 |
|
Important gene controlling tree growth and development found
May 05, 2006Scientists at the UmeĆå Plant Science Centre (UPSC) and the Swedish University of Agricultural Sciences (SLU) report today about a breakthrough in our understanding of how the growth and development of forest trees is controlled. In an article published in the international journal Science, they show that the FT gene that was previously shown to control the flowering time of annual plants, also controls tree flowering. With the help of this gene poplar trees can be stimulated to flower after a few weeks instead of after the normal 10-15 years. The scientists also show that the same gene not only controls the flowering time of trees, but also the timing of when the trees stop growing and set bud in the fall. That the same gene was involved in all these processes was highly unexpected.
The breakthrough for our understanding of the regulation of tree growth and development might revolutionize forest tree breeding and can lead to the development of new tree seedlings with a dramatically improved growth and also "tailor made" quality parameters suited for improved pulp and paper production, better construction materials and enhanced bioenergy production.
Trees are extremely important for life on earth. They are often a dominating part of the ecosystems and 30 per cent of the earths landmass is covered with forests. Trees produce many important products for mankind such as renewable fuel, cellulose for the pulp and paper industry and construction materials.
Compared to most other plants, trees display some key features. They are the latest flowering plants known many trees do not form their first flower until they are 10-20 years old, sometimes even older! Trees also have the ability to cycle between growth and dormancy. This is a way to adopt to harsh winter conditions when the supply of water is low and the tree might be damaged from both drought and cold. The trees have adopted to these conditions by stopping growth and forming buds at the end of summer or early fall. Decidious trees also shed their leaves. The tree is now dormant and is as such much more resistant to drought and frost than if it had been actively growing.
It has been known for a long time that the trees sense that fall is coming by measuring the length of the day. When the days get shorter the trees "know" that it is time to stop growing and set buds, even if it is a very warm fall. The trees are known to display a "critical daylength". If the days get shorter than this critical daylength the tree responds with growth cessation and bud set. The further north the trees grow the more important it is to stop growing and form buds sufficiently early in late summer. This means that trees originating from different latitudes (different origins in the north to south direction, so called "provenances", display different critical daylengths. For instance, an aspen tree from the middle of Germany stops growing and sets buds when the days get shorter than 16 hours. Compare this with a tree from northern Sweden which stops growing and prepares for winter already when the days get shorter than 21 hours long. Trees from northern Norway can even display critical daylengths of 23 hours! This trait is genetically inherited and is kept if the tree is moved to a new climate.
How the trees control their flowering, and why trees set bud at a certain time in the fall have been important questions for the scientists to answer. This is for two reasons. These are important traits that "makes a tree into a tree". There is a considerable applied interest in these traits. If one can induce early tree flowering it should be possible to dramatically enhance the speed of forest tree breeding. Plant breeding has been extremely successful for the development of superior plant material for agriculture. It has, however, had a small impact on forestry. To a large extent this has been caused by the fact that a forest tree breeder has to wait for 10-20 years between each cross in his breeding program.
The poplar tree FT gene, controlling both the flowering time of trees and the time for growth cessation and bud set in the fall, has been identified by a research group led by professor Ove Nilsson at the UmeĆå Plant Science Centre (UPSC) and the Swedish University of Agricultural Sciences. The gene is very similar to the Arabidopsis FT gene, the gene that is producing the messenger molecule that controls the flowering of annual plants and that is considered to be the so called ³Florigen². Results concerning the Arabidopsis gene were published last year by the Nilsson group, also in Science. This finding was ranked by Science to belong to the third most important scientific discovery in 2005.
The scientists now show that the poplar FT gene is turned on before the tree starts flowering for the first time after 10-15 years. If the gene is activated prematurely in a transgenic tree, the tree can be stimulated to flower already in just a few weeks. After a few months completely normal flowers are formed.
It is also shown that the poplar FT gene is turned off in late summer just before the trees stop growing and set bud. By changing the activity of the FT gene the scientists could either prolong or shorten the growing season of the tree. They could also determine the mechanisms involved in growth cessation and bud set in the fall. This knowledge is vital if we want to adopt plants and trees to new climates.
Swedish Research Council
Compared to most other plants, trees display some key features. They are the latest flowering plants known many trees do not form their first flower until they are 10-20 years old, sometimes even older! Trees also have the ability to cycle between growth and dormancy. This is a way to adopt to harsh winter conditions when the supply of water is low and the tree might be damaged from both drought and cold. The trees have adopted to these conditions by stopping growth and forming buds at the end of summer or early fall. Decidious trees also shed their leaves. The tree is now dormant and is as such much more resistant to drought and frost than if it had been actively growing.
It has been known for a long time that the trees sense that fall is coming by measuring the length of the day. When the days get shorter the trees "know" that it is time to stop growing and set buds, even if it is a very warm fall. The trees are known to display a "critical daylength". If the days get shorter than this critical daylength the tree responds with growth cessation and bud set. The further north the trees grow the more important it is to stop growing and form buds sufficiently early in late summer. This means that trees originating from different latitudes (different origins in the north to south direction, so called "provenances", display different critical daylengths. For instance, an aspen tree from the middle of Germany stops growing and sets buds when the days get shorter than 16 hours. Compare this with a tree from northern Sweden which stops growing and prepares for winter already when the days get shorter than 21 hours long. Trees from northern Norway can even display critical daylengths of 23 hours! This trait is genetically inherited and is kept if the tree is moved to a new climate.
How the trees control their flowering, and why trees set bud at a certain time in the fall have been important questions for the scientists to answer. This is for two reasons. These are important traits that "makes a tree into a tree". There is a considerable applied interest in these traits. If one can induce early tree flowering it should be possible to dramatically enhance the speed of forest tree breeding. Plant breeding has been extremely successful for the development of superior plant material for agriculture. It has, however, had a small impact on forestry. To a large extent this has been caused by the fact that a forest tree breeder has to wait for 10-20 years between each cross in his breeding program.
The poplar tree FT gene, controlling both the flowering time of trees and the time for growth cessation and bud set in the fall, has been identified by a research group led by professor Ove Nilsson at the UmeĆå Plant Science Centre (UPSC) and the Swedish University of Agricultural Sciences. The gene is very similar to the Arabidopsis FT gene, the gene that is producing the messenger molecule that controls the flowering of annual plants and that is considered to be the so called ³Florigen². Results concerning the Arabidopsis gene were published last year by the Nilsson group, also in Science. This finding was ranked by Science to belong to the third most important scientific discovery in 2005.
The scientists now show that the poplar FT gene is turned on before the tree starts flowering for the first time after 10-15 years. If the gene is activated prematurely in a transgenic tree, the tree can be stimulated to flower already in just a few weeks. After a few months completely normal flowers are formed.
It is also shown that the poplar FT gene is turned off in late summer just before the trees stop growing and set bud. By changing the activity of the FT gene the scientists could either prolong or shorten the growing season of the tree. They could also determine the mechanisms involved in growth cessation and bud set in the fall. This knowledge is vital if we want to adopt plants and trees to new climates.
Swedish Research Council
Tree Growth News and Current Tree Growth Events RSSVine invasion? UWM ecologist looks at coexistence of trees and lianas
Among the hundreds of species of woody vines that University of Wisconsin-Milwaukee ecologist Stefan Schnitzer has encountered in the tropical forests of Panama, the largest has a stalk nearly 20 inches in circumference.
Scattered nature of Wisconsin's woodlands could complicate forests' response to climate change
If a warmer Wisconsin climate causes some northern tree species to disappear in the future, it's easy to imagine that southern species will just expand their range northward as soon as the conditions suit them.
Forests Could Benefit When Fall Color Comes Late
Do those fall colors seem to show up later and later-if at all? Scientists say we can blame increasing amounts of carbon dioxide in the atmosphere for prolonging the growing season of the trees. And that may actually be good news for forestry industries.
UGA forest genetics researcher leads effort to sequence and catalog conifer genes for future biofuels research
Jeffrey Dean, professor of forest biotechnology in the University of Georgia Warnell School of Forestry and Natural Resources, is spearheading a project at the U.S. Department of Energy's Joint Genome Institute (JGI) that will greatly expand the gene catalog for pines and initiate the first gene discovery efforts in five other conifer families.
Chickadee, nutchatch presence in conifers increases tree growth, says CU-Boulder study
Chickadees, nuthatches and warblers foraging their way through forests have been shown to spur the growth of pine trees in the West by as much as one-third, according to a new University of Colorado at Boulder study.
Presence of wolves allows aspen recovery in Yellowstone
The wolves are back, and for the first time in more than 50 years, young aspen trees are growing again in the northern range of Yellowstone National Park.
Heatwave on the top of the world
The French Intergovernmental Panel on Climate Change (IPPC, or GIEC in French) has just announced the conclusions of its 4th report, which restates that global warming has increased the average temperature by 0.74°C over the last century.
Soil nutrition affects carbon sequestration in forests
On December 11, USDA Forest Service (FS) scientists from the FS Southern Research Station (SRS) unit in Research Triangle Park, NC, along with colleagues from Duke University, published two papers in The Proceedings of the National Academy of Science (PNAS) that provide a more precise understanding of how forests respond to increasing atmospheric concentrations of carbon dioxide (CO2), the major greenhouse gas driving climate change.
Historic volcanic eruption shrunk the mighty Nile River
Volcanic eruptions in high latitudes can greatly alter climate and distant river flows, including the Nile, according to a recent study funded in part by NASA.
NASA satellites can see how climate change affects forests
A NASA-funded study shows that satellites can track the growth and health of forests and detect the impact of a changing climate on them.
More Tree Growth News Articles
 | The Secret by Rhonda Byrne Fragments of a Great Secret have been found in the oral traditions, in literature, in religions and philosophies throughout the centuries. For the first time, all the pieces of The Secret come together in an incredible revelation that will be life-transforming for all who experience it.In this book, you'll learn how to use The Secret in every aspect of your life -- money, health, relationships,... |
 | The Proper Care and Feeding of Husbands by Laura Schlessinger In her most provocative book yet, Dr. Laura urgently reminds women that to take proper care of their husbands is to ensure themselves the happiness and satisfaction they yearn for in marriage. Women want to be in love, get married, and live happily ever after. Yet disrespect for men and disregard for the value, feelings, and needs of husbands has fast become the standard for male-female... |
 | Ten Stupid Things Women Do to Mess Up Their Lives by Laura C. Schlessinger Dr. Laura Schlessinger is the incredibly popular and controversial psychotherapist who hosts a nationally syndicated, top-rated midday radio talk show. She has strong convictions and doesn't hesitate to voice them to callers. She urges women emphatically to lose a domineering jerk of a lover and pick one of the "good guys," to stay home and parent the babies they've made, and to follow the dream... |
 | Self Matters: Creating Your Life from the Inside Out by Phillip C. McGraw What if there is a You that has never seen the light of day, has never got to say, "Hey, what about me?" What if there is a You that you have never even met and certainly never permitted to just be, without fear of judgment or condemnation? What if you live your life on the sidelines in constant fear of failing to please those who forever seem to stand in judgment of you and your life? What... |
 | Stop Whining, Start Living by Dr. Laura Schlessinger Dr. Laura Schlessinger agrees that there are things worth whining about! A certain amount of whining allows for some venting of reasonable pain, disappointment, fear, frustration, or frank rage. However, staying stuck in whining mode can become a life-long problem. This is where Dr. Laura steps in with Stop Whining, Start Living to help folks conquer the temptation to retreat from living life to... |
 | Men Are from Mars, Women Are from Venus: A Practical Guide for Improving Communication and Getting What You Want in Your Relationships by John Gray Relationship counselor John Gray focuses on the differences between men and women--men are from Mars, and women are from Venus, after all--and offers a simple solution: couples must acknowledge and accept these differences before they can develop happier relationships. In this unabridged version, Gray gives a spirited delivery of his message, especially when role-playing typical male/female... |
 | Bad Childhood---Good Life: How to Blossom and Thrive in Spite of an Unhappy Childhood by Dr. Laura Schlessinger In this important book, Dr. Laura Schlessinger shows men and women that they can have a Good Life no matter how Bad their Childhood. For each of us, there is a connection between our early family dynamics and experiences and our current attitudes and decisions. Many of the people Dr. Laura has helped did not realize how their histories impacted their adult lives, or how their choices in people,... |
 | The Dance of Anger: A Woman's Guide to Changing the Patterns of Intimate Relationships by Harriet Lerner "Anger is a signal and one worth listening to," writes Dr. Harriet Lerner, in her renowned classic that has transformed the lives of millions of readers.While anger deserves our attention and respect, women still learn to silence our anger, to deny it entirely, or to vent it in a way that leaves us feeling helpless and powerless. In this engaging and eminently wise book, Dr. Lerner teaches women... |
 | Take Time for Your Life by Cheryl Richardson Personal coach Cheryl Richardson helps people create the lives they want. In Take Time for Your Life, she shows you how to switch from being stressed, unfulfilled, and overworked, to "living a life you love" by using a seven-step process. First, she gives you permission to "make the quality of your life your top priority" by honoring your self-care--a difficult choice for fast-track readers, but... |
 | The Oak Inside the Acorn by Max Lucado It was hard for Little Acorn to believe he would ever be a big, strong oak tree. Soon Little Acorn grew into Little Oak. But now what was he to do? He couldn't grow oranges like the orange tree or flowers like the rose bush. He just grew and grew until he became Big Oak, and his branches were big and strong-but still he didn't know what he was to do. Then one day Big Oak found that his strong... |
| © 2008 BrightSurf.com |