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13.4.3.4. Ethylene
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Today, we will discuss a fascinating plant growth regulator called ethylene. Can anyone tell me what they know about gaseous growth regulators?
I think they help plants grow faster or control certain processes.
That's correct! Ethylene is a key gaseous regulator that stimulates various physiological processes, especially in fruit ripening and senescence. Remember, ethylene is the only gaseous plant hormone.
How does it actually affect the fruit ripening process?
Great question! Ethylene enhances the respiration rate of fruits, which accelerates ripening. In fact, this increase in respiration is called the 'respiratory climactic'.
What about its role in senescence? Does it make plants age faster?
Yes, ethylene also promotes the aging process in plants, contributing to the senescence of leaves and flowers, as well as the detachment of these parts, known as abscission. Let's remember the mnemonic: 'Ethylene Eases Aging = EEA'.
That's a good way to remember it!
At the end of today’s session, keep in mind that ethylene also assists with seed germination and breaking dormancy, which are vital during different stages of a plant's life.
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Now that we understand ethylene's roles in plants, let's talk about its applications in agriculture. Can anyone guess how farmers use ethylene?
I think they use it to make fruits ripen faster.
Exactly! Farmers use ethylene to promote ripening in fruits like tomatoes and bananas. They often use a compound called ethephon, which slowly releases ethylene.
What about other uses in agriculture?
Ethylene also helps induce flowering in crops such as pineapples and can accelerate the abscission of flowers and fruits, which is helpful for thinning out certain crops.
So, it's like a plant's signal to start maturing?
Exactly! Remember: 'E for Ethephon means Ethylene', reflecting the strong relationship between these elements in agricultural practices.
This makes ethylene sound really important for getting produce to the market!
Yes, and summarizing today, ethylene's role in agriculture is crucial for improving yield and quality, alongside its physiological effects.
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Create a free accountToday, we will delve deeper into the different physiological effects that ethylene has on plants. Who can recall some of these effects?
It helps with fruit ripening and can make leaves drop.
Correct! Ethylene indeed helps with fruit ripening and induces abscission of flowers and leaves. It also has interesting effects on stem growth.
When you say it affects stem growth, what do you mean?
Ethylene promotes horizontal growth in seedlings and is crucial when plants face flooding, encouraging rapid internode elongation, particularly in deep-water rice.
That’s fascinating! Does it also play a role in the germination of seeds?
Yes! Ethylene helps break seed dormancy and initiates germination in plants. A good way to remember its diverse effects is by saying: 'Ethylene Empowers Every effect = EEE'.
I’ll use that mnemonic for my exam preparations!
Excellent! Ethylene is indeed versatile, influencing many vital processes in plant development. Always remember its many contributions during your studies.
Overview
Short Summary
Ethylene is a gaseous plant growth regulator that influences various physiological processes including fruit ripening, senescence, and abscission.
Medium Summary
Ethylene, a simple gaseous plant growth regulator, plays crucial roles in several physiological processes within plants. It is involved in fruit ripening, promoting senescence, and aiding in the abscission of leaves and flowers. Its significant effects make it one of the most widely used regulators in agriculture.
Detailed Summary
Ethylene
Ethylene is a small, gaseous plant growth regulator that is produced in large amounts by tissues undergoing senescence and ripening fruits. Its synthesis has critical physiological effects throughout the plant lifecycle. Its known influences include:
- Growth Regulation: Ethylene promotes various types of growth, including horizontal growth of seedlings and swelling of stems.
- Senescence and Abscission: It significantly influences the aging process in plants, contributing to the senescence of leaves and flowers and the detachment of these organs from the plant through abscission.
- Fruit Ripening: Ethylene is best known for its role in the ripening of fruits, enhancing respiration rates during ripening, which is termed as the 'respiratory climactic'.
- Dormancy Regulation: Ethylene helps break seed and bud dormancy, initiating germination and sprouting in various plants.
- Flood Response: In deep-water rice plants, ethylene promotes rapid internode elongation, assisting plants to grow above water surfaces for better light access.
- Agricultural Applications: Ethylene is extensively used to facilitate fruit ripening and induce flowering in crops like pineapples and mangoes. The compound most commonly utilized as a source of ethylene in agriculture is ethephon, which releases ethylene over time when introduced to plants.
As a result of these functions, ethylene is a vital tool in both horticultural and agricultural practices.
Reference YouTube Videos
Audio Book
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Create a free accountEthylene is a simple gaseous PGR. It is synthesised in large amounts by tissues undergoing senescence and ripening fruits.
Detailed Explanation
Ethylene is a plant growth regulator that exists in a gaseous form. It's produced mainly in parts of the plant that are aging or undergoing ripening, such as fruits and leaves. This means that as fruits begin to ripen, they produce ethylene, which then influences various growth processes in the plant.
Examples & Analogies
Think of ethylene like the aroma of cookies baking in the oven. As the cookies bake (ripening), the smell (ethylene) fills the room and signals to everyone that they are ready to eat! In the same way, fruits release ethylene gas to signal that they are ripening.
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Create a free accountInfluences of ethylene on plants include horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot seedlings.
Detailed Explanation
Ethylene has several key effects on how plants grow. It can cause seedlings to grow sideways rather than straight up, resulting in more horizontal growth. It also leads to the swelling of plant stems and forms a distinctive apical hook in certain seedlings during their early growth stages.
Examples & Analogies
Imagine a young plant as a person learning to walk. Sometimes, to avoid an obstacle or to reach towards the sunlight, it might bend sideways or twist slightly (horizontal growth). Just like a child learning to balance, this sideways growth can help the plant stabilize and grow effectively.
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Create a free accountEthylene promotes senescence and abscission of plant organs especially of leaves and flowers.
Detailed Explanation
Ethylene plays a crucial role in the aging process of plants. It triggers senescence, which is the process of aging in plant tissues, particularly in flowers and leaves. Additionally, ethylene influences abscission, the shedding of these aged organs, helping the plant maintain health and resource allocation.
Examples & Analogies
Consider ethylene as a 'goodbye' signal from the plant. When a leaf reaches the end of its life, ethylene tells it it's time to drop off, similar to how we might say goodbye to a friend who is moving away. This ensures that the plant can focus its energy on growing new leaves and flowers.
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Create a free accountEthylene is highly effective in fruit ripening. It enhances the respiration rate during ripening of the fruits.
Detailed Explanation
Ethylene is particularly important for the ripening of fruits. When fruits produce ethylene, it increases their respiration rate, which is a process that kickstarts ripening. This process helps develop the flavor and color of fruits, making them more appealing to eat.
Examples & Analogies
Picture a fruit salad. An unripe banana sitting next to a ripe one can produce ethylene that encourages the other fruits to ripen faster. It's like having a friend who hypes you up—that extra encouragement makes you want to break out into dance!
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Create a free accountEthylene breaks seed and bud dormancy, initiates germination in peanut seeds, sprouting of potato tubers. Ethylene promotes rapid internode/petiole elongation in deep water rice plants.
Detailed Explanation
Ethylene has various other roles, including breaking dormancy in seeds and buds, allowing them to germinate and sprout when conditions are favorable. In plants like deep-water rice, ethylene helps with elongation of stems, so they can grow upwards and reach above the water.
Examples & Analogies
Imagine a seed as a kid waiting for the right moment to jump into a pool. Ethylene serves as the lifeguard who says, 'Jump in now!' It helps the seeds and buds realize that conditions are perfect for growth, just like a lifeguard signals it's safe to dive.
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Create a free accountEthylene is used to initiate flowering and for synchronising fruit-set in pineapples. It also induces flowering in mango.
Detailed Explanation
In agriculture, the use of ethylene is quite important. Farmers utilize ethylene to induce flowering and synchronize the fruit-setting process in crops like pineapples and mangos. This means that farmers can ensure that their crops produce fruit all at once for better harvest efficiency.
Examples & Analogies
Think of ethylene like a director on a movie set, calling all the actors to perform their scenes together. When the farmer uses ethylene, it ensures that all the flowers on the plants bloom and produce fruit at the same time, making it easier to collect them all in one go, just like capturing the final scene of a movie!
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Key Concepts
Core takeaways and short definitions to help you quickly recall the key ideas from this section.
Ethylene: A key plant growth regulator with significant roles in growth, ripening, and abscission.
Ethephon: A compound that releases ethylene and is used in horticultural practices.
Senescence: The aging process in plants that is influenced by ethylene.
Abscission: The shedding of plant parts, promoted by ethylene.
Respiratory climactic: Enhanced respiration during fruit ripening.
Dormancy: A state where a seed is inactive but can germinate under the right conditions.
Examples
Step-by-step examples to apply the section's ideas and test your understanding.
Ethylene is used to hasten the ripening of bananas during transportation.
Ethephon is sprayed on pineapples to induce flowering and fruit set.
In deep-water rice, ethylene allows for rapid internode elongation to keep the shoots above water.
Memory Aids
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Stories
Flash Cards
Glossary
Ethylene
A small gaseous plant growth regulator that influences ripening, senescence, and abscission.
Ethephon
Compound that releases ethylene over time and is used in agriculture to promote ripening.
Abscission
The process in which plants shed leaves, flowers, or fruits.
Senescence
The process of aging in plants.
Respiratory climactic
The increase in respiration rate associated with fruit ripening.
Dormancy
A survival mechanism in seeds that prevents germination until conditions are favorable.