Event Title

Exploring RCA Heat Stress Acclimation Strategies in C4 Grasses

Session Number

Project ID: BIO 07

Advisor(s)

Dr. Sarah Stainbrook, Washington University in St. Louis

Discipline

Biology

Start Date

20-4-2022 11:25 AM

End Date

20-4-2022 11:50 AM

Abstract

As global temperatures continue to rise, food security has become an increasingly relevant problem growing out of maintaining crop yield under adverse environments, and one approach is to improve photosynthesis activity in plants. Photosynthesis in many plant species is limited when ambient temperatures increase past their optimal range. As a result, our research aims to explore and improve the performance of Rubisco activase (RCA), a key enzymein photosynthesis. We investigate the effectiveness of different heat stress acclimation strategies across three C4 grasses, namely Zea mays, Sorghum bicolor, and Setaria viridis, where regulation could potentially mitigate some of the decrease in RCA’s ATPase activity due to denaturation. Each purified plant sample has a multitude of incubation periods: 0hr, 1hr, 6hr, and 48hr. Using a molybdate arsenite assay, we measure both the effect of different Mg2+ ion concentrations on RCA performance and the correlation between ADP-to-ATP ratios and RCA activity. Lastly, we measure the effect of different preincubation temperatures on RCA activity using an NADH-linked assay. Our progress with all three protocols currently indicate strong correlation to expected results and regulatory effects.

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Apr 20th, 11:25 AM Apr 20th, 11:50 AM

Exploring RCA Heat Stress Acclimation Strategies in C4 Grasses

As global temperatures continue to rise, food security has become an increasingly relevant problem growing out of maintaining crop yield under adverse environments, and one approach is to improve photosynthesis activity in plants. Photosynthesis in many plant species is limited when ambient temperatures increase past their optimal range. As a result, our research aims to explore and improve the performance of Rubisco activase (RCA), a key enzymein photosynthesis. We investigate the effectiveness of different heat stress acclimation strategies across three C4 grasses, namely Zea mays, Sorghum bicolor, and Setaria viridis, where regulation could potentially mitigate some of the decrease in RCA’s ATPase activity due to denaturation. Each purified plant sample has a multitude of incubation periods: 0hr, 1hr, 6hr, and 48hr. Using a molybdate arsenite assay, we measure both the effect of different Mg2+ ion concentrations on RCA performance and the correlation between ADP-to-ATP ratios and RCA activity. Lastly, we measure the effect of different preincubation temperatures on RCA activity using an NADH-linked assay. Our progress with all three protocols currently indicate strong correlation to expected results and regulatory effects.