Mechanism of Action of Auxin

Mechanism of action of auxin involves following steps:

1. Receptor Binding: Auxin binds to specific receptor proteins located in the cell membrane or cytoplasm.
2. Activation of Signal Transduction Pathways: Binding of auxin to its receptors triggers a series of reaction leading to changes in gene expression and cellular responses.
3. Gene Regulation: Auxin signaling pathways regulate the expression of genes involved in various physiological processes, including cell elongation, division, and differentiation.
4. Cell Expansion and Elongation: Auxin promotes cell expansion and elongation by activating proton pumps in the cell membrane, leading to increased acidity and cell wall loosening.
5. Tropism Responses: Auxin gradients in plant tissues mediate tropic responses such as phototropism (response to light) and gravitropism (response to gravity) by influencing cell growth and elongation.
6. Apical Dominance: Auxin inhibits the growth of lateral buds, maintaining apical dominance and promoting the growth of the main shoot.
7. Root Development: Auxin regulates root development by promoting cell division and elongation in the root meristem and influencing the formation of lateral roots.
8. Vascular Tissue Differentiation: Auxin plays a role in the differentiation of vascular tissues, promoting the formation of xylem and phloem elements.

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Auxin is a plant hormone. Auxin hormone function is to control growth and developmental processes in plants, including cell expansion, root initiation, and bud and flower growth. Auxin, discovered by Charles Darwin and his son Francis, was first isolated from human urine.

Auxin plays a key role in plant adaptation to the environment, and its functions are associated with signal transduction, transport, homeostasis, and biosynthesis pathways. In this article, we will study the auxin, its types, mechanism of action, and functions in detail.