Effects Of Potassium On Physiological Characteristics And Expression Of Potassium Transporters KUP6 And KUP7 In Potato Seedlings

Potassium is an essential element for plant growth,which can improve the cold tolerance and drought tolerance of plants.Potato is the fourth largest food crop in the world and is a potassium plant.Therefore,studying the physiological mechanism of potassium absorption by potato has positive significance for improving its yield and rational use of resources.Using potato Favorita tissue culture seedlings as experimental materials,five potassium leves were set by hydroponic experiments to study the impact of growth potential,photosynthetic metabolism,membrane permeability and protective enzyme system,osmotic adjustment substance,potassium content and potassium transporter KUP6 and KUP7 gene expression of potato seedlings with different potassium concentrations.The experiments indicate that:At each stage of hydroponic culture,potato seedlings grew best at the potassium concentration of 5 mmol/L,and had an adverse effect on the growth of potato seedlings when the potassium concentration was too high or too low.When the potassium concentration was 5 mmol/L,the net photosynthetic rate and stomatal conductance were both maximum,which was beneficial to the photosynthesis of potato.When the potassium concentration was too high or too low,the transpiration rate of potato seedling leaves was low.The treatment of different potassium concentrations had little effect on the intercellular CO2 concentration in the leaves of potato seedlings.With the increase of potassium concentration,the contents of MDA,soluble sugar,SOD and proline in potato seedlings decreased first and then increased,and the minimum value was obtained at 5 mmol/L potassium concentration.Potassium concentration of 5 mmol/L was most suitable for potassium accumulation in roots and leaves of potato seedlings,while potassium transporter KUP6 and KUP7 genes were highest at 1 mmol/L potassium concentration.