Regulation of adenosine 5′‐phosphosulfate sulfotransferase by sulfur dioxide in primary leaves of beans (Phaseolus vulgaris)

Abstract

AbstractSO2 inhibited the light‐induced increase of extractable adenosine 5′‐phosphosulfate sulfotransferase in greening primary leaves of bean seedlings (Phaseolus vulgaris L. cv. Saxa (Radio) Stamm Vatter). In green primary leaves containing appreciable extractable adenosine 5′‐phosphosulfate sulfotransferase activity, SO2 treatment for 20 h decreased the activity of the enzyme to between 10 and 20% of the initial level. After removal of SO2 from the air, the extractable adenosine 5′‐phosphosulfate sulfotransferase activity increased after a lag, both in green and greening primary leaves, and was back to the control level after about 48 h. The sulfate concentration was increased about fourfold during SO2 treatment. An increase in sulfate sulfur accompanied by a decrease in adenosine 5′‐phosphosulfate sulfotransferase was also observed when bean seedlings, after excision of the roots, were transferred to nutrient solutions containing high sulfate concentrations, suggesting that sulfate is involved in the regulation of the enzyme.