Stress-Induced Factor Involved in Flower Formation of Lemna is an α-Ketol Derivative of Linolenic Acid.

Yokoyama, Mineyuki; Yamaguchi, Shoko; Inomata, Shinji; Komatsu, Kazuo; Yoshida, Seiichi; Iida, Toshii; Yokokawa, Yoshihiro; Yamaguchi, Michihiro; Kaihara, Sumiko; Takimoto, Atsushi

A stress-induced substance(s) (factor C) incubated with norepinephrine (NE) has strong flower-inducing activity in Lemna paucicostata. We isolated an essential component (FIF) of factor C, and clarified its chemical structure as 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid, an α-ketol derivative of linolenic acid, which is formed via 9-hydroperoxy linolenic acid. Synthesized FIF showed flower-inducing activity after incubation with NE (factor C activity) equivalent to that formed in the stressed Lemna. Jasmonic acid and 13-hydroxy-12-oxo-9(Z),15(Z)-octadecadienoic acid (12,13-α-ketol linolenic acid), both of which are formed via 13-hydroperoxide of linolenic acid and all other derivatives of FIF synthesized by chemical and enzymatic processes failed to show the factor C activity. These results suggest that the molecular structure of FIF is very specific for the factor C activity.

LEMNA; LINOLENIC acids; NORADRENALINE; LINOLEIC acid; HYDROPEROXIDES; MOLECULAR structure; PLANT enzymes

Plant & Cell Physiology, 2000, Vol 41, Issue 1, p110

0032-0781

Academic Journal

10.1093/pcp/41.1.110