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International Workshop CAMo: from molecules to modeling Università di Torino, Italy September 14th–15th, 2015 PROVISIONAL Abstract Collection FA COST Action FA1405 Using three-way interactions between plants, microbes and arthropods to enhance crop protection and production July 15th, 2015 Editors: ii Simona Bonelli∗ , Roberto Cavoretto† , Alessandra De Rossi† , Ezio Venturino† ∗ Dipartimento di Scienze della Vita e Biologia dei Sistemi, via Accademia Albertina 13, † Dipartimento di Matematica “Giuseppe Peano”, Università di Torino, via Carlo Alberto 10, 10123 Torino, Italy. Contents Ofir Bahar: Molecular mechanisms of Insect-vectored-bacterial diseases . . . . . . . . . . . Paula Baptista: Role of endophytes and epiphytes microorganisms in the mediation of olive tree resistance to plant pathogens . . . . . . . . . . . . . . . . . . . . . . . . . . Alison Bennett: Arbuscular mycorrizal fungi influence plant-insect interactions . . . . . . Arjen Biere: Effects of soil biota on aboveground plant-insect interactions . . . . . . . . . Aleksandra Bulajić: Quarantine and economically important plant viruses in Serbia: detection, characterization and epidemiology . . . . . . . . . . . . . . . . . . . . . . . . Henryk Czosnek: Expression of whitefly primary endosymbiotic GroEL in plants provides tolerance to several virus families . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maria Cristina Digilio: Trichoderma and insect control . . . . . . . . . . . . . . . . . . . . Tomas Erban: The role of pathogenesis-related proteins in defense against fungal diseases and insect pests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Enric Frago: Insect symbionts mediate interactions at the community level . . . . . . . . . David Giron: Insect Reprogrammers and associated bacterial symbionts: From Strategies for Manipulating Plants to Agriculture . . . . . . . . . . . . . . . . . . . . . . . . . . Kristina Gruden: Potato Virus Y infection hinders potato defence response and renders plants more vulnerable to Colorado potato beetle attack . . . . . . . . . . . . . . . . Barbara H. Łabanowska: Insect Reprogrammers and associated bacterial symbionts: From Strategies for Manipulating Plants to Agriculture . . . . . . . . . . . . . . . . . . . . Anna-Liisa Laine: How sensitive are species interactions to stressful environmental conditions? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Brian R. Murphy: Translating from 2-way interactions to 3-way interaction research with fungal endophytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Photini Mylona: Enhancement of pollination services as a measure of biodiversity improvement in Mediterranean cropping systems . . . . . . . . . . . . . . . . . . . . . Kalliope Papadopoulou: Tripartite interactions of fungal endophytes and arbuscular mycorrhizal fungi (AMF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Eduardo de la Peña: Induced plant defences mediated by glandular trichomes in tomato: mechanism of induction and implications for plant-insect-natural enemy interactions Sergio Rasmann: Genetic variation drives ecological outcomes of the three-way interaction between plant herbivores and microorganisms . . . . . . . . . . . . . . . . . . . . . . Jaka Razinger: Utilizing rhizosphere competence of entomopathogenic or insect associated fungi to enhance crop production and resistance to soil pests . . . . . . . . . . . . . . Kari Saikkonen: Trophic interactions mediated by fungal endophytes . . . . . . . . . . . . Carolin Schneider: Beneficial endophytes: Development of biofertilizers and biocontrol products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jean-Christophe Simon: Aphid-plant-microbe interactions: from ecological to functional studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ayco Tack: Plant-microbe-insect interactions across space . . . . . . . . . . . . . . . . . . Radomira Vankova: Hormonal dynamics in the roots of Brassica napus during infection with Plasmodiophora brassicae - comparison of tolerant and sensitive cultivar . . . . Maria Carlota Vaz Patto: Biotic-abiotic interactions in Portuguese common bean. A case study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ezio Venturino: Pathogens influence on interacting populations . . . . . . . . . . . . . . . K. Vrandečić: Plant pathogenic fungi in Croatia . . . . . . . . . . . . . . . . . . . . . . . . 1 1 2 3 4 5 6 6 7 7 8 9 10 10 11 11 12 13 14 15 17 18 18 19 19 20 20 iii iv Molecular mechanisms of Insect-vectored-bacterial diseases Ofir Bahar Dept. Of Plant Pathology and Weed Science Agricultural Research Organization, Volcani Center POB 155, Bet-Dagan, 5025001, ISRAEL Email: ofi[email protected] Many arthropod insects are major agricultural pests causing severe crop damage and loss. Some of these pests directly damage crop plants by feeding of them, but some convey their damage mainly by transmitting plant disease agents. These agents belong to different classes of microorganisms and viruses. Our focus in the lab is on bacterial diseases of plants, vectored by insect. These include the bacterial species Ca. Phytoplasma, Spiroplasma and Ca. Liberibacter. These disease agents are the cause of many agriculturally important diseases such as yellows disease of multiple crops, greening disease (Huanglongbing) of citrus, Zebra-chip disease of potatoes and more. On top of the complexity of working with three interacting organisms, many of these disease agents cannot be grown in axenic culture or be inoculated onto the plant artificially and therefore pose great challenge when it comes to study them in the lab. Our research goals focus on understanding the molecular dialog between the three interacting partners in order to gain insight to the molecular mechanisms that enable successful transmission of the pathogen and disease. Understanding the very basis of these mechanisms can allow us to think of and generate new approaches to be added to the very limited toolbox of management of insect-vectored diseases. More specifically, we work on yellows disease of grapevines, carrots and sesame and also on citrus greening and olive quick decline. Role of endophytes and epiphytes microorganisms in the mediation of olive tree resistance to plant pathogens Paula Baptista Mountain Research Centre (CIMO), School of Agriculture, Polytechnic Institute of Bragança, Campus Sta Apolónia, 5300-253 Bragança, PORTUGAL Email: [email protected] Keywords: Olive tree, diseases, epiphytes, endophytes, sustainable agriculture, biocontrol. Olive (Olea europaea L.) is one of the most important crops in the Mediterranean region, where 95% of the world’s olive production is located. Several insect pests and diseases attack the olive crop, reducing its production by 30%. Among diseases, anthracnose (caused mostly by the airborne fungi Colletotrichum acutatum), olive knot (caused by the bacterium Pseudomonas savastanoi pv. savastanoi), Verticillium wilt (caused by the fungus Verticillium dahliae) and olive leaf spot (caused by the fungus Spilocaea oleaginea), are considered to be the major cause of olive-crop damage 1 worldwide. No effective biological or cultural controls are available against these diseases; therefore, protection relies on chemical control. However, many of the chemical products currently used cause a variety of health problems and environmental impacts. During the last three years we have been carried out studies aiming to explore plant-associated microorganisms, in an integrative perspective, in order to designed new strategies for the control of these diseases. Specifically, we intend to disclose the role of microorganisms (both endophytes and epiphytes) inhabiting olive trees in the mediation of plant defense against the aforementioned diseases, under field conditions, and select the strains with the greatest biocontrol potential. For this, both epi- and endophyte bacteria and fungi inhabiting olive trees from five cultivars (Cobrançosa, Madural, Verdeal Transmontana, Picual and Galega) with different susceptibilities to the aforementioned diseases have been isolated, and further identified by sequencing the 16S (for bacteria) and the ITS region (for fungi) of rRNA genes. Since this approach only detects cultivable microorganisms (uncultured ones will not be represented) the diversity will be additionally assessed recurring to next generation sequencing approaches that allow metabarcoding (in an illumina platform). Disease incidence and severity as well as several chemical and physical factors of the phyllosphere will be evaluated for each olive tree cultivar, and the results obtained will be related with their microbial composition. These results are expected to clarify microbiome mediated beneficial effects on plant protection and also to identified the isolates that appear to be most correlated with disease biological control. The real capability of those isolates to reduce disease symptoms and proliferation of plant pathogens will be studied for selecting the most efficient BCA, by using “in vitro” and “in planta” assays. The results from this study will form the basis for the identification of olive tree microorganisms for the biological control of these four diseases. Results will also uncover previously unrecorded mechanisms of microorganism-olive tree and microorganism-microorganism relationships, which may be of relevance for plant health and for designing a new strategy for the biological control of these diseases. Acknowledgements: This work is supported by FEDER funds through the COMPETE (Operational Programme for Competitiveness Factors) and by National funds through the FCT (Foundation for Science and Technology) in the framework of the projects PTDC/AGR-PRO/4354/2012 and EXCL/AGR-PRO/0591/2012. Arbuscular mycorrizal fungi influence plant-insect interactions Alison Bennett Ecological Sciences James Hutton Institute Errol Road Invergowrie, Dundee DD2 5DA UK Email: [email protected] 044 (0) 1382 568700 ext 7567 In our group we research the influence of arbuscular mycorrhizal (AM) fungi on plant-insect interactions above and belowground. AM fungi are plant mutualists that uptake nutrients (predominantly P) in return for carbon, and prime the salicyclic acid pathway in plants potentially leading to greater and faster responses by plants to antagonists. We study a wide variety of herbivores and pollinators visiting different plant hosts, and apply our results to both natural and managed systems. We are 2 particularly interested in replicating actual systems and assessing the generality of the influence of AM fungi on insects. Effects of soil biota on aboveground plant-insect interactions Arjen Biere Dept. Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW) Droevendaalsesteeg 10, 6708 PB Wageningen, The NETHERLANDS Email: [email protected] The Department of Terrestrial Ecology of the Netherlands Institute of Ecology (Wageningen, NL) broadly studies biotic interactions in terrestrial ecosystems. In particular we study how plants mediate multi-trophic interactions between above- and belowground organisms and how these interactions are affected by (human induced) changes in climate, land use and species invasions. One of the topics that we focus on is so-called “plant soil feedback”. During plant growth, plants change the composition of the community of soil biota in their rhizosphere. These changes (“soil legacies”) subsequently affect the performance of the same plant, its conspecifics, or heterospecific plants that grow in that same soil later in time, e.g. in the next season (“soil feedback”). Such feedbacks can be either positive or negative, and can play an important role in processes such as succession, species invasions, and the outcome of multitrophic interactions. For instance, soil legacies not only affect the performance of ensuing plants, but also that of the insects that feed on their leaves. Strikingly, we have shown that insect feeding modifies the type of soil legacy that their host plants leave in the soil in a way that it benefits conspecific insects that feed on (the offspring of) their host plants grown in that soil in the ensuing year (facilitation)([1]). We could view this as a form of “delayed” three-way interaction between plants, microbes and insects. At a more mechanistic level we try to unravel how plant symbionts (mycorrhizae) in roots and rhizosphere affect plant interactions with arthropods feeding on their leaves. Mycorrhizae can affect interactions with aboveground arthropods in a variety of ways. For instance, they can alter plant size, phenology and primary chemistry, induce or prime plants for systemic resistance or susceptibility, alter plant tolerance, and modulate plant indirect defense by altering the blend of herbivore-induced plant volatiles emitted upon herbivory (affecting the attraction of the natural enemies of the herbivores and hence the efficacy of their biocontrol). We are interested in the role of secondary metabolites mediating such interactions ([2]), whether there is genetic variation in these three-way interactions, the raw material for selection ([3]), and how their outcome depends on environmental conditions (context-dependency). References [1] Kostenko O, van de Voorde TFJ, Mulder PPJ, Van der Putten WH, Bezemer TM (2012) Legacy effects of aboveground-belowground interactions. Ecol. Lett. 15: 813-821 [2] De Deyn GB, Biere A, van der Putten WH, Wagenaar R, Klironomos JN (2009) Chemical defense, mycorrhizal colonization and growth responses in Plantago lanceolata L. Oecologia 160: 433-442. 3 [3] Biere A, Tack AJM (2013) Evolutionary adaptation in three-way interactions between plants, microbes and arthropods. Funct. Ecol. 27: 646-660. Quarantine and economically important plant viruses in Serbia: detection, characterization and epidemiology A. Bulajić, I. Stanković, A. Vučurović, D. Nikolić, K. Milojevi, B. Krstić Institute of Plant Protection, Department of Phytopathology, University of Belgrade, Faculty of Agriculture, Nemanjina 6, 11080 Belgrade, SERBIA Email: [email protected] Viruses cause many important plant diseases with significant agricultural and economic losses, and also have consequences for biodiversity conservation. Vast majority of plant viruses are completely dependent on their vectors, mainly insects for their epidemiology, spreading and infecting susceptible host plants. Changes in vector diversity, efficacy, or epidemiology, as well as changes in interactions between vectors and host plants, determine the population structure of all plant viruses and their capability of spatial-temporal spreading. Understanding of virus–vector interactions as epidemiological information is essential to develop effective integrated management strategies designed for viruses transmitted by vectors. During past decade, our team has developed expertise in research of detection of new viruses for our country which is in close correlation with the emergence of their vectors or changes in vector-plant interactions. Our realized and future research topics include several viruses as model organisms and clarification on their epidemiology throughout investigation of interactions among viruses, insect vectors and host plants, including thrips transmitted Iris yellow spot virus (IYSV), aphid transmitted cucurbit viruses (Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV), Cucumber mosaic virus, CMV), etc. Our research objective will focus on IYSV, Thrips tabaci as its vector, and onion and other known and unknown host plants in Serbia, and their interaction. The first occurrence of IYSV on onion in Serbia was documented in 2007 at two localities. In the years following the first outbreak (2008-2013), IYSV was not detected in any of the tested plants and was, thus, regarded as eradicated. During 2014, serious outbreaks of IYSV in onion crops planted from true seed were observed in eight locations. Infected plants showed symptoms suggestive of IYSV infection, with high incidence estimated at over 90%, leading to nearly total crop failure. A large population of T. tabaci was also noted. Our future research focus is to identify natural reservoir hosts of the virus, alternative host plants supporting thrips population, and the most important to determine what triggered such sudden and epidemic occurrence of the virus in order to contribute in prevention similar outbreaks. Insecticides have been the primary tactic for T. tabaci management; however, repeated applications often lead to resistance in the thrips population, suppression of natural enemies, and unsustainable management. We hope that we will be able to contribute to the efficient control of IYSV and T. tabaci by defining elements in their interaction and thus to prevent substantial onion yield losses in Serbia and worldwide. 4 Expression of whitefly primary endosymbiotic GroEL in plants provides tolerance to several virus families Henryk Czosnek Institute of Plant Sciences and Genetics in Agriculture The Robert H. Smith Faculty of Agriculture, Food and Environment The Hebrew University of Jerusalem, Rehovot 76100 ISRAEL Email: [email protected] The whitefly Bemisia tabaci is a major pest to agriculture because of its feeding habits and because it transmits many families of viruses, the begomoviruses being one of the most deleterious. B. tabaci harbors a diverse fauna of endosymbionts housed in specialized cells called bacteriocytes, including the primary endosymbiont Portiera aleyrodidarum, and several other facultative secondary symbionts: in Israel, in addition to Portiera, the B biotype harbors Hamiltonella, and the Q biotype Wolbachia and Arsenophonus [1]. The facultative B. tabaci endosymbiont Rickettsia can be found free in the insect digestive tract of both biotypes. A chaperone GroEL protein produced by Hamiltonella in B. tabaci B biotype was shown to be essential for the transmission of the begomovirus Tomato yellow leaf curl virus TYLCV to tomato by interacting with the virus coat protein CP. In contrast, GroEL proteins produced by secondary endosymbionts do not interact with the TYLCV CP [2]. The facultative endosymbiont Rickettsia found free in B. tabaci and its presence was correlated with increased amounts of TYLCV associated with the insect digestive tract [3]. The CP-binding property of GroEL was exploited to engineer tomato and Nicotiana benthamiana plants expressing the B. tabaci GroEL gene resistant to TYLCV. In these plants, GroEL trapped the virus in the phloem [4, 5]. The GroEL-producing plants may be used as rootstock to confer resistance to grafted susceptible plants. References [1] Chiel E, Gottlieb Y, Zchori-Fein E, Mozes-Daube N, Katzir N, Inbar M and Ghanim M (2007). Biotype-dependent secondary symbiont communities in sympatric populations of Bemisia tabaci. Bull. Entomol. Res. 97:407-413. [2] Gottlieb Y, Zchori-Fein E, Mozes-Daube N, Kontsedalov S, Skaljac M, Brumin N, Sobol I, Czosnek H, Vavre F, Fleury F and Ghanim M (2010) The transmission efficiency of Tomato yellow leaf curl virus is correlated with the presence of a specific symbiotic bacterium species. J. Virology 84:9310-9317. [3] Kliot A, Cilia M, Czosnek H and Ghanim M (2014) Implication of the bacterial endosymbiont Rickettsia spp. in the whitefly Bemisia tabaci interactions with Tomato yellow leaf curl virus. J. Virology 88:5652-5660. [4] Akad F, Eybishtz A, Edelbaum D, Gorovits R, Dar-Issa O, Iraki N and Czosnek H (2007) Making a friend from a foe: Expressing a GroEL gene from the whitefly Bemisia tabaci in the phloem of tomato plants confers resistance to Tomato yellow leaf curl virus. Arch. Virol. 152:1323-1339. [5] Edelbaum D, Gorovits R, Sasaki S, Ikegami M and Czosnek H (2009) Expressing a whitefly GroEL protein in Nicotiana benthamiana plants confers tolerance to Tomato yellow leaf curl 5 virus (TYLCV) and Cucumber mosaic virus (CMV), but not to Grapevine virus A (GVA) and Tobacco mosaic virus (TMV). Arch. Virol. 154:399-407. Trichoderma and insect control Maria Cristina Digilio Laboratorio di Entomologia “E. Tremblay” Dipartimento di Agraria Università degli Studi di Napoli "Federico II" Via Università 100, Portici, ITALY Email: [email protected] Soil microorganisms living in symbiosis with plant roots can be beneficial, either by promoting plant growth and its defense response against biotic stressors. PGPFs (Plant Growth Promoting Fungi) belonging to the genus Trichoderma are among the most widespread soil symbionts, which are effective biocontrol agents of plant pathogens. However, their impact on insect pests is still controversial. In fact, while several mechanisms active against pathogenic fungi have been described, in the case of phytophagous insects the increase of plant defense responses can be, in some cases, counterbalanced by plant growth promotion which may have positive effects on feeding insects. Therefore, it is of pivotal importance to understand the mechanisms underpinning the plant-Trichoderma interaction and how this complex symbiosis is modulated by environmental factors. Our group focuses on this research issue, looking at the symbiosis between tomato plants and Trichoderma, which appears to be strain-specific. Root colonization by T. harzianum strain T22 results in effective control against two tomato pests with different plant attack strategies, the aphid Macrosiphum euphorbiae and the caterpillar Spodoptera littoralis. However, other strains supported aphid growth (T. longibrachiatum MK1) or had an intermediate effect (T. atroviride P1). It is interesting to note that all the strains considered induce an enhanced production of volatile compounds, reinforcing the indirect defense barriers as a result of a more intense attraction towards aphid parasitoids. Collectively, these results indicate that selected Trichoderma strains may offer interesting tools for developing new IPM protocols against insects. The role of pathogenesis-related proteins in defense against fungal diseases and insect pests Tomas Erban, Bronislava Hortova Crop Research Institute, Drnovska 507/73, Prague, CZECH REPUBLIC, CZ-16106 6 Email: [email protected]; [email protected] Keywords: pathogenesis-related proteins; proteomics; chitinase; thaumatin; mass spectrometry; allergen Plant pathogenesis-related (PR) proteins are produced in plants in the event of a pathogen attack such as bacteria, viruses, fungi or invertebrates. The PRs according to their enzymatic properties suggested to act against fungi are: PR-2 (β-1,3-glucanases) and PR-3, -4, -8 and -11 (chitinases). Both β-1,3-glucanases and chitinases are able to hydrolyze components of fungal cell walls β-1,3-glucans and chitin. Also some lipid transfer proteins (PR-14) exhibit the antifungal activity. Proteinase-inhibitory properties of PR-6 (protease inhibitor) may confer anti-insect and anti-nematode effects, inactivating the proteins secreted by these pests in the invaded plant tissues. Another candidate for the anti-invertebrate activity is thaumatin, i.e. it has been shown that maize protein homological to thaumatin is potent in vitro inhibitor of trypsin and α-amylase. We analyzed storage disease of apple caused by Neofabraea and Alternaria using mass-spectrometry based proteomics approach. Overall, four proteins were identified after the non-redundant (nr) NCBI database search: β-1,3-glucanases (PR-2), Mal d 2 and Pru p 2.01B (PR-5), and proteins of class PR-8. Both pathogenic fungi showed similar proteins identified; the exception was protein homological to Pru p 2.01B detected only in Alternaria disease. The detected apple proteins belong to group of proteins with antifungal activity that could play also role in the defense against insects. The detected proteins are known human allergens; therefore their increased level in fruits means higher allergy risks. Insect symbionts mediate interactions at the community level Enric Frago Laboratory of Entomology, Wageningen University Droevendaalsesteeg 1, Building 107 6708 PB Wageningen, the NETHERLANDS Email: [email protected] It has long been known that insect mutualistic symbionts, and bacteria in particular, provide their herbivorous hosts with nutrients that are missing in the diet. In the last decade, it has become apparent that these symbionts can be important mediators of direct and indirect (i.e. separated by more than one trophic link) interactions between insects, their host plants and their natural enemies. For example, insect symbionts can directly influence host plant range, but also indirectly through manipulation of plant state or physiology. Symbionts can also benefit their insect hosts by protecting them from natural enemies. Currently I investigate these interactions using aphids as a model system. I am particularly interested in the consequences these symbionts have for the aphid’s host plants, and for aphid-parasitoid communities. 7 Insect Reprogrammers and associated bacterial symbionts: From Strategies for Manipulating Plants to Agriculture David Giron Institut de Recherche sur la Biologie de l’Insecte (IRBI) UMR 7261 CNRS/Université François-Rabelais de Tours Tours, FRANCE Email: [email protected] Plants constitute key nutritional resources for many organisms on Earth and protect these resources by enhancing interactions with mutualists while reducing interactions with antagonists. Interactions with different members of their ecological community can lead to a profound metabolic reconfiguration of the plant’s physiology, which favors beneficial organisms like symbionts and harms antagonists like pathogens or herbivores. Among the insect herbivores that attack plants, some species have evolved a peculiar feeding strategy that allows them to hijack the plant’s machinery for their own benefit. By “reprogramming” the plant genome, the insect forces the plant to create specialized nutritional resources that benefit the insect at the expense of the plant’s growth and reproduction. This attack strategy can have serious economic consequences in agroecosystems by reducing crop yield or quality. Mechanisms underlying this attack strategy and the plant’s options for effective defense remain largely unknown. Our research focus on: 1. physiological modifications induced in susceptible and resistant plants, 2. changes in phytohormones that accompany these modifications; 3. secreted salivary effectors that are produced by insect ’reprogrammers’ to suppress defense responses and alter plant metabolic processes; and 4. insect bacterial endosymbionts and their role in the plant reconfiguration. Feeding strategies of a number of different plant-manipulating insects are compared using an evolutionary framework to discover similarities and differences in their strategies for exploiting plants. Strategies used by insect “reprogrammers” are also compared to those of antagonistic microbes and nematodes that “reprogram” the plant. Knowledge gained from this research should contribute to new ideas for using natural plant traits to protect agricultural plants from biotic stress. Potato Virus Y infection hinders potato defence response and renders plants more vulnerable to Colorado potato beetle attack Kristina Gruden National Institute of Biology Večna pot 111, 1000 Ljubljana, SLOVENIA Email: [email protected] In the field, plants are challenged by more than one biotic stressor at the same time. In the present study, the molecular interactions between potato (Solanum tuberosum L.), Colorado potato bee8 tle (Leptinotarsa decemlineata Say; CPB), and Potato virus YNTN (PVYNTN) were investigated through analyses of gene expression in the potato leaves and the gut of the CPB larvae, and of the release of potato volatile compounds. CPB larval growth was enhanced when reared on secondary PVYNTN-infected plants, which was associated with decreased accumulation of transcripts associated with the antinutritional properties of potato. In PVYNTN-infected plants, the ethylene signalling pathway induction and induction of auxin response transcription factors was attenuated, while no differences were observed in JA signalling pathway. Similarly to rearing on virus-infected plants, CPB larvae gained more weight when reared on plants silenced in the JA receptor gene (coi1). Although herbivore induced defence mechanism is regulated predominately by JA, response in coi1silenced plants only partly corresponds to the one observed in PVYNTN-infected plants, confirming the role of other plant hormones in modulating response. The release of β barbatene and benzyl alcohol was different in healthy and PVYNTN-infected plants before CPB larvae infestation, implicating the importance of PVYNTN infection in plant-to-plant communication. This was reflected in gene expression profiles of neighbouring plants showing different degree of defence response. The present study thus contributes to our understanding of plant responses in agro-ecosystems. Insect Reprogrammers and associated bacterial symbionts: From Strategies for Manipulating Plants to Agriculture Barbara H. Łabanowska1 , Małgorzata Tartanus1 , Eligio Malusa1 , Cezary Tkaczuk2 , Loredana Canfora3 Research Institute of Horticulture, Skierniewice, POLAND 1 Siedlce University of Natural Science and Humanities, POLAND 2 Council for Agricultural Research and Economics, Rome, ITALY 3 Email: [email protected] Experiments on testing various species of entomopathogenic fungi and nematodes are performed in our laboratory since several years. We have tested Beauveria bassiana (biopesticide Naturalis) to control Phytonemus pallidus on strawberry, B. bassiana and Heterorhabditis megidis (as Larvanem) against Otiorhynchus ovatus and O. sulcatus on strawberry and Beauveria brongniartii (biopesticide Melocont) against “white grubs” larvae (Melolontha melolontha). The main results will be presented. In the last two years, the fungi Beauveria bassiana, B. brongniartii (applied as an aqueous suspension of conidia) and Metarhizium anisopliae (biopesticide Met 52 Granular used as granulate and mixed with the soil), as well as entomopathogenic nematodes Heterorhabditis bacteriophora (as Nemasys G and Larvanem applied as an aqueous suspension) and Seinernema kraussei (applied as an aqueous suspension) have been used to control larvae and adults of O. sulcatus (laboratory experiments) and to control larvae L1 −L4 of M. melolontha (laboratory and field experiments). The field experiments have been carried out on strawberry organic plantations. Microorganisms were applied to the soil before planting the plants and/or on plantations of different ages (one year old and older). The efficacy of the treatments was assessed by visually checking the health condition of plants (healthy 9 and damaged by the larvae). Microorganisms used in the field reduced the number of damaged plants at the level of about 50% in comparison to untreated plots. However, when they were applied before establishing the plantation, the efficacy was 45-67%. The persistence and amount of microorganisms in the soil was also assessed by DNA-based and microbiological analyses (number of colony forming units - CFU). In all experiments, following the introduction of the microorganisms into the soil an increase in the amount of CFU for the relevant species was recorded. We might conclude that the results obtained in these initial experiments are promising, but the effects of the treatments are not immediate. How sensitive are species interactions to stressful environmental conditions? Anna-Liisa Laine, Marjo Saastamoinen, Minna-Maarit Kytöviita, Stafva Lindström Metapopulation Research Centre, PO Box 65, University of Helsinki, FINLAND Email: anna-liisa.laine@helsinki.fi In their natural populations, plant individuals interact with a diverse community of species associated with either the above-ground (AG) or below-ground (BG) parts of the plant. Simultaneous or sequential use of a shared host plant may generate a network of interactions whereby species may affect each other either directly or through host mediated responses. We have studied whether AMF colonization affects infection by a foliar pathogen of a shred host under natural epidemics. We then measure rates of AMF colonization in natural populations of the host to understand whether there is the potential for variation in AMF colonization to generate heterogeneity in disease dynamics, as suggested by the experimental work. The work was carried out with host plant Plantago lanceolata L. (Plantaginceae) and its powdery mildew pathogen in the Åland archipelago of Finland. Ongoing work is focused on investigating the impact of AMF colonization on plant drought tolerance, and how the effects of drought cascade to higher trophic levels including a specialist insect herbivore and a powdery mildew pathogen. Translating from 2-way interactions to 3-way interaction research with fungal endophytes Brian R. Murphy Department of Botany School of Natural Sciences Trinity College Dublin, Dublin 2, IRELAND 10 Email: [email protected] At Trinity College Dublin we have been working with novel fungal endophytes recovered from a wild barley species (Hordeum murinum). We have tested the effects of these endophytes on biotic and abiotic stress resistance in cultivated barley (Hordeum vulgare). During this research we discovered that an endophyte related to the nematophagous Metarhizium anisopliae enhanced several important agronomic traits in barley. We now aim to collaborate with other academic institutions to research the effects of fungal endophytes on arthropod resistance in important forage grasses. This research will focus on both root and shoot insect pests, and will form part of a whole suite of research which aims to manipulate the fungal microbiome to improve forage crops. The declared purpose of this experimental work is to reduce chemical use in grassland forage systems through novel technological methods focusing on seed treatment with endophytes. Enhancement of pollination services as a measure of biodiversity improvement in Mediterranean cropping systems Photini Mylona Institute of Plant Breeding and Genetic Resources HAO-DEMETER 57001 Thermi GREECE Email: [email protected] In modern agriculture intensified weed management in association to farming practices and monocultures have led to a decline of both plant and invertebrate diversity in arable land and in the surrounding non-cropping areas. To counteract with this biodiversity loss a number of agro-ecological schemes have been employed that led to the development of a set of measures in the current Common Agricultural Policy (CAP 2014-2020). In that respect border zones and field edges of cropping systems are essential in enhancing ecosystem’s biodiversity and services, while providing key mitigation measures for buffering. Recent studies have shown that habitat manipulation including intentional provisioning of natural vegetation along crop edges, and interventions of floral addition have enhanced beneficial insect activity counting pollination in many agricultural settings, but little research has been conducted in Mediterranean arable land. Mediterranean agro-systems are complex subjected to a variety of pressures including anthropogenic, natural disasters and environmental perturbations. To date our knowledge is limited of the network of interactions, associations and mutualisms among agro-system participants, components in response to environmental perturbations. As climate changes will further intensify such perturbations, the need for a comprehensive understanding of agro-systems interactions and mutualism will provide valuable knowledge and tools for the development of sustainable management procedures to protect and enhance plant, animal and microbial diversity in Mediterranean farming areas. The study is focused in enhancement of ecosystem services by improving floral and plant diversity. In that respect the influences on crop yield, the invertebrate and the soil microbial communities are explored. 11 Tripartite interactions of fungal endophytes and arbuscular mycorrhizal fungi (AMF) Kalliope Papadopoulou University of Thessaly, Department of Biochemistry and Biotechnology, Larissa, GREECE Email: [email protected] We are interested to determine factors that act commonly during plant colonization by endophytic fungi and distinguish key molecular components that lead to mutualistic and beneficial interactions. We focus our studies on a proprietary endophytic Fusarium solani strain (FsK), which was shown to be capable of promoting plant growth, protecting against root pathogens and eliciting induced systemic resistance in tomato plants (1,2). On the basis of this disease protection capability, we hold a Greek patent. Using a genetic approach of mutant tomato plant lines, we show that colonization and ingress of FsK in tomato roots is affected by ethylene and ABA signalling pathways. Establishment of colonization is also studied in the model legume Lotus japonicus. The interaction between FsK and AMF is investigated in L.japonicus roots, co-inoculated with both fungal strains. Colonization patterns are recorded and quantitatively assessed. Genes involved in signaling during AMF establishment are analysed. In addition, towards a more applied point of view, we perform a series of experiments to examine effects on plant growth in various plants (tomato, lettuce, olive), grown under normal or under abiotic stress conditions. A main focus is on osmotic stress alleviation effects (salinity and water stress). The mycorrhizal strains used in the latter studies also include newly isolated strains from organically cultivated field sites or from marginal ecosystems in Greece, that comprise a large collection available in our laboratory. Isolates from the same localities/rhizospheres are tested on their own or in combination (reconstructed communities) to assess potential complementarity effects. [1] Kavroulakis N, Ntougias S, Zervakis G, Ehaliotis C, Haralampidis K. Papadopoulou KK (2007) Role of ethylene in the protection of tomato plants against fungal pathogens conferred by an endophytic Fusarium solani strain. Journal of Experimental Botany, 58 (14): 3853-3864 [2] Karpouzas DG, Karatasas A, Spiridaki E, Rousidou C, Bekris F, Omirou M, Ehaliotis C, Papadopoulou KK (2011) Impact of a beneficial and of a pathogenic Fusarium strain on the fingerprinting based structure of microbial communities in tomato (Lycopersicon esculentum Milll.) rhizosphere. European Journal of Soil Biology, 47: 400-408. Induced plant defences mediated by glandular trichomes in tomato: mechanism of induction and implications for plant-insect-natural enemy interactions Eduardo de la Peña Ghent University, Faculty of Science, Department of Biology K.L. Ledeganckstraat 35, 12 Ghent 9000 BELGIUM Spanish National Research Council, Institute for Mediterranean and Subtropical Horticulture Finca Experimental La Mayora, Algarrobo-Costa 29750, SPAIN Email: [email protected] Tomato, Solanum lycopersicum is one of the most important crops worldwide, but its agricultural production is often severely impaired by different insect species that adversely affect its growth and productivity. Some species of aphids (Aphididae) and the whitefly (Bemisia tabaci) occupy a prominent place as they not only limit the growth of the plant but are vectors of devastating viruses and other plant-pathogens. On a global scale, the managing strategies for these insect pests mainly rely on the use of insecticides which often result in the development of insect resistances. This situation requires improving and developing alternative production methods that reduce the use of phytochemicals. In this sense, there are two complementary lines: (1) the development of crop varieties resistant to insects (2) improving biological control strategies using natural enemies of insect pests. In either case, it is necessary to understand the defense mechanisms of the plant as they mediate not only the interaction between plant and the insect herbivores, but also the interaction with natural enemies. Glandular trichomes show a key role in the defense against herbivorous insects as they are involved in direct defenses (by producing acylsucroses) and indirectly by producing other allelochemicals that potentially mediate the interaction of the plant with the herbivorous insects and their natural enemies. Moreover, induced defenses mediated by trichomes depend of other biotic factors acting on the plant, such as the interactions of the plant with different groups occurring in the soil (e.g. mycorrhizal fungi) and the genetic background of the tomato; since not all tomato lines have the same natural defenses. During this meeting, the current research and knowledge gaps regarding the mechanisms of defence in tomato in relation with multitrophic interactions will be outlined. Genetic variation drives ecological outcomes of the three-way interaction between plant herbivores and microorganisms Sergio Rasmann Institute of Biology Université de Neuchâtel CH-2000 Neuchâtel SWITZERLAND Email: [email protected] Accumulating evidence indicates that arbuscular mycorrhizal fungi (AMF) can affect plant interactions with other organisms, including above- and belowground herbivores, but the mechanisms underlying these effects remain unclear. I will here show that plant attractiveness and resistance to foliar and root herbivores is mediated by intra and interspecific variation of plants and mycorrhizae. 13 First, I will show that AMF genotypic variation drives host plant selection for caterpillar larvae. Similarly, root herbivores tend to differentially colonize different plant species, but this is mainly mediated by the quantity of AMFs on the plants. Finally, I will show that deficient plants in phytohormonal production can benefit AMF colonization for better resisting herbivores. Taken together, our findings suggest that AMF should be incorporated in future studies investigating ecology and evolution of communities and biotic interactions. Utilizing rhizosphere competence of entomopathogenic or insect associated fungi to enhance crop production and resistance to soil pests Jaka Razinger, Hans-Josef Schroers Agricultural Institute of Slovenia Hacquetova ulica 17, Ljubljana, SI-1000 SLOVENIA Email: [email protected] Keywords: Agriotes spp., biological control, cabbage root fly, Delia radicum, endophytes, entomopathogenic fungi, plant-microbe interactions; rhizosphere, wireworms Soil-borne microorganisms influence significantly abiotic and biotic stress tolerance of crops. Most interactions between soil-borne microorganisms and plants take place in the rhizosphere presenting one of the most complex ecosystems on Earth. Interactions are maintained through plant exudations/rhizodeposition, as up to 25% of the net carbon fixed during photosynthesis is released into the rhizosphere. Rhizodeposits promote the growth and multiplication of microbial cells. We hypothesized that an increased availability of nutrients (rhizodeposits) in the rhizosphere can be utilized also by non-plant symbiotic microbial communities. The aim of our research is the development of protective microbial communities in the rhizosphere via bioaugmentation, i.e. the addition of microbes with plant beneficial metabolic or ecological traits, specifically bioaugmentation with entomopathogenic or insect associated fungi. Systems such as cabbage root fly (CRF) Delia radicum (Diptera: Anthomyiidae) on brassicas or Agriotes spp. wireworms on maize and wheat are looked at. The CRF is a major threat for many brassica crops in Europe; wireworms, the soil-burrowing larval stages of click beetles (Coleoptera: Elateridae) are major pests of crops including wheat, maize, and numerous vegetables in many parts of the world. The aim of our studies was to assess the virulence of several entomopathogenic or insect associated fungal strains against laboratory bred CRF or field-collected wireworms. The fungi were also tested for their rhizosphere competence, plant tissue colonization (endophytism) and potential growth stimulating effects to cauliflower or maize and wheat. The following fungal species were tested: Trichoderma atroviride, T. koningiopsis, T. gamsii, Beauveria brongniartii, B. bassiana, Metarhizium robertsii, M. anisopliae, Purpureocillium lilacinum and Clonostachys solani. The presentation will show Abbott’s corrected mortality values of a set of performed experiments. The results showed that rhizosphere competence of the tested strains to cauliflower varied considerably, possibly due to the ecological preferences of the different fungal species. Trichoderma spp. colonized the cauliflower rhizoplane most efficiently and were also most often detected inside plant tissue. C. solani was not detected on the rhizoplane when added through seed coating inoculation method, but was positively identified on roots inoculated with colonized agar plugs. This indicates that the method of fungal exposure influences their colonization ability. Regarding maize and wheat, all strains colonized the rhizoplane, however to varying extent. The isolates tested were not isolated as endophytes in maize and wheat. Some isolates 14 stimulated growth of maize and wheat seedling, whereas others decreased root or shoot length or biomass. This effect was plant-fungus pair specific. On several occasions, contrasting results were observed between maize and wheat and the same fungal isolate. We conclude that the ecological preferences of the fungal species might influence their performance (i.e. virulence to insect pests) in different environments, method of bioaugmentation influences the plant-microbe interaction, and plant-microbe interactions can depend on the specific fungal strain and plant cultivar. Acknowledgments The research was financed partly by the Crop production research group (0401009) of the Agricultural Institute of Slovenia and grant J4-5527 from the Slovenian Research Agency (ARRS). It was realized in the frame of the EU FP7 Project CropSustaIn, grant agreement FP7REGPOT- CT2012-316205. Trophic interactions mediated by fungal endophytes Kari Saikkonen Natural Resources Institute Finland (Luke) Management and Production of Renewable Resources Itäinen Pitkäkatu 3 20520 Turku FINLAND Tel. +358 29 532 6510 Email: kari.saikkonen@luke.fi The ongoing research of my team focuses on ecological and evolutionary implications of genetic, species and functional diversity of plants (both grasses and trees), microfungi and herbivores by emphasizing importance of habitat diversity, consequences of human activities and climate change. Majority of our recent research has concentrated on the role of extended asymptomatic (endophytic) phase of foliar fungi, and how endophytes should be taken into account in agriculture. Historically endophytes were found in agronomic arena in 1970’s when agricultural scientists demonstrated that livestock disorders in USA and New Zealand were attributable to endophyte origin alkaloids. Noteworthy is that nearly all fungi invading plant foliage have an asymptomatic period in their life cycle. In the largest sense then, all internal plant fungi are endophytic. The length of asymptomatic phase varies from an imperceptibly short period, as for many pathogens, to lifelong abeyance in strictly asexual Epichloë edophytes in grasses. However, the majority of the interactions fall between these extremes. Because of different viewpoints among the disciplines of natural sciences, endophytic fungus-plant associations are generally treated separately from parasitic, pathogenic and saprophytic interactions. However, such a functional distinction is erroneous and may be misleading. Niches for these fungal groups are often indistinguishable, their ecological role appears to be complex and labile, and functionally different fungi are sprinkled throughout phylogenetic lineages. Thus, we propose that (1) the evolution of endophytic fungal life histories and their hosts, like any other complex ecological interaction, is dynamic, and that (2) varying selection pressures, phylogenetic constraints, and stochastic factors canalize fungal life history traits somewhere between the extremes of sexuality and asexuality and pathogenic and mutualistic. We want to emphasize that despite the seeming “endophyte” stamp of our research, our research interests lie in the trophic interactions, with particular emphasis on the ecology and life history evolution of foliar microfungi and their host plants. Throughout our research, common threads have been (1) plant resistance to microfungi and other plant associated heterotrophic organisms (e.g. 15 herbivores and mycorrhizae) and (2) fungal mediated trophic interactions in changing environments. This has required a multidisciplinary approach combining both theory and experimental work, and a good overall picture of ecosystem functions. Indeed, we are convinced that more knowledge about multi-species interactions is required to fully understand bilateral ecological interactions between plants and organisms subsisting on them. This perspective provides novel insights into agricultural entomology in changing environmental conditions in the future. References [1] Saikkonen, K., S.H. Faeth, M.L. Helander and T.J. Sullivan (1998): Fungal endophytes: a continuum of interactions with host plants. Annual Review of Ecology and Systematics 29: 319-343. [2] Saikkonen K., U. Ahonen-Jonnarth, A.M. Markkola, M. Helander, J. Tuomi, M. Roitto and H. Ranta (1999): Defoliation and mycorrhizal symbiosis: a functional balance between carbon sources and below-ground sinks. Ecology Letters 2: 19-26. [3] Ahlholm, J., M. L. Helander, P. Elamo, I. Saloniemi, S. Neuvonen, And S. Hanhimäki and K. Saikkonen (2002): Micro-fungi and invertebrate herbivores on birch trees: fungal mediated plant-herbivore interactions or responses to host quality? Ecology Letters 5: 648-655. [4] Saikkonen K., Wäli P., Helander, M. and S.H. Faeth (2004) Evolution of endophyte-plant symbioses. Trends in Plant Science 9: 275-280. [5] Lehtonen, P., M. Helander, M. Wink, F. Sporer and K. Saikkonen (2005) Transfer of endophyteorigin defensive alkaloids from a grass to a hemiparasitic plant. Ecology Letters 8: 1256-1263. [6] Lehtonen, P., M. Helander, S. Siddiqui, K. Lehto and K. Saikkonen (2006) Endophytic fungus decreases plant virus infections in meadow ryegrass (Lolium pratense). Biology Letters 2: 620623. (doi:10.1098/rsbl.2006.0499). [7] Saari, S., J. Sundell, O. Huitu, M. Helander, E. Ketoja, H. Ylönen and K. Saikkonen (2010) Fungal-mediated multitrophic interactions - do grass endophytes in diet protect voles from predators? PLoS ONE 5(3): e9845. doi:10.1371/journal.pone.0009845. [8] Vesterlund, S.-R., M. Helander, S. H. Faeth, T. Hyvönen and K. Saikkonen (2011) Environmental conditions and host plant origin override endophyte effects on invertebrate communities. Fungal Diversity 47: 109-118. [9] Saikkonen, K., K. Taulavuori, T. Hyvönen, P. E. Gundel, C. E. Hamilton, I. Vänninen, A. Nissinen and M. Helander (2012) Climate change-driven species’ range shifts filtered by photoperiodism. Nature Climate Change 2: 239–242, Doi:10.1038/Nclimate1430 [10] Saikkonen, K., K. Ruokolainen, O. Huitu, P. E. Gundel, T. Piltti, C. E. Hamilton and M. Helander (2013) Fungal endophytes help prevent weed invasions. Agriculture, Ecosystems and Environment 165: 1-5. [11] Wäli, P. P., P.R. Wäli, K. Saikkonen and J. Tuomi (2013) Is the pathogenic ergot fungus a conditional defensive mutualist for its host grass? PLoS ONE 8(7): e69249. doi:10.1371/journal.pone.0069249. [12] Gundel, P. E., L. I. Pérez, M. Helander and K. Saikkonen (2013) Symbiotically modified organisms: non-toxic fungal endophytes in grasses. Trends in Plant Science 18: 420-427. 16 [13] Saikkonen, K., P. E. Gundel and M. Helander (2013) Chemical ecology mediated by fungal endophytes in grasses. Journal of Chemical Ecology 39: 962-968. [14] Li, T., J. D. Blande, P. E. Gundel, M. Helander and K. Saikkonen (2014) Epichloë endophytes alter inducible indirect defences in host grasses. PLoS ONE 9(6): e101331. doi:10.1371/journal.pone.0101331. [15] Saikkonen, K., J. Mikola and M. Helander (2015). Endophytic phyllospere fungi and nutrient cycling in terrestrial ecosystems. Current Science 109: 121-126. Beneficial endophytes: Development of biofertilizers and biocontrol products Carolin Schneider Institut für Pflanzenkultur e.K., Inoq GmbH, GERMANY Email: schneider@pflanzenkultur.de Plants are colonized by diverse microbial communities containing of bacterial, archaeal, fungal and protistic taxa. Some of these microbial endophytes promote plant growth and protection against biotic and abiotic stress by triggering the host induced systemic resistance response, production of antibiotics and other secondary metabolites, synthesis of phytohormones, ACC deaminase, solubilization of phosphor in soil, assimilation of nutrients and fixation of atmospheric nitrogen. These beneficial characteristics render endophytes (well-known: mycorrhiza) attractive for biotech companies producing biofertilizers and biocontrol agents for agriculture, forestry and horticulture. But the endophytic lifestyle also bears unknown facts: F.e. can phytopathogens change their liefstyle and be “sleepers”? Some examples of our industrial and scientific work: 1. Endophytic bacteria from different excellent-growing in vitro clones of Prunus avium (Wild cherry for timber or veneer) are isolated and cultivated. In a second step their ability to produce auxin, ACC deaminase, siderophores and solubilize phosphor via spectrophotometric measurements and plate assays as markers for plant growth promotion have been tested. Inoculation of poorly growing cherry clones with bacterial suspensions of selected endophytes improved plant quality. 2. A mycorrhizal inoculum manufacturer has to face that definition of quality in those products is still controversial: Is it the richness of the inoculum (number of spores or propagules)? Is it based on the tests of most probable number (MPN)? Quality could be also based on the capacity of the inoculum to induce/elicitate the plant to establish mycorrhizal symbiosis. With the use of different elicitors, applied both in leaves and in the substrate/soil, increased mycorrhizal colonization rates and spore production are achieved. 3. There are observations that the phytopathogen Rhabdocline pseudotsugae can live latently as endophyte in seeds and trees of Pseudotsuga menziesii (Douglas fir) without causing any symptoms. With lightmicroscopy of callus, induced from seeds, specific fungal structures could be discovered. 17 4. Finally the use of insects as vectors for inoculation of beneficial endophytes is promising in future. Aphid-plant-microbe interactions: from ecological to functional studies Jean-Christophe Simon INRA Institute of Genetics, Environment and Plant Protection UMR 1349, IGEPP, FRANCE Email: [email protected] Aphids are engaged in multiple forms of interactions with micro-organisms. In addition to their obligate symbiont (Buchnera aphidicola), these insects may harbour one to several heritable facultative bacterial symbionts from Proteobacteria and Mollicutes. While obligate symbionts supply aphids with key nutrients, facultative symbionts influence their hosts in many ways such as protection against natural enemies, heat tolerance, color change and reproduction alteration. Besides heritable symbionts, little is known about gut associates, the bacteria colonizing the aphid digestive tract. In my group, we are working on aphid-microbe-plant interactions with three types of objectives: First, we analyse the diversity and structure of aphid microbial communities in relation to host ecology. For that, we characterize microbial communities hosted by aphids by using with and without a priori techniques (next generation sequencing) and attempt to link environmental factors with aphid microbiota. Second, we study the influence of microbial communities on the host. This is achieved by measuring different traits on natural and manipulated aphid lines with different symbiotic composition and by carrying out the biological and functional validation of symbiont effects. Third, we wish to better understand the dynamics of symbiotic associations by gaining knowledge in costs and benefits of symbiont infection, in within-host interactions, in acquisition and loss events of microbial partners, and sources and routes of transmission of microbial communities within ecological network. Most of these researches are performed on the pea aphid, Acyrthosiphon pisum, and its microbial associates, in interaction with legume species and natural enemies (aphid parasitoids and predators). Plant-microbe-insect interactions across space Ayco Tack Department of Ecology, Environment and Plant Sciences Stockholm University Stockholm SWEDEN 18 Email: [email protected] Microbes and insects frequently interact within terrestrial food webs. Despite this, we know little about i) their patterns of co-occurrence across spatial and temporal scales and ii) the impact of their interactions on the structure of plant-based communities. In our study, we investigate the metacommunity dynamics of specialist pathogens and insects sharing the same spatially fragmented resource (the oak tree Quercus robur ). We focus on a target set of 89 oak trees on which we have tracked spatial and temporal variation in the composition of the insect and pathogen community for already 12 years. As of 2014, we have added the monitoring of microclimatic conditions. More recently, we have started to explore the role of endosymbionts within this food web. Overall, our findings indicate that knowledge on microbe-insect interactions may be crucial for understanding the dynamics of plant-based food webs. Hormonal dynamics in the roots of Brassica napus during infection with Plasmodiophora brassicae - comparison of tolerant and sensitive cultivar Radomira Vankova Institute of Experimental Botany AS CR Rozvojova 263 165 02 Prague 6 CZECH REPUBLIC Email: [email protected] Plasmodiophora brassicae is a soil pathogen, which infects readily Brassica napus plants. Recently, it has been spreading in a worldwide scale. As the resting spores of this pathogen can stay viable in the soils for more than twenty years, the long-term contamination of soils has become a serious problem. The aim of our study is to characterize differences in hormonal pools of resistant and sensitive cultivars, both under control conditions and during the infection, in order to contribute to the selection of more resistant cultivars. When sensitive cultivar Hornet was compared with the resistant one Alister, we detected earlier elevation of cytokinins and auxins, plant hormones involved in gall formation, in roots of sensitive cultivar. The increase in auxins and cytokinins was accompanied (or followed) by elevation of gibberellin GA4 in both cultivars. In contrast, elevation of the stress hormone salicylic acid was delayed and not so profound in Hornet. In this cultivar, the early increase of abscisic acid was found. The achieved results indicate an intensive cross-talk among plant hormones, as well as difference between the magnitude and dynamics of the response among the sensitive and resistant cultivars. Biotic-abiotic interactions in Portuguese common bean. A case study Maria Carlota Vaz Patto ITQB Av. da Republica, EAN Apartado 127 19 2781-901 Oeiras, PORTUGAL Email: [email protected] Plants respond to multiple stresses in a different way from what they do to individual stresses, activating a specific programme of gene expression to the exact environmental conditions encountered. These responses are very complex and involve changes in many levels such as physiological, cellular and transcriptional. Understanding the molecular basis of multiple stress resistance is of primary importance for the development of breeding approaches, since the combination of an abiotic stress with a biotic stress can result in reduced or enhanced disease severity. Common bean (Phaseolus vulgaris L.) has a history of more than five centuries of cultivation in Portugal. Diverse landraces are still widely grown at farmers’ fields, commonly in intercropping systems, for example with maize. These traditional landraces, well adapted to local environmental conditions and to quality farmers’ preferences, may represent important sources of biotic and abiotic resistance, not yet explored in breeding programmes. Screening this germplasm for resistance against major diseases affecting common bean, such as fusarium wilt and rust and simultaneously also for water deficit tolerance may reveal new interesting sources common to all these stress factors. Through a Genome-Wide Association Study, we are generating a comprehensive view of the genetic control of drought, rust and fusarium wilt resistance in this germplasm, revealing their potential interactions. A subsequent transcriptomic analysis of contrasting landraces will allow us to identify pathways and candidate genes involved in the multiple-stress response. This approach, at the same time that will value this national germplasm, will also provide novel molecular tools, such as functional markers for multiple selection, to expedite common bean multiple stress resistance improvement. Pathogens influence on interacting populations Ezio Venturino Dipartimento di Matematica “Giuseppe Peano”, Università di Torino, via Carlo Alberto 10, 10123 Torino, ITALY Email: [email protected] In this talk I would like to briefly present the type of models that I study and how these investigations can reveal phenomena that at first sight may be unforeseen. Mathematical modelling via dynamical systems can help in assessing the future behavior of ecosystems. It is instrumental in planning actions to possibly drive them toward the ultimate desired or expected configuration. Some examples will be outlined involving: biological control in fruit orchards and vineyards; an epidemiological model for goat breeding; the interplay of herbivores, grass and trees. 20 Plant pathogenic fungi in Croatia K. Vrandečić and J. Ćosić J. J. Strossmayer University, Faculty of Agriculture in Osijek, Kralja Petra Svačića 1d, 31 000 Osijek, CROATIA Email: [email protected] Most fungi are associated with plants as saprotrophs and decomposers but one very important group is plant pathogenic fungi. Crop losses to pathogens continue to reduce available production of food and the total global potential loss due to fungi and bacteria could be more than 80%. During past decade, our team has been focused in research of detection of new and emerging fungal pathogens of arable crops (Alternaria helianthinficiens, Diaporthe phaseolorum etc.) cereals (Puccinia striiformis, Fusarium venenatum, Fusarium concolor etc.) vegetables (Fusarium oxysporum f.sp. lycopersici, Uromyces lineolatus etc.) and ornamental plants (Septoria lavanulae, Fusarium sporotrichioides etc.) for our country. Except that, one of our research objective was focused on application of biofungicide based on Trichoderma harzianum spores against Pythium debaryanum and Rhizoctonia solani in tomato, cauliflower and lettuce seedlings production. In all tested crops biofungicide showed statistically significant reduction of diseases compared with untreated control and application of two chemical fungicides. Boifungicide on the base of T. harzianum also showed good results as growth promotor. Important part of our investigation was related with weeds as alternative hosts for fungal pathogen. We found out that many fungi, known as crops pathogens are developed on alternative hosts (e.g. Diaporthe helianthi, Diaporthe longicolla, Fusarium graminearum etc.). On the other hand they can also serve as host to mycopopulation, which usually does not attacks cultivated plants (e.g. Alternaria crassa, Erysiphe convolvuli, Puccinia malvacearum etc.) and many research are directed towards the use of fungi in biological control of weeds. 21 22