Some Effects of 1-Amino-2-Nitrocyclopentane-1-Carboxylic Acid on Flowering Plants

A study has been made of the effects on higher plants of i-amino-2-nitrocyclo-pentane-1-carboxylicacid (ANPCA), a metabolite of Aspergillus wentii Wehmer. ANPCAwas rapidly translocated to young tissues when injected intothe stems of pea seedlings, but when applied to the roots ofvery young seedlings only trace amounts entered the plants.In intact plants ANPCA produced loss of apical dominance andshorter internodes but was without effect on isolated stem orleaf sections. There was some reduction of cell extension inthe internodes of intact pea seedlings, but the main effectwas on cell numbers. ANPCA inhibited mitosis in root tips andapical buds, the degree of inhibition varying with the species.There appeared to be a block in the mitotic cycle between theend of DNA synthesis and prophase. Inhibition caused by ANPCAcould be reversed by L-leucine. Chlorophyll synthesis was inhibitedby ANPCA in newly formed tissue and in etiolated leaves transferredto the light. There was a considerable increase in the freeamino-acid pool and a decrease in gibberellin content due totreatment with ANPCA. It is suggested that the primary effectof ANPCA may be on protein or RNA synthesis.