Synthesis and degradation of a 28-kDa pod storage protein in French bean (Phaseolus vulgaris) plants

Pod storage protein (PSP) accumulated in developing pods of French bean (Ph aseolus vulgaris L.) plants, and increasing the PSP mRNA level by pod remov al resulted in the enhancement of PSP accumulation in pods that formed late r. Pod storage protein tvas detected in flowers, young leaves and young ste m internodes in addition to pods. Accumulation of PSP and its mRNA was indu ced by sink-removal in an organ-specific manner. In addition, wounding indu ced PSP accumulation systemically in leaves. Methyl jasmonate did not induc e PSP synthesis but enhanced the synthesis that was induced by wounding. In senescing pods, PSP was degraded, and degradation products with molecular masses of 20 and 17 kDa were detected in the pods. The amount of 20-kDa deg radation product was greater than that of the 17 kDa product.