during abscission and senescence nutrients

1. What happens during leaf senescence?
2. What is senescence and abscission?
3. What hormones are involved in abscission of leaves senescence?
4. Which hormone is responsible for senescence?
5. Does auxin promote senescence?
6. What causes leaf abscission?
7. What is senescence stage?
8. What does abscission mean?
9. What is senescence What are its causes?
10. What is the main function of ethylene?
11. Which hormone is a gas?
12. What are the effects of abscisic acid?

What happens during leaf senescence?

During senescence, leaf cells are subject to massive physiological and biochemical changes, including a dramatic metabolic transition from anabolism to catabolism which results in nutrient redistribution to newly developing organs (Lim et al., 2007).

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 hormones are involved in abscission of leaves senescence?

As most developmental processes in plants, the regulation of abscission involves the plant hormone auxin. Auxin functions as a brake — if high auxin concentrations reach the AZ cells, abscission is not activated.

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.

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).

What causes leaf abscission?

The reduction of chlorophyll production in leaves due to decreased sunlight in the autumn explains why some leaves turn yellow. However, the yellow color can attract aphids, so some trees turn the leaves red instead by injecting a bright pigment. The loss of chlorophyll may also contribute to the abscission process.

What is senescence stage?

The senescent phase is the period after reproductive phase, when a cell loses its ability to reproduce. ... Here, the cell may age and stops dividing, but it does not die. Termed as cell ageing, in this process such cells stay within the body and may cause various illness.

What does abscission mean?

1 : the act or process of cutting off : removal. 2 : the natural separation of flowers, fruit, or leaves from plants at a special separation layer.

What is senescence What are its causes?

The most widely known cause of ceased cell division is telomere erosion. ... At this point, cells undergo a DNA damage response (DDR); they can no longer divide and they are thus considered senescent. Because this is a natural process of aging, more cells become senescent as we grow older.

What is the main function of ethylene?

Ethylene as a Plant Hormone

This plant hormone is essentially produced in all parts of grown plants including roots, stems, tubers, leaves, flower, fruits and seeds. Ethylene is the most widely used plant growth regulator as it plays a vital role in: Stimulating fruit ripening. Helps in determining the sex of a flower.

Which hormone is a gas?

Ethylene, the Gaseous Plant Hormone.

What are the effects of abscisic acid?

Abscisic acid stimulates the growth and development of the root system including adventitious roots of the hypocotyl, the formation and growth of the lateral shoots of the cotyledonary node and to a much lesser extent the growth of the main shoots of axenically cultivated 17 days old Phaseolus coccineus seedlings.