Root Proteomic Analysis of Two Grapevine Rootstock Genotypes Showing Different Susceptibility to Salt Stress

Abstract

Salinity represents a very limiting factor that affects the fertility of agricultural soils. Although grapevine is moderately susceptible to salinity, both natural causes and agricultural practices could worsen the impact of this abiotic stress. A promising possibility to reduce this problem in vineyards is the use of appropriate graft combinations. The responses of grapevine rootstocks to this abiotic stress at the root level still remain poorly investigated. In order to obtain further information on the multifaceted responses induced by salt stress at the biochemical level, in the present work we analyzed the changes that occurred under control and salt conditions in the root proteomes of two grapevine rootstock genotypes, M4 and 101.14. Moreover, we compared the results considering that M4 and 101.14 were previously described to have lower and higher susceptibility to salt stress, respectively. This study highlighted the greater capability of M4 to maintain and adapt energy metabolism (i.e., synthesis of ATP and NAD(P)H) and to sustain the activation of salt-protective mechanisms (i.e., Na sequestration into the vacuole and synthesis of osmoprotectant compounds). Comparitively, in 101.14 the energy metabolism was deeply affected and there was an evident induction of the enzymatic antioxidant system that occurred, pointing to a metabolic scenario typical of a suffering tissue. Overall, this study describes for the first time in grapevine roots some of the more crucial events that characterize positive (M4) or negative (101.14) responses evoked by salt stress conditions.

Grapevine salt tolerance

“…Membrane‐localised pyrophosphatase, such as the cation stimulated tonoplast V‐PPase (Walker and Leigh 1981a, Rea and Poole 1993) and the predominantly anion stimulated tonoplast V‐ATPase (Walker and Leigh 1981b), may also have roles in maintaining intracellular ion gradients between the cytoplasm and vacuole. In grapevine, the possible roles of H + ‐ATPases and VPPase in salt tolerance have not yet been clarified, although proteomic analysis on the rootstock M4 may support a possible function of grapevine ATPases in Na + vacuolar internalisation (Prinsi et al 2020).…”

“…An analysis of M4 under saline irrigation showed an increase of proteins related to carbohydrate catabolism and an increased activity of ATP and coenzyme biosynthesis pathways (Prinsi et al 2020), potentially indicating a metabolic shift to supply the energy needed for the salt stress responses, while being restricted by photoinhibition (Munns et al 2020). The M4 rootstock has also been shown to display a higher amount of enzymes related to ROS scavenging and secondary metabolism, which may relate to increases in antioxidative activity (Prinsi et al 2020). No apparent increase in ion transport proteins was observed, however, which may relate to the higher leaf ion accumulation that has been observed for the M4 variety previously (Meggio et al 2014).…”

Challenges of viticulture adaptation to global change: tackling the issue from the roots

“…In a subsequent study, Henderson et al (2018), successfully mapped a QTL that controls Na + exclusion in rootstocks and identified the causal gene ( VisHTK1;1 ) underlying that trait; these findings may assist with breeding Na + tolerant grapevine rootstocks. Recently, Prinsi et al (2020) characterised the root‐level response to salt stress of two grapevine rootstocks (M4 and 101‐14), indicating that M4 had a greater capability to maintain and adapt energy metabolism and to sustain the activation of salt‐protective mechanisms, while, in 101‐14, the energy metabolism was deeply affected and an evident induction of the enzymatic antioxidant system occurred. Overall, the information provided by this group of studies constitutes the basis for further research on the performance of different graft combinations against salt stress.…”

“…Therefore, the selection of new rootstocks could be an interesting solution to overcome some of the risks associated with salinity, such as preventing excess of Cl − and Na + in leaves and bunches, and the subsequent negative effect on yield and fruit composition, and should rely on the research efforts mentioned in this section (Gong et al 2014, Henderson et al 2018, Prinsi et al 2020), despite these being restricted to only three genotypes. In this context, a recent survey (Heinitz et al 2020) identified promising Cl − ‐excluding accessions within a collection of Vitis species native to south‐western USA and northern Mexico.…”

Biochemical and Proteomic Changes in the Roots of M4 Grapevine Rootstock in Response to Nitrate Availability

“…In the present work, we adopted biochemical and proteomic approaches to analyze, in the root of M4 grapevine rootstock, the responses occurring after the addition of NO 3 − to the nutrient solution in hydroponics. This rootstock genotype was selected on the basis of its good response to abiotic stress [ 31 , 32 , 33 , 34 , 35 ], which is contributing to the expansion of its use in viticulture. The biochemical evaluations were devoted to verifying the role played by roots in the response to NO 3 − resupply, monitoring key parameters.…”