The effect of inorganic phosphate on the ethylene production in tomato and apple fruits

Tomato fruits on stems immersed in phosphate solution 0.2 M K₂HPO₄ produced less ethylene than control fruits on stems immersed in water. Phosphate mediated inhibition of ethylene production was found to be the highest in fruits in the pink stage of maturity, which produced ethylene at the highest rate. Phosphate also inhibited ethylene production in slices prepared from maturing fruits, both apple and tomato. We suggest that phosphate is an inhibitor of ethylene biosynthesis in sufficiently mature tomato and apple fruits in which the rise of ethylene production is already very rapid. Presented at the International Symposium “Plant Growth Regulators” held on June 18–22, 1984 at Liblice, Czechoslovakia.