Plant-Environment Signaling, Institute of Environmental Biology, Utrecht University, Utrecht, The Netherlands.
Laboratory of Molecular Biology, Wageningen University, Wageningen, The Netherlands.
Nat Commun. 2024 Oct 1;15(1):8489. doi: 10.1038/s41467-024-52828-y.
Plants growing at high densities can detect competitors through changes in the composition of light reflected by neighbours. In response to this far-red-enriched light, plants elicit adaptive shade avoidance responses for light capture, but these need to be balanced against other input signals, such as nutrient availability. Here, we investigated how Arabidopsis integrates shade and nitrate signalling. We unveiled that nitrate modulates shade avoidance via a previously unknown shade response pathway that involves root-derived trans-zeatin (tZ) signal and the BEE1 transcription factor as an integrator of light and cytokinin signalling. Under nitrate-sufficient conditions, tZ promotes hypocotyl elongation specifically in the presence of supplemental far-red light. This occurs via PIF transcription factors-dependent inhibition of type-A ARRs cytokinin response inhibitors. Our data thus reveal how plants co-regulate responses to shade cues with root-derived information about nutrient availability, and how they restrict responses to this information to specific light conditions in the shoot.
高密度生长的植物可以通过邻居反射光的成分变化来检测竞争者。为了应对这种富含远红光的光，植物会引发适应性的避荫反应以进行光捕获，但这需要与其他输入信号（如养分供应）相平衡。在这里，我们研究了拟南芥如何整合遮荫和硝酸盐信号。我们揭示了硝酸盐通过一种以前未知的遮荫反应途径来调节避荫反应，该途径涉及源自根的玉米素（tZ）信号和 BEE1 转录因子，作为光和细胞分裂素信号的整合因子。在硝酸盐充足的条件下，tZ 仅在补充远红光的情况下促进下胚轴伸长。这是通过 PIF 转录因子依赖性抑制类型 A ARRs 细胞分裂素反应抑制剂来实现的。因此，我们的数据揭示了植物如何与根源信息共同调节对遮荫线索的反应，以及它们如何将这种信息的反应限制在芽中的特定光照条件下。
