Influence of NaCl stress on ABA synthesis and hardness of Vitis vinifera L. ‘Cabernet Sauvignon’ berry in veraison

Taking the wine grape ‘Cabernet Sauvignon’ as test material, the effect of 50 mmol·L−1 NaCl spraying treatment on ABA synthesis and hardness of grape berry in veraison was investigated. The influence of NaCl and water on the initiation of fruit ripening and the formation of fruit quality were studied. The results showed that the hardness of salt-treated berry was higher than control in veraison. Additionally, compared with control group, the accumulation rate of anthocyanin and soluble solids in berry were both significantly reduced under NaCl treatment during the development process. While the content of titratable acidity showed an inverse change with increasing the content of tartaric acid and malic acid. Furthermore, the ABA synthesis of grape skin and flesh was delayed under salt stress, which decreased the accumulation rate of ABA accumulation. Quantitative real-time PCR analysis showed that VvNCEDs, the key gene of ABA synthesis, was down-regulated under salt stress, which was consistent with the change of ABA content.