Bacterial diseases can cause considerable damage and loss of quality in some crops. But there are hardly any plant protection products available to combat the plant pathogenic bacteria. That is why the Business Unit Greenhouse Horticulture and Flower Bulbs of Wageningen University & Research investigated the different options for the prevention and control of the outbreaks of bacterial diseases during the cultivation in the greenhouse.
The research focused on the prevention and control of three bacterial diseases in different crops: hairy roots in tomatoes (caused by infection with Rhizobium rhizogenes), bacterial blight of Pelargonium (caused by Xanthomonas hortorum pv pelargonii), and bacterial brown spot of Phalaenopsis (caused by Acidovorax cattleyae). Various measures for the prevention and control of bacterial diseases have been investigated within the project.
Prevent biofirm
The first possible intervention is the selective prevention of the build-up of biofilm of plant pathogenic bacteria on the leaf or root surfaces . Bacterial infections begin very often within the biofilm formed on the plant surface. On the other hand, there are also beneficial bacteria present within this biofilm, which are important for the proper functioning of the crop. That is why it is important to check if it is possible to selectively influence the ability of plant pathogenic bacteria to form a biofilm.
The second mechanism of preventing bacterial disease that has been investigated is the disruption of communication between the individual cells of the plant pathogenic bacteria. Infection process requires a lot of energy, and plant pathogenic bacteria can only do that if enough bacterial cells are present in the vicinity of the plant and work 'together.' Bacterial cells must therefore communicate with each other. They use signal molecules for this purpose. However, there are many beneficial microorganisms that are able to break down these signaling molecules (via enzymatic biodegradation). If there are not enough signaling molecules present, the individual cells of plant pathogenic bacteria cannot 'see' each other and are unable to infect the plant.