CRC for Plant Biosecurity - russian wheat aphid

Polymorphisms in salivary transcripts of Russian wheat aphid biotypes 1 and 2

CRICHTONA — Fri, 20 Apr 2012 06:10:20 +0000

Polymorphisms in salivary-gland transcripts of Russian wheat aphid biotypes 1 and 2

Russian wheat aphid experts convene in Singapore to safeguard Australian crops

VANMEURSA — Mon, 03 May 2010 07:48:55 +0000

Scientists from across the globe convened last week at a workshop focused on the Russian wheat aphid; a pest that could be devastating to Australia’s barley and wheat crops.

The workshop was held from April 26 – 28 in Singapore and attended by 27 of the world’s top wheat aphid scientists. Our chairman, Professor John Lovett and Murdoch University’s Associate Professor Mehmet Cakir hosted the two and a half day workshop.

The CRC along with our participant organisation Grains Research and Development Corporation sponsored the workshop, while Murdoch University and CSIRO offered their expertise in developing the scientific program.

Australia is currently free of the Russian wheat aphid and through international collaboration this workshop provided scientists with the opportunity to continue safeguarding Australia’s crops from this serious and harmful pest. An incursion of the Russian wheat aphid would be devastating to Australia's $5 billion wheat industry.

A wide range of presentations were given throughout the workshop including CRC researchers, Dr Owain Edwards, Dr Susan Fuller and Dr Gerald Reeck. CRC presentations were based on Russian wheat aphid research from project CRC40006 and PhD project CRC60111.

CRC40006 led by CSIRO’s Dr Owain Edwards is focused on research involving genomic sequencing of the salivary glands of the aphids, in an attempt to map how they evolve to secrete new forms of proteins that wheat plants no longer recognise as precursors to attack. QUT’s Dr Susan Fuller is supervising Bo Zhang, our PhD candidate based in China. Dr Fuller gave a presentation on Bo’s behalf, discussing the invasion genetics of Russian wheat aphid in western China and worldwide. Dr Gerald Reeck is also working on the PhD project with Dr Fuller and Ms Zhang. He presented work on the characterisation of proteins secreted in aphid saliva.

The international workshop provided an opportunity for scientists to present their research, as well as the opportunity for further discussion and collaboration. To enhance these networking opportunities, the program also included two social functions, a trip to Singapore Zoo and a formal dinner held at the Orchard Hotel.

Genome Sequence of the Pea Aphid Acyrthosiphon

K.Scott — Wed, 03 Feb 2010 23:07:01 +0000

Surveillance planning tool for exotic grain pests - Russian wheat aphid

VANMEURSA — Thu, 21 Jan 2010 04:26:30 +0000

Gene search into the secrets of a super-bug crop destroyer

VANMEURSA — Thu, 22 Oct 2009 00:02:32 +0000

Media Release: 22 October 2009

The genetic make-up of one of the world’s most devastating crop pests, the Russian wheat aphid, is being analysed as part of a sophisticated biosecurity effort to protect Australia’s wheat industry – and the numerous regional communities it supports.

Australian researchers are part of an international consortium that is sequencing the genes of aphids in a bid to eventually breed wheat varieties that have long-term resistance to the pest.

Australia’s wheat industry is worth almost $5 billion annually and Australia is the only major wheat-growing region of the world currently free of the pest, which can wipe out entire crops. Both barley and wheat are affected.

So destructive is the pest that none of the aphids can be brought into the country even for research purposes. Instead, Australian scientists are relying on their international partners to assist them in studying this insect. Australian researchers are also using the pea aphid as a surrogate for their local research.

CSIRO entomologist Dr Owain Edwards is leader of a Cooperative Research Centre (CRC) for National Plant Biosecurity project to develop Australia’s response to any incursion by the Russian wheat aphid.

Dr Edwards says since the 1970s the aphid has spread rapidly through the major wheat-growing regions of the world from the Middle East and Balkan states where it appears to be endemic.

“It causes major crop destruction for the first five to seven years after it appears in a new region, until the ecosystem establishes a balance, with occasional outbreaks causing ongoing problems.

"It remains a major pest in the US and South Africa. These countries spent 10 years developing and rolling out resistant wheat varieties, but all of the original resistant wheats relied on a single resistance gene. Within six or seven years the aphids evolved to overcome that resistance,” Dr Edwards says.

His research involves genomic sequencing of the salivary glands of the aphids, in an attempt to map how they evolve to secrete new forms of proteins – proteins that wheat plants no longer recognise as precursors to attack. Dr Edwards says the changes in aphid saliva indicates a rate of evolution 50 to 100 times faster than that of other insects.

When aphids attack a resistant plant, the plant detects particular proteins in the aphid saliva and cuts off the flow of sap to that part of the plant. Finding no sap, the aphids leave the plant and fly on to neighbouring plants.

Tasting is the primary mechanism aphids have for identifying their food. If, after several attempts to feed, they are unsuccessful, they can launch themselves into the air currents and can travel hundreds of kilometres in search of a new food source.

In non-resistant plants, the wheat does not recognise the protein and allows Russian wheat aphids to feed without triggering any defence mechanisms. This results in white streaks on the wheat leaves – symptoms similar to drought stress. The leaves also curl, trapping the heads of the plants and making it impossible to harvest the grain.

“Contact insecticides are relatively ineffective because the aphids are inside the curled leaves, where the chemicals can’t reach them,” Dr Edwards says. “It only takes relatively small numbers of these aphids to cause significant damage.”

None of the wheat or barley varieties currently released in Australia have Russian wheat aphid resistance, and rolling out resistant varieties from the US or South Africa would be relatively ineffective if aphids arriving in Australia are those that have already evolved to overcome plant resistance.

“Identifying the mechanisms aphids use to generate new proteins and developing resistance to those proteins at a more fundamental level is the strategy we are pursuing. Once we understand the underlying mechanism, the appropriate resistance can be developed for a range of different aphid species and crops,” Dr Edwards says.

Collaborators in the CRC for National Plant Biosecurity project include CSIRO, the Grains Research and Development Corporation, and Kansas State University in the US. The Chinese Academy of Sciences will also join the research this year.

Instructions for downloading images

To download and save images, right-click on the link and click ‘save target as’. If you experience any problems, please contact Communications Manager, Kate Scott on 0402 299 611 or k.scott@crcplantbiosecurity.com.au

CRC60111: Russian Wheat Aphid – Supervisors Meeting and Strengthening Collaborations

VANMEURSA — Thu, 15 Oct 2009 23:08:33 +0000

Dr Susan Fuller travelled to China to meet with PhD candidate, Ms Bo Zhang and her supervisors Owain Edwards (CSIRO) and Dr Le Kang (Chinese Academy of Science). Susan is the principal supervisor for Bo’s PhD project CRC60111: Russian Wheat Aphid. The purpose of Susan’s visit was to ensure that field sampling and initial lab work was well planned and that Bo’s project continued to meet proposed timelines. Travelling to China was also an opportunity for Susan to guide Bo in her laboratory studies, particularly in the area of microsatellite DNA marker development and screening. Furthermore, this trip helped Susan to deepen collaborative relationship between Australian and Chinese researchers.

The CRCNPB project 60111: Russian Wheat Aphids represents an extremely important step in Susan’s research career, as the project is helping her to build professional links both domestically (with CSIRO) and internationally (with the Chinese Academy of Sciences). Linkages of this type are extremely beneficial for both short and long term career progression.

Susan found that travelling to China was extremely beneficial, as meeting face-to-face with international partners, in their home laboratories was much more valuable in developing personal links than a year’s worth of exchanged emails.

The Chinese Academy of Sciences in Beijing will act as a base to study populations of the Russian wheat aphid in its native range, western China. This collaboration is ideal in terms of facilitating collection of samples, which when compared with samples from invasive populations, will provide valuable management information for what is considered to be one of the greatest biosecurity threats to the grains industry in Australia. The expected outcome of the project is the development of an improved, pre-emptive biosecurity plan for the Russian Wheat Aphid.

This travel proposal has lead to the further strengthening of collaborative links between Australian and Chinese researchers. It has also facilitated knowledge transfer and research approaches in invasion biology/biosecurity amongst the researchers and organisations involved. This travel grant has allowed Susan to meet with all partners involved in the CRC60111: Russian Wheat Aphid project and to coordinate the management of the research program for the next 12 months.

During this visit, Susan also had the opportunity to meet with Dr Qiao, a world-renowned aphid taxonomist, who has agreed to provide Bo with access to the aphid collection in the Beijing Museum of Zoology. This represents a very valuable connection and future collaboration.

CRC60111: Russian Wheat Aphid - PhD

VANMEURSA — Wed, 15 Jul 2009 06:08:45 +0000

CRC40006: Russian Wheat Aphid

K.Scott — Tue, 22 Jul 2008 06:00:11 +0000

Program

Impact Management