Aluminum-induced abiotic stress counteractsFusariuminfection inCajanus cajan(L.) Millsp.

Interaction between Al and fungal pathogen Fusarium incarnatum-equiseti was investigated in Cajanus cajan (L.) Millsp. Germinating seeds of C. cajan conditioned by treating presoaked seeds with Al at concentrations 0, 10, 50, and 100 µM, pH 4.5, for 24 h were subjected to fungal infection. Subsequently, generation of reactive oxygen species (ROS: O2 •− and H2O2), cell death, and activity of antioxidant enzymes (catalase [CAT], superoxide dismutase [SOD], guaiacol peroxidase [GPX], and ascorbate peroxidase [APX]) in the root tissue of seedlings were estimated. Both Al conditioning and Fusarium infection resulted in a significant increase in ROS generation, cell death, and SOD, but inhibited CAT activity significantly. CAT as well as GPX displayed isomorphic differences between treatments. APX activity was increased in response to Al conditioning, but decreased in response to Fusarium infection. Al conditioning at 50 µM significantly counteracted against Fusarium infection that was marked by a concomitant decrease in ROS generation and cell death whereas little changes were observed in activities of antioxidant enzymes. The findings underscored the importance of controlled ROS homeostasis in counteracting Fusarium infection.