Cryptochrome-mediated hypocotyl phototropism was regulated antagonistically by gibberellic acid and sucrose in ArabidopsisOO
Cryptochrome-mediated hypocotyl phototropism was regulated antagonistically by gibberellic acid and sucrose in ArabidopsisOO
复制标题
拟南芥中隐花色素介导的下胚轴向光性受到赤霉酸和蔗糖的拮抗调节
DOI：
10.1111/jipb.12813
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发表时间：
2020
影响因子：
11.4
通讯作者：
Xiao Zhang
中科院分区：
文献类型：
--
作者：
Qing-Ping Zhao;Jin-Dong Zhu;Nan-Nan Li;Xiao-Nan Wang;Xiang Zhao;Xiao Zhang
光致蛋白（phot 1和phot 2）和隐花色素（cry 1和cry 2）都是拟南芥的蓝光受体。向光蛋白主要在光运动中起作用，隐花色素在光形态建成中起作用。虽然隐花色素已被提出作为向光性反应的正调节剂，但其潜在机制仍不清楚。在这里，我们报告说，从培养基中消耗蔗糖或添加赤霉酸（GAs）可以部分恢复phot 1 phot 2双突变体在高强度蓝光下的向光性曲率的缺陷;这种恢复不发生在phot 1 phot 2 cry 1 cry 2四倍突变体和nph 3（nonphototropichypocotyl 3）突变体中，这些突变体在含蔗糖的培养基中的向光性反应受损。这些结果表明，GAs和蔗糖拮抗调节下胚轴向光性的隐花色素依赖的方式，但它表现出与NPH 3的向光性信号转导的串扰。此外，蓝光激活的隐花色素抑制了GAs的合成，从而稳定了DELLAs，抑制了下胚轴的生长，导致下胚轴阴面的GAs含量高于阳面，支持了下胚轴的不对称生长。通过蔗糖消耗或添加GAs对DELLA丰度的调节，揭示了隐花色素在调节向光性曲率中的功能。
Both phototropins (phot1 and phot2) and cryptochromes (cry1 and cry2) were proven as theArabidopsis thalianablue light receptors. Phototropins predominately function in photomovement, and cryptochromes play a role in photomorphogenesis. Although cryptochromes have been proposed to serve as positive modulators of phototropic responses, the underlying mechanism remains unknown. Here, we report that depleting sucrose from the medium or adding gibberellic acids (GAs) can partially restore the defects in phototropic curvature of thephot1 phot2double mutants under high‐intensity blue light; this restoration does not occur inphot1 phot2 cry1 cry2quadruple mutants andnph3(nonphototropichypocotyl 3) mutants which were impaired phototropic response in sucrose‐containing medium. These results indicate that GAs and sucrose antagonistically regulate hypocotyl phototropism in a cryptochromes dependent manner, but it showed a crosstalk with phototropin signaling on NPH3. Furthermore, cryptochromes activation by blue light inhibit GAs synthesis, thus stabilizing DELLAs to block hypocotyl growth, which result in the higher GAs content in the shade side than the lit side of hypocotyl to support the asymmetric growth of hypocotyl. Through modulation of the abundance of DELLAs by sucrose depletion or added GAs, it revealed that cryptochromes have a function in mediating phototropic curvature.