Biochemical responses of pathogen infestation-cum-salinity stress in Zat12 wheat transgenics

Investigation of Zat12 -induced biochemical responses was carried out in Zat12 transgenic lines (Z-8-12 1A, Z-8-12 1B, Z-8-19 and Z-15-10) generated from wheat cv. PBW621 in response to pathogen infection and salinity stress (150 and 250 mM NaCl). Pathogen infection (after 48 h) led to a significant increase in ascorbate levels and activity of ascorbate peroxidase (APX) along with decreased hydrogen peroxide (H 2 O 2 ) and malondialdehyde content in Zat12 transgenics as compared to PBW621. However, under salinity stress (250 mM NaCl), a marked elevation in H 2 O 2 and malondialdehyde content followed by low content of ascorbate and ascorbate peroxidase activity was found in PBW621 as compared to transgenics. The results thus emphasized that the transformed lines combat abiotic and biotic stress by accumulating higher ascorbate via increased activity of APX triggered by Zat12 gene, suggesting low membrane injury and higher antioxidant potential in these lines. Histochemical localization pattern also revealed correlation of H 2 O 2 with activity of ascorbate peroxidase in Zat12 transgenics.