Featured Research

from universities, journals, and other organizations

Biologists Discover Protein's Impact On Plant-Water Balance

Date:
June 18, 2001
Source:
Penn State
Summary:
Researchers at Penn State and the University of North Carolina at Chapel Hill have discovered that a protein in plant guard cells impacts how well a plant holds water. Eventual application of the researchers' work could help control the amount of water in a plant and lead to more ecologically friendly, effective, and efficient means to raise crop plants.

Researchers at Penn State and the University of North Carolina at Chapel Hill have discovered that a protein in plant guard cells impacts how well a plant holds water. Eventual application of the researchers' work could help control the amount of water in a plant and lead to more ecologically friendly, effective, and efficient means to raise crop plants.

In response to drought, sunlight, and other stimuli, guard cells control the opening and closing of microscopic stomatal pores on leaves of plants through which the plant gives off water vapor and oxygen to the atmosphere and takes in carbon dioxide for photosynthesis. Guard cells thereby moderate the amount of water and carbon dioxide in the plants. Researchers Sarah M. Assmann, professor of biology at Penn State, and Xi-Qing Wang, a postdoctoral scholar at Penn State, along with collaborators at the University of North Carolina, discovered that by altering a specific protein in the guard cells those cells had less control over the amount of water lost by the plants through their stomatal pores. The research team's results will be published in the 15 June 2001 edition of Science.

"The potential agricultural significance is being able to regulate stomatal apertures," Assmann says. "From a farmer's perspective, finding a way to maximize photosynthesis and yield, and a way to minimize irrigation, which can be expensive, would be important."

In Arabidopsis thaliana, the researchers' model organism, also known as mouse-ear cress, the natural hormone abscisic acid (ABA) usually promotes water conservation under drought conditions by signaling guard cells to change their volume, thereby decreasing the size of the stomatal pores and limiting the amount of water lost by plants. The North Carolina researchers identified Arabidopsis plants in which a naturally occurring G-protein component within the guard cells, the G-protein alpha subunit, had been eliminated. The Penn State group analyzed those plants and found that they had lost a typical response to ABA regulation of the guard cells. As a result, opening of the stomatal pores was no longer inhibited by ABA and water loss from the plants was greater than in unaltered plants.

Animals, including humans, have approximately two dozen G proteins that fulfill fundamentally important roles by relaying signals for smell, taste, and vision. Plants have a much smaller family of G proteins that perform similar duties regarding response and signaling about their environment, and those proteins are not as well understood as their counterparts in animals and humans. With their findings, the researchers gained a better appreciation of the proteins' role in plants. Because the plant system has fewer G proteins, and therefore less "crosstalk" between G-protein pathways, its simplicity also may allow researchers to unravel universal questions regarding G-protein mechanisms more easily than in animal systems.

"These proteins have been of interest to me for a long time because of their fundamental importance for environmental responses," Assmann says. "Until recently, though, we did not have the genetic tools that allowed us to completely prevent the plants from expressing just one particular type of response. With that capability, we have been able to learn a great deal about what happens to the plants."

With the G-protein information as a starting point, researchers should be able to learn even more about environmental response and signaling in plants. In addition, because Hong Ma, associate professor of biology at Penn State and the first to identify plant G-protein genes, already has identified G-protein components in crop species such as corn and tomatoes, the research results present some interesting possibilities.

"We cannot state that the G proteins will do the same thing in agronomic species that they do in Arabidopsis, but it's a testable hypothesis and it's a reasonable hypothesis," Assmann says. "There are also many potential applications, such as controlling stomates to allow plants like feed corn to dry faster in the field before harvest. Conversely, if we could control the guard cells to increase plant water retention during the growing season and reduce the need for expensive irrigation, we also would improve the agroenviroment because irrigation increases the amount of salt left behind in the soil and saline soils are toxic to most crop plants."

Collaborators from North Carolina were: Alan Jones, professor of biology, and Hemayet Ullah, graduate student. This research was supported by the National Science Foundation and the U.S. Department of Agriculture.


Story Source:

The above story is based on materials provided by Penn State. Note: Materials may be edited for content and length.


Cite This Page:

Penn State. "Biologists Discover Protein's Impact On Plant-Water Balance." ScienceDaily. ScienceDaily, 18 June 2001. <www.sciencedaily.com/releases/2001/06/010615071843.htm>.
Penn State. (2001, June 18). Biologists Discover Protein's Impact On Plant-Water Balance. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2001/06/010615071843.htm
Penn State. "Biologists Discover Protein's Impact On Plant-Water Balance." ScienceDaily. www.sciencedaily.com/releases/2001/06/010615071843.htm (accessed September 30, 2014).

Share This



More Plants & Animals News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
Argentina Worries Over Decline of Soybean Prices

Argentina Worries Over Decline of Soybean Prices

AFP (Sep. 27, 2014) The drop in price of soy on the international market is a cause for concern in Argentina, as soybean exports are a major source of income for Latin America's third largest economy. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Mama Bear, Cubs Hang out in California Backyard

Mama Bear, Cubs Hang out in California Backyard

Reuters - US Online Video (Sep. 27, 2014) A mama bear and her two cubs climb trees, wrestle and take naps in the backyard of a Monrovia, California home. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
'Crazy' Climate Forces Colombian Farmers to Adapt

'Crazy' Climate Forces Colombian Farmers to Adapt

AFP (Sep. 26, 2014) Once upon a time, farming was a blissfully low-tech business on Colombia's northern plains. Duration: 02:05 Video provided by AFP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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