Plants
In plant physiology, dormancy is a period of arrested plant growth. It is a survival strategy exhibited by many plant species, which enables them to survive in climates where part of the year is unsuitable for growth, such as winter or dry seasons.
Many plant species that exhibit dormancy have a biological clock that tells them when to slow activity and to prepare soft tissues for a period of freezing temperatures or water shortage. On the other hand, dormancy can be triggered after a normal growing season by decreasing temperatures, shortened day length, and/or a reduction in rainfall. Chemical treatment on dormant plants has been proven to an effective method to break dormancy, particularly in woody plants such as grapes, berries, apples, peaches and kiwis. Specifically, hydrogen cyanamide stimulates cell division and growth in dormant plants, causing budbreak when the plant is on the edge of breaking dormancy. Slight injury of cells may play a role in the mechanism of action. The injury is thought to result in increased permeability of cellular membraines. The injury is associated with the inhibition of catalase, which in turn stimulates the pentose phosphate cycle. Hydrogen cyanamide interacts with the cytokinin metabolic cycle, which results in triggering a new growth cycle. The images below show two particularly widespread dormancy patterns amongst sympodially growing orchids:
Read more about this topic: Dormancy
Famous quotes containing the word plants:
“Probably if our lives were more conformed to nature, we should not need to defend ourselves against her heats and colds, but find her our constant nurse and friend, as do plants and quadrupeds.”
—Henry David Thoreau (1817–1862)
“All plants move, but they don’t usually pull themselves out of the ground and chase you.”
—Philip Yordan (b. 1913)
“The holly and the ivy
Are plants that are well known
Of all the trees that grow in the woods
The holly bears the crown.”
—Unknown. The Holly and the Ivy (l. 1–4)