​Auxins

Auxins are a group of plant hormones that play a crucial role in the regulation of plant growth and development. They are primarily involved in promoting cell elongation, particularly in the stems and roots, by loosening cell walls. Auxins also influence the formation of roots, flowers, and fruit by guiding their growth and differentiation. Additionally, they are essential in the process of phototropism and gravitropism, where plants grow in response to light and gravity, respectively.

Tropisms are directional growth responses in plants triggered by external stimuli, such as light, gravity, water, or touch. Phototropism occurs when plants grow toward or away from light, helping them maximize photosynthesis. Geotropism ensures roots grow downward into the soil for stability and nutrient absorption, while shoots grow upward toward light. Other types include hydrotropism, where roots grow toward water sources, and thigmotropism, where plants respond to physical contact, such as climbing vines wrapping around a support.

Tropisms

Plants respond to gravity. Roots grow down, shoots grow up.

Geotropism

Plants respond to sunlight. Shoots grow toward the light.

​​Phototropism

Plants respond to water. Roots grow toward the water

​​Hydrotropism

Plants respond to touch. Shoots grab onto objects to climb

​​Thigmotropism