Featured Research

from universities, journals, and other organizations

Researchers ID Chlorophyll-regulating Gene

Date:
September 24, 2004
Source:
University Of California - Berkeley
Summary:
Researchers at the University of California, Berkeley, have identified a critical gene for plants that start their lives as seeds buried in soil. They say the burial of seeds was an adaptation that likely helped plants spread from humid, wet climates to drier, hostile environments.

Berkeley - Researchers at the University of California, Berkeley, have identified a critical gene for plants that start their lives as seeds buried in soil. They say the burial of seeds was an adaptation that likely helped plants spread from humid, wet climates to drier, hostile environments.

In a study published in the Sept. 24 issue of the journal Science, the researchers describe how a gene called phytochrome-interacting factor 1, or PIF1, affects the production of protochlorophyll, a precursor of the chlorophyll used by plants to convert the sun's energy into food during photosynthesis.

While a seed germinates under soil, in the dark, it is producing a controlled amount of protochlorophyll in preparation for its debut above ground. Much like a baby takes his or her first breath of air after emerging from the womb, seedlings must quickly convert protochlorophyll into chlorophyll once they are exposed to light for the first time.

"It's a delicate balancing act," said Peter Quail, professor of plant and microbial biology at UC Berkeley's College of Natural Resources and principal investigator of the study. "The young plant needs some protochlorophyll to get the ball rolling in photosynthesis. But if the plant accumulates too much of the compound, it leads to photo-oxidative stress, which is seen as bleaching on the leaves. The overproduction of protochlorophyll is like a ticking time bomb that is set off by the sun."

Quail is also research director of the Plant Gene Expression Center, a joint research center of the Agricultural Research Service of the U.S. Department of Agriculture and the University of California.

The researchers targeted the PIF1 gene because it binds to phytochrome, a protein that is triggered by light and that controls a plant's growth and development. The researchers disabled the PIF1 gene in the species Arabidopsis thaliana, a mustard plant, and compared the mutant seedlings with a control group of normal plants.

They grew the seedlings in the dark to mimic conditions beneath the soil, bringing groups out into the light at different time points throughout a six-day period. In nature, seeds are typically buried under 2 to 10 millimeters of soil, taking anywhere from two to seven days to germinate and break through the soil surface.

"We found that mutated plants had twice the levels of protochlorophyll than normal, wild-type plants, suggesting that phytochrome acts as a negative regulator for protochlorophyll," said lead author Enamul Huq, who conducted the study while he was a post-doctoral researcher at UC Berkeley's Department of Plant and Microbial Biology. "We also saw that the longer the seedlings were grown in the dark, the more likely they would die when they were exposed to light."

The mutated seedlings failed to switch off production of protochlorophyll throughout the germination period, so the longer the seedlings stayed in the dark, the more toxic the levels became.

Huq, now an assistant professor of molecular cell and developmental biology at the University of Texas at Austin, pointed out that it is an "unbound" form of protochlorophyll that is toxic. Normal plants, he said, produce enough of an enzyme, called protochlorophyllide oxidoreductase, to bind with typical levels of protochlorophyll. But not enough of the enzyme is produced to handle the overabundance of unbound protochlorophyll churned out by the mutant seedlings.

The researchers say the ability of plants to precisely regulate production of protochlorophyll was probably an evolutionary development designed to ensure seed survival among higher plants.

Primitive plants, such as mosses and some species of fern, thrive in moist, humid environments where their spores can stay safely above the soil surface. But all higher plants - from grasses to trees to agricultural crops such as wheat and corn - must have the ability to transition from the darkness of an underground environment to life above ground.

"The development of seed burial in plants provided a long-term survival benefit through protection from predators and hostile surface conditions," said Quail. "The true test of our hypothesis would be to verify whether primitive plants have the PIF1 gene, and whether the gene is functional."

The finding may also have implications for agricultural biotechnology, allowing researchers to manipulate the gene to improve the efficiency with which plants carry on photosynthesis.

Other co-authors of the study are Bassem Al-Sady and Matthew Hudson of UC Berkeley's Department of Plant and Microbial Biology, and Chanhong Kim and Klaus Apel of the Swiss Federal Institute of Technology's Institute of Plant Sciences in Zurich, Switzerland.

The study was supported by grants from the Department of Energy, the National Institutes of Health, the USDA and Syngenta.


Story Source:

The above story is based on materials provided by University Of California - Berkeley. Note: Materials may be edited for content and length.


Cite This Page:

University Of California - Berkeley. "Researchers ID Chlorophyll-regulating Gene." ScienceDaily. ScienceDaily, 24 September 2004. <www.sciencedaily.com/releases/2004/09/040924091507.htm>.
University Of California - Berkeley. (2004, September 24). Researchers ID Chlorophyll-regulating Gene. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2004/09/040924091507.htm
University Of California - Berkeley. "Researchers ID Chlorophyll-regulating Gene." ScienceDaily. www.sciencedaily.com/releases/2004/09/040924091507.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
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