Experiments with coleoptiles showed that these substances decreased the pH of the growth substrate, which along with the uptake of water is thought to cause one of their major functions.
One model for the long distance transport of these substances sees uptake by passive diffusion in a protonated form and export actively in a dissociated anion form by PIN proteins, in the polar transport model. These substances is generally thought be derived through some combination of transamination and oxidative decarboxylation from tryptophan. Experiments with coleoptiles showed that these substances decreased the pH of the growth substrate, which along with the uptake of water is thought to cause one of their major functions. High concentrations of these substances can cause bent tissue, as well as the formation of adventitious roots. They also inhibit growth in lateral buds to reduce competition with the apical meristem and are involved in gravitropism and phototropism. These hormones are most famous for causing cell elongation. For 10 points, name these plant hormones that include IAA.
One model for the long distance transport of these substances sees uptake by passive diffusion in a protonated form and export actively in a dissociated anion form by PIN proteins, in the polar transport model.
{auxins}