Postgraduate Profiles

Rachel Shingaki-Wells

Rachel Shingaki-Wells profile photo

Thesis: On the responses of rice and wheat seedlings to anoxia and re-oxygenation.

I am interested in the impact of anoxia and re-oxygenation on rice and wheat seedlings at the proteomic, metabolomic and physiological level. Oxygen deprivation is a debilitating stress that results in blockage of the mitochondrial electron transport chain. As a result, ATP synthesis is reduced and an energy crisis results. Despite this, anoxia-tolerant rice plants are able to synthesise proteins that improve their chances of survival. In contrast, anoxia-intolerant wheat appears to have a subtle response to anoxia, with few proteome changes observed.

Amino acid metabolism appears to play an important role during anoxia. When deprived of oxygen, rice seedlings rapidly accumulate a variety of amino acids as well as the proteins that synthesise them. Wheat does not accumulate these amino acids and thus shows improved cell integrity upon amino acid supplementation.

The next step of this research involves understanding differences between these plants in their responses to post-anoxia, as re-oxygenation poses an oxidative stress itself.

Why my research is important

1. To identify genes important for tolerance to anoxia and re-aeration. This could be important in defining new approaches to plant breeding.

2. To identify successful tolerance mechanisms by comparing tolerant and intolerant plants (rice and wheat, respectively).

3. Re-oxygenation stress is a relatively unexplored topic in plant research. Its major consequences involve the re-activation of oxidative phosphorylation (enabling efficient production of ATP) and reactive oxygen species production. I intend to gain insight into how plants re-arrange their metabolism, with particular interest in proteomics and amino acid production, upon re-exposure to oxygen.


May 2010

May 2013