Institute of Bio- and Geosciences (IBG)

Plant Sciences (IBG-2)

Viruses against pathogenic bacteria help plants combat disease

Five current and former members of IBG-2 (Shoot Dynamics, Alternative Biomass) participated in the 2^nd European Congress on Photosynthesis Research (ePS2) in Padua, Italy. With three oral presentations and two poster presentations, IBG-2 was strongly represented and appreciated in the European photosynthesis research community.

Plant pathogenic bacteria are estimated to account for more than 10% of annual yield losses and are gaining resistance against classical control strategies. Bacteriophages - viruses of bacteria may point the way to sustainable biocontroll.

Here, we isolated several novel phages against five different pathogenic bacteria including: Agrobacterium tumefaciens, Pseudomonas syringae, and Xanthomonas campestris. All bacteriophages were characterized, and their ability to suppress bacterial growth was proven in microbiological assays (Erdrich et al., 2022).

As many bacterial pathogens are soil or seed transmitted, we tested phage binding on seeds, particularly the interaction with the seed-coat mucilage (SCM, a gelatinous matrix exuded by the seeds when they encounter moist conditions). Comparing the phage binding on Arabidopsis seeds with and without SCM we found that 2 of the 3 phages were dependent on the SCM for binding. To discern how the phage-SCM binding occurs we checked the physical matrix characteristic of the extracted SCM using transmission electron microscopy and even more interestingly using Arabidopsis SCM mutants. We identified the diffusible cellulose of SCM as important component for phage binding. (Erdrich et al., 2024)

Stability tests showed that phages can be coated onto seeds and will remain active up to one month, which is relevant for further application in agriculture.