Efficacy of hydrogen peroxide treatment for control of hairy root disease caused by rhizogenic agrobacteria

Abstract

This is the first study that examined the effectiveness of H2 O2 to control HRD in hydroponic systems, and the effect of catalase activity on H2 O2 effectiveness. Our study has direct relevance for the highly intensive horticultural sector.

Potential for Biocontrol of Hairy Root Disease by a Paenibacillus Clade

“…As different lineages of rhizogenic Agrobacterium strains are able to form biofilms in which they can be protected from chemical disinfectants (Bosmans et al, 2015), or are able to tolerate high disinfectant concentrations (Bosmans et al, 2016c) or even diverse antibiotics (Khodykina et al, 2014), there is an urgent need for alternative, effective means to prevent, and control the disease including the use of biocontrol organisms.…”

“…Preliminary characterization of the antagonistic compounds of AD117 and ST15.15/027 revealed that the compounds are water-soluble molecules of low molecular weight (<600 Da). There also seems to be an important role of Ca 2+ to produce and/or secrete potential toxins/antibiotics against rhizogenic agrobacteria (Bosmans et al, 2016c). Further research, however, is necessary to structurally identify and characterize these compounds.…”

“…Instead, preventative actions should be taken, such as preventing, and/or removing Agrobacterium containing biofilms that are often associated with the disease in the greenhouse irrigation system (Danhorn and Fuqua, 2007; Bosmans et al, 2015). However, to effectively prevent the disease generally high concentrations of chemical disinfectants are required, including levels that may be phytotoxic (Bosmans et al, 2016c). Moreover, several of these chemicals may be converted to unwanted by-products with human health hazards (Damstra, 2002).…”

Rhizogenic agrobacteria in hydroponic crops: epidemics, diagnostics and control

“…However, as several rhizogenic Agrobacterium biovar 1 strains are catalase-positive and able to tolerate H 2 O 2 (Bosmans et al, 2015), H 2 O 2 concentrations as high as 100 ppm are needed to significantly reduce rhizogenic agrobacteria populations containing catalase-positive strains. For catalase-negative strains, a treatment with 50 ppm H 2 O 2 resulted in a significant reduction of the population in both biofilm and water (Bosmans et al, 2016c). However, greenhouse experiments have shown that H 2 O 2 concentrations in the water circuit decrease with distance from the application point and are consistently lower at the end of the irrigation circuit, most probably because it reacts with organic material in the (biofilms) piping system (Bosmans et al, 2016c).…”

“…For catalase-negative strains, a treatment with 50 ppm H 2 O 2 resulted in a significant reduction of the population in both biofilm and water (Bosmans et al, 2016c). However, greenhouse experiments have shown that H 2 O 2 concentrations in the water circuit decrease with distance from the application point and are consistently lower at the end of the irrigation circuit, most probably because it reacts with organic material in the (biofilms) piping system (Bosmans et al, 2016c). Interestingly, the lower H 2 O 2 concentrations measured at the end of the irrigation circuits correlate with a higher disease incidence at the end of the circuits, illustrating the need for monitoring actual H 2 O 2 concentrations in the water circuit and/or H 2 O 2 applications at additional sites throughout the irrigation system.…”