Cell wall components regulate photosynthesis and leaf water relations of Vitis vinifera cv. Grenache acclimated to contrasting environmental conditions.

Environmental conditions determine plants performance as they shape - among other key factors - leaf features and physiology. However, little is known regarding to the changes occurring in leaf cell wall composition during the acclimation to an environmental stress and, specially, if these changes have an impact on other leaf physiology aspects. In order to induce changes in photosynthesis, leaf water relations and cell wall main components (i.e., cellulose, hemicelluloses and pectins) and see how they co-vary, Vitis vinifera cv. Grenache was tested under four different conditions: (i) non-stress conditions (i.e., control, with high summer temperature and irradiance), (ii) growth chamber conditions, (iii) growth chamber under water stress and (iv) cold growth chamber. Plants developed in growth chambers decreased net CO2 assimilation (AN) and mesophyll conductance (gm) compared to control. Although cold did not change the bulk modulus of elasticity (ε), it decreased in growth chamber conditions and water stress. Control treatment showed the highest values for photosynthetic parameters and ε as well as for leaf structural traits such as leaf mass area (LMA) and leaf density (LD). Whereas cellulose content correlated with photosynthetic parameters, particularly AN and gm, pectins and the amount of alcohol insoluble residue (AIR) - an approximation of the isolated cell wall fraction - correlated with leaf water parameters, specifically, ε. Although preliminary, our results suggest that cell wall modifications due to environmental acclimations can play a significant role in leaf physiology by affecting distinctly photosynthesis and water relations in a manner that might depend on environmental conditions.