Wilting is the loss of rigidity of non-woody parts of
plants. This occurs when the
turgor pressure
Turgor pressure is the force within the cell that pushes the plasma membrane against the cell wall.
It is also called ''hydrostatic pressure'', and is defined as the pressure in a fluid measured at a certain point within itself when at equilibriu ...
in non-
lignified plant cells falls towards zero, as a result of diminished water in the
cells
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...
. Wilting also serves to reduce water loss, as it makes the leaves expose less surface area. The rate of loss of water from the plant is greater than the absorption of water in the plant. The process of wilting
modifies the
leaf angle distribution of the plant (or
canopy
Canopy may refer to:
Plants
* Canopy (biology), aboveground portion of plant community or crop (including forests)
* Canopy (grape), aboveground portion of grapes
Religion and ceremonies
* Baldachin or canopy of state, typically placed over an a ...
) towards more erectophile conditions.
Lower water availability may result from:
*
drought conditions, where the
soil moisture drops below conditions most favorable for plant functioning;
* the temperature falls to the point where the plant's vascular system cannot function;
* high
salinity, which causes water to diffuse from the plant cells and induce shrinkage;
* saturated soil conditions, where
roots are unable to obtain sufficient
oxygen for
cellular respiration
Cellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP. Cellular respiration may be des ...
, and so are unable to transport water into the plant; or
*
bacteria or
fungi that clog the plant's
vascular system.
Wilting diminishes the plant's ability to
transpire and grow. Permanent wilting leads to plant death. Symptoms of wilting and
blights resemble one another.
The plants may recover during the night when evaporation is reduced as the stomata closes.
In
woody plant
A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposite to herbaceous plants that die back to the ground until ...
s, reduced water availability leads to
cavitation
Cavitation is a phenomenon in which the static pressure of a liquid reduces to below the liquid's vapour pressure, leading to the formation of small vapor-filled cavities in the liquid. When subjected to higher pressure, these cavities, cal ...
of the
xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...
.
Wilting occurs in plants such as
balsam and
holy basil. Wilting is an effect of the plant growth-inhibiting hormone,
abscisic acid
Abscisic acid (ABA) is a plant hormone. ABA functions in many plant developmental processes, including seed and bud dormancy, the control of organ size and stomatal closure. It is especially important for plants in the response to environmental s ...
.
With
cucurbits
The Cucurbitaceae, also called cucurbits or the gourd family, are a plant family consisting of about 965 species in around 95 genera, of which the most important to humans are:
*''Cucurbita'' – squash, pumpkin, zucchini, some gourds
*'' Lagena ...
, wilting can be caused by the
squash vine borer.
References
Plant physiology
Plant pathogens and diseases
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