背景回顾：Exogenous application of CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (CLE) peptides suppresses protophloem differentiation and leads to the consumption of the proximal root meristem. 

提出问题：However, the exact CLE peptides and the corresponding receptor complex regulating protophloem differentiation have not been clarified yet.

结果1-关键CLE鉴定：Through expression pattern and phylogenetic analyses, CLE25/26/45 were identified as candidate peptides. 

结果2-受体复合物：Further genetic analyses, physiological assays, and specific protophloem marker observations indicated that CLE25/26/45, BARELY ANY MERISTEM1/3 (BAM1/3), and CLV3 INSENSITIVE KINASES (CIKs) are involved in regulating protophloem differentiation. 

结果3-BRX和OPS下游：The cle25 26 45 and cik2 3 4 5 6 mutation can greatly rescue the root defects of brevis radix (brx) and octopus (ops) mutants.

结果4-CLE25/26/45、BAM1/3、CIK2/3/4/5/6功能：The protophloem differentiation and proximal root meristem consumption of clv1bam1 3 and cik2 3 4 5 6 were insensitive to CLE25/26/45 treatments. cle25 26 45, clv1 bam1 3, and cik2 3 4 5 6 displayed similar premature protophloem. 

结果5-蛋白水平调控：In addition, CLE25/26/45 induced the interactions between BAMs and CIKs in vivo. Furthermore, CLE25/26/45 enhanced the phosphorylation levels of CIKs, which were greatly impaired in clv1 bam1 3 mutant. 

结论：Our work clarifies that the CLE25/26/45–BAM1/3–CIK2/3/4/5/6 signaling module genetically acts downstream of BRX and OPS to suppress protophloem differentiation.

 摘 要 

外施CLV3/CLE多肽能够抑制原生韧皮部分化，导致近端根分生组织的消耗。但是，调控原生韧皮部分化的具体CLE以及相对应的受体复合物还不清楚。本文中，作者通过表达模式分析和系统发育分析，发现CLE25/26/45是候选的多肽。进一步的遗传分析、生理实验以及特异性原生韧皮部标记显示，CLE25/26/45、BAM1/3和CIKs参与了原生韧皮部分化的调控。cle25 26 45和cik2 3 4 5 6突变能够极大的恢复brx和ops突变体的根缺陷。clv1 bam1 3和cik2 3 4 5 6突变体的原生韧皮部分化和近端根分生组织消耗对于CLE25/26/45处理不敏感。cle25 26 45、clv1 bam1 3以及cik2 3 4 5 6表现出相似的早熟原生韧皮部。另外，CLE25/26/45能够诱导BAMs和CIKs的体内互作。此外，CLE25/26/45能够增强CIKs的磷酸化水平，而CIKs的磷酸化在clv1 bam1 3突变体中的水平受到很大程度的抑制。本文的研究鉴定了CLE25/26/45–BAM1/3–CIK2/3/4/5/6信号转导模块作用于BRX和OPS的下游，抑制原生韧皮部分化。

 通讯作者 

** 苟小平 **