Countering the New Threat from Stem Rust Disease in Wheat

There are many international responses to the threat for wheat production posed by the evolution of a highly damaging race of the stem rust pathogen Puccinia graminis f. sp. tritici in east Africa.

One major response by CIMMYT, ICARDA, FAO, USDA-ARS and Cornell University was the establishment of an expert panel which published a report in 2005 entitled "Sounding the Alarm on Global Stem Rust" (click here). This gave important background to countering the disease over the past century in other parts of the world, and then focused on race Ug99 in Kenya and Ethiopia and the potential for its spread to neighbouring regions and beyond.

Ug99 was named from its impact in Uganda in 1999. It arose by evolving virulence against the resistance gene Sr31, which had long been effective and widely used in Africa and many other parts of the world. Sr31 is on the 1B/1R chromosomal translocation, a piece of chromosome from rye that has been introduced into many wheat cultivars.

The Borlaug Global Rust Initiative (BGRI) emerged in response to a recommendation in the report of the earlier panel. The BGRI has a wider objective of systematically reducing the world's vulnerability to stem (P. graminis), yellow or stripe (P. striiformis), and leaf (P. recondita) rusts of wheat. It also aims to develop a sustainable international system to contain the threat of these rusts and to continue enhancements in productivity for withstanding future global threats to wheat.

For information on progress by BGRI, collaborations and events until early 2008, including FAO reports of the detections of Ug99 in Yemen and Iran, see http://www.globalrust.org/.

At the International Congress of Plant Pathology in Turin, Italy in August 2008, R P Singh, Y Jin, J Huerta-Espino, P Njau, R Wanyer and R W Ward presented a paper "Strategies to Mitigate the Threat to Wheat Production from the Ug99 (TTKS) Race of Stem Rust". This is published as an abstract in Journal of Plant Pathology (2008), 90 (2, Supplement), S2.19.

An FAO Wheat Rust Disease Global Programme and a declaration adopted in November 2008 at the International Conference on Wheat Stem Rust Ug99: "A Threat to Food Security" in Delhi, India may be found as links in FAO news at  http://www.fao.org/news/story/en/item/8391/icode/ .

The conference in Delhi noted that the scientific community is addressing the challenge as evidenced by Ug99 Workshops held at Shimla, India in November, during the Eleventh International Wheat Genetics Symposium, Brisbane, Australia in August, and at the International Centre for Agriculture in Dry Areas (ICARDA), Aleppo, Syria in March, all during 2008.

CIMMYT's GIS unit has developed RustMapper. This aims to provide up to date information on the current status and potential spread of wheat stem rust race Ug99 or derivatives. RustMapper uses Google Earth as a visualization tool. It shows the current known sites and status of Ug99 or derivatives; country summary information on wheat production and susceptibility to Ug99; near-real time wind trajectories from known sites using the NOAA HYSPLIT model; and, major wheat production areas in Africa & Asia. See: http://www.cimmyt.org/gis/rustmapper/.

There will be a BGRI 2009 Technical Workshop in Cd. Obregon, Sonora, Mexico, from 17-19 March 2009. See "Coming Events".

The vulnerability of many wheat cultivars to the evolving Ug99, which has developed virulences to some other resistance genes, and the likely spread of these races from present locations to regions to the east and to other parts of the world require the vigilance, actions and planning emphasised in all of the above.

British Society for Plant Pathology (BSPP)

BSPP will be holding its Presidential Meeting for 2008 at Queen Mary College, London, UK from 16-17 December as indicated in "Coming Events". Professor Graham Jellis is President in 2008.

BSPP has just announced its Presidential Meeting for 2009. This will be a special one day event in celebration of Charles Darwin's 200th birthday and it will be held at the University Museum, Oxford, UK on 22 September 2009. Professor Sarah Gurr of Oxford University is the President for 2009. The meeting will be preceded by a one day Molecular Biology of Plant Pathogens Workshop at Somerville College, Oxford.

For more details, see: http://www.bspp.org.uk/.

Reports from ISPP Subject Matter Committees

Several Subject Matter Committees (SMCs) sent reports on their activities to ISPP in the period before ICPP2008. Reports came from the SMCs for: Common Names of Plant Diseases (ISPP-CCN); Fusarium; Grapevine Trunk Diseases; Plant Virus Epidemiology; Taxonomy of Plant Pathogenic Bacteria (CTPPB); Teaching. Most of the reports are on the ISPP web-site for SMCs  http://www.isppweb.org/about_subject.asp . For the Fusarium SMC report, see:  http://www.isppweb.org/nljan08.asp#3 .

Reports on the activities of other Subject Matter Committees would be welcome.

Australasian Plant Pathology Society Conference

The 17th Australasian Plant Pathology Society Conference (APPS 2009) marks the 40th anniversary of the Society. It will be held in the Civic Centre of Newcastle, NSW, Australia, from 29 September-1 October 2009 (see: Coming Events).

The Convenor of the Organising Committee is Professor David Guest of the University of Sydney. He writes that "The conference offers participants an opportunity to reflect on achievements in a time of unprecedented scientific discovery about the nature of plant disease. It is also a time to ponder the directions of the profession amidst the challenges posed by emerging diseases, food security, climate change, water, trade, bioterrorism, consumer safety and preferences, and the opportunities presented to agriculture and horticulture by biofuels, phytomedicines and leisure activities."

The theme "Plant Health Management: an integrated approach" addresses these challenges from three angles - fundamental discovery, the application of these discoveries to practical problems and the adoption of research. Keynote speakers will lead plenary sessions focused on each theme, with concurrent sessions based around offered papers and posters, with a supporting program of special interest workshops and field trips.

Newcastle is a bustling, historic, post-industrial seaside city 150 km north of Sydney. It has easy access from all major Australasian cities, a range of accommodation, exciting cultural activities, superb beaches, and other nearby attractions including the Hunter Valley, Barrington Tops National Park and much superb coastal scenery.

See: http://www.apps2009.org.au/ .

9th International Mycological Congress (IMC9)

The British Mycological Society (BMS) will host the 9th International Mycological Congress (IMC9) in Edinburgh, Scotland, UK during 1-6 August 2010.

Other societies and organizations will contribute to and support IMC9. These include the British Lichen Society, British Society for Medical Mycology, British Society for Plant Pathology, European Mycological Association, Society for Applied Microbiology, Society for General Microbiology, the Royal Botanic Gardens at Edinburgh, and the Royal Botanic Gardens at Kew.

See: http://www.imc9.info/ .

Book Review - Plant Pathogenic Bacteria

Plant Pathogenic Bacteria: Genomics and Molecular Biology. Ed. Robert W Jackson. xii + 330 pp. ISBN: 978-1-904455-37-0. Pounds Stg 150 or $310.

The first whole genome sequence, that of the human respiratory pathogen Haemophilus influenzae, was published in 1995, and of a plant pathogen, Xylella fastidiosa, five years later. At that time the sequencing procedures in use were logistically complex and the cost substantial; since 2000 there has been at least a one hundredfold reduction in cost and sequencing can now be accomplished in one reaction rather than carried out on thousands of subclones of DNA. The expansion of sequencing has been dramatic and whole genome sequences are now available for hundreds of different species of prokaryote. In parallel there has been an increase in the content of databases and improvements in the management and analysis of large amounts of sequence data. Appropriately the last chapter in the book addresses the bioinformatic aspects of high throughput sequencing technology.

Chapters and authors are listed at: http://www.horizonpress.com/ppb .

The book is generaly comprehensive in coverage. There are chapters on the fastidious prokaryotes (Xylella fastidiosa and Leifsonia xyli subsp. xyli) as well as all of the major phytopathogenic bacteria which are readily cultivated in standard media. The first chapter also includes a summary of work on diversity in Candidatus Liberibacter, the cause of an emerging plant disease, Huanglongbing, also known as greening diseases of citrus. This phloem-restricted pathogen has not yet been cultivated in artificial medium. No part of the book deals with the uncultivated phytopathogenic mollicutes.

The first three chapters make up almost one quarter of the book and taken together are a tour de force. They provide a most valuable perspective on the development of the subject, not neglecting some of the visionary ideas in work published 50 years ago. These chapters would be appropriate foundation reading for any plant scientist entering the field.

The following seven chapters describe the developments in the comparative genomics of specific pathogen groups. A consistent feature of these chapters is the importance of lateral (or horizontal) gene transfer in the make up and evolution of bacterial genomes and of the role of plasmids, insertion sequences and other mobile genetic elements in this process. The diversity of secretion systems in phytopathogenic bacteria and their role in the delivery of effectors (virulence factors) to host plants is introduced in the first chapter and given extensive later coverage.

The type III secretion system (as well as type IV) has evolved primarily to inject proteins or DNA-protein complexes directly into plants cells. There is detailed coverage on the type III system in relation to Pseudomonas syringae in chapter 10, and more generally in chapter 12 ("The art of manipulation: bacterial type III effectors and their plant targets").

Other chapters with unifying content are entitled "MAMPs/PAMPs - effectors of innate immunity in plants", "Cyclic Di-GMP signalling and the regulation of virulence in bacterial plant pathogens" and "Gene traders: characteristics of native plasmids from plant pathogenic bacteria".

One recurring theme in the book is that comparative genomics has shown the commonality of pathogenic mechanisms in different pathosystems. Several authors comment on the importance of cross fertilization of ideas between those working with plants and those working with animal or human pathogens, and the advantages of testing hypotheses in the plant Arabidopsis for which there is a whole genome sequence.

Authors have generally made a faithful selection of the most relevant recent literature but a few anomalies and inconsistencies were noted. In Chapter 4, pp. 104-106, the discussion of chromosome evolution in Photobacterium and Vibrio and between Burkholderia and Ralstonia does not include reference to any of the primary literature. Chapter 9 might have included reference to the comprehensive review on the plant pathogenic Ralstonia species by Denny in "Plant-Associated Bacteria" edited by Samuel S Gnanamanickam (Springer 2006).

A few typographical errors were noted and several of fact. On p. 13, race 3 (biovar 2) of R. solanacearum is referred to as being "nutritionally versatile". It is less nutritionally versatile (Palleroni and Doudoroff, 1971) than most other races and biovars, consistent with its relative host specialization. This relative lack of nutritional versatility is comparable to that described in Chapter 3, p.71, for Pseudomonas syringae pv. phaseolicola in comparison with other pathovars of P. syringae with a wider host range, or the non-plant pathogenic fluorescent pseudomonads colonizing the rhizosphere.

Chapter 9 on "Ralstonia solanacearum and bacterial wilt in the post-genomics era" includes a concise explanation of the taxonomic complexity of what is now regarded as a species complex. The distribution of strains of the pathogen into four phylotypes is well described; phylotype I (Asiaticum) comprising isolates from Asia and Australia, phylotype II (Americanum) isolates from the southeastern USA, South and Central America and the West Indies, phylotype III (Africanum) including isolates from Africa and phylotype IV isolates from Indonesia. This system of classification, based on sequencing of several conserved regions of the genome is gradually gaining acceptance in the scientific community, though the separation of isolates into the geographical groupings is not entirely consistent. For example phylotype 1 (Asiaticum) is found in northeastern Brazil and other parts of northern South America as well as in Central America. The strain GMI 1000 which was the first to be fully sequenced is a strain of anomalous distribution; it conforms to phylotype I but was isolated from tomato in French Guyana. It is a representative of Asiaticum not Americanum as erroneously stated on p.189. A similar slip-up occurs on p. 300 where R. solanacearum, a pathogen mainly confined to the xylem, is described as a coloniser of the phloem.

As one author states: "Although genomics does not provide immediate solutions, the science does offer the opportunity to create hypotheses and to design precise experiments". The reading of the genome sequence reveals many biological issues that can be further addressed. This book is a timely addition to the literature in a rapidly expanding field which provides ample evidence of hypothesis testing on a broad front. There is the prospect in the long term of using the science to implement improved disease management.

Chris Hayward November 4, 2008

Potato - its History, Genetics and Potential for Improvement

Dick Hamilton, a former President of ISPP now at rihamilto@shaw.ca , draws attention to an article on a brief history of the potato and an introduction to its complex genome and variation. This is timely in 2008, The International Year of the Potato, and highly relevant to attempts at improving and sustaining resistance to the seemingly ever present and constantly evolving late blight pathogen. The article by Sandra Knapp s.knapp@nhm.ac.uk  is published in the 11 July 2008 edition of Science 321 (5886) 206-207. See: http://www.scienceonline.org/cgi/content/full/321/5886/206#AFF1.

More News from Societies Associated with ISPP

A report from the American Phytopathological Society (APS) on its activities from 2003-2008 has now joined other reports received by the ISPP Secretary-General Greg Johnson for the occasion of ICPP2008 and listed in the November issue of this Newsletter. It is also on the ISPP web-site. See: http://www.isppweb.org/about_associated.asp .

Botryosphaeria web-site

This site http://www.crem.fct.unl.pt/botryosphaeria_site/index.htm  is hosted by the Faculty of Sciences and Technology, New University of Lisbon, Portugal.

According to the Introduction to the site, species in the genus Botryosphaeria are found in all temperate, tropical and subtropical regions of the world, apparently being absent from polar regions. They occur on a wide range of monocotyledons, dicotyledons and gymnosperms and can cause diebacks, cankers, witches' brooms and leaf blights or they can be endophytes.

The last ten years has seen increased attention paid to Botryosphaeria resulting in much new information and a proliferation of species names. This web-site has been developed so that new information can be added, irrelevant or outdated details deleted and current concepts updated.

Latest Volume of Crop Disease Management Reports

The 2008 volume of Plant Disease Management Reports (PDMR), published by the Plant Management Network, contains more than 560 searchable reports on the effectiveness of fungicides/nematicides, resistant varieties and other biological controls that defend against diseases of agricultural and horticultural crops. Each 1-2 page report consists of a summary outlining trial conditions and results. Test plot trial data, also in the report, includes treatment rates, application timings, and pertinent efficacy data for each product tested. Users can search the reports by keyword or section. Keyword searches can include product names, active ingredients, host crops and authors. Sections include cereals and forage crops; citrus, tropical, and vegetable crops; field crops; ornamentals and trees; pome fruits; seed treatments (for all crops); small fruits; stone fruits and nuts; turfgrass.

See: www.plantmanagementnetwork.org/pdmr .

International Meeting on Emerging Diseases and Surveillance 2009

IMED 2009 will cover a wide range of emerging human and animal diseases and surveillance issues including outbreak preparedness, prediction maps, climate change, emerging zoonoses, vaccines against emerging pathogens, and vectorborne diseases along with many other topics. It is being held in Vienna, Austria, from 13-16 February 2009, and is being co-sponsored by ProMED-mail along with OIE, the European Commission, the Wildlife Conservation Society, and the European CDC.

IMED 2009 intends to bring together the public health community, scientists, health care workers, and other leaders in the field of emerging infectious diseases. The meeting welcomes the full participation of both the human and veterinary health sectors.

See the IMED 2009 website: http://imed.isid.org/ .

Coming Events

2008 National Fusarium Head Blight Forum in Indianapolis, Indiana, USA. 2-4 December 2008. See: http://www.scabusa.org/forum08.html . Contact: scabusa@scabusa.org .

International Conference on Legume Genomics and Genetics in Puerto Vallarta, Mexico. 7-12 December 2008. See www.ccg.unam.mx/iclgg4/index.html .

Global Potato Conference 2008 "Opportunities and Challenges in the New Millennium" in New Delhi, India. December 9-12, 2008. See:  www.gpc2008.in . Contact Dr J S Minhas at  minhasjs@excite.com .

Second International Symposium on Papaya in Madurai, Tamil Nadu, India. 9-12 December 2008. See:  http://www.ishs-papaya2008.com/Home%20page.html . Contact: Dr N Kumar  kumarhort@yahoo.com .

The International Soybean Processing and Utilization Conference at the Soybean Processing and Utilization Centre, Central Institute of Agricultural Engineering in Bhopal, India. 10-14 December 2008. Contact: Dr S D Kulkarni at  sdk@ciae.res.in  or  ispuc.v@gmail.com .

BSPP Presidential Meeting "Cereal Pathosystems" at Queen Mary College, London, UK. 16-17 December 2008. See:  http://www.bsppmeetings.org.uk/ .

XV Latinamerican Congress of Plant Pathology and XVIII Congress of the Chilean Society of Plant Pathology at Pontificia Universidad Catolica de Chile in Santiago, Chile. 12-16 January 2009. Papers in English, Portuguese and Spanish are welcome. Contact Gloria Caro at  gcaro@uc.cl  or  fitopatologia@uc.cl . See:  http://www.puc.cl/agronomia/congresoalf .

The French Plant Virology Congress in Aussois, France. 18-22 January 2009.

5th Australasian Soilborne Diseases Symposium at the Thredbo Alpine Hotel, NSW, Australia. 5-7 February 2009. Registrations are now open but the deadline for abstracts was 31 October 2008. See: http://www.conlog.com.au/asds/ . Contact:  conference@conlog.com.au .

International Conference on Plant Abiotic Stress Tolerance in Vienna, Austria. 8-11 February 2009. Contact:  stressplants.pflanzenmolbio@univie.ac.at . See:  www.univie.ac.at/stressplants/  .

Crop Protection in Southern Britain at the East of England Showground, Peterborough, UK. 10-11 February 2009 See: http://www.aab.org.uk/contentok.php?id=184&basket=wwsshowconflist .

International Meeting on Emerging Diseases and Surveillance 2009 (IMED) in Vienna, Austria. For the public health community (human and animal), scientists, health care workers, and other leaders in the field of emerging infectious diseases. 13-16 February 2009. See:  http://imed.isid.org .

International Conference on Grain Legumes: Quality Improvement, Value Addition and Trade in Kanpur, India. 14-19 February 2009. See:  http://www.icar.org.in/internconference.pdf .

International Forest Biosecurity Conference, incorporating the 6th International Forest Vegetation Management Conference, in Rotorua, New Zealand. 16-20 March 2009. See:  http://forestbiosecurity.com/ . Contact: Dr Brian Richardson, General Manager, Ensis Forest Biosecurity and Protection, Private Bag 3020, Rotorua, New Zealand. Phone: +64-7-343-5516; Fax: +64-7-343-5333; Mobile: 021-913-221.

Borlaug Global Rust Initiative (BGRI) 2009 Technical Workshop in Sonora, Mexico. 17-19 March 2009. Note that there will be a registration fee of $US300. Contact:   BGRI@cornell.edu  .

FEBS Workshop 'Adaptation Potential in Plants' at the Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria. 19-21 March 2009. Contact:  maria.siomos@gmi.oeaw.ac.at . See:  www.gmi.oeaw.ac.at/febs2009 .

7th World Potato Congress "Nourishing Our Future" in Christchurch, New Zealand. 22-25 March 2009. See:  http://www.wpcnz.org.nz/ .

Greenhouse 2009: Climate Change and Resources, in Perth, Western Australia. 23-26 March 2009. See:  http://www.greenhouse2009.com .

International Conference on Plant Virology to be held at the Harrogate International Center, UK. 1-3 April 2009. See: www.aab.org.uk/contentok.php?id=73&basket=wwsshowconfdets .

The Second European Ramularia Workshop, Edinburgh 2009 - a new disease and challenge in Barley Production in Edinburgh, UK. 7-8 April 2009. See:  www.aab.org.uk .

VI International Postharvest Symposium in Antalya, Turkey. 8-12 April 2009. Contact:  erkan@akdeniz.edu.tr  . See:  http://www.postharvest2009.com/  .

Advances in epidemiology and control of rusts at Science and Advice for Scottish Agriculture (SASA), Edinburgh, UK. 22-23 April 2009. See:  http://www.aab.org.uk/page.php?start=184&conf=78 .

The 5th International Conference on Biopesticides: Stakeholders' Perspective (ICOB-V 2009) in New Delhi, India. 26-30 April 2009. Contact:  icob5.biopest@nic.in  . See:   http://www.icob5.nic.in  .

3rd International Symposium on Crop Plant Resistance to Biotic and Abiotic Factors: Current Potential and Future Demands in Berlin, Germany. 14-16 May 2009. Contact:  dpg@phytomedizin.org  . See:  www.dpg-bcpc-symposium.de  .

8th International PGPR Workshop in Portland, Oregon, USA. 17-22 May 2009. See: www.capps.wsu.edu/pgpr.

Training Program: Integrated Pest Management and Food Safety in Wageningen, The Netherlands. 18 May-12 Jun 2009. Contact: training.wi@wur.nl  .

14th International Sclerotinia Workshop in Wilmington, North Carolina, USA. 31 May-4 June 2009. See:  http://www.cals.ncsu.edu/sclerotinia_conference/index.html .

SFP National Congress (in French) in Lyon, France. 8-11 June 2009.

Canadian Phytopathological Society Annual General Meeting in Winnipeg, Manitoba, Canada. 22-25 June 2009. See:  www.cps-scp.ca  .

XXIth International Symposium on Virus and Virus-Like Diseases of Temperate Fruit Crops and XIIth International Symposium on Small Fruit Virus Diseases in Germany. 5-10 July 2009. See  http://www.phytomedizin.org/index.php?id=193 . Source: Professor Dr Wilhelm Jelkmann  Wilhelm.Jelkmann@jki.bund.de  Julius Kühn-Institut, Bundesforschungsinstitut für Kulturpflanzen, Institut für Pflanzenschutz in Obst- und Weinbau, Schwabenheimer Str. 101, 69221 Dossenheim, Germany.

Plant ROS 2009 in Helsinki, Finland. 8-10 July 2009. Contact:  organizers@pog2009.org  . See:  pog2009.org/ .

APS Annual Meeting 2009 at the Portland Convention Center, Portland, Oregon, USA. 1-5 August 2009. See:  http://www.apsnet.org .

14th Australasian Plant Breeding Conference and 11th SABRAO Conference in Cairns, North Queensland, Australia. 10-14 August 2009. See:  http://www.plantbreeding09.com.au/ .

BSPP Presidential Meeting 2009 "Celebrating Darwin's 200th Birthday" at University Museum, Oxford, UK. 22 September 2009. See:   http://www.bspp.org.uk/  .

APPS 2009 "Plant Health Management-An Integrated Approach" at the Civic Precinct, Newcastle, NSW, Australia. 30 September-2 October 2009. See:  http://www.apps2009.org.au/ . Contact: Conference Secretariat, PO Box 6150, Kingston, ACT 2604, Australia. Phone: +61 2 6281 6624, Fax: +61 2 6285 1336. Email:  conference@conlog.com.au .

The 13th World Forestry Congress (Forests in development - a vital balance) in Buenos Aires, Argentina. 18-25 October 2009. See  http://www.wfc2009.org/index_1024.html . E-mail:  info@wfc2009.org .

9th International Congress on Plant Molecular Biology in St Louis, Missouri, USA. 25-30 October 2009. Contact:  ipmb2009@missouri.edu  . See:  www.ipmb2009.org  .

The 2009 International Conference on Horticulture in Bangalore, Karnataka, India. 9-12 November 2009. See:  http://www.pnasf.org/ich2009.htm .

5th International Conference on Plant Pathology, with the theme "Plant pathology in the globalized era", at the Indian Agricultural Research Institute, New Delhi, India. 10-13 November 2009. Contact:  ipsdis@indiatimes.com  or  ipsdis@yahoo.com .

National Soybean Rust Symposium in New Orleans, Louisiana, USA. 9-11 December 2009. Contact:  dorrance.1@osu.edu  .

9th International Mycological Congress (IMC9) in Edinburgh, Scotland, UK. 1-6 August 2010. See:  http://www.imc9.info/  .

APS Annual Meeting 2010 at Opryland, Nashville, Tennessee, USA. 7-11 August 2010. See:  http://www.apsnet.org .

Plant Virus Epidemiology Symposium at Cornell University, Ithaca, New York, USA. August 2010. See:  http://www.isppweb.org/ICPVE/  .

XXVIII International Horticultural Congress (IHC2010) in Lisbon, Portugal. 22-27 August 2010. Contact:  info@ihc2010.org  . See:  http://www.ihc2010.org  .

The 8th International Conference on Pseudomonas syringae and Related Pathogens in Oxford, UK. 31 August-3 September 2010. See:  www.reading.ac.uk/Psyringae2010 . Contact:  syringae2010@plants.ox.ac.uk .

The 18th Biennial Australasian Plant Pathology Meeting and 4th Asian Conference for Plant Pathology, a Joint Conference, at the Darwin Convention Centre, Darwin, Northern Territory, Australia. 27-29 April 2011. Watch:  http://www.australasianplantpathologysociety.org.au/ .

10th International Congress of Plant Pathology 2013 (ICPP2013) "Bio-security, Food Safety and Plant Pathology: The Role of Plant Pathology in a Globalized Economy" in Beijing, China. 25-31 August 2013. Watch:  http://www.isppweb.org/congress.asp .

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