phytohormone –> plant growth substances (Science: plant biology) substances that, at low concentration, influence plant growth and differentiation. Plant Hormone(Phytohormones) Phytohormones are naturally occurring organic chemical substances present in plant which bring about control and coordination of various activities in them. Its transport from cell to cell occurs through the parenchyma. Plants are sessile and prone to multiple stresses in changing environmental conditions.
The main phytohormones present in plants are: Auxins; Gibberellins; Cytokinin; Ethylene and

Further, through the optimal mix of phytohormones, plants maintain homeostasis and adapt to the environmental changes. This is only possible by an efficient and systemic cross talk between various phytohormones which help plants to maintain a critical balance between growth and environmental response.

Phytohormones can also be used to regulate the growth of in-vitro plants, weeds, cultivated plants and even cells. Auxins alone or in combination with other hormones are responsible for … Phytohormones. These are known as PGR’s or Plant Growth Regulators. Plant hormones are without exception small molecules. In any case is no regulated plant growth possible without them. In plants nervous system is absent. Phytohormones or plant hormones, are naturally occurring small organic molecules or substances which influence physiological processes in plants at very low concentrations (Davies, 2004). In all plants, this hormone has also been shown to heavily influence transcription levels and gene expression. It is produced primarily in the shoot tips and in developing flowers and seeds. More cautious people do also speak of growth regulators. These phytohormones are synthesised in minute quantities in one part of plant body and simply diffuse to other parts where they influence specific physiological process. In other words, phytohormones are chemical messengers that coordinate cellular activities of plants … Auxin, indole-3-acetic acid (IAA), was the first plant hormone identified. In these cases, an artificial form of manmade phytohormones is used. Even if certain classical definitions do not apply is it spoken of plant hormones or phytohormones. Of the several strategies adopted by plants to counteract the adverse effects of abiotic stress, phytohormones provide signals to allow plants to survive under stress conditions.

Phytohormones. So, plants control and coordinate their activities by the action of chemical substances called plant hormones or phytohormones present in them.