Drought effects on root proteome in two grapevine rootstocks with different susceptibility

This work focused the attention on the changes induced by water stress (WS) in the root proteome, comparing the susceptible commercial rootstock 101.14 with the new tolerant genotype M4. The biological samples, consisting in lignified root organ of one-year-old plants grown in soil, posed technical challenges related to the paucity of biochemical active tissues as well as to the high content of phenolic substances. In order to overcome these aspects, we used SDS-PAGE combined with nLC-nESI-Q-TOF analyses. The MS/MS experiments were optimized to quantify and to compare the identified proteins and showed both high reproducibility and dynamic range, whit no limits for protein hydrophobicity and pI. The study allowed to quantify one-thousand proteins in each genotype, providing the first proteomic characterization of root organ in Vitis and showing as WS significantly affected the levels of about the 15% of the proteome. The main changes were especially linked to energy and redox metabolism, protein turn-over and (a)biotic stress responses, highlighting interesting differences between the two rootstocks. Acknowledgments: Work was supported by SERRES-AGER project (n°2010-2105).