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

Abstract

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