Lutte contre les maladies bactériennes de la pomme de terre dues aux Pectobacterium spp. (Erwinia carotovora)

Abstract

Les bactéries macergènes appartenant aux espèces Pectobacterium atrosepticum et Pectobacterium carotovorum sont responsables de dégâts importants lors de la culture et de la conservation après récolte des tubercules de pomme de terre. L'espèce bactérienne impliquée et la gravité des pertes dépendent de facteurs environnementaux, en particulier de l'humidité et de la température, ainsi que du potentiel infectieux des sols. Aucun traitement ne permet aujourd'hui de lutter efficacement contre cette maladie. Dans cette revue, nous présentons les travaux récents concernant les méthodes de lutte chimique, génétique et biologique mises en oeuvre pour limiter l'action néfaste de ces bactéries. De nouvelles stratégies dont le but est de perturber la communication quorum-sensing des Pectobacteria sont discutées. L'utilisation d'inocula bactériens et/ou de biostimulateurs des populations bactériennes non pathogènes est notamment envisagée pour dégrader les signaux de quorum-sensing produits par l'agent pathogène. Abstract Control of bacterial diseases of potato caused by Pectobacterium spp. (Erwinia carotovora)Pectinolytic bacteria belonging to Pectobacterium atrosepticum and Pectobacterium carotovorum species are the causal agents responsible for important damage during the culture and storage of potato tubers. The bacterial species involved and the severity of damages depend on several environmental factors, such as humidity and temperature, as well as infectious potential of soils. There is currently no treatment to effectively control the virulence of the pathogens. In this review, recent works on chemical, genetic and biological strategies developed to limit the harmful action of these bacteria are presented. Novel strategies targeting the quorum-sensing communication of Pectobacteria are also discussed. The use of bacterial inocula and/or bioactivators stimulating the nonpathogenic bacteria are proposed to degrade the quorum-sensing signals of the pathogen.

Potato soil-borne diseases. A review

“…Application of fungicides and nematicides are protecting strategies (see Section 4.5 and Table 8) whose application time and doses can be advised by DSS. However, pesticides are sometimes inefficient against pathogens, such as Pectobacterium carotovorum (Latour et al 2008), or their use is limited by environmental regulations. Consequently, alternative methods based on adapted cultural practices have to be recommended (see Section 4 and Tables 3 and 8).…”

“…When a disease is established in a production site, its spread must be avoided as much as possible. All diseased plants have to be eliminated or burned and tools should be properly disinfected before use in another field (Salas et al 2000;Latour et al 2008).…”

“…Biocontrol can also be performed by disrupting pathogens molecular pathways. P. carotovorum quorum-sensing mechanism is controlled by a quorum-quenching strategy aiming at interrupting the quorum-sensing by using compounds or organisms able to cause interferences in the bacterial signal (Latour et al 2008). Finally, it is also possible to enhance plant defense reactions against soil-borne pathogens by foliar spraying with different inducers such as salicylic acid, di-potassium hydrogen phosphate, and tripotassium phosphate (Mahmoud 2007).…”

Identification of Three Elicitins and a Galactan-Based Complex Polysaccharide from a Concentrated Culture Filtrate of Phytophthora infestans Efficient against Pectobacterium atrosepticum

“…There are currently no efficient curative methods to protect potato against Pectobacterium spp. [7], although biocontrol strategies have been tested to control soft rot development. For example, the application of biocontrol agents that are safe for the environment has become an important research area in pest management, and some fluorescent Pseudomonas strains can act as biological control agents against Pectobacterium spp.…”

Extension de la pourriture molle du céleri branche en maraîchage périurbain de Yaoundé (Cameroun)*

“…symptômes de pourriture molle ont révélé le véritable agent causal, Pectobacterium carotovorum, connu jusqu'en 2006 sous l'appellation taxonomique Erwinia carotovora(Latour et al, 2008). Cette bactérie cosmopolite pathogène de nombreuses plantes cultivées se multiplie en milieu chaud (25°C) et très humide.…”