Mercurial inhibition of root hydraulic conductance in Vitis spp. rootstocks under water stress.

This work aims to quantify the contribution to whole-root water transport of the fraction controlled by cellular metabolism in grape rootstocks upon water stress. We used mercuric chloride as inhibitor of cell metabolism on genotypes obtained from hybridization of Vitis berlandieri with either Vitis rupestris or Vitis riparia, and we found that the fraction of root water transport under metabolic control is higher in former, which are known to be more resistant to water stress. In addition, as these rootstocks showed lower vessel embolization during water stress, we suggested a possible role of cellular metabolism on the control of root embolism.