Inhibitory effect of lepidimoide on senescence in Avena leaf segments

The effect of lepidimoide (Na 2-O-rhamnopyranosyl-4-deoxy-α-L-threo-hex-4-enopyranosiduronate) and its free carboxylic acid (hereafter referred as lepidimoic acid), on senescence in oat (Arena sativa L. cv. Victory I) leaf segments in the dark was studied. Lepidimoic acid inhibited loss of total chlorophyll in excised oat leaf segments during the initial phase of senescence. The loss of total chlorophyll was also retarded in the presence of 10 μmol/L, kinetin. Lepidimoic acid preserved chlorophyll content synergistically with kinetin. Lepidimoide (Na salt) preserved chlorophyll content in the absence or presence of kinetin to a similar extent as did lepidimoic acid. These facts suggest that lepidimoide causes, especially in cooperation with cytokinin, a retardation of leaf senescence as characterized by the loss of total chlorophyll in the leaves.