Combination of biocontrol strageties targeting the complex populations of the Pectobacterium and Dickeya bacterial pathogens in potato cultures – COMBICONTROL

Potato, the 4th worldwide food crop culture, represents a major economic stake both in developed and developing countries. Its culture is recommended by Food and Agriculture Organization of the United Nations. A limiting factor in the expansion of potato culture is its sensitivity to a wide diversity of pathogens. As a consequence potato culture exhibits a high level of treatment frequency. Since the increasing interest of European and National governments for limiting chemical inputs, biocontrol appears as one of the alternative tools instead of or in complement to chemical treatments. The National plan Ecophyto claims to reduce by half the chemical treatments -if possible-, hence stimulates the development and use of all novel practices including biocontrol.

In addition to the endemic Pectobacterium populations (P. atrosepticum, P. carotovorum, P. wasabiae), two Dickeya species (D. dianthicola and D. solani) emerged successively and recently in potato cultures in Europe though Dickeya populations were, initially, considered to be restricted to tropical and subtropical plant hosts and areas. The P. atrosepticum, P. carotovorum, P. wasabiae, D. dianthicola and D. solani species co-exist in a same contaminated field or in symptomatic tissues. Hence, treatment against blackleg and soft rot diseases should take into account the natural and complex diversity of the pathogen populations and its dynamics.

COMBICONTROL project aims at evaluating, combining and accommodating biocontrol strategies against the highly diverse and dynamic populations of the Pectobacterium and Dickeya bacterial pathogens which induce blackleg and soft rot diseases on potato plants and tubers. Hence, COMBICONTROL will produce basic knowledge (1) in the dynamics and function (protection efficiency) of biocontrol agents when they colonize the potato rhizosphere; (2) in the structure and dynamics (including the characterization of novel taxons) of Pectobacterium and Dickeya populations pathogens which will be annually collected from fields, as well as in their sensitivity to the studied biocontrol agents; (3) in the genetic and functional characterization of the potential emergence traits (species-specific and virulence traits) of Dickeya solani and Dickeya dianthicola pathogens. COMBICONTROL will also strengthen a dialog between academic researchers and potato seed producers about Pectobacterium and Dickeya disease and control.

To achieve these objectives, COMBICONTROL associate 3 academic partners and 2 private partners. The 3 academic partners are teams belonging to the Integrative Biology of the Cell (I2BC)-Saclay Plant sciences (at Gif-sur-Yvette), Institut d’Ecologie et des Sciences de l’Environnement de Paris (IEES at Paris) and Laboratory Microbiology, Adaptation & Pathogenesis (MAP at Villeurbanne). The private partners SIPRE and RD3PT are R&D sectors of the CNPPT and FN3PT organizations, respectively. They are the main national actors in the production and certification of potato seeds. Though COMBICONTROL focuses on biocontrol approach, it will be conducted in a tight coordination with other emerging projects of SIPRE and RD3PT about pathogen survey and development of other plant protection strategies. All together, the partners are already updated in the use of omics, and combine expertise in plant pathology, biocontrol, ecology, epidemiology, taxonomy, structural and functional genomics, genetics and agronomy.

COMBICONTROL is the first ANR-network on Pectobacterium and Dickeya potato pathogens that associate academic and private partners. This consortium will accelerate knowledge transfer from research to applied fields (and reciprocally) and will produce data of national and international interests. Because Pectobacterium and Dickeya diseases are present in Europe and world wide, this consortium will be a solid interlocutor for developing further research programs in collaboration with laboratories from other countries.