Disruption of the Arabidopsis thaliana inward-rectifier K+ channel AKT1 improves plant responses to water stress.
The Arabidopsis thaliana inward-rectifier K(+) channel AKT1 plays an important role in root K(+) uptake. Recent results show that the calcineurin B-like (CBL)-interacting protein kinase (CIPK) 23-CBL1/9 complex activates AKT1 in the root to enhance K(+) uptake. In addition, this CIPK-CBL complex has been demonstrated to regulate stomatal movements and plant transpiration. However, a role for AKT1 in plant transpiration has not yet been demonstrated. Here we show that disruption of AKT1 conferred an enhanced response to water stress in plants. Experiments performed in hydroponics showed that, when water potential was diminished by adding polyethylene glycol, akt1 adult plants lost less water than wild-type (WT) plants. Under long-term water stress in soil, adult akt1 plants displayed lower transpiration and less water consumption than WT plants. Finally, akt1 stomata closed more efficiently in response to ABA. Such results were also observed in cipk23 plants. The similar responses shown by cipk23 and akt1 plants to water stress denote that the regulation of AKT1 by CIPK23 may also take place in stomata and has a negative impact on plant performance under water stress conditions.
Departamento de Nutrición Vegetal, CEBAS-CSIC, Campus de Espinardo, 30100 Murcia, Spain.
Manuel
M
Nieves-Cordones
Fernando
F
Caballero
Vicente
V
Martínez
Francisco
F
Rubio
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003681:Dehydration; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D018527:Hydroponics; D054046:Plant Stomata / Q000502:physiology; D018526:Plant Transpiration; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D013312:Stress, Physiological; D014867:Water / Q000502:physiology*
D029681:Arabidopsis Proteins; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D014867:Water; C074500:AKT1 protein, Arabidopsis; C514581:CIPK23 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases