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Coordination in plants

Gibberellin hormone flowering, with different effects in short
Gibberellins are a class of plant hormones and long-day plants. It inhibits cambium
that play an important role in various activity during winter, helping the plant to
developmental processes. Gibberellins adapt to cold conditions. ABA also plays a
stimulate both stem and cell elongation which role in fruit development, its involvement
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support growth, leading to increased stem in ripening varies depending on the type
growth. It also promotes seed germination of fruit. In some fruits, it helps to regulate
by breaking seed dormancy. Their roles in the timing of ripening and influences the
breaking bud dormancy allows for earlier development of colour and flavour. This
growth and they are used commercially is done by triggering the production of
to enhance plant growth and productivity another hormone called ethylene which
in agriculture. The hormones also induce controls fruit ripening. Generally, ABA
production of hydrolytic enzymes like is essential for plant survival under harsh
α-amylase in the endosperm during environmental conditions and in regulating
germination. Gibberellins also, facilitate developmental processes such as growth,
fruit formation, by increasing fruit size and improve drought resistance and maintaining
developing seedless fruits (parthenocarpy). seed dormancy.
Additionally, gibberellins delay senescence, Ethylene hormone
and can influence sex determination in
certain plants. The hormone also plays part Ethylene is another growth hormone which
in regulating time of flowering and flower promotes growth of shoots and roots.
formation especially in plants that require Ethylene affects the growth and shape of
cold conditions. plant cells. When a new shoot emerges
and is exposed to light, the plant starts
to decrease the production of ethylene.
Abscisic acid hormone This causes the cells of the leaf and shoot

Abscisic acid (ABA) is a plant hormone to expand. But if the growing shoot hits
involved in various physiological processes an obstacle while it is still underground,
of the plant. It plays a significant role in production of ethylene increases to prevent
stress responses, by inducing stomatal cell elongation. This results to the swelling
closure to prevent water loss. During of the stem, making the stem stronger, a
drought conditions, ABA is produced in the condition which enables the stem to pass
roots and transported to the leaves, where it through the obstacle.
triggers stomata to close, thereby reducing
water loss through transpiration. ABA
inhibits seed germination and promotes Ethylene accelerate fruit ripening by
triggering colour change, softening and
seed dormancy, counteracting the effects sweetness. Ethylene gas can be used
of gibberellins. It also regulates growth commercially in post harvest to uniformly
by inhibiting cell division and promoting ripen bananas, tomatoes and mangoes.
leaf senescence. Additionally, ABA affects

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