COST Action 850: Scientific Programme

Working Group 1: Symbiosis Biology
Working Group 2: Bioactive Molecules
Working Group 3: Biotechnology
Working Group 4: Interactions with field biota
Working Group 5: Socio-economics

Working Group 1: Symbiosis Biology

Objectives:

Evolutionary scientists consider that symbiosis is one of the important macro-mechanisms by means of which evolution has taken place. This is because, in symbiosis, two different genomes cooperate in creating a "super-organism" which possesses new and different capabilities. These capabilities enable the symbiotic complex to occupy and exploit a new, and sometimes surprising, ecological niche. One of the most striking models is deep-sea hydrothermal vent worms. These animals now live autotrophically like plants due to their exploitation of metabolic processes operated by their symbiotic bacteria (Childress et al., 1991, Biological Bulletin 180: 135-153). A more classical example is provided by lichens which combine fungal and algal genomes to give composite organisms that can occupy extremely poor and harsh environments (Honegger, 1998, Lichenologist 30: 193-212) These examples illustrate the possibilities that symbiosis offer for the conquest of extreme environments and new conditions.
In this COST Action WG1 will concentrate effort on symbioses that present applications relevant to agriculture and biotechnology. In addition to the extracellular bacterial symbionts of slug and insect parasitic nematodes, endocellular symbionts (symbionts that live inside the cells of the host) of these nematodes and their insect and slug hosts will also be investigated. Today we estimate that half of all insect species live with endocellular symbionts such as Wolbachia (Werren et al., Proc. R. Soc. Lond. B 1995, 261: 55-71). Study of these organisms has expanded recently and will almost certainly open up very important biotechnological possibilities. Aside from the high likelihood that they will provide novel bioactive molecules (below), endocellular symbionts interacting with their host nematodes should offer tools for pest control in sustainable agriculture, when the mechanisms of the interactions between the genomes are understood. Genome sequencing projects have been initiated in Europe for the symbiont bacteria Wolbachia and Photorhabdus. The data resulting from these sequencing efforts will allow members of WG1 to carry out functional genomics (e.g. using knock-out mutants) to identify key symbiotic genes in these bacterial symbionts.

Working Group 2: Bio-active Molecules

Objectives:

This Working Group is proposed because new insights have been reported on the occurrence of toxins produced by the bacterial symbionts Photorhabdus. This emphasises the possibilities offered by exploitation of functional diversity from the bacteriological side of the bacterium/helminthic symbiosis. These toxins are proteins encoded by several genes, which may be cloned and used in transformation. On the one hand this is a window to genetic engineering of insecticidal toxins into plants, and on the other hand it provides the possibility of enhancing the pathogenicity of the symbionts themselves in order to provide new symbiotic entomopathogenic combinations. Other toxins have been described from a strain of the bacterial symbiont Xenorhabdus and more are anticipated.
Several antimicrobial organic molecules are believed to arise from secondary metabolism of the bacterial/nematode complexes. The processes need to be better defined, but in the meantime, some antimicrobial proteinic molecules are already being characterised. The genes for these can then be identified and will again provide new possibilities for industry, medicine and agriculture.
Nematode partners of these complexes are also providing evidence of new molecules, which are involved in the pathogenic process, particularly in the early stages of the parasitism (proteases, immune depressive factors, proteases acting on the proPO system of insects). These should be cloned, sequenced and examined for medical or agricultural value. Molecules involved in the interactions between, on the one hand, the nematode and its symbiont, and on the other hand the symbiotic complex and insect defences, require refined investigation. This will be mainly the characterisation of semiomolecules where signal molecules, hormonal compounds and their corresponding receptors in the target organisms are involved. This new area of investigation is a promising way to examine symbiotic diversity for valuable molecules and ways of modifying the complexes themselves for biological control of pests.

Working Group 3: Biotechnology

Objectives:

The object ive of this Working Group is to promote the commercial exploitation of biocontrol nematodes. The Working Group will deal with production biotechnology and related activities in downstream processing. This includes the harvest and cleaning of nematode material coming out of the liquid cultures and the storage and formulation technologies aimed at prolonging the shelf-life of nematode products. This will help to ease marketing logistics and thus contribute to widening the use of these biocontrol agents. Commercial producers will cooperate with academics in order to improve the product quality and methods of monitoring quality from production down to the end user. This Working Group will also deal with testing new targets for biocontrol nematodes in semi-field and field experiments.
Intensifying the cooperation between industry, extension services and entomologists will result in the development of appropriate technical instructions for nematode use and thus help to transfer innovative nematode technology to farmers and growers. The delivery of the biocontrol nematodes to the pest will be improved through the development of novel application technology. All these tasks will be approached in close contact with the seven European companies currently producing biocontrol nematodes, with distributors and extension personnel, and with the Industrialists' Committee of this COST Action.

Working Group 4: Interactions with Field Biota

Objectives:

Successful biocontrol in practice relies on, and is affected by, a multitude of biotic interactions in the environment where the biocontrol agents are used. The agents should be synergistic, or at least compatible, with other applied or naturally occurring enemies of the pest. Such enemies include: entomopathogenic fungi, other biocontrol nematodes, bacteria, parasitoids and predators. Furthermore, the application of bio-pesticides must not have deleterious long-term effects on non-target organisms such as soil detritivores, pollinators, or rare and endangered organisms.
This Working Group will focus on synergistic and antagonistic biotic interactions of biocontrol nematode/bacterial complexes in the target environments, including knock-on effects in multitrophic interactions. The Working Group will consider interactions with both micro-organisms and macro-organisms. The impact of crop management practices that involve biological control agents will be addressed, since they are a very influential part of integrated use of the biological agents. This Working Group will find common interests with several other COST Actions.
The possibility of using biocontrol nematodes for inoculative release will be examined. There is evidence that these nematodes can disappear from the fields during cultivation, or perhaps are naturally extinct in some cases. Re-colonisation of agricultural fields by such nematodes may be feasible. Inoculation and management strategies need to be devised and tested to determine the circumstances under which sustainable biocontrol of pests may be obtained through inoculative release, and which management practices suit persistence of the nematode/bacterial complexes.

Working Group 5: Socio-economics

Objectives:

Socio-economic factors play a key role in the practical use of nematode/bacterial complexes as insect biocontrol agents. Farmers, extension officers and dealers in crop protection products are familiar with the efficacy, technology, speed and reliability of chemical pesticides, but they know little about modern, living, biocontrol products. One task of WG5 is to provide these user groups with easy, understandable and accessible information.
Direct costs of nematode use are higher than those of competing chemicals. But these higher costs can be compensated for by less frequent application and higher market prices following chemical free production. A good economic analysis of the costs and benefits of the use of nematodes in pest control is required for advice purposes.
Symbiotic nematodes are only one tool for the farmer in crop protection. They must be compatible with other crop protection methods and agricultural practices. The Working Group will work through links with other COST Actions and with the IOBC Working Groups on integrated control of pests and diseases, to identify where compatibilities should occur.
Nematode/bacterial symbioses are exempted from registration in most COST countries, but a form of registration for macro-organisms used in biocontrol is under discussion. An inappropriate set of requirements could hinder commercial development of nematodes greatly. This Working Group will provide members of the public, politicians and registration offices with adequate information on nematodes and the risks and benefits involved in their use as biocontrol agents.
The Working Group will bring together technology generation and technology transfer aspects in cooperation with WG4, in particular. This is a two-way process whereby the issues and questions that need to be investigated and the puzzles to be solved are fed into the laboratory in one direction, and the outcome and findings of the laboratory research are sent back to the field in the opposite direction. In other words, a combined "pull and push" situation has to be created, where the push from the field regarding specific research questions for biocontrol researchers has to be coupled with the pull arising from the research sector to bring the "user community" more into the research programme.
In order to provide special expertise in socio-economic affairs, WG5 will incorporate researchers dealing with participatory research methodology, in addition to biological research.