Plants detect and respond to the proximity of competitors using light signals perceived by photoreceptor proteins. A low ratio of red to far-red radiation (R:FR ratio) is a key signal of competition that is sensed by the photoreceptor phytochrome B (phyB). Low R:FR ratios increase the synthesis of growth-related hormones, including auxin and gibberellins, promoting stem elongation and other shade-avoidance responses. Other photoreceptors that help plants to optimize their developmental configuration and resource allocation patterns in the canopy include blue light photoreceptors, such as cryptochromes and phototropins, and UV receptors, such as UVR8. All photoreceptors act by directly or indirectly controlling the activity of two major regulatory nodes for growth and development: the COP1/SPA ubiquitin E3 ligase complex and the PIF transcription factors. phyB is also an important modulator of hormonal pathways that regulate plant defense against herbivores and pathogens, including the jasmonic acid signaling pathway. In this Perspective, we discuss recent advances on the studies of the mechanisms that link photoreceptors with growth and defense. Understanding these mechanisms is important to provide a functional platform for breeding programs aimed at improving plant productivity, stress tolerance, and crop health in species of agronomic interest, and to manipulate the light environments in protected agriculture.

植物使用光感受器蛋白感知的光信号检测并响应竞争者的接近。红光与远红光辐射的低比率（R:FR 比率）是竞争的关键信号，由光感受器光敏色素 B (phyB) 感知。低 R:FR 比增加生长相关激素的合成，包括生长素和赤霉素，促进茎伸长和其他避荫反应。其他有助于植物优化其在冠层中的发育配置和资源分配模式的光感受器包括蓝光光感受器，如隐花色素和向光素，以及紫外线感受器，如 UVR8。所有光感受器通过直接或间接控制生长和发育的两个主要调节节点的活动来发挥作用：COP1/SPA 泛素 E3 连接酶复合物和 PIF 转录因子。phyB 也是一种重要的激素通路调节剂，可调节植物对食草动物和病原体的防御，包括茉莉酸信号通路。在这个观点中，我们讨论了将光感受器与生长和防御联系起来的机制研究的最新进展。了解这些机制对于为旨在提高农艺物种的植物生产力、胁迫耐受性和作物健康的育种计划提供功能平台以及在受保护的农业中操纵光环境非常重要。我们讨论了将光感受器与生长和防御联系起来的机制研究的最新进展。了解这些机制对于为旨在提高农艺物种的植物生产力、胁迫耐受性和作物健康的育种计划提供功能平台以及在受保护的农业中操纵光环境非常重要。我们讨论了将光感受器与生长和防御联系起来的机制研究的最新进展。了解这些机制对于为旨在提高农艺物种的植物生产力、胁迫耐受性和作物健康的育种计划提供功能平台以及在受保护的农业中操纵光环境非常重要。