Photoexcited Cryptochrome2 Interacts Directly with TOE1 and TOE2 in Flowering Regulation
Photoexcited Cryptochrome2 Interacts Directly with TOE1 and TOE2 in Flowering Regulation
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光激发隐花色素2在开花调节中直接与TOE1和TOE2相互作用
DOI：
10.1104/pp.20.00486
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发表时间：
2020-09-01
期刊：
影响因子：
7.4
通讯作者：
Yang, Hong-Quan
中科院分区：
文献类型：
--
作者：
Du, Sha-Sha;Li, Ling;Yang, Hong-Quan
隐色素是一种类似于光酶的蓝光（BL）光感受器，存在于各种生物体中。拟南芥（Arabidopsis thaliana）隐色素（cryys； CRY1和CRY2）介导许多光响应，包括光周期花的形成。隐色素与COP1和SPA1相互作用，稳定CONSTANS (CO)，促进开花位点T（开花位点T）转录和开花。ap2样转录因子TOE1通过间接抑制CO转录激活活性并直接与FT结合而负向调控FT表达和开花。本研究表明，CRY1和CRY2在开花调控中以依赖于b1的方式与TOE1和TOE2物理相互作用。遗传研究表明，TOE1和TOE2的突变部分抑制了cry1 cry2突变株的晚花表型。bl触发的CRY2与TOE1和TOE2的相互作用促进了TOE1和TOE2与CO的分离，从而减轻了它们对CO转录活性的抑制，并增强了FT的转录。此外，我们发现CRY2抑制了TOE1与FT的Block E增强子内调节元件的结合。这些结果表明，TOE1和TOE2是CRY2的下游组分。从而通过调节CO活性和FT转录部分介导CRY2对光周期开花的调控。
Cryptochromes are photolyase-like, blue-light (BL) photoreceptors found in various organisms. Arabidopsis (Arabidopsis thaliana) cryptochromes (CRYs; CRY1, and CRY2) mediate many light responses including photoperiodic floral initiation. Cryptochromes interact with COP1 and SPA1, causing the stabilization of CONSTANS (CO) and promotion of FLOWERING LOCUS T (FT) transcription and flowering. The AP2-like transcriptional factor TOE1 negatively regulates FT expression and flowering by indirectly inhibiting CO transcriptional activation activity and directly binding to FT. Here, we demonstrate that CRY1 and CRY2 physically interact with TOE1 and TOE2 in a BL-dependent manner in flowering regulation. Genetic studies showed that mutation of TOE1 and TOE2 partially suppresses the late-flowering phenotype of cry1 cry2 mutant plants. BL-triggered interactions of CRY2 with TOE1 and TOE2 promote the dissociation of TOE1 and TOE2 from CO, resulting in alleviation of their inhibition of CO transcriptional activity and enhanced transcription of FT. Furthermore, we show that CRY2 represses TOE1 binding to the regulatory element within the Block E enhancer of FT. These results reveal that TOE1 and TOE2 act as downstream components of CRY2, thus partially mediating CRY2 regulation of photoperiodic flowering through modulation of CO activity and FT transcription.