What is the primary role of Cobalt (Co) in plants?

Cobalt's primary role in plants is indeed associated with its essential function for nitrogen-fixing bacteria. Cobalt is a crucial component of vitamin B12, which is necessary for the metabolism of these bacteria, enabling them to convert atmospheric nitrogen into a form that plants can utilize. This symbiotic relationship is particularly evident in legume plants, which host these bacteria in their root nodules.

This process significantly enhances soil fertility and plant growth by providing an essential nutrient that plants cannot obtain from the atmosphere directly. Such interactions emphasize the importance of cobalt in the nitrogen cycle and its contribution to plant health and productivity.

While cobalt may have secondary roles in enhancing root development, improving flowering, and potentially influencing photosynthesis, these are not its primary functions. The direct and critical role of cobalt in supporting nitrogen-fixing bacteria stands out as its most significant contribution to plant biology.