Effect of ABA on physiological characteristics and expression of salt tolerance-related genes in Tartary buckwheat

Salt-tolerant variety Chuanqiao No. 1 and salt-sensitive variety Chuanqiao No. 2 of Tartary buckwheat were used as experimental materials, and the effect of different concentrations of ABA on physiological characteristics of Tartary buckwheat under salt stress and the optimal ABA concentration on expression of salt tolerance-related genes were analyzed. The results showed that the ABA treatment with appropriate concentration improved the stress resistance of Tartary buckwheat seedlings, and the optimal ABA concentration varies in Chuanqiao No. 1 and Chuanqiao No. 2 with 30 and 20 μM. Under salt stress, the ABA treatment with appropriate concentration increased the fresh weight, root vigor of seedlings and leaf SOD, POD, and CAT activity of Tartary buckwheat, and reduced the leaf plasma membrane permeability of Tartary buckwheat, and the optimal ABA concentration under salt stress varies in Chuanqiao No. 1 and Chuanqiao No. 2 with 40 and 10 μM. The ABA treatment with optimal concentration promoted the expression of FtNHX1, FtSOS1, potassium channel, and four ABA receptor-related genes in the stem and root of two Tartary buckwheat varieties. The expression of salt tolerance-related genes is consistent with the improvement of physiological characteristics in Tartary buckwheat.