senescence and abscission diagram

1. What is senescence and abscission?
2. What is the process of abscission?
3. What is meant by leaf senescence?
4. What is abscission layer in plants?
5. What happens during senescence?
6. Which hormone is responsible for senescence?
7. What is the purpose of abscission?
8. Which hormone is a gas?
9. Where is the abscission layer?
10. What causes leaf senescence?
11. What is another name for senescence?
12. Does auxin promote senescence?

What is senescence and abscission?

Abscission refers to the normal separation of a senescent plant part or organ, e.g. old leaves or ripe fruits. It occurs to shed or separate the unnecessary plant parts or organs. For instance, shedding of old leaves at the base of the petiole which usually occurs during autumn. ... It is not associated with aging.

What is the process of abscission?

Abscission (from Latin ab, "away", and scindere, "to cut'") is the shedding of various parts of an organism, such as a plant dropping a leaf, fruit, flower, or seed. ... In cell biology, abscission refers to the separation of two daughter cells at the completion of cytokinesis.

What is meant by leaf senescence?

Leaf senescence is an 'altruistic death' that allows for the degradation of the nutrients that are produced during the growth phase of the leaf and their redistribution to developing seeds or other parts of the plant, and thus is a strategy that has evolved to maximize the fitness of the plant.

What is abscission layer in plants?

The abscission layer, a barrier of thin-walled parenchyma cells, develops across the stem (or petiole) at the base of a leaf, flower, or fruit as it approaches the time of falling from a plant.

What happens during senescence?

Cellular senescence is an essentially irreversible growth arrest that occurs in response to various cellular stressors, such as telomere erosion, DNA damage, oxidative stress, and oncogenic activation, and it is thought to be an antitumor mechanism.

Which hormone is responsible for senescence?

Cytokinin and ethylene have the most extensively documented roles in delaying or inducing leaf-senescence, respectively. Hormones that were reported to delay senescence are giberellic acid, auxin and cytokinin, i.e. hormones that promote growth.

What is the purpose of abscission?

Abscission, from the Latin words ab (away) and sciendere (to cut), is a tightly controlled cellular progression that occurs at given developmental stages during the lifespan of a plant and ensures that plants can shed organs when they are no longer required – such as flowers after pollination or senescent leaves in the ...

Which hormone is a gas?

Ethylene, the Gaseous Plant Hormone.

Where is the abscission layer?

layer of tissue called the abscission layer develops at the base of each leaf stalk, and at this point the stalk breaks and the leaf is shed. The massive leaf drop that ensues during autumn has earned the season its alternate designation, fall.

What causes leaf senescence?

Leaf senescence occurs by age-dependent internal factors and is also influenced by a range of other internal and environmental factors, such as phytochrome, darkness, drought, pathogen attack, and oxidative stress (Hensel et al., 1993; Quirino et al., 2000).

What is another name for senescence?

Senescence Synonyms - WordHippo Thesaurus.
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What is another word for senescence?

Does auxin promote senescence?

Auxins function in multiple aspects of plant development and growth, including apical dominance, vascular differentiation, and shoot elongation. ... On the other hand, auxin can stimulate the biosynthesis of senescence-promoting hormones such as ethylene and ABA (Hansen and Grossmann, 2000; Vandenbussche et al., 2003).