Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers ID chlorophyll-regulating gene

24.09.2004


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.

Sarah Yang | EurekAlert!
Further information:
http://www.berkeley.edu

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>