The role of karrikin in regulating photo- and thermomorphogenesis

烟来源的卡瑞金最近被证明可以诱导拟南芥的萌发和抑制下胚轴的伸长。尽管人们对Karrikin如何在分子水平上调节这些反应知之甚少，但很明显，该信号通路与光信号密切相关。除了Karrikin信号突变体KAI2和smax 1smxl2的幼苗表现出改变的光响应外，光信号的中央调节因子HY5也是依赖Karrikin抑制下胚轴伸长所必需的。此外，植物对环境温度升高的反应(热形态发生)显示出与光信号的密切联系。温度升高导致下胚轴伸长，叶片生长和叶柄伸长，这些反应都在PIF4突变体中得到改善，该突变体最初被描述为在光信号通路中发挥作用。此外，HY5还被证明在热形态发生中发挥重要作用，拮抗PIF4的影响。在这里，我们的目标是描绘新描述的Karrikin信号网络与光信号通路之间的联系，重点是拟南芥B-box蛋白和HY5的作用。此外，我们将探索这些相互作用最终如何调节植物对高温的反应。

Smoke derived karrikins have recently been shown to induce germination and inhibit hypocotyl elongation in Arabidopsis. Although relatively little is known about how karrikin regulates these responses at the molecular level, it is clear that the signalling pathway is closely connected to light signalling. Besides the fact that seedlings of the karrikin signalling mutants kai2 and smax1smxl2 show altered light responsiveness, also the central regulator of light signalling, HY5, is required for karrikin dependent inhibition of hypocotyl elongation. Also plant’s responses to an elevation in the ambient temperature (thermomorphogenesis) show a close connection to light signalling. Elevated temperatures result in an elongated hypocotyl, hyponastic leaf growth and petiole elongation, responses all ameliorated in the pif4 mutant that was first described for its role in the light signalling pathways. Furthermore, HY5 has also been shown to play important roles in thermomorphogenesis, antagonising the effects of PIF4. Here, we aim to delineate the connections between the newly described karrikin signalling network with light signalling pathways focusing on the role of Arabidopsis B-box proteins and HY5. Furthermore, we will explore how these interactions ultimately might regulate the plants responses to elevated temperatures.