Question

Review Figure 10.4 and Figure 10.6. If a plant has mycorrhizae, where might carbon that enters the plant’s stomata as CO₂ eventually be deposited: in the plant, in the fungus, or both? Explain.

Short answer

Carbon enters the plant via its stomata. During photosynthesis, the carbon attaches to the sugar molecules. The fungus absorbs some of the total sugar produced by the plants. The fungus having a mutualistic relationship with that plant and developing mycorrhiza will only absorb the nutrition.

The rest of the sugar will be transported inside the plants, and they will use the sugar. Thus, carbon can be deposited either in the plant’s body or in the fungus.

Step-by-step solution

Step: 1 Mycorrhiza

Mycorrhiza is known as a symbiotic association. This association occurs between green plants and fungi. The function of mycorrhizal fungus is to allow plants to obtain moisture & nutrients (nitrogen, phosphate) and increase the host’s stress resistance.

Mutualistic relationship between fungus and plants 

The plants produce organic molecules (for example, glucose/sugar) during photosynthesis. Plants transport those produced organic molecules to the fungus, and the fungus transports nutrients (for example, phosphorous) and water to the plants.

The fungi grow on their host plants' roots and provide water & nutrients to that host plant. The plant provides carbohydrates (easily accessible food for fungi) to the fungus. Thus, both are advantageous for each other.

Deposition of carbon

Some fungi play a role in the absorption of carbon dioxide by the forests. The fungi are known as climate change warriors because they help the forests or plants to absorb CO₂ and decrease the impacts of global warming to save Earth.

Hence, the carbon gets deposited inside both of them (fungus and plants).