School of Life Sciences, Central South University, Changsha, 410078, China.
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, 410082, China.
J Integr Plant Biol. 2022 Oct;64(10):1901-1915. doi: 10.1111/jipb.13336. Epub 2022 Sep 6.
Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1 (phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1's role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with and phosphorylate FERONIA (FER), a known cell growth regulator, and trigger downstream phototropic bending growth in Arabidopsis hypocotyls. fer mutants showed defects in phototropic growth, similar to phot1/2 mutant. FER also interacts with and phosphorylates phytochrome kinase substrates, the phot1 downstream substrates. The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light, both of which are critical for phototropic bending growth in hypocotyls. Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants.
植物茎的向光性是由光驱动的生长素梯度的形成触发的，导致弯曲生长。蓝光受体光受体 1（phot1）感知光的方向，但这如何导致生长素梯度的形成和生长调节仍不清楚。先前的研究表明，phot1 对调节质外体酸化起作用，但它与光受体和下胚轴向光性的关系尚不清楚。在此，我们表明蓝光可以使 phot1 与已知的细胞生长调节剂 FERONIA（FER）相互作用并使其磷酸化，并在拟南芥下胚轴中触发下游的向光弯曲生长。 fer 突变体表现出向光性生长缺陷，类似于 phot1/2 突变体。FER 还与phytochrome 激酶底物相互作用并使其磷酸化，phytochrome 激酶底物是 phot1 的下游底物。在侧部蓝光下，phot1-FER 途径在上胚轴质外体酸化和生长素梯度形成之前起作用，这两者对于下胚轴的向光性弯曲生长都是至关重要的。我们的研究强调了 FER 在植物中 phot1 介导的向光性细胞生长调节中的关键作用。
