Recent Advances in Genome-wide Analyses of Plant Potassium Transporter Families

Plants require potassium (K(+)) as a macronutrient to support numerous physiological processes. Understanding how this nutrient is transported, stored, and utilized within plants is crucial for breeding crops with high K(+) use efficiency. As K(+) is not metabolized, cross-membrane transport becomes a rate-limiting step for efficient distribution and utilization in plants. Several K(+) transporter families, such as KUP/HAK/KT and KEA transporters and Shaker-like and TPK channels, play dominant roles in plant K(+) transport processes. In this review, we provide a comprehensive contemporary overview of our knowledge about these K(+) transporter families in angiosperms, with a major focus on the genome-wide identification of K(+) transporter families, subcellular localization, spatial expression, function and regulation. We also expanded the genome-wide search for the K(+) transporter genes and examined their tissue-specific expression in Camelina sativa, a polyploid oil-seed crop with a potential to adapt to marginal lands for biofuel purposes and contribution to sustainable agriculture. In addition, we present new insights and emphasis on the study of K(+) transporters in polyploids in an effort to generate crops with high K(+) Utilization Efficiency (KUE).