BSPP News Spring 2000 - Online Edition

The Newsletter of the British Society for Plant Pathology
Number 36, Spring 2000 

Conference and Travel Reports

Applied biotechnologies to the conservation and improvement of genetic resources of marginal native crops of Latin America
Bogota, Colombia : September 20 - October 1 1999

This seminar-workshop was aimed at young Latin-American researchers, to promote the use of molecular biology tools for the conservation and management of biological resources in their centres of biodiversity, and the application of these tools to augment productivity of agriculture in the region, particularly of marginal crops.  It was organised by The Instituto Italo-Latino Americano (IILA), the Pontificia Universidad Javeriana (PUJ) in Bogota, and the Ente per le Nouve Tecnologie, l'Energia e l'Ambiente (ENEA), and was held at the PUJ. Eighteen scientists from nine different countries participated in the event.

The seminar-workshop was structured in morning lectures and afternoon laboratory sessions.  The first week was centred in crop improvement through plant transformation.  Dr Elizabeth Hodson of the PUJ gave an introductory lecture on developments and applications of plant bioengineering for plant genetic resources. Ricardo Peñuela also from PUJ, gave the bases of risk assessment and biosafety, and benefits on the production of transgenic plants. Dr Eva Garcia from the Universidad Central of Venezuela explained about plant improvement through biotechnological methods, and also about her own experience on the transformation of potatoes with the anti-freeze gene from fish.  Dr Myriam de Peña from the Federacion Nacional de Cafeteros (National Coffee Federation) talked about plant transformation, especially through protoplasts, and the application of the technique to other crops besides coffee.  We also watched videotapes describing promising crops in Latin America prepared by the Convenio Andres Bello.

The laboratory sessions were very well blended with the morning lectures.  We were able to do hands-on plant transformation mediated by Agrobacterium tumefaciens infecting Passiflora leaves, later detecting the expression of the b-gus gene by histochemical and fluorescence reactions.  The detection of the nptII gene was done through PCR and acrylamide gel electrophoresis.  We also worked with protoplast mediated transformation on coffee.  We made direct transformation of coffee protoplasts with PEG.  The evaluation of the activity of the nptII gene was done by  PCR and gus gene by fluorescence.  There must have been a real good karma in the laboratory because fortunately all of our experiments worked!

On the second week of the seminar-workshop, themes regarding conservation and characterisation of germplasm were addressed.  Dr Rolando Estrada from the Universidad de San Marcos, Peru, gave an overview of  plant genetic resources mainly from the Andes, their conservation, characterisation and use.  Dr Paolo Donini from the National Institute of Agricultural Botany in the UK, referred to the use of molecular markers for the assessment of genetic diversity, plant breeding, marker assisted selection, and a look into future molecular techniques that will be available.  Dr Geo Coppens from CIRAD/FLHOR-IPGRI presented a talk on the diversity and potential of neotropical fruits, and gave a description of the various programmes working in that field in Latin America.  Finally, Dr Myriam de Peña spoke again, this time with relation to the use and creation of genomic libraries.

The laboratory sessions on this second half of the workshop were a bit more demonstrative.  We worked on AFLPs and microsatellites for the molecular markers area using silver staining, finished up some tests on our transformed Passiflora leaves and coffee protoplasts, and also had the opportunity to partially construct a coffee genomic library with lambda gt10.

On the evening of Thursday September 30th, we were awarded our diplomas for participating in the seminar-workshop, and on Friday, our last day, a roundtable discussion was organised on 'Use of transgenic plants in their area of origin and regulation of plant biotechnology: patents and biosafety'.  There were talks presented by various guests: Dr Rodrigo Artunduaga (Colombian Agriculture Institute) 'XXI Agro-century: The roll of transgenic plants in the technological development of the agricultural sector'; Dr Ricardo Torres (Colciencias) 'Access to genetic resources and assessment of biosafety'; Dr Rafael Armendariz (Colciencias) 'Regulatory frame for plant biotechnology'; PhD(c) Ricardo Peñuela (PUJ/University of Sussex) 'Public scientific counselling: risk, safety and uncertainty';  and Dr Gilberto Cely (PUJ) 'Towards a bioethical perspective in plant biotechnology'.   The urgent need for national and international law regulations on the use, safety and patents of transgenic plants and plant biotechnology seemed to be the consensus and main concern.

As one of the intentions of the seminar-workshop, good relationships were established between participants, lecturers and staff, all aiming towards a more collaborative approach to deal with research priorities in Latin America. I must say that I was impressed by the quality of research that is being carried out in several institutes and organisations in Latin America, and by the great future it holds, which can only be enhanced by the participation and collaboration of developed countries' institutions, scientists and funding.

I would like to thank the various Institutes that organised the event, all lecturers who participated, and the BSPP for the travel fund. I would also like to express my condolences for Dr Julio Samper's unexpected death in Bogota, shortly after the event, who was the mentor and promoter of the seminar-workshop.

Maria Eugenia Ordoñez
Universidad Tecnologica Equinoccial, Quito, Ecuador


American Phytopathological Society and Entomological Society of America Joint Annual Meeting
Las Vegas, Nevada, USA : November 8 - 12 1998

The 90th annual meeting of the American Phytopathological Society was held in association with the Entomological Society of America. The venue for the meeting was the Las Vegas Hilton, a gargantuan 3000-bed edifice in a city described as a 'family entertainment destination' in the middle of the Nevada desert. Oh yes, and a casino too - all in all a more appropriate venue for joint meeting of the Hedonist Society (if one exists) and the Society for Applied Probability or perhaps Improbable Results (any bets?). Before the end of the first day, unlikely tales of the Ph.D student who had cleaned up on the blackjack tables and had promptly disposed of his poster over the Hoover Dam, were circulating.

The scientific programme was ambitious, challenging and imaginatively put together. The normal APS format of specialist symposia, colloquia, discussion sessions, workshops, and offered paper sessions (oral and poster), structured according to the special interest committees was followed, but was enhanced by joint sessions with the ESA. These were too numerous to mention individually and certainly to attend, but included symposia on Aerial Dispersal of Pests and Pathogens (see below), Genomics research, Ecologically-based Pest Management, Virus Transmission by Insect Vectors,  Molecular Signalling in Plant Interactions, Pesticide Policy and Sampling  for Decision Making. Sole APS symposia included one devoted to Burkholderia cepacia (see below).

The joint symposium on Aerial Dispersal of Pests and Pathogens: Implications for Developing and Deploying Integrated Pest Management Strategies was organized by Don Aylor (Connecticut) and Mike Irwin (Illinois), each of whom spoke in the symposium; Mike in terms of setting the IPM context for dispersal research, while Don gave an authoritative account of biophysical scaling in relation to dispersal of fungus spores. In fact, scaling, whether ecological (Stuart Gage, Michigan) or meteorological (Westbrook, Texas A&M), was a   recurring theme in the symposium. Plant pathological interest was maintained by Eckhert Limpert  (ETH, Zurich) who gave a comprehensive account of the Zurich group's research on cereal powdery mildew dispersal across Europe using genetic markers. The different aspects of insect dispersal were illustated by talks on the 'weaker flying' whiteflies (Byrne, Arizona) and 'stronger flying' leafhoppers (Shields, Cornel) - with obvious relevance to plant virus epidemiology. Finally Mike Jeger (Wageningen) attempted a summary  in terms of how an improved understanding of dispersal affects current options and future directions in pest management.

Mike Jeger took the opportunity to form preliminary views on how the BSPP Presidential meeting for 1999 on 'Biotic Interactions in Plant Pathogen Associations' might develop, and attended Sessions where such interactions were highlighted by speakers. Two colloquia in particular, on Insects and Pathogens in Forest Ecosystems and on Multitrophic Interactions in Soil between Arthropods and Plant-Associated Microrganisms, were very productively mined and these two topics will feature in presentations to be made in December. He also took the opportunity to sit in on Sessions concerned with topics slightly apart from his main interests. These included presentations on baculovirus application for the control of insect pests;  where recombinant technology has made rapid strides recently, without raising too much public ire other than in the insertion of the gene for scorpion venom toxin. Virtually no reference was made to the value of modelling the implications of such interventions, either in the case of pest management or from a broader environmental perspective. A Ph.D student from Wageningen (Felix Bianchi) presented a poster at the meeting on this important topic. As would be expected in current times, the GMO issue arose during different sessions. The implications for  managing weed resistance in transgenic herbicide-resistant crops were raised by Mallory-Smith (Oregon). Educated guesses it seems are still the norm.

The APS symposia Burkholderia cepacia Friend or Foe, was the first time key researchers from the fields of phytopathology, medical microbiology, and biocontrol had gathered together to present papers and provide a global outlook on the potential environmental impact of B. cepacia. James Lorbeer described initial detection of B.cepacia as the causal agent of soft rot in onions. Bob Lumsden went on to detail the use of environmental B. cepacia isolates as biocontrol agents, the types of fungal pathogens which B.cepacia has been shown to be effective against, and the development and testing of DENYTM, a licensed biocontrol product. The epidemiology of B. cepacia as an opportunistic pathogen of immunocompromised humans, particularly the clinical incidence of B. cepacia syndrome in cystic fibrosis sufferers formed the basis of J. Lipuma's presentation. P. Vandamme explained how the B. cepacia taxa was poorly defined and how his use of whole cell protein profiles and DNA-DNA hybridisations had led to the classification of B.cepacia into five separate genomovars, but that these genomovars could not separate clinical isolates from environmental isolates.

The most compelling presentation of the day was given by J. Govan, who provided an insight into the dramatic impact of B.cepacia colonisation on the cystic fibrosis community, and the fear of B. cepacia experienced by sufferers and relations alike. T. Lessie revealed that B. cepacia has multiple genomes and numerous insertion sequences, explaining the plasticity of the B. cepacia genome . Finally J. Andersen made clear the requirements for a B.cepacia product to be licensed as a biopesticide within the USA. A lively discussion ensued, as to the criteria which any future B.cepacia biocontrol products would have to meet given the increasing concerns about the organism's human pathogenic potential, the risks to workers involved in the production and application of B.cepacia biocontrol products, and the emergence of so called growth promoting bioproducts which use B.cepacia but slip through a loophole in the American licensing procedure.

 Many of the offered papers in a Session on Bacteria Genetics, Molecular Biology, Cell Biology attended by Jane Richardson  considered virulence genes. Two talks were particularly good. Q. Huang showed that two genes pehA and pehB which code for polygalacturonases have a role in virulence in Ralstonia solanacearum, by looking at the localisation within tomato plants of bacteria with mutations in these genes. R. Loria talked about the nec1 gene which was found to be conserved in plant pathogenic strains of Streptomyces species, it's G+C content was found to be different to the genomic content, and the gene appeared to be linked to a transposase gene, suggesting plant pathogenicity  in Streptomyces species may have been conferred by horizontal transfer.

Offered papers in Biological Control  were also of interest to Jane,  ranging from the use of supressive soils, crop rotation with plants such as marigolds and mustard, and use of parasitic fungi. V.  Kempster's presentation was intriguing, it reported that the use of killed fluorescent pseudomonads produced an induced systemic response in clover to soil dwelling nematodes. H. Heungens had looked at the mode of action of the proposed biocontrol agent AMMDR1, which is a strain of B. cepacia, on Pythium and  Aphanomyces. It was found that the bacterium could have a detrimental effect at a number of different stages in the life cycle of the two fungi.

We would like to thank the BSSP for the  travel awards, without which we would have been unable to attend the APS-ESA  meeting and present our respective paper and poster which were well-received at the Sessions.

Mike Jeger (Wye College) and Jane Richardson (CSL, Sand Hutton)