Root K+ Acquisition in Plants: The Arabidopsis thaliana Model

K+ is an essential macronutrient required by plants to complete their life cycle. It fulfills important functions and it is widely used as a fertilizer to increase crop production. Thus, the identification of the systems involved in K+ acquisition by plants has always been a research goal as it may...

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Detalles Bibliográficos
Autores: Alemán, Fernando, Nieves-Cordones, Manuel, Martínez, Vicente, Rubio, Francisco
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2011
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/344341
Acceso en línea:http://hdl.handle.net/10261/344341
Access Level:acceso abierto
Palabra clave:Arabidopsis
Nutrition
Potassium
Salinity
Uptake
Descripción
Sumario:K+ is an essential macronutrient required by plants to complete their life cycle. It fulfills important functions and it is widely used as a fertilizer to increase crop production. Thus, the identification of the systems involved in K+ acquisition by plants has always been a research goal as it may eventually produce molecular tools to enhance crop productivity further. This review is focused on the recent findings on the systems involved in K+ acquisition. From Epstein's pioneering work >40 years ago, K+ uptake was considered to consist of a high- and a low-affinity component. The subsequent molecular approaches identified genes encoding K+ transport systems which could be involved in the first step of K+ uptake at the plant root. Insights into the regulation of these genes and the proteins that they encode have also been gained in recent studies. A demonstration of the role of the two main K+ uptake systems at the root, AtHKA5 and AKT1, has been possible with the study of Arabidopsis thaliana T-DNA insertion lines that knock out these genes. AtHAK5 was revealed as the only uptake system at external concentrations <10 μM. Between 10 and 200 μM both AtHAK5 and AKT1 contribute to K+ acquisition. At external concentrations >500 μM, AtHAK5 is not relevant and AKT1's contribution to K+ uptake becomes more important. At 10 mM K+, unidentified systems may provide sufficient K+ uptake for plant growth