Fitting photosynthetic carbon dioxide and irradiance response curves for C4 leaves.

Updated C4 photosynthesis model and fitting routines enable precise estimation of key biochemical and physiological parameters from gas exchange data.

• Why it matters: Understanding C4 photosynthesis responses is essential for improving crop efficiency and modeling plant productivity, but existing models often lack accurate parameterization of C4-specific processes.
• What they did: Researchers refined the C4 model by incorporating experimentally derived cyclic electron flow values from Setaria viridis and developed two Excel-based fitting routines to analyze CO2 and irradiance response curves, estimating parameters like Vpmax, Vcmax, Jmax, Rd, and quantum yield.
• The result: These tools facilitate accessible, accurate parameter estimation at measurement and standard temperatures, supporting broader application in C4 plant research and crop improvement efforts.