Effect of potassium nutrition on leaf protein concentrations and growth of young tomato plants

Abstract

The effect of potassium nutrition on the protein, total nitrogen and phosphorus concentrations in tomato leaves was studied in relation to plant growth. The concentration of protein in shoot apices significantly increased as a result of decreasing the supply of potassium to the plants. Compared to the potassium-sufficient plants, the expanding leaves of potassium-deficient plants exhibited up to 130 per cent increase in protein concentration while the amount of protein per leaf was much reduced (up to 25-fold reduction). In conditions of both potassium deficiency and excess, the concentration of total nitrogen in the laminae of expanding leaves increased. The phosphorus concentration and also the activity of a phosphatase increased in expanding leaf tissue with potassium deficiency.