Poster: Reproductive development

Abs # 362: COI1, an F-box protein involved in jasmonic acid perception, is required for gametophyte viability and embryo development in Lycopersicon esculentum

Presenter:	McCaig, Bonnie C., mccaig@msu.edu
Authors	McCaig, Bonnie C. (A)   Sage, Tammy L. (B)   Wasternack, Claus  (C)   Howe, Gregg A. (A)
Affiliations:	(A): D.O.E.-Plant Research Laboratory, Michigan State University (B): Department of Botany, University of Toronto (C): Department of Natural Product Biotechnology, Institute for Plant Biochemistry
Web Site:	http://www.prl.msu.edu/howe.shtml

The jasmonic acid insensitive1 (jai1-1) mutant of tomato is defective in jasmonate perception as a result of loss of function of COI1, an F-box protein involved in the ubiquitin pathway. In addition to lacking resistance to certain herbivores, jai1-1 plants display an array of developmental abnormalities including reduced glandular trichome density on leaves, absence of trichomes on green fruit, reduced pollen viability and seedlessness. Though previous work has shown that JA is involved in a range of developmental processes, analysis of jai1-1 demonstrates for the first time that COI1 and the jasmonate response pathway are also associated with female reproduction in plants. In this study, we investigated the role of COI1 in tomato flower development and seed production. Histological and embryo rescue techniques were used ascertain the stage at which female reproduction is blocked by jai1-1. We also used cDNA subtraction techniques and in situ hybridization to identify and characterize genes that are differentially regulated by COI1 in flowers. Among the genes identified were those encoding vegetative storage proteins, proteinase inhibitors, cell wall-associated proteins, and enzymes involved in various aspects of primary and secondary metabolism. Our results are consistent with the idea that COI1 controls ovule and seed development in tomato by regulating one or more JA-dependent processes involved in nutrient allocation to the embryo.