what are plant hormones ? what is the relationship between their site of production and site of action?
Answers
Answer:
Plant hormones as signalling molecules play an essential role in the control of plant growth and development. Typically, sites of hormonal action are usually distant from the site of biosynthesis thus relying on efficient transport mechanisms.
Lack of the plant hormone auxin can cause abnormal growth (right)
Plant hormones (also known as phytohormones) are signal molecules produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of growth and development, from embryogenesis,[1] the regulation of organ size, pathogen defense,[2][3] stress tolerance[4][5] and through to reproductive development.[6] Unlike in animals (in which hormone production is restricted to specialized glands) each plant cell is capable of producing hormones.[7][8] The term 'phytohormone' was coined by Went and Thimann and used in the title of their book in 1937.[9]
Phytohormones are found across the plant kingdom, and even in algae, where they have similar functions to those seen in higher plants.[10] Some phytohormones also occur in microorganisms, such as unicellular fungi and bacteria, however in these cases they do not play a hormonal role and can better be regarded as secondary metabolites.[11]