EFFECT OF SINK MANIPULATION ON NITROGEN ACCUMULATION AND DISTRIBUTION AMONG ORGANS OF GRAMINEAE AND LEGUMINOSAE

Accumulation and distribution of dry matter and nitrogen were examined by the sink cut treatment. The results obtained were as follows. 1) In Gramineae except for maize, the amount of nitrogen in leaves decreased and nitrogen was translocated to stems regardless of the sink cut treatment, whereas the amount increased by the sink cut treatment in Leguminosae. Thus, it is assumed that leaf growth was autonomous in Gramineae, but was affected be the sink activity in Leguminosae. 2) By the sink cut treatment, no specific protein bands were detected in leaves of both Gramineae and Leguminosae, as well as in stems of Gramineae. The vegetative storage proteins (VSP) were detected in stems of soybean and field bean, and its amount increased by the sink cut treatment. However, as the amount of soluble protein fraction in the stems of soybean and field bean was not affected by the sink cut treatment, the effect of VSP on nitrogen storage was negligible even when the sink was cut.