Poster: Hormone synthesis & metabolism

Abs # 469: Reactive oxygen species (ROS) mediate the IAA-induced ethylene production.

Presenter:	Lee, June Seung , jslee@mm.ewha.ac.kr
Authors	Lee, June Seung  (A) (B)  Song, Yoon Jung  (B)   Joo, Jung Hee  (A)   Cho, Hyung Jung  (B)   Bae, Yun Soo  (A)   Nam, Kyoung Hee  (A) (B)
Affiliations:	(A): Center for Cell Signaling Reserch,Department of Biological sciences,EWHA Womans University (B): Department of Life sciences, EWHA Womans University
Web Site:	http://jslee@mm.ewha.ac.kr

It is well known that auxin induces the ethylene production through the activation of ethylene biosynthetic enzyme, ACC synthase. Recently we reported ROS generation is also increased by auxin treatment in maize roots. As the ROS has been considered as a seconding signaling molecule at low concentration, we investigated whether ROS is involved in the ethylene production in presence of auxin in mungbean hypocotyls. While treatment of ethylene biosynthetic inhibitor, AVG, had little effect on the ROS generation induced by auxin, ethylene production was reduced with the treatment of NAC, ROS scavenger, in a dose dependent manner. This indicates ROS can act in upstream to promote the ethylene production. To persue this, we measured the ethylene production. Indeed, H2O2-treated mungbean hypocotyls showed higher ethylene accumulation compared with that of untreated samples, resulting from the activation of biosynthetic gene expressions for ACC synthase (ACS1,ACS7) and ACC oxidase (ACO1,ACO2).