AUTHOR=Zhang Linan , Sun Xiangyu , Li Yanfang , Luo Xuan , Song Shaowen , Chen Yan , Wang Xiaohui , Mao Dandan , Chen Liangbi , Luan Sheng TITLE=Rice Na+-Permeable Transporter OsHAK12 Mediates Shoots Na+ Exclusion in Response to Salt Stress JOURNAL=Frontiers in Plant Science VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.771746 DOI=10.3389/fpls.2021.771746 ISSN=1664-462X ABSTRACT=

Soil salinity has become a major stress factor that reduces crop productivity worldwide. Sodium (Na⁺) toxicity in a number of crop plants is tightly linked with shoot Na⁺ overaccumulation, thus Na⁺ exclusion from shoot is crucial for salt tolerance in crops. In this study, we identified a member of the high-affinity K⁺ transport family (HAK), OsHAK12, which mediates shoots Na⁺ exclusion in response to salt stress in rice. The Oshak12 mutants showed sensitivity to salt toxicity and accumulated more Na⁺ in the xylem sap, leading to excessive Na⁺ in the shoots and less Na⁺ in the roots. Unlike typical HAK family transporters that transport K⁺, OsHAK12 is a Na⁺-permeable plasma membrane transporter. In addition, OsHAK12 was strongly expressed in the root vascular tissues and induced by salt stress. These findings indicate that OsHAK12 mediates Na⁺ exclusion from shoot, possibly by retrieving Na⁺ from xylem vessel thereby reducing Na⁺ content in the shoots. These findings provide a unique function of a rice HAK family member and provide a potential target gene for improving salt tolerance of rice.