title: FERONIA receptor-like kinase regulates RHO GTPase signaling of root hair development.
abstract: Plant RHO GTPases (RAC/ROPs) mediate multiple extracellular signals ranging from hormone to stress and regulate diverse cellular processes important for polarized cell growth, differentiation, development, reproduction, and responses to the environment. They shuttle between the GDP-bound inactive state and the GTP-bound activated state and their activation is predominantly mediated by a family of guanine nucleotide exchange factors (GEFs) referred to as ROPGEFs. Using the Arabidopsis ROPGEF1 as bait, we identified members of a receptor-like kinase (RLK) family as potential upstream regulators for RAC/ROP signaling. NADPH oxidase-derived reactive oxygen species (ROS) are emerging as important regulators for growth and development and play a crucial role in mediating RAC/ROP-regulated root hair development, a polarized cell growth process. We therefore screened T-DNA insertion mutants in these RLKs for root hair defects and found that mutations in one of them, At3g51550 encoding the FERONIA (FER) receptor-like kinase, induced severe root hair defects. We show that the fer phenotypes correlated with reduced levels of active RAC/ROPs and NADPH oxidase-dependent, auxin-regulated ROS accumulation in roots and root hairs and that up-regulating RAC/ROP signaling in fer countered the mutant phenotypes. Taken together, these observations strongly support FER as an upstream regulator for the RAC/ROP-signaled pathway that controls ROS-mediated root hair development. Moreover, FER was pulled down by ROP2 GTPase in a guanine nucleotide-regulated manner implying a dynamic signaling complex involving FER, a ROPGEF, and a RAC/ROP.
authors.affiliation: Department of Biochemistry and Molecular Biology, Molecular Cell Biology Program, and Plant Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Qiaohong
authors.initials: Q
authors.lastname: Duan
authors.forename: Daniel
authors.initials: D
authors.lastname: Kita
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Cheung
authors.forename: Hen-Ming
authors.initials: HM
authors.lastname: Wu
mesh_terms: D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D005453:Fluorescence; D019204:GTP-Binding Proteins / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology / Q000254:growth & development*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D020798:Two-Hybrid System Techniques; D020741:rho GTP-Binding Proteins / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases
chemical_list: D029681:Arabidopsis Proteins; D019204:GTP-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D010770:Phosphotransferases; D017382:Reactive Oxygen Species; D020741:rho GTP-Binding Proteins; C522131:At3g51550 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; C501663:ROP1 protein, Arabidopsis