度和GA依赖于这种相互作用。

Temperature is an important environmental cue controlling flowering time. In Arabidopsis, the experience of cold temperatures delays growth and flowering and, at the molecular level, cold results in the accumulation of DELLA proteins, major plant growth and flowering time repressors of the gibberellin (GA) signalling pathway. DELLA abundance responds rather instantly to changes in the temperature and the effects of DELLA accumulation can be suppressed by GA (treatments). We have previously shown that the Arabidopsis MADS-box transcription factor APETALA1 (AP1) is repressed by direct interactions with DELLAs. Furthermore, we have evidence that increased AP1 expression may be causative for the early flowering of two Arabidopsis accessions in cold temperature. Here, we would like to test the hypothesis that increased AP1 levels in these accessions outcompete the growth repressive effects of DELLAs in the cold. Second, we would like to test whether this AP1-DELLA regulatory module is conserved in cereal species. In barley and wheat, VERNALIZATION1 (VRN1) proteins, the closest homologues to Arabidopsis AP1, are major flowering time regulators. We therefore would like to examine whether barley and wheat VRN1 can also interact with the respective DELLAs and whether flowering time control in response to temperature and GA is dependent on this interaction.