Effect of Manganese Deficiency on Chloroplasts of Lemon Leaves

Manganese deficiency in chloroplasts of Eureka lemon leaves resulted in 23% and 40% increase of chloroplast nitrogen and protein, respectively, on a chlorophyll unit basis. Acrylamide gel electrophoresis carried out on extracts of these chloroplasts disclosed also qualitative differences between the normal and deficient leaves. Calculated on chloroplast N basis there is an increase of 17% in the chloroplast protein under Mn deficiency. This increase apparently indicates a more intense protein synthesis in the Mn deficient chloroplasts. Hill activity of the –Mn leaves was about one-third of the analog control leaves. Manganese infiltration into detached but intact leaves restored the activity in the –Mn leaves up to 70% of the control. Lemon leaves affected by other macro- and micro- nutrient deficiencies did not respond to the manganese infiltration; therefore, the use of this infiltration method is suggested for the evaluation of the manganese nutrition status of citrus and probably other higher plants.