Here's how they work together:
* Roots: The roots anchor the plant in the soil and absorb water and nutrients. They also produce a hormone called auxin which plays a crucial role in growth.
* Shoot: The shoot grows upwards towards sunlight for photosynthesis. It is also sensitive to gravity and auxin.
How they interact:
1. Gravitropism: Roots grow downwards due to gravity (positive gravitropism), while shoots grow upwards (negative gravitropism).
2. Auxin Distribution: Auxin, produced in the shoot tip, moves downwards through the stem. It accumulates on the lower side of the roots and the upper side of the shoot.
3. Growth Response: The higher concentration of auxin on the lower side of the roots promotes cell elongation, causing the root to bend downwards. On the shoot, the higher concentration of auxin on the upper side promotes cell elongation, causing the shoot to bend upwards.
This interaction between roots and shoots, mediated by auxin and gravity, ensures that seedlings grow in the optimal direction for survival.
