Transcript White paper from the EPSO Workshop “Environmental Plant Biology”

Environmental plant biology:
Interactions between plants pathogenic,
beneficial and multitrophic organisms
EPSO workshop
Amsterdam, 21 November – 22 November 2005
organized by
John Mundy, Hans van Veen & Pierre de Wit
Aim of the EPSO workshop
• Bring together scientists to discuss and exchange ideas
on future directions of research on molecular and
ecological aspects of interactions between plants and
their pathogenic and beneficial organisms and discuss
possible applications for sustainable agriculture.
• Participants should produce a white paper on the subject
that will aid EPSO to suggest new directions in research
at European level, including the Strategic Research
Agenda in “Plants for the Future”.
Theme 1: Interactions between plants, arbuscular and ectomycorrhiza
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Francis Martin, Nancy, France
Ectomycorrhizal symbiosis
Paola Bonfante, Turino, Italy
Arbuscular mycorrhizal symbiosis
Theme 2: Interactions between plants and nitrogen fixing communities
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Jens Stougaard, Aarhus, Denmark
Rhizobium-legume symbiosis
Katharina Pawlowski, Stockholm, Sweden
Nitrogen fixation outside the legumes
Alfred Puehler, Bielefeld, Germany
Ecology and evolution of alfalfa nodulating Sinorhizobium meliloti strains
Theme 3: Interactions between plants and plant growth stimulating
bacteria and fungi
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Jos Vanderleijden, Leuven, Belgium
Rhizosphere bacterial signaling: A love parade beneath our feet
Jos Raaijmakers, Wageningen, The Netherlands
Cyclic lipopeptide surfactants: versatile molecules in the interactions
between beneficial bacteria, fungal pathogens and plants
Matteo Lorito, Portici, Italy
Biological control with non-pathogenic fungi
Theme 4: Interactions between plants and pathogenic bacteria
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Ulla Bonas, Halle, Germany
Xanthomonas campestris pv. vesicatoria interaction with the host plant
John Mansfield, London, UK
Bacterial virulence and basal resistance – lessons from Pseudomonas
syringae
Christian Boucher, Castanet Tolosan, France
Integrated approach of Ralstonia solanacearum pathogenicity determinants
and of their plant targets
Theme 5: Interactions between plants and pathogenic fungi
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Marc-Henry Lebrun, Lyon, France
Fungus-plant interactions: perspectives from the pathogen side
James Brown, Norwich, UK
Fitness costs of resistance and pathogenicity in fungal diseases of cereals
Jane Parker, Cologne, Germany
Intersection of obligate biotrophs with multi-layered plant defence
Theme 6: Interactions between plants and pathogenic nematodes
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Wim van der Putten, Heteren, The Netherlands
Plant adaptation to parasitic nematodes in a multitrophic environment
Pierre Abad, Sofia Antipolis, France
Root-knot nematode parasitism and plant host response
Theme 7: Multitrophic interactions between plants and biotic agents
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Philippe Reymond, Lausanne, Switzerland
Transcriptional responses of Arabidopsis after herbivore attack
Marcel Dicke, Wageningen, The Netherlands
Multitrophic interactions in plant-pathogen-herbivore systems
Challenges for future research on plant
pathogens
Pathogenicity factors
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Determine functions of bacterial and fungal effectors.
Determine plant targets of bacterial and fungal effectors.
Sequence genomes of relatives of plant pathogens.
Compare strategies of pathogens with different life styles by
comparative genomics, transcriptomics, bio-informatics, proteomics,
metabolomics.
Plant responses to pathogens
• Dissect signaling pathways in susceptible plants (intrinsic functions
of effectors).
• Dissect basal defense pathways (innate immunity induced by
pathogen- associated molecular patterns; PAMPs).
• Dissect signaling pathways in resistant plants (resistance genemediated defense pathways).
Challenges for future research on
resistance breeding against pathogens
Study various types of resistance
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Basal resistance mechanisms.
Major, minor resistance genes.
Plant tolerance.
QTL-type of resistance.
Exploit genetic diversity of resistance present in wild relatives (only
10% is exploited).
Plants to be studied (model and crop plants)
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Arabidopsis, tomato, potato.
Rice, corn, wheat, barley.
Medicago, Lotus.
Poplar.
Conclusions of discussions on plantpathogen interactions
• More research needed on viruses, bacteria, fungi, oomycetes
nematodes, vectors of pathogens.
• More microbial genomes (oomycetes, fungi, bacteria) need to be
sequenced in order to understand pathogenic evolution.
• Compare life styles of necrotrophs, biotrophs, beneficial fungi and
bacteria, saprophytes, endophytes.
• Discover new pathogenicity factors by comparative genomics, bioinformatics, functional analysis and identify their plant targets.
• Apply new scientific discoveries in breeding for durable resistance.
Challenges for future research on
beneficial micro-organisms
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Analysis of molecular basis of interactions between plants and beneficial
micro-organisms (perception and signaling).
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Comparative genomics of host and microbe: (i) compare symbiotic
relationships of Lotus sp. with those of Populus sp.; (ii) compare
mycorrhizal relations with those of biotrophic pathogens.
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Comparison of nitrogen fixation by micro-organisms in association with
plants and by free-living micro-organisms.
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Analysis of energy costs for the host plant when interacting with different
beneficial micro-organisms.
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Study of culturable and non-culturable micro-organisms in the rhizosphere
(including metagenomics).
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Study ecology and evolution of endophytes.
Conclusions on beneficial plant-microbe
interactions
• Reduce dependency on chemicals and fertilisers
in crop production.
• Reduce energy costs in agriculture and forestry.
• Change crop production systems in relation to
future needs and climate change.
• Improve soil quality including safeguarding
biodiversity and soil organic matter levels.
Challenges for future research on multitrophic
interactions between plants biotic agents
Biology:
• Complex system trials, including evaluation of Arabidopsis mutants and
other model or bridging species for translational genomics to crops.
• Metabolome and transcriptome analysis of plants interacting with different
organisms including analyses of indirect resistance and signaling between
hosts and biotic agents.
• Plant resistance to herbivores requires genomics of both herbivores and
their natural enemies.
• Mechanisms and extent of signaling crosstalk needs to be elucidated.
Ecology:
• Metabolomics is required to identify costs and benefits of plant defense in
above- and below-ground multitrophic networks.
• Unraveling the defense strategies of wild plants against combinations of
above- and below- ground biotic agents.
• Understanding ecological processes that are affected by trade-offs between
growth and defense, or trade-offs between direct and indirect defense.
Challenges for future research on multitrophic
interactions between plants biotic agents
Evolutionary biology
• Evaluation of the fitness costs for plants and parasites with increased resistance and
pathogenicity, respectively.
• Analyses of trade-offs between resistances to different types of disease.
• Evaluation of fitness costs in different environments and the contribution of these
costs to variation in natural populations.
Plant breeding
• Development of selection schemes for durability (resistance, yield, sustainability),
• Support plant breeding in the public sector.
• Plant breeding is the technology with the capacity to integrate advances in many
aspects of plant performance simultaneously.
• Plant Breeding is the most cost-effective technology to develop crop varieties with
reasonably stable performance in variable environments.
• It is now vital that plant breeding is revived in public-sector research and teaching to
develop crop varieties with traits that are essential in 20-50 years’ time (which would
not be profitable to develop in a purely market-driven economy).
Conclusions of discussions on multitrophic
interactions between plants and biotic agents
• Interactions between plants and multiple biotic agents are significant
in crop plants.
• Selection of crop varieties with all-round resistance to diseases,
pests and abiotic stresses is a challenge.
• Global climate change will make the environment and crop
production more variable and less predictable
• There is concern about negative impacts of agriculture on the
environment, but also climate change can have a negative impact
on food production.
• Multidisciplinary research is required to find cost-effective methods
for future sustainable food production.
Overall conclusions for national and
European research agenda
Set up European consortia supported by national and
international agencies (FP7, ERA-PG) that combine
efforts on:
• Joint sequencing of additional microbial genomes.
• Joint research on plant pathogen interactions.
• Joint research on plant-beneficial micro-organism
interactions.
• Joint research on plant-multitrophic interactions.
Implementation of workshop
• Complete white paper on interactions between plants
pathogenic, beneficial and multitrophic organisms.
• Disseminate white paper nationally and internationally to
stimulate (financial) support for this subject.
• Incorporate new ideas for future research on this subject
in the FP7 and ERA-PG survey.
• Establish consortia that perform trans-national research
within FP7 or ERA-PG on this subject.