Ethylene is a gaseous plant hormone essential for fruit ripening, with production levels increasing as fruit matures, impacting shelf-life and marketability. Fruits are categorized as climacteric, which can ripen post-harvest due to increased ethylene production, or non-climacteric, which must be harvested ripe. Various preharvest and postharvest regulators can manipulate ethylene levels to influence ripening, with potential effects on fruit quality and storability.

1. http://www.free-powerpoint-templates-design.com
Ethylene: Biosynthesis, its regulation, Action,
Ripening Processes, inhibitors and mode of action

2. What is Ethylene?
 Ethylene is a gaseous plant hormone that plays an important role in
inducing the ripening process for many fruits, together with other
hormones and signals. An unripe fruit generally has low levels of ethylene.
 As the fruit matures, ethylene is produced as a signal to induce fruit
ripening. Ethylene production continues to increase after harvest, thus
decreasing fruit shelf-life, storability capacity, and increasing its
susceptibility to pathogen attacks.
 Thus, monitoring and managing ethylene production rates is of crucial
importance so fruit does not become over-ripe on the tree or during
postharvest storage, which will render it unmarketable and decrease
profitability.

3. Fruit Ripening Patterns
 Fruits are generally divided in two categories: climacteric and non-climacteric fruits. In
general terms, climacteric fruits can ripen after harvest, whereas non-climacteric fruits
cannot ripen after harvest. Climacteric fruit ripening is characterized by an increased rate
of respiration, and then a burst of ethylene biosynthesis during ripening
 The production of ethylene in climacteric fruits is also known as autocatalytic, which
means an initial concentration of ethylene causes an increase in production of ethylene.
This means once ethylene production starts, the fruit naturally increases the amount of
signal made accelerating ripening. Some examples of climacteric fruits include peaches,
bananas, apples, and avocados
 Non-climacteric fruits have a different ripening pattern. They do not have a peak of
ethylene production or respiration during ripening. thus, they need to be harvested when
they are fully ripe. Some examples of non-climacteric fruits include cherries, grapes,
strawberries, and blueberries
 Understanding the ripening pattern of the fruits you grow is very important for developing
management strategies during development, determining their optimum harvest date, as
well as designing postharvest storage practices.

4. Ethylene is a gas and is measured in the laboratory using a gas
chromatograph, an analytical instrument that can measure different components
in a gaseous sample. Ethylene production can be measured non-destructively by
placing a single, or multiple fruits, inside a sealed container. After a determined
amount of time, the gas inside the container is withdrawn with a syringe and
analyzed with the gas chromatograph. For apples, a needle can be injected in the
core cavity of the fruit and a gas sample is withdrawn for ethylene measurement.
The amount of ethylene that a fruit produces can be used to determine the
ripeness of a fruit and its storability potential.

5. Pre-harvest and Postharvest Ethylene Regulators
Ethylene production can be manipulated in different ways in preharvest and postharvest. For example, three preharvest
plant growth regulators that manage and alter ethylene production, or perception, to influence ripening include Ethephon,
ReTain®, and HarvistaTM.
Ethephon (Ethrel®, Bayer Crop Science; MotivateTM, Fine Americas; Ethephon 2, Arysta LifeScience North America, LLC), is
an ethylene-releasing chemical. This can be applied as a preharvest growth regulator to promote fruit ripening. This
would be used to accelerate the ripening process. However, Ethephon also accelerates fruit abscission, and may negatively
impact fruit storability.
ReTain® (active ingredient: Aminoethoxyvinylglycine (AVG), Valent USA) inhibits the production of ethylene. This would
be used to decelerate, or slow down, the ripening process. This also leads to delay in color development, which may have
an impact on fruit quality and consumer opinion.
HarvistaTM (active ingredient: 1-Methylcyclopropene (1- MCP), AgroFresh) binds to ethylene receptors in the fruit. This
blocks the fruit from “seeing” the ethylene, mimicking a low amount of perceived ethylene. This prevents the response to
ethylene in the fruit, therefore, delaying ripening.
ReTain® and Harvista® both delay the fruit ripening process, which allows for keeping fruit on the tree for a longer time
and preventing fruit drop. Additionally, the delay in fruit ripening allows for consistent maturity throughout the orchard.
This helps to manage fruit harvest windows.
Regarding postharvest ethylene management, 1-MCP (SmartFreshTM) is a synthetic chemical that has a very similar
structure to ethylene. It blocks perception of ethylene by the fruit, thus delaying post-harvest ripening. This can help
maintain fruit quality, a high fruit firmness, and extend storage capacity, but can also have negative effects such as
enhancement of physiological disorders during storage.

6. Function of Ethylene

7. Function of Ethylene

8. Function of Ethylene

9. Effect of Ethylene in Ornaments plants

10. Role of Ethylene in Post Harvest

11. Ethylene Biosynthesis