Format: ORAL

Bhumi N. Tripathi1, Vijetna Singh1, Babita Chaudhary1, Rimjhim Joshi1

1 Department of Biotechnology, Indira Gandhi National Tribal University, Amarkantak, 484887, Madhya Pradesh, India

Wheat is a globally significant staple grain crop due to its high nutritional content and adaptability to a variety of agroclimatic situations. Wheat output must rise on current agricultural acreage to avoid agricultural expansion. Most wheat-growing locations face soil restrictions, including acidity, which hinders crop productivity. Due to excessive usage of ammonium-containing fertilizers and acid rain, 30-40% of global arable soil is acidified. Aluminum (Al) toxicity limits plant development in acidic soil. In Raj 3077, an Al-resistant wheat genotype, an antioxidant defense mechanism against Al-induced oxidative damage and external malate detoxification provide Al-resistance. Raj 4120 (Al-sensitive) inhibited growth more than Raj 3077. Both genotypes roots were tested for lipid peroxidation and H2O2 concentration. These indicators were greater in Raj 4120 shoots, indicating oxidative stress. Antioxidant enzymes as SOD (EC 1.15.1.9), CAT (EC 1.11.1.6), and APX (EC 1.11.1.11) protected Raj 3077 against Al-induced oxidative damage. Inefficient antioxidant enzyme activity in Raj 4120s roots indicated severe oxidative damage and a greater number of harmful Al ions translocated to the shoot, creating Al stress there. Interestingly, Raj 4120s shoot had more CAT activity than Raj 3077, but it wasnt adequate to counteract Al-induced reactive oxygen species. Raj 3077 had stronger malate efflux and ALMT gene expression than Raj 4120. The root length of Raj 3077 seedlings was especially reduced by niflumic acid, an anion channel inhibitor, suggesting that malate detoxification is needed for root Al-resistance. Al-induced antioxidant defense and external malate detoxifying mechanisms help Raj 3077 cope with Al toxicity.