Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UGA researchers edit plant DNA using mechanism evolved in bacteria

05.06.2015

Researchers at the University of Georgia have used a gene editing tool known as CRISPR/Cas to modify the genome of a tree species for the first time. Their research, published recently in the early online edition of the journal New Phytologist, opens the door to more rapid and reliable gene editing of plants.

By mutating specific genes in Populus--a genus of deciduous trees that includes poplar, aspen and cottonwood--the researchers reduced the concentrations of two naturally occurring plant polymers.


Poplar plants produced from a lignin-gene-targeting experiment in C.J. Tsai's lab at the University of Georgia had red-colored wood. Red stem is a known side effect of lignin modification, so the researchers knew the CRISPR system worked when they saw the red stems on their plants.

Credit: University of Georgia

One is called lignin, which traps sugars and starches used for biofuel production inside the tree's sturdy cell walls. The other is known as condensed tannin, and its presence in leaves and barks of the tree deters feeding by ruminants, such as deer, cattle, goats and sheep.

"CRISPR is a relatively new technology, but it could improve our ability to produce novel varieties of food crops, animal feeds and biofuel feedstocks," said the study's lead researcher C.J. Tsai, a Georgia Research Alliance Eminent Scholar in UGA's Warnell School of Forestry and Natural Resources and department of genetics. "Compared to some other gene editing techniques, this is incredibly simple, cost-effective and highly efficient, and it could serve as the foundation for a new era of discovery in plant genetics."

CRISPR technology is derived from a defense mechanism evolved by bacteria and other single-celled organisms. When a bacterium is attacked by an invader like a virus, it captures some of the virus's DNA, chops it up into pieces and incorporates a segment of the viral DNA into its own genome.

As the bacterium experiences more threats, it accumulates a bank of past infections in a special part of its genetic code called CRISPRs--short for clustered regularly interspaced short palindromic repeats--which act as a kind of immune system to protect against future invasions.

"This is a mechanism that evolved naturally, but we can borrow the bacteria's gene-cutting abilities and use it to edit very specific genes in all kinds of organisms, including plants and animals," said Tsai, who is also director of UGA's Plant Center. "It's like using a pair of scissors with GPS tracking to locate and snip out tiny bits of DNA--enough to nullify the gene you don't want, while leaving everything else unchanged."

Tsai credits her collaborator Thomas Jacobs, a former doctoral student in UGA's Institute of Plant Breeding, Genetics and Genomics, who adapted the CRISPR system for plant genome editing.

"Tom was a student in my class a few years back, and we were testing some of the gene silencing systems he developed for soybean in poplars," Tsai said. "It was a side project, also involving Xiaohong Zhou, a visiting doctoral student from Nanjing Forestry University, to test the new CRISPR system, and its high efficiency exceeded all of our expectations."

Every single poplar plant Zhou produced from the lignin-gene-targeting experiment had red-colored wood. Red stem is a known side effect of lignin modification found in natural mutants of maize, sorghum and pine, Tsai explained, so the researchers knew the CRISPR system worked when they saw the telltale red stems on their Populus plants.

"I was blown away by the results," Jacobs said. "This is one of the highest efficiencies ever reported, even in mouse and other animal models where the technology has been more extensively tested."

The modified Populus plants contained about 20 percent less lignin and 50 percent less condensed tannins than wild trees.

"We thought we knew what genes control lignin and condensed tannin production, and we did target the right genes, but the work showed us that there are other genes with overlapping roles," Tsai said. "The CRISPR system can now guide researchers seeking to identify these previously unknown gene family members."

###

The article on "Exploiting SNPs for biallelic CRISPR mutations in the outcrossing woody perennial Populus reveals 4-coumarate:CoA ligase specificity and redundancy" is available online at http://onlinelibrary.wiley.com/doi/10.1111/nph.13470/abstract.

Media Contact

C.J. Tsai
cjtsai@uga.edu
706-542-1271

 @universityofga

http://www.uga.edu 

C.J. Tsai | EurekAlert!

Further reports about: CRISPR DNA GPS tracking Tsai UGA bacteria bacterium biofuel production genes genetic code poplar specific genes

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 >>>