Accumulation of agmatine in chayote (Sechium edule) leaves during development

Arginine, agmatine, putrescine and spermidine were found in the apical parts and leaves of chayote ( Sechium edule Swartz ) at various stages of development. The concentration of agmatine, the immediate decarboxylation product of L-arginine, increased considerably in young leaves at the first emergence of floral buds. Young leaves always had a relatively higher content of agmatine than older ones. There was a decrease in the concentration of agmatine from the apical part to the basal leaves. Agmatine was the predominant amine in young leaves at every stage of development (50–90% of the whole amine pool). It was also predominant in mature leaves when the floral buds appeared (70% of the total amine content). An accumulation of agmatine could not be found in other Cucurbitaceae species.     

Fatty acids in callus cultures: Stage of reversal in the proportion of unsaturated to saturated acids and of change in major components

The lipids of the cotyledon of Cucumis melo contain a large proportion of unsaturated fatty acids with linoleic acid as the major component, whereas those of cotyledon callus show a marked reduction in linoleic acid, an increase in linolenic acid and a predominance of palmitic acid which results in an increase in total saturated acids. The fatty acid compositions of total lipids in the cotyledons at different stages of seedling development, excised cotyledon tissue at different stages of callus initiation and in isolated callus show that the observed changes manifested in the established callus occur in the newly formed meristimatic cells as a result of the action of growth substances used for callus initiation.