Latest revision as of 14:19, 21 February 2025

Plant Hormone[edit]

Auxin, a key plant hormone.

Plant hormones, also known as phytohormones, are naturally occurring organic compounds that play crucial roles in regulating the growth, development, and responses of plants. These hormones are produced in small quantities and can have significant effects on plant physiology.

Types of Plant Hormones[edit]

Plant hormones are classified into several major groups, each with distinct functions and effects on plant growth and development.

Auxins[edit]

File:Indol-3-ylacetic acid.svg

Chemical structure of Indole-3-acetic acid, a common auxin.

Auxins are a class of plant hormones that primarily regulate cell elongation, apical dominance, and root initiation. The most common naturally occurring auxin is Indole-3-acetic acid (IAA). Auxins are involved in various plant processes, including phototropism and gravitropism.

Cytokinins[edit]

File:Zeatin.png

Chemical structure of Zeatin, a type of cytokinin.

Cytokinins are a group of hormones that promote cell division and differentiation. They are involved in processes such as shoot initiation and growth, leaf expansion, and delay of senescence. Zeatin is a well-known cytokinin found in many plants.

Gibberellins[edit]

File:Gibberellin A1.svg

Chemical structure of Gibberellin A1.

Gibberellins are a group of hormones that stimulate stem elongation, seed germination, and flowering. They are essential for breaking seed dormancy and promoting growth in various plant parts. Gibberellin A1 is one of the many gibberellins identified in plants.

Abscisic Acid[edit]

File:Abscisic acid.svg

Chemical structure of Abscisic acid.

Abscisic acid (ABA) is a plant hormone that plays a crucial role in stress responses, such as drought tolerance, and in the regulation of stomatal closure. It is also involved in seed dormancy and abscission processes.

Ethylene[edit]

File:Ethene-2D-flat.png

Chemical structure of Ethylene.

Ethylene is a gaseous plant hormone that influences fruit ripening, flower wilting, and leaf abscission. It is unique among plant hormones due to its gaseous state and is involved in the response to mechanical stress and pathogen attack.

Brassinosteroids[edit]

File:Brassinolide.png

Chemical structure of Brassinolide, a type of brassinosteroid.

Brassinosteroids are a class of polyhydroxysteroids that promote cell expansion and elongation, vascular differentiation, and stress tolerance. Brassinolide is one of the most studied brassinosteroids.

Functions of Plant Hormones[edit]

Plant hormones regulate a wide range of physiological processes, including:

Growth and Development: Hormones like auxins, cytokinins, and gibberellins are crucial for cell division, elongation, and differentiation.
Stress Responses: Abscisic acid and ethylene play significant roles in plant responses to environmental stresses such as drought, salinity, and pathogen attack.
Reproductive Development: Hormones regulate flowering, fruit development, and seed germination.
Senescence and Abscission: Ethylene and abscisic acid are involved in leaf senescence and the abscission of leaves and fruits.

Related Pages[edit]

@@ Line 1: / Line 1: @@
-{{Short description|Overview of plant hormones and their functions}}
+= Plant Hormone =
-==Overview==
+[[File:Auxin.jpg|thumb|right|Auxin, a key plant hormone.]]
-[[Plant hormones]], also known as [[phytohormones]], are naturally occurring organic compounds that play crucial roles in regulating the growth, development, and responses of plants to environmental stimuli. These hormones are produced in low concentrations and can have profound effects on plant physiology, influencing processes such as cell division, elongation, flowering, fruit development, and senescence.
-==Types of Plant Hormones==
+'''Plant hormones''', also known as '''phytohormones''', are naturally occurring organic compounds that play crucial roles in regulating the growth, development, and responses of plants. These hormones are produced in small quantities and can have significant effects on plant physiology.
-Plant hormones are classified into several major groups, each with distinct functions and mechanisms of action:
-===Auxins===
+== Types of Plant Hormones ==
-[[Auxins]] are a class of plant hormones that primarily regulate cell elongation, apical dominance, and root initiation. They are synthesized in the shoot apical meristem and young leaves and are transported downwards through the plant. Auxins play a key role in phototropism and gravitropism, allowing plants to grow towards light and against gravity.
-===Cytokinins===
+Plant hormones are classified into several major groups, each with distinct functions and effects on plant growth and development.
-[[Cytokinins]] are involved in promoting cell division and differentiation, particularly in the roots and shoots. They work in conjunction with auxins to regulate growth and development, influencing processes such as leaf senescence and nutrient mobilization. Cytokinins are synthesized in the roots and transported to other parts of the plant.
-===Gibberellins===
+=== Auxins ===
-[[Gibberellins]] are a group of hormones that stimulate stem elongation, seed germination, and flowering. They are essential for breaking seed dormancy and promoting the growth of young seedlings. Gibberellins also play a role in fruit development and can influence the size and shape of fruits.
+[[File:Indol-3-ylacetic_acid.svg|thumb|left|Chemical structure of Indole-3-acetic acid, a common auxin.]]
+Auxins are a class of plant hormones that primarily regulate cell elongation, apical dominance, and root initiation. The most common naturally occurring auxin is [[Indole-3-acetic acid]] (IAA). Auxins are involved in various plant processes, including phototropism and gravitropism.
-===Ethylene===
+=== Cytokinins ===
-[[Ethylene]] is a gaseous hormone that regulates fruit ripening, leaf abscission, and response to stress. It is produced in response to environmental cues such as wounding, drought, and flooding. Ethylene is unique among plant hormones due to its gaseous nature, allowing it to diffuse easily through plant tissues.
+[[File:Zeatin.png|thumb|right|Chemical structure of Zeatin, a type of cytokinin.]]
+Cytokinins are a group of hormones that promote cell division and differentiation. They are involved in processes such as shoot initiation and growth, leaf expansion, and delay of senescence. Zeatin is a well-known cytokinin found in many plants.
-===Abscisic Acid===
+=== Gibberellins ===
-[[Abscisic acid]] (ABA) is primarily involved in stress responses and the regulation of stomatal closure. It plays a critical role in helping plants cope with drought and other environmental stresses by reducing water loss through transpiration. ABA also influences seed dormancy and germination.
+[[File:Gibberellin_A1.svg|thumb|left|Chemical structure of Gibberellin A1.]]
+Gibberellins are a group of hormones that stimulate stem elongation, seed germination, and flowering. They are essential for breaking seed dormancy and promoting growth in various plant parts. Gibberellin A1 is one of the many gibberellins identified in plants.
-===Brassinosteroids===
+=== Abscisic Acid ===
-[[Brassinosteroids]] are a class of polyhydroxysteroids that promote cell expansion and elongation, vascular differentiation, and reproductive development. They are essential for normal plant growth and development and help plants respond to various environmental stresses.
+[[File:Abscisic_acid.svg|thumb|right|Chemical structure of Abscisic acid.]]
+Abscisic acid (ABA) is a plant hormone that plays a crucial role in stress responses, such as drought tolerance, and in the regulation of stomatal closure. It is also involved in seed dormancy and abscission processes.
-===Jasmonates===
+=== Ethylene ===
-[[Jasmonates]] are involved in plant defense responses and the regulation of growth and development. They play a key role in the plant's response to herbivory and pathogen attack, as well as in the regulation of reproductive processes.
+[[File:Ethene-2D-flat.png|thumb|left|Chemical structure of Ethylene.]]
+Ethylene is a gaseous plant hormone that influences fruit ripening, flower wilting, and leaf abscission. It is unique among plant hormones due to its gaseous state and is involved in the response to mechanical stress and pathogen attack.
-===Salicylic Acid===
+=== Brassinosteroids ===
-[[Salicylic acid]] is a phenolic compound that plays a crucial role in plant defense mechanisms, particularly in systemic acquired resistance (SAR) against pathogens. It is also involved in the regulation of flowering and thermogenesis.
+[[File:Brassinolide.png|thumb|right|Chemical structure of Brassinolide, a type of brassinosteroid.]]
+Brassinosteroids are a class of polyhydroxysteroids that promote cell expansion and elongation, vascular differentiation, and stress tolerance. Brassinolide is one of the most studied brassinosteroids.
+== Functions of Plant Hormones ==
-==Functions of Plant Hormones==
 Plant hormones regulate a wide range of physiological processes, including:
-* '''Growth and Development''': Hormones like auxins, cytokinins, and gibberellins coordinate cell division, elongation, and differentiation, influencing overall plant architecture.
+* '''Growth and Development''': Hormones like auxins, cytokinins, and gibberellins are crucial for cell division, elongation, and differentiation.
-* '''Stress Responses''': Abscisic acid and ethylene help plants respond to abiotic stresses such as drought, salinity, and temperature extremes.
+* '''Stress Responses''': Abscisic acid and ethylene play significant roles in plant responses to environmental stresses such as drought, salinity, and pathogen attack.
-* '''Reproductive Development''': Gibberellins and brassinosteroids are involved in flowering and fruit development, while jasmonates and salicylic acid play roles in defense during reproduction.
+* '''Reproductive Development''': Hormones regulate flowering, fruit development, and seed germination.
-* '''Senescence and Abscission''': Ethylene and cytokinins regulate leaf senescence and abscission, allowing plants to shed old or damaged tissues.
+* '''Senescence and Abscission''': Ethylene and abscisic acid are involved in leaf senescence and the abscission of leaves and fruits.
-==Images==
+== Related Pages ==
-[[File:Auxin transport.png|thumb|right|Diagram showing auxin transport in plant tissues.]]
+* [[Phototropism]]
+* [[Gravitropism]]
-[[File:Ethylene production.png|thumb|left|Ethylene production in response to stress factors.]]
+* [[Seed dormancy]]
+* [[Apical dominance]]
-==Related Pages==
-* [[Plant physiology]]
-* [[Photosynthesis]]
-* [[Plant anatomy]]
-* [[Botany]]
+[[Category:Plant physiology]]
 [[Category:Plant hormones]]
-[[Category:Plant physiology]]

Plant hormone: Difference between revisions