Response of rice-mycorrhizal association to arsenate exposure

Varsha Pathare; Anurakti Shukla; Sudhakar Srivastava; Penna Suprasanna

Varsha Pathare Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW 2751, Australia
Anurakti Shukla Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi â€“ 221005, , U.P., India
Sudhakar Srivastava Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi â€“ 221005, , U.P., India
Penna Suprasanna Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Center, Mumbai â€“ 400085, Maharashtra, India

Abstract

Rice-mycorrhizal association helps the plants in phosphate acquisition and improves stress tolerance. The aim of present study was to analyse the impact of arsenic (As) - stress on mycorrhiza colonized (Co) and non-colonized (NCo) rice plants with respect to antioxidant mechanism. The rice seedlings were grown initially under control conditions for 45 d for establishment of mycorrhizal association. The Co and NCo plants were then subjected to 12.5 Â¹M arsenate [As(V)] exposure for 1 d and 3 d in hydroponics. The Co plants showed significant stimulation in activities of various antioxidant enzymes viz., superoxide dismutase (SOD), guaiacol peroxidase (GPX), catalase (CAT) and glutathione reductase (GR) in both root and shoot upon As(V) exposure as compared to that of NCo plants. Consequently, a notable increase in the photosynthetic pigments and decrease in H2O2 level and lipid peroxidationwas observed in Co plants subjected to As(V) stress in comparison to that of NCo plants. Hence, myccorhizal symbiosis was found to be effective in imparting tolerance to As stress and could serve as a potential strategy to mitigate As toxicity in rice in future.