Using controlled salt stress and β-aminobutyric acid signaling to decrease transplant failure

Abstract Root injuries, heat and desiccation after transplanting are abiotic stresses that may cause transplant failure. Stress signal transduction for preventing transplant failure due to root injuries and growing in hot dry conditions was evaluated using Pistacia vera , a species highly sensitive to transplanting, as the model plant. Pistachio seedlings were primed by exposure to salt stress using 100 mM CaCl 2 100 mM KNO 3 , 50 mM CaCl 2  + 50 mM KNO 3, and three foliar applications of 2.0 mM β-aminobutyric acid (BABA) for 7 days. After removing 30% of the root length, the plants were then grown under hot dry conditions for 60 days. Significant increases were observed in the plasma membrane thermostability and proline and malondialdehyde leaf concentrations after the priming treatments. The BABA and KNO 3 treatments increased leaf H 2 O 2 content by 26% while the KNO 3  + CaCl 2 treatment increased it by 63%. Detached leaves of non-primed plants lost water more quickly than leaves of primed plants. The BABA and KNO 3  + CaCl 2 treatments were most effective at limiting water loss from detached leaves. Transplanting killed all the non-primed plants. The CaCl 2 treatment increased transplant survival by 42.9% and the KNO 3  + CaCl 2 treatment by 100%. The survival rate of BABA and KNO 3 primed plants was 57.1%. These results suggest controlled salt stress could be a simple, rapid and efficient method of for controlling transplant shock.