Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Plant Cell. 2018 Oct;30(10):2383-2401. doi: 10.1105/tpc.17.00586. Epub 2018 Sep 10.
Appropriate cell division and differentiation ensure normal anther development in angiosperms. BARELY ANY MERISTEM 1/2 (BAM1/2) and RECEPTOR-LIKE PROTEIN KINASE2 (RPK2), two groups of leucine-rich repeat receptor-like protein kinases, are required for early anther cell specification. However, little is known about the molecular mechanisms underlying these two RLK-mediated signaling pathways. Here, we show that CLAVATA3 INSENSITIVE RECEPTOR KINASEs (CIKs), a group of novel coreceptor protein kinase-controlling stem cell homeostasis, play essential roles in BAM1/2- and RPK2-regulated early anther development in The archesporial cells of triple and quadruple mutant anthers perform anticlinal division instead of periclinal division. Defective cell division and specification of the primary and inner secondary parietal cells occur in these mutant anthers. The disordered divisions and specifications of anther wall cells finally result in excess microsporocytes and a lack of one to three parietal cell layers in mutant anthers, resembling or mutant anthers. Genetic and biochemical analyses indicate that CIKs function as coreceptors of BAM1/2 and RPK2 to regulate archesporial cell division and determine the specification of anther parietal cells.
适当的细胞分裂和分化确保了被子植物正常的花药发育。胚珠顶端 1/2（BAM1/2）和受体样蛋白激酶 2（RPK2）这两个富含亮氨酸重复受体样蛋白激酶组，对于早期花药细胞的特化是必需的。然而，这两种 RLK 介导的信号通路的分子机制知之甚少。在这里，我们表明 CLAVATA3 不敏感受体激酶（CIKs），一组新的核心受体蛋白激酶控制干细胞的自我平衡，在 BAM1/2 和 RPK2 调控的早期花药发育中发挥重要作用。在三倍体和四倍体花药中，原表皮细胞进行的是垂周分裂而不是平周分裂。在这些突变体花药中，初级和内周壁细胞的细胞分裂和特化出现缺陷。花药壁细胞的分裂和特化紊乱最终导致小孢子细胞过多，以及突变体花药中缺少一个到三个壁细胞层，类似于 或 突变体花药。遗传和生化分析表明，CIKs 作为 BAM1/2 和 RPK2 的共受体，调节原表皮细胞的分裂，并决定花药壁细胞的特化。
