UV-B detected by the UVR8 photoreceptor antagonizes auxin signaling and plant shade avoidance
UV-B detected by the UVR8 photoreceptor antagonizes auxin signaling and plant shade avoidance
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DOI：
10.1073/pnas.1403052111
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发表时间：
2014-08-12
影响因子：
11.1
通讯作者：
Franklin, Keara A.
中科院分区：
文献类型：
--
作者：
Hayes, Scott;Velanis, Christos N.;Franklin, Keara A.
植物通过特定的光感受器探测辐射环境的不同方面来调节生长发育。UV- b由光感受器UV RESISTANCE LOCUS 8 （UVR8）感知。然而，将UVR8激活与植物生长联系起来的分子机制尚不完全清楚。当生长在邻近的植被附近时，不耐阴的植物开始戏剧性的茎伸长到超过竞争对手。在这里，我们发现UVR8检测到的UV-B提供了一个明确的阳光信号，通过拮抗植物激素生长素和赤霉素来抑制拟南芥的遮荫躲避反应。UV-B触发转录因子光敏色素相互作用因子4和光敏色素相互作用因子5的降解，稳定生长抑制蛋白，通过双重机制抑制生长素的生物合成。我们的研究结果表明，UVR8信号通路与其他光感受器通路密切结合，调节生长素信号和植物在阳光下的生长。
Plants detect different facets of their radiation environment via specific photoreceptors to modulate growth and development. UV-B is perceived by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8). The molecular mechanisms linking UVR8 activation to plant growth are not fully understood, however. When grown in close proximity to neighboring vegetation, shade-intolerant plants initiate dramatic stem elongation to overtop competitors. Here we show that UV-B, detected by UVR8, provides an unambiguous sunlight signal that inhibits shade avoidance responses in Arabidopsis thaliana by antagonizing the phytohormones auxin and gibberellin. UV-B triggers degradation of the transcription factors PHYTOCHROME INTERACTING FACTOR 4 and PHYTOCHROME INTERACTING FACTOR 5 and stabilizes growth-repressing DELLA proteins, inhibiting auxin biosynthesis via a dual mechanism. Our findings show that UVR8 signaling is closely integrated with other photoreceptor pathways to regulate auxin signaling and plant growth in sunlight.