Abstract
In higher plant, brassinosteroid had been identified as phytosteroid hormones, and these biolosical functions for plant growth have been clarified. Recently, we identified progesterone from Arabidopsis, rice, and pea, suggesting that progesterone is a ubiquitous constituent of plants. Progesterone is an animal steroid hormone that functions as a corpus luteum hormone which maintains pregnancy and implantation of fertilized egg. Furthermore, progesterone is the precursor of teststerone and estradiol, which are sex steroidal hormone in vertebrates. We have not known the role and importance of progesterone for plant yet.
To clarify the biological function of progesterone in plants, Arabidopsis was germinated and grown in the presence or absence of progesterone under the various light conditions. Arabidopsis hypocotyl and petiole showed trends in elongation in some conditions. These functions might be similar to brassinolide functions. Analysis of possible function of progesterone for another plant organ is in progress.
