Enhancement in wheat leaf photophosphorylation and photosynthesis by spraying low concentration of NaHSO3

Spraying 1—2 mmol/L NaHSO₃ on the leaf of wheat results in enhancement of photosynthesis in leaves for about 3 d. The amount of ATP has been increased and the millisecond delayed light emission of the leaves has been enhanced, showing that the transmembrane proton motive force related to photophosphorylation is increased. Spraying PMS (a cofactor catalyzing cycle photophosphorylation) and NaHSO₃ separately or together on the leaves, 20% increase in photosynthesis has been observed in all the treatments. There is no additive effect when a mixture is applied, suggesting that the mechanism for NaHSO₃ promotion of photosynthesis is similar to PMS, and both of them enhance the supply of ATP.