This picture is of a developing bud of a plant. This area of the plant has a lot of a particular plant hormone called Auxin. Auxin is a hormone in plants that promotes development and growth of shoots. Auxin may be one of the causes of phototropism by promoting plant growth in a certain direction. Auxin also helps with the elongation of the stem, differentiation, the growth of roots, the development of fruits and flowers, the growth of branches, a plant’s response to gravity and apical dominance. Auxin can be found in embryos that are in seeds, new leaves, and the meristems of apical buds.