Modulation of K+ translocation by AKT1 and AtHAK5 in Arabidopsis plants
Root cells take up K+ from the soil solution, and a fraction of the absorbed K+ is translocated to the shoot after being loaded into xylem vessels. K+ uptake and translocation are spatially separated processes. K+ uptake occurs in the cortex and epidermis whereas K+ translocation starts at the stele...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/344463 |
| Acceso en línea: | http://hdl.handle.net/10261/344463 |
| Access Level: | acceso abierto |
| Palabra clave: | AKT1 AtHAK5 K+ retrieval from xylem K+ translocation K+ uptake SKOR |
| Sumario: | Root cells take up K+ from the soil solution, and a fraction of the absorbed K+ is translocated to the shoot after being loaded into xylem vessels. K+ uptake and translocation are spatially separated processes. K+ uptake occurs in the cortex and epidermis whereas K+ translocation starts at the stele. Both uptake and translocation processes are expected to be linked, but the connection between them is not well characterized. Here, we studied K+ uptake and translocation using Rb+ as a tracer in wild-type Arabidopsis thaliana and in T-DNA insertion mutants in the K+ uptake or translocation systems. The relative amount of translocated Rb+ to the shoot was positively correlated with net Rb+ uptake rates, and the akt1 athak5 T-DNA mutant plants were more efficient in their allocation of Rb+ to shoots. Moreover, a mutation of SKOR and a reduced plant transpiration prevented the full upregulation of AtHAK5 gene expression and Rb+ uptake in K+-starved plants. Lastly, Rb+ was found to be retrieved from root xylem vessels, with AKT1 playing a significant role in K+-sufficient plants. Overall, our results suggest that K+ uptake and translocation are tightly coordinated via signals that regulate the expression of K+ transport systems |
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