Answer:
The mesocotyl is a stem-like structure that develops in some plants during seed germination.
Step-by-step explanation:
It is located between the seed and the coleoptile, which is a protective sheath that encloses the young leaves. The mesocotyl is responsible for pushing the coleoptile up through the soil surface, allowing the seedling to emerge.
The mesocotyl is particularly important in plants that are planted deep in the soil, such as corn. It can elongate rapidly, even in the dark, to ensure that the seedling reaches the soil surface. The mesocotyl also serves as a temporary pipeline between the seed and the coleoptile, providing nutrients and water to the growing seedling until nodal roots begin to develop.
In addition to its role in seedling emergence, the mesocotyl may also play a role in plant stress tolerance. For example, studies have shown that the mesocotyl of maize seedlings is longer under conditions of water stress. This suggests that the mesocotyl may help to ensure that the seedling reaches the water table during drought conditions.
Overall, the mesocotyl is an important plant structure that plays a vital role in seedling emergence and stress tolerance.