1. Sources of endogenous NO in plants 2. NO homeostasis in plants 3. Implication of endogenous NO in regulating Cd toxicity 4. Implication of endogenous NO in regulating As toxicity 5. Implication of endogenous NO in regulating Al toxicity 6. Exogenous application of NO and Cd stress tolerance 7. Exogenous application of NO and As stress tolerance 8. Exogenous application of NO and Al stress tolerance 9. NO and regulation of Cr stress in plants 10. NO and regulation of Pb stress in plants 11. NO and regulation of Fe stress in plants 12. NO and regulation of Zn stress in plants 13. Post translational modifications and metal stress tolerance in plants 14. NO signalling under Cd toxicity 15. NO signalling under Al toxicity 16. NO signalling under As toxicity 17. NO signalling under Zn toxicity 18. NO signalling under Fe toxicity 19. Adventitious root formation and NO signalling under metal stress 20. Crosstalk of NO with other signalling molecules under metal stress 21. Biotechnological attributes of NO for relieving metal toxicity