Surface Display of Multiple Metal-Binding Domains in Deinococcus radiodurans Alleviates Cadmium and Lead Toxicity in Rice

Author: mycolabadmin
11/22/2024
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Summary

Scientists created genetically engineered bacteria (Deinococcus radiodurans) that can grab and absorb harmful heavy metals like cadmium and lead from soil and water. When these specially designed bacteria colonize rice plant roots, they protect the plants from metal toxicity by removing metals from the environment and boosting the plant’s natural defense systems. This approach could help make rice safer to eat by preventing dangerous metal accumulation in crops grown in contaminated areas.

Background

Cadmium and lead are hazardous heavy metals that accumulate in crops like rice and pose significant risks to public health through the food chain. Bioremediation using engineered microorganisms has shown promise for managing heavy metal contamination. Deinococcus radiodurans is an extremophile bacterium with exceptional resistance to oxidative stress that could be useful for this application.

Objective

This study aimed to express multiple metal-binding domains on the outer membrane of Deinococcus radiodurans to enhance both cadmium and lead adsorption and reduce heavy metal toxicity in rice plants. The researchers investigated whether a recombinant strain displaying PbBD and MTT5 metal-binding domains could colonize rice roots and alleviate heavy metal stress.

Results

The LOPM strain showed 4.9-fold higher cadmium adsorption and 3.2-fold higher lead adsorption compared to wild-type. Rice colonized with LOPM reduced cadmium content to 47.0% in roots and 43.4% in shoots, and lead content to 55.4% in roots and 26.9% in shoots. LOPM also reduced reactive oxygen species levels and enhanced antioxidant enzyme activities in rice under heavy metal stress.

Conclusion

Surface display of multiple metal-binding domains in D. radiodurans effectively reduces cadmium and lead accumulation and toxicity in rice through enhanced metal adsorption and improved antioxidant defense. This genetic engineering approach using extremophile bacteria represents a promising bioremediation strategy for managing multi-heavy metal contamination in crops and protecting food safety.

Published in:International Journal of Molecular Sciences,
Study Type:Experimental Study,
Source: 10.3390/ijms252312570, 39684280