Leaves, trunk and roots: Geneticists reveal how a tree knows to grow

Apr 29, 2010 by Stu Hutson

(PhysOrg.com) -- Countless words have been put to paper over the years in attempts to describe the beauty of a tree -- including carefully crafted passages by the world?s most gifted writers. But those writings pale in comparison to the intricacy of a tree?s own genetic script.

A team at the University of Florida’s Institute of Food and Agricultural Sciences, led by geneticist Matias Kirst, has completed a first study of how the byzantine interplay of elements within a tree’s spell out different structures, such as leaves, trunk and roots.

All cells in a tree have the same , whether it’s in a leaf or a root. However, how that genetic information is translated into the various tree structures is based on a complex set of interactions, said Kirst, a researcher with the UF Genetics Institute.

In the English language, a silent “e” on the end of a word can affect how the vowels in the middle of the word are pronounced. Even a word’s placement in a sentence can change its meaning.

Similarly, the expression of genes spelled out in one section of DNA is often regulated by a gene or multiple genes somewhere else in the genetic code. In turn, those genes moderate the activities of others — forming networks of intertwined genetic activity.

In a paper that will be published in the May 4 issue of the journal , the team reports the first mapping of these networks of interactions as they affect different parts of two types of cottonwood trees.

While similar genetic network mapping has been done of , this represents the first time that this level of understanding has been reached in the plant world.

“These are relationships we could never begin to understand without advanced computer modeling techniques that are only now possible,” said Arthur Berg, who contributed genetic statistical analysis to the study while at UF, and is now a professor of biostatistics at Penn State College of Medicine in Hershey.
The analysis also revealed that certain gene networks are active only within specific parts of the tree. Meanwhile, other gene networks were active throughout the tree.

Knowing which genes are expressed only in some parts of the tree and which are expressed throughout the tree is key to researchers and breeders attempting to develop trees and other plants best suited for biofuel, pulp, paper and timber production, Kirst said.

One of the common problems encountered by plant breeders is that breeding for one trait can have negative outcomes in other parts of the plant. For example, a florist breeding for larger flowers may find that the flowers have less scent. This is because the genes responsible for one trait, such as flower size, may have other responsibilities within the plant.

By recognizing such genes, researchers can find solutions, such as specifically targeting secondary active only in the desired part of the plant.
The work will help develop trees that are specifically suited to being used as feedstock for cellulosic ethanol, an environmentally friendly and renewable substitute for gasoline.

However, it is likely that many other plants will have similar to those discovered in the cottonwood — potentially leading to more sophisticated ways of improving food crops.

Explore further: Researchers decipher genetic mechanism that makes the midge invulnerable to harsh conditions

Related Stories

Discovery May Speed Tree Breeding, Biotechnology

May 31, 2006

Researchers have discovered the genetic controls that cause trees to stop growing and go dormant in the fall, as well as the mechanism that causes them to begin flowering and produce seeds – a major step forward in understanding ...

Researchers demonstrate way to control tree height

Jun 18, 2007

Forest scientists at Oregon State University have used genetic modification to successfully manipulate the growth in height of trees, showing that it’s possible to create miniature trees that look similar to normal trees ...

Researchers find genes that 'tune' flower fragrances

Feb 09, 2010

(PhysOrg.com) -- Shakespeare famously wrote, "That which we call a rose by any other name would smell as sweet." With all due respect to the Bard, University of Florida researchers may have to disagree: no matter what you ...

Plant Gene Mapping May Lead to Better Biofuel Production

Apr 13, 2009

(PhysOrg.com) -- By creating a 'family tree' of genes expressed in one form of woody plant and a less woody, herbaceous species, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory ...

Proper flower and leaf development tied to the same gene

Jan 12, 2010

(PhysOrg.com) -- A group of Dartmouth researchers have discovered a new role for an important plant gene. Dartmouth Biology Professor Tom Jack and his colleagues have learned that a gene regulator called miR319a (micro RNA ...

Recommended for you

'Most famous wheat gene' found

Sep 15, 2014

Washington State University researchers have found "the most famous wheat gene," a reproductive traffic cop of sorts that can be used to transfer valuable genes from other plants to wheat.

Mosses survive climate catastrophes

Sep 15, 2014

Mosses have existed on Earth for more than 400 million years. During this period they survived many climate catastrophes that wiped out more robust organisms such as, for example, dinosaurs. Recently, British ...

Final pieces to the circadian clock puzzle found

Sep 14, 2014

Researchers at the UNC School of Medicine have discovered how two genes – Period and Cryptochrome – keep the circadian clocks in all human cells in time and in proper rhythm with the 24-hour day, as well ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

gwrede
not rated yet May 01, 2010
However, it is likely that many other plants will have similar gene networks...


Duh! Ever seen a red haired person with dark brown eyes? Or an African American with green eyes? Didn't think so.

I'd be amazed if even an amoeba didn't have such networks.