Question

Short term changes in plant growth mediated by the plant hormone auxin are hypothesized to result from................

Answer 1

Short term changes in plant growth mediated by auxin can include cell elongation in response to light and gravity (phototropism and gravitropism), as well as changes from environmental factors leading to phenomena such as apical dominance and bending in direction of stimulus.

Step-by-step explanation:

Short term changes in plant growth mediated by the plant hormone auxin are hypothesized to result from processes like cell elongation, tropisms, and changes in patterns of growth due to environmental factors.

Auxins are key in regulating various aspects of growth and development in plants. Specifically, they are responsible for cell elongation in processes like phototropism and gravitropism, whereby plants grow towards or away from light and gravity. The differential distribution of auxin stimulates cells on one side of the plant to elongate faster than on the other, causing the plant to bend in the direction of the growth stimulus.

Moreover, auxins play a crucial role in apical dominance, which is the inhibition of lateral bud formation, resulting from auxin produced in the apical meristem. This hormone is actively involved in various stages of plant development such as flowering, fruit setting, ripening, and the inhibition of leaf abscission. Auxin also interfaces with other hormonal signals and environmental factors, such as brassinosteroids and light, to induce complex developmental and growth responses.

Answer 2

Short-term changes in plant growth mediated by the plant hormone auxin are hypothesized to result from the modification of cell wall plasticity, leading to cell elongation.

Auxin triggers the activation of proton pumps in the plasma membrane, which acidify the cell wall. This acidification causes the cell wall to become more pliable, allowing the cell to expand more easily.

Additionally, auxin is believed to influence the expression of certain genes related to cell growth and to interact with other signaling pathways. These actions facilitate rapid changes in plant cell size and shape, contributing to growth responses such as phototropism and gravitropism.