“The Effects of Heat Stress on Stigmatic Receptivity in Arabidopsis thaliana”

The purpose of Dr. Erica Kipp and my research project is to study the effects of heat stress on plants, specifically Arabidopsis thaliana.  Environmental and ecological changes due to temperature increases, such as those associated with global climate change, have been well documented, sparking research in quantifying plant responses to heat stress.  Current research suggests that temperature changes can be associated with altered morphology, decreased crop production and lower fecundity for many species.  This can have far-reaching effects on economically valuable ornamental and agricultural plants.   Literature shows that the stigma of optimally grown (23°C) Arabidopsis thaliana, a commonly used “lab rat,” is receptive to pollen during a very narrow window of time.  Stigma receptivity (to pollen) is associated with the presence of stigmatic enzymes: peroxidase, esterase, and alcohol dehydrogenase, in particular.

In order to test how heat stress can affect stigmatic receptivity, and thus reproductive success of the plant, we would like to test for the presence of these enzymes during flowering and compare heat stressed plants with optimally grown plants.  How does heat affect these enzymes in terms of presence and concentrations?  Is the window of receptivity altered?  Are there any morphological changes to the stigma as a result of heat stress?  And if so, can the morphological changes be associated with enzyme changes?

Many labs currently approach quantifying heat stress with what has become known as “cook and look,” a research approach where plants are heated to 45 degrees Celsius or more during a specific developmental phase.  In this research project, plants will be heat stressed at 29 degrees Celsius, not much higher than optimum temperature, and for the life of the plant, not just during one stage.  Also we will be coordinating 12/12 hr days, meaning 12 hours of day and 12 hours of night.  This is more in line with actual field conditions and thus more applicable to what is likely to happen in the face of global warming. Thus far, Dr. Kipp and I are still in the premature stages of our research, and have been working on developing protocols for harvesting seeds from optimally grown Arabidopsis plants encorporating seed collection, sterilization, and storage.

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