| Abstract: | Excised leaves from one-month old rice seedlings grown in potassiumdeficient nutrient solution were fed with acetate-l-14C for20 to 180 min. Rate of respiration of those leaves was significantlyhigher than that of control leaves supplied with sufficientpotassium. Incorporation of UC into organic acid and sugar fractionswere greater in potassium deficient leaves than in normal leaves.The reverse was true as for the incorporation into amino acidfraction. In comparison with normal leaves, potassium deficientleaves acquired much 14C in succinic acid and glutamine. Therewere distinct differences in the labeling pattern of citrateand in the order of magnitude of specific activities among theorganic acids included in the TCA cycle. From these results,it was assumed that the increase of respiratory rate causedby the potassium deficiency was related to accelerated operationof the TCA cycle. The decreased rate of conversion of organicacids to amino acids and the accumulation of glutamine werealso concluded. (Received April 13, 1967; ) |
