Studies on pigeon pea sterility mosaic disease. IX. Effect on nitrogen metabolism

Abstract

Diseased pigeon pea leaves at all ages had a higher level of total nitrogen than comparable healthy leaves. While increased levels of nitrate nitrogen, nitrite nitrogen, amide nitrogen and protein nitrogen were observed in diseased leaves, ammoniacal nitrogen and non-protein nitrogen recorded a fall in diseased leaves. The levels of both free and bound amino-acids increased in diseased leaves at all ages. A high concentration of free amino-acids like valine, leucine and arginine was observed in young diseased leaves. These were in lower concentration in older diseased leaves. Their probable incorporation into the virus protein is suggested by the finding of a high level of these amino-acids in the bound form in diseased leaves.