Laboratory of Plant Chemical Regulation, School of Agriculture, Meiji University, 1-1-1, Higashi-Mita, Tama-ku, Kawasaki, Kanagawa, Japan.
Department of Biochemistry, Okayama University of Science, Okayama City, Okayama, 700-0005, Japan.
Biochem Biophys Res Commun. 2023 Mar 15;649:110-117. doi: 10.1016/j.bbrc.2023.01.086. Epub 2023 Feb 1.
DWARF14 (D14) and HTL/KAI2 (KAI2) are paralogous receptors in the α/β-hydrolase superfamily. D14 is the receptor for a class of plant hormones, strigolactones (SLs), and KAI2 is the receptor for the smoke-derived seed germination inducer, Karrikin (KAR), in Arabidopsis. Germinone (Ger) was previously reported as a KAI2 agonist with germination-inducing activity for thermo-inhibited Arabidopsis seed. However, Ger was not specific to KAI2, and could also bind to D14. It was reported that SL analogs with a desmethyl-type D-ring structure are specifically recognized by KAI2. On the basis of this observation, we synthesized a desmethyl-type germinone (dMGer). We found that dMGer is highly specific to KAI2. Moreover, dMGer induced Arabidopsis seed germination more effectively than did Ger. In addition, dMGer induced the seed germination of Arabidopsis in a manner independently of GA, a well-known germination inducer in plants.
DWARF14（D14）和 HTL/KAI2（KAI2）是α/β-水解酶超家族中的同源受体。D14 是一类植物激素——独脚金内酯（SLs）的受体，而 KAI2 是拟南芥中烟衍生种子萌发诱导剂——卡罗琳（KAR）的受体。Germinone（Ger）先前被报道为 KAI2 的激动剂，具有热抑制拟南芥种子萌发的活性。然而，Ger 并不特异于 KAI2，也可以与 D14 结合。据报道，具有去甲基型 D-环结构的 SL 类似物特异性地被 KAI2 识别。基于这一观察，我们合成了一种去甲基型 germinone（dMGer）。我们发现 dMGer 对 KAI2 具有高度特异性。此外，dMGer 诱导拟南芥种子萌发的效果比 Ger 更显著。此外，dMGer 以一种不依赖于 GA 的方式诱导拟南芥种子萌发，GA 是植物中一种众所周知的萌发诱导剂。
