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Activity Discussion Science & Technology What are plant harmones?

  • Aparajita Karmakar

    Member
    June 3, 2021 at 11:56 pm

    Plant hormones are also known as phytohormones.

    In general, plants need carbon dioxide, sunlight and water for healthy growth. Their development depends on these basic facts the most.

    These factors itself are known as plant hormones.

    Biologically, plant hormones are present at a very low concentration in the plants, though these hormones are generated in all parts of the plant and are also transmitted to different parts.

    These hormones make plant act synergistically or individually.

    I hope this answer helps!๐Ÿ˜Š

  • Manpreet

    Member
    June 4, 2021 at 1:35 pm

    Growth is one of most fundamental and irreversible characteristics of a living being. Growth can be defined as โ€œan irreversible permanent increase in size of an organ or its parts or even of an individual cellโ€ whereas development can be defined as โ€œa term that includes all changes that an organism goes through during its life cycle from germination of the seed to senescenceโ€.

    Plant hormones are chemicals secreted by plants. These act as growth regulators and help in the development of plants, both morphologically and physiologically. These can induce seed germination or dormancy, can promote senescence and abscission. These are secreted in quite low concentrations. They are as follows:

    1. Auxin โ€“

    ยท Produced by growing meristems

    ยท These help to initiate rooting in stem cuttings

    ยท Induces floweing in pineapples

    ยท These induce parthenocarpy in tomatoes

    ยท These can also be used as herbicides (example โ€“ 2,4-D) to kill dicot weeds

    ยท Promotes abscission of older leaves and fruits

    ยท IAA (Indole-3-acetic acid) is a natural auxin

    ยท NAA (Naphthalene acetic acid) is a synthetically produced auxin

    2. Gibberellin โ€“

    ยท These increase length axis. Example โ€“ in grapes

    ยท Helps apples to improve their shapes

    ยท These delay senescence so that fruits can be left on trees for a longer time to extend its market period.

    3. Cytokinins โ€“

    ยท These help in cell division

    ยท These are found on parts of plants where rapid cell div occurs. Example- root apical, buds, young fruits

    ยท These help in delaying senescence

    4. Ethylene โ€“

    ยท It promotes senescence and abscission of leaves and flowes

    ยท It promotes fruit ripening

    ยท Enhances respiration

    5. Abscisic acid โ€“

    ยท It is known as the stress hormone

    ยท It is a growth inhibitor

    ยท It inhibits seed germination

    ยท Closes stomata

    ยท It induces dormancy

    Since plant hormones have a wide variety of uses, they can be produced synthetically. They have been using in propagation and development of plants.

    This was the summary of plant hormones. I hope it helps.

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