Enhanced values of various physiological traits and VvNAC1 gene expression showing better salinity stress tolerance in some grapevine cultivars as well as rootstocks

- 'Yaghooti' and '1103 Paulson' had much better performance while exposing to salinity stress.
- VvNAC1 gene expression had close relationship with salinity stress tolerance.
- Glycine betaine biosynthesis was more effective reliable factor than proline to be correlated with salinity tolerance.

Soil salinity is a growing problem in the agriculture around the world and grapes are classified as a relatively sensitive plant to salinity. NAC transcription factor plays a significant role in abiotic stress, such as salinity. In the present study, grapevine cultivars ('Bidane-Sefid', 'Sefid-Fakhri', and 'Yaghooti') as well as three rootstocks ('Ramsey', 'Riparia', and 1103 'Paulson') were subjected to salinity stresses of NaCl (0, 25, 50, and 100 mM), in hydroponics conditions. Effects of salinity stress were measured on VvNAC1 gene expressions, as well as some physiological characteristics. At 0 and 25 mM sodium chloride no leaf edge burning (0%) was observed. However, with increasing salinity levels up to 50 and 100 mM, leaf edge burning was observed in all tested plants. Results showed that Yaghooti and 1103 Paulson had better performance in various morphological, physiological, and molecular parameters such as leaf edge burning, chlorophyll, glycine betaine, electrolyte leakage, and malondialdehyde content. Furthermore it was concluded that in tolerant grape cultivars and rootstocks the biosynthesis of glycine betaine is more correlated than proline with increase in salinity tolerance. VvNAC1 was significantly up-regulated in leaves of all tolerant cultivars and rootstocks compared to susceptible grapevines consistent with increasing of salinity level and the expression of this gene was significantly higher in 'Yaghooti' and 1103 'Paulson'. Considering the physiological attributes and VvNAC1 gene expression, 'Yaghooti' and '1103 Paulson', may have higher performance to tolerate salt stress condition among all other studied rootstocks and cultivars.