Grant: Discovery Grants Program - Individual

Abscisic acid (ABA) and gibberellin (GA) are among the plant produced signaling compounds that influence a wide range of developmental processes at very low concentrations, usually described as "plant hormones". These two hormones act as major regulators of seed germination and dormancy, which is defined as the inability of intact viable seeds to germinate under favorable conditions, through their antagonistic action. Therefore, the balance between ABA and GA is a critical determinant of the ability of seeds to germinate, or to remain dormant; imbalance in favor of ABA promotes dormancy while imbalance in favor of GA induces germination. The ABA/GA balance in a seed is determined not only by the amounts of ABA and GA present in the seed but also by the seed's response to these two hormones. Seeds employ different strategies to modulate the balance between ABA and GA, and thereby maintain or lose their dormancy status, such as the crosstalk of ABA and GA with other plant hormones and deployment of regulatory elements that control the seed's levels of and/or response to ABA and GA. Several of these strategies have been identified in the seeds of dicot species, but understanding these phenomena in the seeds of cereals, particularly in wheat has been lagging. The overall goal of my research program is to understand how plant hormones regulate developmental processes in sufficient detail to enable genetic manipulation for enhancing the yield and quality of cereal crops. Within this context, the long term objective of the research proposed under this Discovery Grant cycle is to identify new strategies deployed by wheat seeds to regulate the balance between ABA and GA, and thereby control seed transition between dormancy and germination. The findings of the proposed research have the potential to advance our understanding of the molecular strategies operating in wheat seeds to modulate the production/inactivation of and sensitivity to ABA and GA, and thereby control their ability to germinate or remain dormant. Thus, the outcomes will provide new avenues to increase our knowledge of hormonal regulation of seed dormancy and germination. The findings of the research will also provide opportunities to develop novel molecular tools for improving the success of wheat seed germination and seedling establishment under diverse environmental conditions and the resistance of maturing wheat seeds to preharvest sprouting, a serious problem in the production of wheat, thus enhancing yield and quality. Furthermore, the proposed research will train 3 Ph.D., 2 M.Sc. and 5 undergraduate students with a wide range of skills highly valued in the area of plant biology, making the trainees well-positioned to succeed in their career goals while contributing to Canada's need for highly qualified plant biologists.