title: RGF1 INSENSITIVE 1 to 5, a group of LRR receptor-like kinases, are essential for the perception of root meristem growth factor 1 in Arabidopsis thaliana.
abstract: RGF1, a secreted peptide hormone, plays key roles in root meristem development in Arabidopsis. Previous studies indicated that a functional RGF1 needs to be sulfated at a tyrosine residue by a tyrosylprotein sulfotransferase and that RGF1 regulates the root meristem activity mainly via two downstream transcription factors, PLETHORA 1 (PLT1) and PLT2. How extracellular RGF1 is perceived by a plant cell, however, is unclear. Using genetic approaches, we discovered a clade of leucine-rich repeat receptor-like kinases, designated as RGF1 INSENSITIVE 1 (RGI1) to RGI5, serving as receptors of RGF1. Two independent rgi1 rgi2 rgi3 rgi4 rgi5 quintuple mutants display a consistent short primary root phenotype with a small size of meristem. An rgi1 rgi2 rgi3 rgi4 quadruple mutant shows a significantly reduced sensitivity to RGF1, and the quintuple mutant is completely insensitive to RGF1. The expression of PLT1 and PLT2 is almost undetectable in the quintuple mutant. Ectopic expression of PLT2 driven by an RGI2 promoter in the quintuple mutant greatly rescued its root meristem defects. One of the RGIs, RGI1, was subsequently analyzed biochemically in detail. In vitro dot blotting and pull-down analyses indicated that RGI1 can physically interact with RGF1. Exogenous application of RGF1 can quickly and simultaneously induce the phosphorylation and ubiquitination of RGI1, indicating that RGI1 can perceive and transduce the RGF1 peptide signal. Yet, the activated RGI1 is likely turned over rapidly. These results demonstrate that RGIs, acting as the receptors of RGF1, play essential roles in RGF1-PLT-mediated root meristem development in Arabidopsis thaliana.
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ou
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Lu
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Quaner
authors.initials: Q
authors.lastname: Zi
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Xun
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Jingjie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Yujun
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Hongyong
authors.initials: H
authors.lastname: Shi
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Zhuoyun
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Baolin
authors.initials: B
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xiaoyue
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Kai
authors.initials: K
authors.lastname: He
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Gou
authors.affiliation: State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Chuanyou
authors.initials: C
authors.lastname: Li
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Li
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D015536:Down-Regulation / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D000090263:Leucine-Rich Repeat Proteins; D018519:Meristem / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D029681:Arabidopsis Proteins; D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; D013431:Sulfates