title: Local positive feedback regulation determines cell shape in root hair cells.
abstract: The specification and maintenance of growth sites are tightly regulated during cell morphogenesis in all organisms. ROOT HAIR DEFECTIVE 2 reduced nicotinamide adenine dinucleotide phosphate (RHD2 NADPH) oxidase-derived reactive oxygen species (ROS) stimulate a Ca2+ influx into the cytoplasm that is required for root hair growth in Arabidopsis thaliana. We found that Ca2+, in turn, activated the RHD2 NADPH oxidase to produce ROS at the growing point in the root hair. Together, these components could establish a means of positive feedback regulation that maintains an active growth site in expanding root hair cells. Because the location and stability of growth sites predict the ultimate form of a plant cell, our findings demonstrate how a positive feedback mechanism involving RHD2, ROS, and Ca2+ can determine cell shape.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK.
authors.forename: Seiji
authors.initials: S
authors.lastname: Takeda
authors.forename: Catherine
authors.initials: C
authors.lastname: Gapper
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kaya
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bell
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kuchitsu
authors.forename: Liam
authors.initials: L
authors.lastname: Dolan
mesh_terms: D019943:Amino Acid Substitution; D017360:Arabidopsis / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000378:metabolism; D002460:Cell Line; D048430:Cell Shape; D020832:EF Hand Motifs; D004705:Endocytosis; D025461:Feedback, Physiological; D006801:Humans; D008387:Marine Toxins; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D019255:NADPH Oxidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010080:Oxazoles / Q000494:pharmacology; D010766:Phosphorylation; D018517:Plant Roots / Q000166:cytology* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D027682:Cation Transport Proteins; D008387:Marine Toxins; D050505:Mutant Proteins; D010080:Oxazoles; D017382:Reactive Oxygen Species; D011993:Recombinant Fusion Proteins; C506817:SCN1 protein, Arabidopsis; C059041:calyculin A; C473291:Rhd2 protein, Arabidopsis; D019255:NADPH Oxidases; D002118:Calcium