Molecular genetics of hormone signaling

点击翻译按钮获取中文摘要

My main research interests are concerned with how hormones regulate developmental responses in higher plants. Through NSERC Discovery Grant funding I have focused the efforts of my laboratory on the roles of a number of hormones including ethylene, gibberellins (GA) and in particular abscisic acid (ABA). However, recently with the advent of chemical genetics we now believe new insights can be gained on how small organic molecules regulate plant growth and development that were not possible using traditional molecular genetics approaches. To this end, we have established a chemical genetics program to dissect germination in Arabidopsis seeds. Using genotypic specific screens, we have identified a collection of chemicals that have similar properties to a group of compounds called strigolactones. Strigolactones were first identified as seed germination stimulants of parasitic weeds. Parasitic weeds are considered the most damaging agricultural agents in the developing world. In Africa alone, Striga species have infested up to two-thirds of the arable land and cause huge losses in crop yields. Parasitic plant seeds are highly dormant and only germinate when they sense strigolactones that are released by the host root. After this point, the root of the germinating seedling penetrates the host and develops a parasitic interaction with the host. Using our model system we have been able to show there is a close relationship between strigolactone action, ABA/GA signaling and light signaling in Arabidopsis. We will use a combination of chemical, genetics and molecular approaches to further understand these relationships. The identification of strigolactones using a a combined approach of chemical genetics with Arabidopsis genetics demonstrates the power of this new technology to identifying new molecules involved in plant growth. With funding from the NSERC Discovery Grants program we will have an opportunity for the first time to understand the molecular underpinnings of strigolactones in host-parasite interactions.