<p>Salinity stress significantly limits the growth and development of grapevines. Various salt-tolerant plant genotypes enhance vineyard cultivation and mitigate the damaging effects of salinity stress by improving physio-biochemical and molecular characteristics. Therefore, the rootstocks ‘3309M’, ‘101–14’, and ‘Kangzhen’ were screened for their response under different salt stress concentrations (50, 100, and 200&#xa0;mmol&#xa0;L⁻¹ NaCl) for 18&#xa0;days under controlled conditions. Salt-treated plants, especially at high concentrations, exhibited leaf etiolation, wilting, chlorosis, necrosis, and leaf abscission, as well as a decrease in plant height, stem diameter, number of internodes, and number of leaves. Salt-treated plants exhibited significant increases in chlorophyll pigments, total conductance to water vapor, total conductance to CO₂, apparent electron transfer rate, variable fluorescence, maximal fluorescence, Mo, Ca, sugar, proline, and protein content. However, P, K, Zn, Mg, Fe, and Cu levels were significantly decreased compared to the control groups. The antioxidant activities significantly increased as a result of salt stress-generated reactive oxygen species. Furthermore, with the rise in salt doses, there were significant alterations in the expression of genes associated with salt stress and ABA level, which were markedly upregulated in rootstock ‘3309M’, followed by ‘101–14’ and ‘Kangzhen’, in comparison to the control groups. Under salt stress, the rootstock ‘3309M’ exhibited superior phenotypic and physiological characteristics, increased antioxidant activities, maintained ion homeostasis, and improved photosynthetic efficiency compared to the 101–14 and ‘Kangzhen’ rootstocks, respectively. The study revealed that ‘3309M’ rootstock exhibits salt stress tolerance, whereas 101–14 demonstrates moderate salt tolerance, and ‘Kangzhen’ is characterized by salt sensitivity.</p>