Phototropism in flowering plants

- Cells in tip of shoot produce IAA, transported down s - IAA is initially transported evenly to all regions - Light causes movement of IAA from light side to darker side of s - A greater conc. of IAA builds up on the darker side than on the lighter side - As IAA causes elongation of shoot cells, greater conc. of IAA on darker side, cells on this side elongate more - Darker side of s elongates faster, causing s tip to bend towards light