How does positive gravitropic response occur in roots?
Gravity causes IAA to move from the upper side of the root to the lower side, this side therefore has a higher concentration of IAA, inhibiting elongation and causing the root to bend downwards.
How does negative gravitropic response occur in shoots?
Gravity causes IAA to move from the upper side of the root to the lower side, this side therefore has a higher concentration of IAA so it elongates causing the shoot to grow upwards.
