Characteristics of Potassium-Enriched, Flue-Cured Tobacco Genotype in Potassium Absorption, Accumulation, and In-Ward Potassium Currents of Root Cortex

This study was to investigate the main traits of potassium-enriched, flue-cured tobacco genotypes related to potassium absorption, accumulation, and in-ward potassium currents of the root cortex. Hydroponic methods, K+-depletion methods, and patch-clamp, whole-cell recordings were conducted to study the accumulation of dry matter and potassium in different organs, and to measure potassium absorption and dynamic and in-ward potassium currents in potassium-enriched, flue-cured tobacco genotypes. The average dry weights of leaves and whole plant of potassium-enriched, flue-cured tobacco genotype ND202 were 10.20, and 14.85 g, respectively, higher than JYH (8.50 and 13.11 g, respectively) and NC2326 (8.39 and 12.72 g, respectively), when potassium concentration in the solution ranged from 0.1 to 50 mmol L−1. Potassium accumulation in the leaves of ND202 was 18.6% higher than JYH and 34% higher than NC2326 when potassium concentration in the solution was superior to 0.5 mmol L−1. The Vmax (the maximum velocity) of ND202 was 118.11 μmol FW g−1 h−1, obviously higher than that of JYH (58.87 μmol FW g−1 h−1) and NC2326 (64.40 μmol FW g−1 h−1). In the in-ward potassium currents, the absolute value of current density (pA/pF) of ND202 was 60, higher than that of JYH (50) and NC2326 (40). Potassium concentration in leaves, Vmax, and in-ward potassium currents, could be used to screen potassium-enriched, flue-cured tobacco genotypes.