Photosynthetic acclimation to temperature is affected by night temperature in Zea mays

Abstract

In this study, Zea mays L. was grown in indoor controlled environment chambers with a uniform daytime temperature of 30°C, and night-time temperatures of 30, 25, 20, or 15°C. Responses of net photosynthesis (P _N) of mature leaves at high PPFD to intercellular CO₂ concentrations (C _i) were measured at 20, 25, and 30°C using a new method that generates a complete P _N vs. C _i curve in less than four minutes. Results indicated that photosynthesis measured at both C _i values of 25 and 150 μmol mol^-1 increased strongly with measurement temperature in plants grown with night temperatures of 25 and 30°C, but there was a much smaller change in photosynthesis with temperature in plants grown with night temperatures of 15 or 20°C. These results indicate that the acclimation of photosynthesis to temperature in this C₄ species is substantially affected by night temperature.

Keywords: C4 photosynthesis; CO2 response of photosynthesis; night temperature; temperature acclimation.