Chemical coordination in plants occurs through the production, transport, and reception of hormones known as phytohormones. These hormones act as chemical messengers that regulate various physiological processes such as growth, development, and responses to environmental stimuli.

Mechanism of Chemical Coordination

• Plants produce hormones like auxins, cytokinins, gibberellins, abscisic acid, and ethylene.
• Hormones are produced in specific regions (e.g., auxins in apical meristems) and transported through the plant’s vascular system (xylem and phloem) or by diffusion.
• Hormone receptors in plant cells detect these hormones, triggering signal transduction pathways that alter gene expression, enzyme activity, or metabolism.
• This coordination allows plants to respond adaptively to stimuli such as light (phototropism), gravity (gravitropism), water availability, and stress conditions.

Examples of Chemical Coordination

• Auxins accumulate on the shaded side of a plant exposed to light, causing cell elongation on that side and bending the plant towards light.
• Abscisic acid signals stomata to close during water scarcity, reducing water loss.
• Ethylene regulates fruit ripening and leaf abscission.

Summary

In essence, chemical coordination in plants is a hormonal system that facilitates communication and coordination between different parts of the plant to ensure proper growth, development, and environmental adaptation. Unlike animals, plants lack a nervous system and rely entirely on these chemical signals for coordination.