OsKAT1 is a short Shaker potassium channel involved in root-to-shoot potassium translocation and contributes to rice grain yield
Abstract
Shaker potassium channels play essential roles in K + uptake and distribution in plants. Studies on Shaker channels in Arabidopsis have provided a paradigmatic framework, but the rice genome encodes an additional member, OsKAT1, whose function remians poorly defined. OsKAT1-type channels are characterized by an innately short cytosolic C terminus, forming a unique clade of monocot-specific short Shakers that is prevalent in Poaceae species. In rice, OsKAT1 is predominantly expressed in the root stele. Disruption of OsKAT1 (KO mutation) leads to a significant reduction in K + secretion into the xylem sap delivered to the shoot. Patch-clamp experiments on root stele protoplasts of WT and KO plants indicate that OsKAT1 functions as an inward channel. Functional analyses in Xenopus oocytes reveal that despite activating at weakly negative voltages, OsKAT1 is intrinsically incapable of mediating substantial outward currents—a property attributed to its truncated C terminus. Together with outward K + channel activity, this feature enables stelar cells to remain significantly permeable to K + around the K + equilibrium potential. When expressed in Arabidopsis , OsKAT1 contributes to K + transport in the xylem sap, but only in wild-type plants that express SKOR, a Shaker channel specialized for this role. These results demonstrate that OsKAT1 constitutes a component of K + translocation to shoots and shed light on the energization and regulation underlying this function. Moreover, OsKAT1 is shown to improve rice adaptation to environmental conditions and enhance grain yield under field conditions through its facilitating root-to-shoot ion translocation.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (18)
Shunying Yang
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences
Thanh-Hao Nguyen
Institute for Plant Sciences of Montpellier, University of Montpellier, Centre National de la Recherche Scientifique (Unité Mixte de Recherche 5004), Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (Unité Mixte de Recherche 386), Institut Agro
Cécile Fizames
Institute for Plant Sciences of Montpellier, University of Montpellier, Centre National de la Recherche Scientifique (Unité Mixte de Recherche 5004), Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (Unité Mixte de Recherche 386), Institut Agro
Junlin Li
Shandong Institute of Sericulture
Sheliang Wang
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University
Aurore Vernet
FranceCentre de coopération internationale en recherche agronomique pour le développement (CIRAD), Unité Mixte de Recherche Amélioration Génétique et Adaptation des Plantes Méditerranéennes et Tropicales Institut
Emmanuel Guiderdoni
FranceCentre de coopération internationale en recherche agronomique pour le développement (CIRAD), Unité Mixte de Recherche Amélioration Génétique et Adaptation des Plantes Méditerranéennes et Tropicales Institut
Shaofei Wang
Yixiu Guo
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences
Weiwei Zhang
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Key Laboratory for Advanced Materials, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering
Tianqi Wei
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences
Yanan Huang
Westlake University , , 600 Dunyu Road , ,
Dongli Hao
Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen)
Jiajin Wang
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences
Hervé Sentenac
Institute for Plant Sciences of Montpellier, University of Montpellier, Centre National de la Recherche Scientifique (Unité Mixte de Recherche 5004), Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (Unité Mixte de Recherche 386), Institut Agro
Anne-Aliénor Véry
Institute for Plant Sciences of Montpellier, University of Montpellier, Centre National de la Recherche Scientifique (Unité Mixte de Recherche 5004), Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (Unité Mixte de Recherche 386), Institut Agro
Ren Fang Shen
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences
Yanhua Su
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences