Occurrence of Lepidimoide-like Substance in Growing Plant Tissues and its Physiological Activity in Arabidopsis thaliana

Abstract

Lepidimoide, which was first identified as an allelopathic substance, was roughly confirmed to be included in growing tissues (rosette leaves, stems+inflorescences and roots) of Arabidopsis thaliana by means of HPLC analysis. Peaks of retention time in HPLC of the lepidimoide fractions extracted from the above organs completely coincided with that of authentic lepidimoide.
The lepidimoide-like substance, which was contained in the fraction below MW 3000 in the molecular exclusion chromatography, promoted hypocotyl growth and inhibited root growth of cockscomb (Celosia cristata). The substance also promoted the growth of hypocotyls and cotyledon-petioles, increased the area of cotyledons, but inhibited the root growth of A. thaliana seedlings. These facts suggest that the lepidimoide-like substance may play some role as an endogenous plant growth regulator in growing plants of A thaliana.