Morphometric and biochemical responses of rice seedlings to heavy metal stress mitigated by Bacillus subtilis
Paper Details
Morphometric and biochemical responses of rice seedlings to heavy metal stress mitigated by Bacillus subtilis
Abstract
This study evaluated the role of Bacillus subtilis in mitigating cadmium (Cd) and arsenic (As) stress (100 mM) in three rice cultivars (ADT 36, CO 51, and TPS 5). Twelve bacterial species were isolated from soil, with Bacillus spp. selected for their adaptability and plant growth-promoting traits. Heavy metal stress significantly reduced root and shoot growth, biomass, pigment levels, and protein and proline contents, while increasing phenol, soluble sugars, and Na⁺ accumulation. Cd caused stronger growth inhibition, whereas As had a greater impact on pigment biosynthesis. Inoculation with B. subtilis enhanced seedling vigor, improved pigment retention, restored protein and proline levels, and reduced phenol and sugar accumulation across cultivars. Ionic balance was also improved, with lower Na⁺ and higher Ca²⁺ and K⁺ compared to stress plants. Among the cultivars, CO 51 and TPS 5 showed the strongest recovery, while ADT 36 exhibited moderate tolerance. Overall, B. subtilis effectively alleviates heavy metal–induced phytotoxicity in rice by improving morphometric, biochemical, and ionic traits, demonstrating its potential for sustainable phytoremediation.
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J. Sujatha, V. Vinotha, R. Rajakumar*, 2026. Morphometric and biochemical responses of rice seedlings to heavy metal stress mitigated by Bacillus subtilis. J. Biodiv. Environ. Sci., 28(3), 28-38.
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