Abstract
Samanea plants close their leaves in the evening, as if to sleep, and open them in the morning according to the circadian rhythm. Potassium β-D-glucopyranosyl-12-hydroxyjasmonate (1) was isolated as leaf-closing factor (LCF) of S. saman. We developed molecular probes consisting of modified LCF1 in order to identify its mode of action. We have already demonstrated that a specific binding protein is involved in the motor cell of S. saman. We synthesized natural-type photoaffinity probe and biologically inactive enantiomer-type probe. We utilized them for photoaffinity labeling of the target protein for LCF1. By using protoplasts of motor cell, we found membrane protein of 38kDa which strictly recognizes the stereochemistry of 1, and it is highly likely that the protein is the target protein for LCF 1. Recently, we observed that LCF shrank motor cell protoplasts prepared from S. saman. And comparing the results of several bioassay using glucosyl jasmonate-type LCF and jasmonic acid, it is also interesting that the mode of action of LCF is completely different with that of jasmonate.
