Effect of β-amino buthyric acid (BABA) on relative leaf water content, osmotic adjustment and antioxidant enzymes in Rapeseed (Brassica napus L.) plants under drought stress

The broad spectrum protective effect of the non-protein amino acid β-aminobutyric acid (BABA) against numerous plant stresses has been well-documented in the literature. This research shows a possibility to increase plant tolerance for drought stress through effective priming of the preexisting defense pathways in rapeseed plant. Results showed that rapeseed plants which were under drought stress had lower percentage of membrane stability index (MSI) and relative water content (RWC), higher lipid peroxidation products when compared with control plants. Pretreatment of plants with BABA increased the MSI and RWC and decreased the amount of aldehydes in water stress plants. H2O2 content was increased under drought stress. Pretreatment of plants with BABA decreased the amount of hydrogen peroxide. In drought stress condition, activity of SOD, APX, GR and POD were elevated over the controls while CAT activity decreased. In plants which pretreated with BABA and then exposed to drought stress the activity of mentioned enzymes increased.