Han Bao (Walker lab)
Date & Location: October 8, 2019, at 12p; Room 168 Plant Biology Building
Subject: Catalase protects against non-enzymatic decarboxylations during photorespiration
Abstract: Photorespiration, a process accompanying and competing with photosynthesis in C3 plants, occurs when RuBisCO reacts with O2 instead of CO2. The oxygenation reaction of RuBisCO creates a product that cannot be used within the Calvin–Benson cycle. While photorespiration recycles this product to make a useful compound, considerable energy is consumed and around 25% of carbon fixed is lost as CO2 during this process. Photorespiration loses CO2 primarily from enzymatic decarboxylation of glycine. Elevated temperatures could reduce the efficiency of photorespiration by releasing additional CO2 which is likely from non-enzymatic decarboxylation reactions between glyoxylate or hydroxypyruvate and H2O2 generated in peroxisome. It has been suggested that catalase plays an important role in protecting plants against the non-enzymatic decarboxylation by decomposing H2O2. Revealing the important reactions affecting photorespiratory efficiency will help to improve crop productivity in the face of the growing global population and climate change challenges.
Speaker Lab: Dr. Berkley Walker