AKT1 and TRH1 are required during root hair elongation in Arabidopsis.
TRH1 is a member of the AtKT/AtKUP/AtHAK family of potassium carriers that is required for root hair elongation and AKT1 is an inward rectifying potassium channel expressed in the root epidermis, endodermis and cortex of Arabidopsis thaliana. Plants homozygous for the trh1-1 mutation form short root hairs. The Trh1(-) phenotype cannot be suppressed by growing plants homozygous for the trh1-1 mutation in the presence of high external KCl concentration. This indicates an absolute requirement for TRH1 in root hair tip growth. Plants homozygous for the akt1-1 mutation develop longer root hairs than the wild type when grown in 0 mM external potassium, but develop shorter hairs than the wild type when grown in higher concentrations [>10 mM] of potassium. These data indicate that both TRH1 and AKT1 are active in the root hair over a wide range of external potassium concentrations, but suggest they have different functions in the growing hair cell.
Desbrosses
Guilhem
G
Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK.
Josefsson
Caroline
C
Rigas
Stamatis
S
Hatzopoulos
Polydefkis
P
Dolan
Liam
L
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D006720:Homozygote; D017136:Ion Transport / Q000187:drug effects; D009154:Mutation; D009994:Osmolar Concentration; D010641:Phenotype; D019441:Plant Epidermis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D027682:Cation Transport Proteins; C111260:KUP1 protein, Arabidopsis; D015221:Potassium Channels; D012333:RNA, Messenger; C474309:TRH1 protein, Arabidopsis; C074500:AKT1 protein, Arabidopsis; D011189:Potassium Chloride