Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Singapore.
Biochem Biophys Res Commun. 2018 Sep 18;503(4):2380-2385. doi: 10.1016/j.bbrc.2018.06.165. Epub 2018 Jun 30.
Light is the most important exogenous stimulus regulating plant growth and various developmental processes. Phytochromes, especially PHYTOCHROME B (PHYB) mediates the various light-mediated processes in Arabidopsis. SPATULA (SPT) is an important transcription factor, which has been reported previously to participate in temperature-mediated transition from seed dormancy to germination. Here we investigate the function of SPT in the floral transition under long day conditions and photomorphogenesis in Arabidopsis. In this study, spt-2 shows significantly delayed flowering time. But mutation of SPT in the background of phyb-1 rescues the phenotype of spt-2. The flowering time of double mutant of spt-2/phyb-1 is similar with the wild type. These results indicate that SPT promotes the transition from vegetative stage to floral stage and it regulates this transition in a PHYB-dependent manner. With qRT-PCR analysis, it is found that SPT regulates flowering time via FLC, SVP, FT and SOC1. Furthermore, SPT also controls photomorphogenesis. spt-2 displays shortened hypocotyls and increased chlorophylls contents compared with the wild type. These phenotypes are also rescued in the double mutant of spt-2/phyb-1. These results indicate that SPT is also involved in photomorphogenic development in Arabidopsis and SPT regulates photomorphogenesis in a PHYB-dependent manner. Collectively, SPT is not only a temperature responder but it is also an important light regulator during plant growth and development.
光是调节植物生长和各种发育过程的最重要的外源性刺激。光敏色素，尤其是 PHYTOCHROME B (PHYB)，介导拟南芥中的各种光介导过程。SPATULA (SPT) 是一种重要的转录因子，先前已被报道参与由温度介导的从种子休眠到萌发的转变。在这里，我们研究了 SPT 在长日条件下的花发育和光形态发生中的功能。在这项研究中，spt-2 表现出明显的开花时间延迟。但在 phyb-1 的背景下突变 SPT 可挽救 spt-2 的表型。spt-2/phyb-1 双突变体的开花时间与野生型相似。这些结果表明 SPT 促进了从营养阶段到花阶段的转变，并以 PHYB 依赖的方式调节这种转变。通过 qRT-PCR 分析，发现 SPT 通过 FLC、SVP、FT 和 SOC1 调节开花时间。此外，SPT 还控制光形态发生。与野生型相比，spt-2 的下胚轴变短，叶绿素含量增加。在 spt-2/phyb-1 双突变体中，这些表型也得到了挽救。这些结果表明，SPT 也参与拟南芥的光形态发生发育，并且 SPT 以 PHYB 依赖的方式调节光形态发生。总之，SPT 不仅是温度响应者，而且在植物生长和发育过程中也是重要的光调节剂。
