Photosynthetic acclimation to high temperature in Syrah and Grenache

Abstract

The main objective of this study was to evaluate (i) the mechanisms underlying the long-term acclimation of photosynthesis to elevated temperature and (ii) to determine whether these responses are similar among Syrah and Grenache, two varieties with different behavior in response to environmental factors (Schultz 2003). In our experiment, we imposed an increase in growth temperature (Tgrowth) between 1.5 and 3.6 °C in field-grown plants during the whole season. We compared the thermal acclimation in terms of optimum temperature for photosynthesis (Topt), the photosynthetic rate at Topt (Aopt) and the temperature dependencies of photosynthetic capacity (Vcmax, Jmax), at each growing temperature during two consecutive seasons.