Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Huge virulence gene superfamily responsible for devastating plant diseases

07.04.2008
A research team from the Virginia Bioinformatics Institute at Virginia Tech has identified an enormous superfamily of pathogen genes involved in the infection of plants.

The Avh superfamily comprises genes found in the plant pathogens Phytophthora ramorum and Phytophthora sojae. The pathogen genes produce effector proteins that manipulate how plant cells work in such a way as to make the plant hosts more susceptible to infection. The results suggest that a single gene from a common ancestor of the both pathogen species has spawned hundreds of very different, fast-evolving genes that encode for these highly damaging effector proteins.

P. sojae causes severe devastation in soybean crops and results in $1–2 million in annual losses for commercial farmers in the United States. P. ramorum, which causes sudden oak death, has attacked and killed tens of thousands of oak trees in California and Oregon. Both pathogens belong to the oomycete group of organisms that also includes the potato late blight pathogen responsible for the Irish potato famine. The scientists probed the recently published genome sequences of both organisms using bioinformatic tools that can look for specific amino acid sequences or motifs. Advanced searches of the genome sequences (BLAST and Hidden Markov Model) revealed that the P. sojae and P. ramorum genomes encode large numbers of effector proteins (374 from P. ramorum and 396 from P. sojae) that likely facilitate the infection of their host plants. Given that there are more than 80 species of Phytophthora pathogens, these findings imply that there are more than 30 000 members of this superfamily within the genus Phytophthora.

Proteins arising from the Avh superfamily have very different amino acid sequences but share two common motifs at one end of the protein (N-terminus). The readily identified RXLR and dEER motifs (single letter code for amino acids) are required for entry of the proteins into plant host cells. Similar motifs are also found in the effector proteins produced by the malarial parasite Plasmodium as it invades red blood cells. The team also detected some conserved amino acid motifs (W, Y and L) at the other end (C terminus) of some of the proteins that have been selected over years of evolution. These C-terminal motifs are usually arranged as a module that can be repeated up to eight times. The functions of these C-terminal motifs are being investigated further.

... more about:
»AvH »Genome »Phytophthora »acid »amino »effector »motifs »ramorum »sojae »superfamily

The Avh gene superfamily is one of the most rapidly evolving parts of the genome. Duplications of genes are common and presumably responsible for the rapid expansion of the family. The diversity and duplication of genes noted in the sequences are consistent with maximizing the number of effector genes in the pathogens while making it increasingly difficult for the host defense systems to recognize invading molecules, ideal features for effector proteins aimed at wreaking havoc on susceptible plant hosts. Professor Brett Tyler of the Virginia Bioinformatics Institute, the leader of the project, remarked: “The extraordinary speed with which the Avh genes are evolving suggests that these genes are key to the pathogens’ ability to outwit the defense systems of the plants.”

Barry Whyte | EurekAlert!
Further information:
http://www.vbi.vt.edu

Further reports about: AvH Genome Phytophthora acid amino effector motifs ramorum sojae superfamily

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke 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: 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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

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

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>