CLE25 peptide regulates phloem initiation in Arabidopsis through a CLERK-CLV2 receptor complex

作  者:Ren SC, Song XF, Chen WQ, Lu R, Lucas WJ, Liu CM*
影响因子:3.824
刊物名称:Journal of Integrative Plant Biology
出版年份:2019
卷:61  期:10  页码:1043-1061

论文摘要:

The phloem, located within the vascular system, is critical for delivery of nutrients and signaling molecules throughout the plant body. Although the morphological process and several factors regulating phloem differentiation have been reported, the molecular mechanism underlying its initiation remains largely unknown. Here, we report that the small peptidecoding gene, CLAVATA 3 (CLV3)/EMBEYO SURROUNDING REGION 25 (CLE25), the expression of which begins in provascular initial cells of 64cellstaged embryos, and continues in sieve elementprocambium stem cells and phloem lineage cells, during postembryonic root development, facilitates phloem initiation in Arabidopsis. Knockout of CLE25 led to delayed protophloem formation, and in situ expression of an antagonistic CLE25G6T peptide compromised the fatedetermining periclinal division of the sieve element precursor cell and the continuity of the phloem in roots. In stems of CLE25G6Tplants the phloem formation was also compromised, and procambial cells were overaccumulated. Genetic and biochemical analyses indicated that a complex, consisting of the CLERESISTANT RECEPTOR KINASE (CLERK) leucinerich repeat (LRR) receptor kinase and the CLV2 LRR receptorlike protein, is involved in perceiving the CLE25 peptide. Similar to CLE25CLERK was also expressed during early embryogenesis. Taken together, our findings suggest that CLE25 regulates phloem initiation in Arabidopsis through a CLERKCLV2 receptor complex.