Elhiti Mohamed, Mira Mohammed M, So Kenny K Y, Stasolla Claudio, Hebelstrup Kim H
Department of Agroecology, University of Aarhus, Forsøgsvej 1, 4200 Slagelse, Denmark.
Department of Botany, Faculty of Science, Tanta University, Tanta 31527, Egypt.
Plants (Basel). 2021 Dec 10;10(12):2720. doi: 10.3390/plants10122720.
Somatic embryogenesis in encompasses an induction phase requiring auxin as the inductive signal to promote cellular dedifferentiation and formation of the embryogenic tissue, and a developmental phase favoring the maturation of the embryos. Strigolactones (SLs) have been categorized as a novel group of plant hormones based on their ability to affect physiological phenomena in plants. The study analyzed the effects of synthetic strigolactone GR24, applied during the induction phase, on auxin response and formation of somatic embryos. The expression level of two SL biosynthetic genes, and and ), which are responsible for the conversion of carotene to carotenal, increased during the induction phase of embryogenesis. mutant studies indicated that the somatic embryo number was inhibited in and mutants, and this effect was reversed by applications of GR24, a synthetic strigolactone, and exacerbated by TIS108, a SL biosynthetic inhibitor. The transcriptional studies revealed that the regulation of GR24 and TIS108 on somatic embryogenesis correlated with changes in expression of known to be required for the production of the embryogenic tissue, as well as the expression of () and (), which are markers of cell dedifferentiation and embryogenic tissue formation. Collectively, this work demonstrated the novel role of SL in enhancing the embryogenic process in and its requirement for inducing the expression of genes related to auxin signaling and production of embryogenic tissue.
体细胞胚胎发生包括一个诱导阶段，该阶段需要生长素作为诱导信号来促进细胞去分化和胚性组织的形成，以及一个有利于胚胎成熟的发育阶段。独脚金内酯（SLs）因其影响植物生理现象的能力而被归类为一类新型植物激素。该研究分析了在诱导阶段施加的合成独脚金内酯GR24对生长素反应和体细胞胚形成的影响。两个负责将胡萝卜素转化为胡萝卜醛的SL生物合成基因，即 和 ，在胚胎发生的诱导阶段表达水平增加。突变体研究表明，在 和 突变体中体细胞胚数量受到抑制，而合成独脚金内酯GR24的应用可逆转这种效应，而SL生物合成抑制剂TIS108则会加剧这种效应。转录研究表明，GR24和TIS108对体细胞胚胎发生的调节与已知胚性组织产生所需的 表达变化相关，以及与细胞去分化和胚性组织形成的标记物 （）和 （）的表达相关。总的来说，这项工作证明了SL在增强 胚性过程中的新作用及其对诱导生长素信号相关基因表达和胚性组织产生的需求。
