Morpho-physiological analysis of tolerance to aluminum toxicity in rice varieties of North East India

• Published in: PloS one Vol. 12; no. 4; p. e0176357
• Main Authors: Awasthi, Jay Prakash, Saha, Bedabrata, Regon, Preetom, Sahoo, Smita, Chowra, Umakanta, Pradhan, Amit, Roy, Anupam, Panda, Sanjib Kumar
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27-04-2017; Public Library of Science (PLoS)
• Subjects: Acidic soils; Agricultural land; Agricultural production; Aluminum; Aluminum - metabolism; Aluminum - toxicity; Arable land; Bioinformatics; Biological Transport; Biology and Life Sciences; Biomass; Biotechnology; Cajanus cajan; Cell Membrane - drug effects; Cell Membrane - metabolism; Cereal crops; Crop production; Crops; Earth crust; Enzymes; Floods; Flowers & plants; Food; Food contamination; Gene Expression Regulation, Plant - drug effects; Genotype; Genotypes; Glutathione; Glutathione reductase; Glycine max; Growth rate; Hemin - metabolism; Hybridization; Hydrogen Peroxide - metabolism; India; Laboratories; Life sciences; Lipid peroxidation; Lipid Peroxidation - drug effects; Lipids; Metabolism; Nutrient uptake; Oryza - drug effects; Oryza - genetics; Oryza - metabolism; Oryza - physiology; Oryza sativa; Oxidative stress; Peroxidation; pH effects; Physical Sciences; Physiology; Phytotoxicity; Plant growth; Plant production; Plant Roots - drug effects; Plant Roots - metabolism; Pollution tolerance; Productivity; Research and Analysis Methods; Rice; Seedlings; Soil chemistry; Soil contamination; Soil pH; Soils; Stress, Physiological - drug effects; Superoxides - metabolism; Toxicity; Water - metabolism; Water uptake; World population; India
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0176357

Aluminum (Al) is the third most abundant metal in earth crust, whose chemical form is mainly dependent on soil pH. The most toxic form of Al with respect to plants is Al3+, which exists in soil pH <5. Acidic soil significantly limits crop production mainly due to Al3+ toxicity worldwide, impacting approximately 50% of the world's arable land (in North-Eastern India 80% soil are acidic). Al3+ toxicity in plants ensues root growth inhibition leading to less nutrient and water uptake impacting crop productivity as a whole. Rice is one of the chief grains which constitutes the staple food of two-third of the world population including India and is not untouched by Al3+ toxicity. Al contamination is a critical constraint to plant production in agricultural soils of North East India. 24 indigenous Indica rice varieties (including Badshahbhog as tolerant check and Mashuri as sensitive check) were screened for Al stress tolerance in hydroponic plant growth system. Results show marked difference in growth parameters (relative growth rate, Root tolerance index, fresh and dry weight of root) of rice seedlings due to Al (100 μM) toxicity. Al3+ uptake and lipid peroxidation level also increased concomitantly under Al treatment. Histochemical assay were also performed to elucidate uptake of aluminum, loss of membrane integrity and lipid peroxidation, which were found to be more in sensitive genotypes at higher Al concentration. This study revealed that aluminum toxicity is a serious harmful problem for rice crop productivity in acid soil. Based on various parameters studied it's concluded that Disang is a comparatively tolerant variety whereas Joymati a sensitive variety. Western blot hybridization further strengthened the claim, as it demonstrated more accumulation of Glutathione reductase (GR) protein in Disang rice variety than Joymati under stressed condition. This study also observed that the emergence of lethal toxic symptoms occurs only after 48h irrespective of the dose used in the study.