Featured Research

from universities, journals, and other organizations

Feeling stressed? So is the poplar -- but hormone suppression could help the tree

Date:
May 8, 2010
Source:
Michigan Technological University
Summary:
Scientists have identified the molecular mechanism that poplar trees use to adapt to changing soil conditions, as well as some of the genes that turn the process on or off.

The plant at the left, with the most vigorous root system, is the one most deficient in a plant hormone known as gibberellin.
Credit: Image courtesy of Michigan Technological University

People aren't the only living things that suffer from stress. Trees must deal with stress too. It can come from a lack of water or too much water, from scarcity of a needed nutrient, from pollution or a changing climate. Helping trees and crops adapt to stress quickly and efficiently is a pressing goal of plant biologists worldwide.

Now research led by Michigan Technological University scientists has identified the molecular mechanism that Populus -- the scientific name for common poplars, cottonwoods and aspens -- uses to adapt to changing soil conditions, as well as some of the genes that turn the process off or on. They hope to apply what they've learned to find ways to use biotechnology or selective breeding to modify the trees to make them more stress-tolerant.

"Our hope is that by understanding how this works, we can manipulate the system so the plants can adapt faster and better to stressful conditions," explained Victor Busov, associate professor in Michigan Tech's School of Forest Resources and Environmental Science and senior author on a paper published in the March 2010 issue of the journal The Plant Cell.

Busov and colleagues at Michigan Tech, the University of Georgia, Oregon State University and the Beijing Forestry University in China analyzed thousands of genes in the Populus genome, the only tree genome that has been completely sequenced. They were searching for the mechanism that regulates the plant's decision to grow tall or to spread its roots out in an extensive underground exploration system that can sample the soil near and far until it finds what the rest of the plant needs.

The key players turned out to be a family of hormones called gibberellins, referred to by the scientists as GAs.

"GAs' role in root development is poorly understood," said Busov, "and the role of GAs in lateral root formation is almost completely unknown." Lateral roots are the tangle of tiny roots that branch out from the primary root of a plant. "They are the sponges," Busov explained, "the ones that go looking for nutrients, for water -- the ones that do most of the work."

The researchers found that GAs interact with other plant hormones such as auxin to tell the plant whether to concentrate on reaching for the sky or on building a bigger, better network of roots under ground. "The GAs and auxin are definitely talking, molecularly," said Busov.

Growing poplar seedlings mutated to make them GA-deficient, the scientists compared their root and stem growth to others that contained moderate amounts of GAs and a control group of wild-type plants with normal GAs. They found that the more GAs, the more a plant's stem flourished, but its roots remained spindly. When GA production was shut down, either by using mutants that lacked the necessary genes or by silencing the genes that form the molecular on-off switch, the resulting plants looked dwarfed, but their lateral roots grew luxuriant and full.

Application of GA to the GA-deficient dwarf plants rapidly reversed the process. The plants grew tall, but their lateral root systems shriveled.

"Clearly, lack of the hormone promotes growth below ground, while the hormone itself promotes growth above ground," said Busov. "This is a natural mechanism that we don't know much about. It's always a tradeoff between growth above ground and growth below ground. Normally there is a fine balance, and this balance is a little disturbed under stress."

In a commentary on the research published in the same issue of the journal, Kathleen Farquharson, science editor of The Plant Cell, wrote: "This study provides important insights into how plant hormones regulate lateral root development."

The research was supported in part by grants from the US Department of Energy's Poplar Genome Based Research for Carbon Sequestration in Terrestrial Ecosystems project ad by the US Department of Agriculture's National Plant Genome initiative.


Story Source:

The above story is based on materials provided by Michigan Technological University. The original article was written by Jennifer Donovan. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. Gou, S. H. Strauss, C. J. Tsai, K. Fang, Y. Chen, X. Jiang, V. B. Busov. Gibberellins Regulate Lateral Root Formation in Populus through Interactions with Auxin and Other Hormones. The Plant Cell, 2010; 22 (3): 623 DOI: 10.1105/tpc.109.073239

Cite This Page:

Michigan Technological University. "Feeling stressed? So is the poplar -- but hormone suppression could help the tree." ScienceDaily. ScienceDaily, 8 May 2010. <www.sciencedaily.com/releases/2010/05/100506152249.htm>.
Michigan Technological University. (2010, May 8). Feeling stressed? So is the poplar -- but hormone suppression could help the tree. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2010/05/100506152249.htm
Michigan Technological University. "Feeling stressed? So is the poplar -- but hormone suppression could help the tree." ScienceDaily. www.sciencedaily.com/releases/2010/05/100506152249.htm (accessed July 23, 2014).

Share This




More Plants & Animals News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins