Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists identify genetic mechanism that contributed to Irish Famine

07.02.2013
Research by UC Riverside plant pathologists is the first to show that RNA silencing regulates plant defense against the notorious Phytophthora pathogens

When a pathogen attacks a plant, infection usually follows after the plant's immune system is compromised. A team of researchers at the University of California, Riverside focused on Phytophthora, the pathogen that triggered the Irish Famine of the 19th century by infecting potato plants, and deciphered how it succeeded in crippling the plant's immune system.

The genus Phytophthora contains many notorious pathogens of crops. Phytophthora pathogens cause worldwide losses of more than $6 billion each year on potato (Phytophthora infestans) and about $2 billion each year on soybean (Phytophthora sojae).

The researchers, led by Wenbo Ma, an associate professor of plant pathology and microbiology, focused their attention on a class of essential virulence proteins produced by a broad range of pathogens, including Phytophthora, called "effectors." The effectors are delivered to, and function only in, the cells of the host plants the pathogens attack. The researchers found that Phytophthora effectors blocked the RNA silencing pathways in their host plants (such as potato, tomato, and soybean), resulting first in a suppression of host immunity and thereafter in an increase in the plants' susceptibility to disease.

"Phytophthora has evolved a way to break the immunity of its host plants," Ma explained. "Its effectors are the first example of proteins produced by eukaryotic pathogens — nucleated single- or multi-cellular organisms — that promote infection by suppressing the host RNA silencing process. Our work shows that RNA silencing suppression is a common strategy used by a variety of pathogens — viruses, bacteria and Phytophthora — to cause disease, and shows, too, that RNA silencing is an important battleground during infection by pathogens across kingdoms."

Study results appeared online Feb. 3 in Nature Genetics.

What is RNA silencing and what is its significance? RNA is made from DNA. Many RNAs are used to make proteins. However, these RNAs can be regulated by "small RNA" (snippets of RNA) that bind to them. The binding leads to suppression of gene expression. Known as RNA gene silencing, this suppression plays an important role in regulating plant growth and development. When RNA silencing is impaired by effectors, the plant is more susceptible to disease.

Basic RNA silencing processes are conserved in plant and mammalian systems. They serve as a major defense mechanism against viruses in plants and invertebrates. RNA silencing has also been implicated in anti-bacterial plant defense. The discovery by Ma's lab is the first to show that RNA silencing regulates plant defense against eukaryotic pathogens.

"Phytophthora effectors have a motif or signature — a specific protein code — that allows the proteins to be delivered into host cells," Ma said. "A similar motif is found in effectors of animal parasites, such as the malaria pathogen Plasmodium, suggesting an evolutionarily conserved means for delivering effectors that affect host immunity."

Next, her lab will work on extensively screening other pathogens and identifying their effectors' direct targets so that novel control strategies can be developed to manage the diseases the pathogens cause.

Ma was joined in the study by UC Riverside's Yongli Qiao, Lin Liu, Cristina Flores, James Wong, Jinxia Shi, Xianbing Wang, Xigang Liu, Qijun Xiang, Shushu Jiang, Howard S. Judelson and Xuemei Chen; Fuchun Zhang at Xinjiang University, China; and Qin Xiong and Yuanchao Wang at Nanjing Agricultural University, China.

The research was supported by a National Science Foundation grant to Ma and grants from the U.S. Department of Agriculture (USDA) to Judelson and Chen.

In 2011, UCR received a $9 million USDA grant to research late blight, caused by Phytophthora infestans, that mainly attacks potatoes and tomatoes. Last year, UCR released avocado rootstocks that can help control Phytophthora root rot, a disease that has eliminated commercial avocado production in many areas of the world.

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 21,000 students. The campus will open a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion. A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.

Iqbal Pittalwala | EurekAlert!
Further information:
http://www.ucr.edu

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>