Comparative Proteomics Unravels the Differences in Salt Stress Response of Own-Rooted and 110R-Grafted Thompson Seedless Grapevines

Thompson Seedless, a commonly grown table grape variety,
is sensitive
to salinity when grown on its own roots, and therefore, it is frequently
grafted onto salinity-tolerant wild grapevine rootstocks. Rising soil
salinity is a growing concern in irrigated agricultural systems. The
accumulation of salts near the root zone severely hampers plant growth,
leading to a decrease in the productive lifespan of grapevine and
causing heavy yield losses to the farmer. In the present study, we
investigated the differences in response to salinity between own-rooted
Thompson Seedless (TSOR) and 110R-grafted Thompson Seedless (TS110R)
grapevines, wherein 110R is reported to be a salt-tolerant rootstock.
The grapevines were subjected to salt stress by treating them with
a 150 mM NaCl solution. The stress-induced changes in protein abundance
were investigated using a label-free shotgun proteomics approach at
three time-points viz. 6 h, 48 h, and 7 days of salt treatment. A
total of 2793 proteins were identified, of which 246 were differentially
abundant at various time-points in TSOR and TS110R vines. The abundance
of proteins involved in several biological processes such as photosynthesis,
amino acid metabolism, translation, chlorophyll biosynthesis, and
generation of precursor metabolites was significantly affected by
salt stress in both the vines but at different stages of stress. The
results revealed that TSOR vines responded fervently to salt stress,
while TS110R vines adopted a preventive approach. The findings of
this study add to the knowledge of salinity response in woody and
grafted plants and hence open the scope for further studies on salt
stress-specific differences induced by grafting.