Effects of irreadiance-sulphur interactions on enzymes of carbon, nitrogen, and sulphur metabolism in maize plants

The effect of sulphur deprivation and irradiance (180 and 750 micromol/m/s) on plant growth and enzyme activities of carbon, nitrogen, and sulphur metabolism were studied in maize (Zea mays) plants over a 15-d-period of growth. Increase in irradiance resulted in an enhancement of several enzyme activities and generally accelerated the development of S deficiency. ATP sulphurylase and o-acetylserine sulphydrylase showed a particular and different pattern as both enzymes exhibited maximum activity after 10 days from the beginning of deprivation period. Hence in maize leaves the enzymes of C, N, and S metabolism were differently regulated during the leaf development by irradiance and sulphur starvation.