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:
“He who plants a tree
Plants a hope.”
—Lucy Larcom (1826–1893)
“... feminism is a political term and it must be recognized as such: it is political in women’s terms. What are these terms? Essentially it means making connections: between personal power and economic power, between domestic oppression and labor exploitation, between plants and chemicals, feelings and theories; it means making connections between our inside worlds and the outside world.”
—Anica Vesel Mander, U.S. author and feminist, and Anne Kent Rush (b. 1945)
“Brute force crushes many plants. Yet the plants rise again. The Pyramids will not last a moment compared with the daisy. And before Buddha or Jesus spoke the nightingale sang, and long after the words of Jesus and Buddha are gone into oblivion the nightingale still will sing. Because it is neither preaching nor commanding nor urging. It is just singing. And in the beginning was not a Word, but a chirrup.”
—D.H. (David Herbert)