Richard Splivallo
Dr. Richard Splivallo
E-mail: ricsi17 (at) hotmail (dot) com
Tel: + 49 551/ 39 3711
Fax: + 49 551/391 2919
Georg-August-University Goettingen
Molecular Phytopathology and Mycotoxin Research
Grisebachstrasse 6
37077 Goettingen
Germany
laboratory website
Research scope
Fungi are an important source of primary and secondary metabolites and have for long been exploited by the pharmaceutical and food industries. A large number of these metabolites can thus be described in terms of their usefulness to our human society (i.e. benzaldehyde, a volatile with a typical almond odor, is the most exploited aroma of the food industry, or citric acid is a major acidifying agent used by the beverage and cosmetics industries). Besides industrial applications, surprisingly little is known about the actual role of fungal metabolite in nature.
I am especially interested in understanding the ecological purpose of fungal metabolites, precisely their role in the interactions with other organisms, including other fungi, bacteria and plants. I use truffle fungi as a model organism to address the above questions. Even if the full life cycle of truffles cannot be completed under laboratory conditions, truffles offer various advantages for scientific investigation. These reside in the facts that (i) truffles are symbiotic fungi that must interact with plants to complete their life cycle (thus some chemical communication is expected) (ii) the genome of the black truffle (Tuber melanosporum) has now been sequenced following the initiative of Dr. Francis Martin (INRA Nancy) opening the door to full genome molecular investigations (iii) last but not least truffle fruiting bodies develop underground and release a blend of volatile compounds potentially involved in communication with soil organisms/roots.
Specific projects
Signal exchange between truffles and plants
Under laboratory conditions, truffles fruiting bodies and/or mycelium are known to produce volatile organic compounds and fungal (phyto)hormones that modify the root architecture of plants. We investigate the interaction between different truffle mycelial strains/species and three plants (Arabidopsis thaliana (non-host), poplar (host) and the shrub Cistus incanus (host)) at two different level, including (i) the chemical one, trying to identify which volatile and non-volatile fungal signals are perceived by the plants (the volatile analysis is done in collaboration with Ivo Feussner and Cornelia Goebel, Georg-August Uni of Goettingen), (ii) how these signals affect the gene expression of the host plant poplar and the non-host Arabidopsis thaliana (collaboration with Francis Martin, INRA Nancy, and Urs Fischer, Georg-August Uni of Goettingen).
Truffle field chemical ecology
Various chemical signals (indole-3-acetic acid, ethylene, and volatiles organic compounds such as the volatile with a typical fungal smell 1-octen-3-ol) produced by truffles and potentially involved in communication with plants (potentially as toxic or symbiotic signals) have been identified in the past years. We are now performing field sampling to understand (i) if these chemical signals can be detected from soil, (ii) how their concentrations vary seasonally, and (iii) if their occurrence correlates with abiotic factors (i.e. soil nutrient analysis in collaboration with Nayer Rastin, Georg-August Uni of Goettingen) and the “burnt”, a zone devoid of herbaceous vegetation observed with some truffle species.
Aroma variability and volatiles biosynthesis in truffles
More than 200 volatile organic compounds have been to date described from various truffle species. A single species typically contains between 20-50 volatiles, and the composition of these volatiles might depend on geographical location and/or maturity. We are specifically interested in explaining what governs the aromatic variability of truffles, and currently investigate two aspects of it: (i) the potential involvement of bacteria (those trapped inside the fruiting bodies) in the production of characteristic truffle volatiles (collaboration with G. Chevalier, INRA Clermont-Ferrand) and (ii) the biosynthetic pathways/genes involved in volatile biosynthesis in Tuber melanosporum (collaborations with Francis Martin, INRA Nancy, Paola Bonfante, Uni of Turin; Alessandra Zambonelli, Uni of Bologna). Volatile fingerprinting is done in collaboration with Ivo Feussner and Cornelia Goebel (Georg-August Uni of Goettingen).
Bacterial diversity in truffles
Truffle fruiting bodies form underground and consequently trap a large number of microorganisms during genesis. Indeed numerous bacteria have already been described in the fruiting bodies of white truffles by the group of V. Stocchi (Urbino, Italy). In relation with the previous project we are currently investigating how the bacterial population varies inside fruiting bodies and mycelia of black truffles (mycelial collection supplied by Gerard Chevalier, INRA Clermont-Ferrand).
On going collaborations
- Prof. Dr. Ivo Feussner and Dr. Cornelia Goebel (Georg-August uni of Goettingen, Germany)
- Dr. Urs Fischer (Georg-August uni of Goettingen, Germany)
- Prof. Dr. Nayerah Rastin (Georg-August uni of Goettingen, Germany)
- Dr. Francis Martin (INRA Nancy, France)
- Dr. Gérard Chevalier (INRA Clermont-Ferrand, France)
- Prof. Dr. Paola Bonfante (Uni of Turin, Italy)
- Prof. Dr. Alessandra Zambonelli (Uni of Bologna, Italy)
Selected Publications
Research Articles
Martin F, Kohler A, Murat C, Balestrini R, Coutinho PM, Jaillon O, Montanini B, Morin E, Noel B, Percudani R, Porcel B, Rubini A, Amicucci A, Amselem J, Anthouard V, Arcioni S, Artiguenave F, Aury JM, Ballario P, Bolchi A, Brenna A, Brun A, Buée M, Cantarel B, Chevalier G, Couloux A, Da Silva C, Denoeud F, Duplessis S, Ghignone S, Hilselberger B, Iotti M, Marçais B, Mello A, Miranda M, Pacioni G, Quesneville H, Riccioni C, Ruotolo R, Splivallo R, Stocchi V, Tisserant E, Viscomi AR, Zambonelli A, Zampieri E, Henrissat B, Lebrun MH, Paolocci F, Bonfante P, Ottonello S, Wincker P (2010) Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis. Nature (accepted January 2010).
Splivallo R, Fischer U, Goebel C, Feussner I, Karlovsky P (2009) Truffles regulate plant root morphogenesis via the production of auxin and ethylene. Plant Phys 150: 2018-2029 download article
Splivallo R, Novero, M., Bertea, C.M., Bossi, S., Bonfante. P. (2007) Truffle volatiles inhibit growth and induce an oxidative burst in Arabidopsis thaliana. New Phytologist 175 (3): 417-424
Splivallo R, Bossi, S., Maffei, M., and Bonfante. P. (2007) Discrimination of truffle fruiting body versus mycelial aromas by stir bar sorptive extraction. Phytochemistry 68 (20): 2584-2598
Nazeeruddin, M.K., Splivallo, R., Liska, P., Comte, P., Gratzel, M. (2003) A swift dye uptake procedure for dye sensitized solar cells. Chemical Communications 12: 1456-1457
Charette, M.A., Splivallo, R., Herbold, C., Bollinger, M.S., Moore, W.S. (2003) Salt marsh submarine groundwater discharge as traced by radium isotopes. Marine Chemistry 84: 113-121
Reviews and book chapters
Sirrenberg A., Splivallo R., Ratzinger A., Pawloswki K, Karlovsky P. (2009) Auxin production by symbiotic fungi: Bioassay and HPLC-MS analysis. In Symbiotic Fungus: Principles and Practice. Varma Ed. Soil Biology Series (Springer-Verlag Berlin Heidelberg) – DOI: 10.1007/978 3 540 95894 9_24.
Splivallo R. (2008) Biological significance of truffle secondary metabolites. In Secondary Metabolites in Soil Ecology. Karlovsky Ed. Soil Biology Series (Springer-Verlag Berlin Heidelberg) 14: 141-165
Invited talks
Splivallo R. (2009) The ecological function of truffle secondary metabolites. Helmoholtz Zentrum für Umweltforschung, Halle, 23 June 2009
Splivallo R. (2008) An overview of the chemical ecology of truffles. Forstbotanik Seminar, Uni of Göttingen, 8 Dec 2008
University of Goettingen
Grisebachstrasse 6
37077 Goettingen
Germany