The photoreceptors UV RESISTANCE LOCUS 8 (UVR8) and CRYPTOCHROMES 1 and 2 (CRYs) play major roles in the perception of UV‐B (280–315 nm) and UV‐A/blue radiation (315–500 nm), respectively. However, it is poorly understood how they function in sunlight. The roles of UVR8 and CRYs were assessed in a factorial experiment with Arabidopsis thaliana wild‐type and photoreceptor mutants exposed to sunlight for 6 or 12 hr under five types of filters with cut‐offs in UV and blue‐light regions. Transcriptome‐wide responses triggered by UV‐B and UV‐A wavelengths shorter than 350 nm (UV‐A_sw) required UVR8 whereas those induced by blue and UV‐A wavelengths longer than 350 nm (UV‐A_lw) required CRYs. UVR8 modulated gene expression in response to blue light while lack of CRYs drastically enhanced gene expression in response to UV‐B and UV‐A_sw. These results agree with our estimates of photons absorbed by these photoreceptors in sunlight and with in vitro monomerization of UVR8 by wavelengths up to 335 nm. Motif enrichment analysis predicted complex signaling downstream of UVR8 and CRYs. Our results highlight that it is important to use UV waveband definitions specific to plants' photomorphogenesis as is routinely done in the visible region.

中文翻译：

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光感受器 UVR8 介导对太阳光中波长高达 350 nm 的 UV-B 和 UV-A 的感知，其响应度由隐花色素调节。


光感受器抗紫外线位点 8 (UVR8) 和隐色色素 1 和 2 (CRY) 分别在 UV-B (280–315 nm) 和 UV-A/蓝色辐射 (315–500 nm) 的感知中起主要作用。然而，人们对它们在阳光下如何发挥作用却知之甚少。 UVR8 和 CRY 的作用在析因实验中进行了评估，拟南芥野生型和光感受器突变体在五种类型的滤光片下暴露在阳光下 6 或 12 小时，在紫外线和蓝光区域具有截止值。由短于 350 nm 的 UV-B 和 UV-A 波长 (UV-A _sw ) 触发的全转录组反应需要 UVR8，而由长于 350 nm 的蓝色和 UV-A 波长 (UV-A _lw ) 引发的转录组反应需要 CRYs。 UVR8 响应蓝光调节基因表达，而缺乏 CRY 则显着增强响应 UV-B 和 UV-A _sw的基因表达。这些结果与我们对这些光感受器在阳光下吸收的光子的估计以及波长高达 335 nm 的 UVR8 的体外单体化一致。基序富集分析预测了 UVR8 和 CRY 下游的复杂信号传导。我们的结果强调，使用特定于植物光形态发生的紫外波段定义非常重要，就像在可见光区域中常规进行的那样。