Team Thomma
@teamthomma.bsky.social
Alexander von Humboldt Professor of Evolutionary Microbiology
@UniCologne & @CEPLAS_1, studying how fungi interact with plants and their environment. He/him. 💛🖤
@UniCologne & @CEPLAS_1, studying how fungi interact with plants and their environment. He/him. 💛🖤
Intriguingly, tomato root microbiota differed between wild-type and Ave1-deficient Verticillium, with Ave1 causing soil-specific shifts in bacterial composition, even where it did not affect virulence.
October 14, 2025 at 8:12 PM
Intriguingly, tomato root microbiota differed between wild-type and Ave1-deficient Verticillium, with Ave1 causing soil-specific shifts in bacterial composition, even where it did not affect virulence.
We hypothesized that effector-mediated microbiota manipulation depends on host-associated soil microbiota. Testing this with tomato plants, Ave1 showed variable contributions to Verticillium virulence across soils.
October 14, 2025 at 8:11 PM
We hypothesized that effector-mediated microbiota manipulation depends on host-associated soil microbiota. Testing this with tomato plants, Ave1 showed variable contributions to Verticillium virulence across soils.
Notably, the fungal composition of the root microbiota is also influenced by plant species across soil samples. Similar as for the bacterial phyllosphere microbiota, we observed strong separation of the fungal phyllosphere community based on plant species.
October 14, 2025 at 8:10 PM
Notably, the fungal composition of the root microbiota is also influenced by plant species across soil samples. Similar as for the bacterial phyllosphere microbiota, we observed strong separation of the fungal phyllosphere community based on plant species.
Using our soil collection, we studied microbiota assembly in tomato, barley, and cotton grown under controlled greenhouse conditions. Soil primarily shaped root bacterial diversity, while plant species more strongly influenced phyllosphere communities.
October 14, 2025 at 8:09 PM
Using our soil collection, we studied microbiota assembly in tomato, barley, and cotton grown under controlled greenhouse conditions. Soil primarily shaped root bacterial diversity, while plant species more strongly influenced phyllosphere communities.
To determine differences in physicochemical properties of our soil samples, we measured pH, the amount of total organic carbon and nitrogen, as well as element levels for all soil samples. Furthermore, we conducted 16S amplicon sequencing and analyzed β-diversities.
October 14, 2025 at 8:08 PM
To determine differences in physicochemical properties of our soil samples, we measured pH, the amount of total organic carbon and nitrogen, as well as element levels for all soil samples. Furthermore, we conducted 16S amplicon sequencing and analyzed β-diversities.
To study microbiota assemblies and the role of antimicrobial effector proteins of fungal plant pathogens in diverse soils we composed a collection of 9 natural soil samples throughout the Netherlands with differences in type, texture and appearance.
October 14, 2025 at 8:07 PM
To study microbiota assemblies and the role of antimicrobial effector proteins of fungal plant pathogens in diverse soils we composed a collection of 9 natural soil samples throughout the Netherlands with differences in type, texture and appearance.
Summer greetings from our lab day out!
August 22, 2025 at 8:56 PM
Summer greetings from our lab day out!
Competition assays revealed that wild-type V. dahliae grows better than the Av2 deletion strain in presence of several Pseudomonas spp. identifying them as antagonists targeted by Av2
June 16, 2025 at 1:29 PM
Competition assays revealed that wild-type V. dahliae grows better than the Av2 deletion strain in presence of several Pseudomonas spp. identifying them as antagonists targeted by Av2
Microbiota sequencing through bacterial 16S ribosomal DNA profiling revealed a strong increase in the relative abundance of Proteobacteria in plants inoculated with the Av2 deletion strain, mainly due to increased Pseudomonadales abundance
June 16, 2025 at 1:28 PM
Microbiota sequencing through bacterial 16S ribosomal DNA profiling revealed a strong increase in the relative abundance of Proteobacteria in plants inoculated with the Av2 deletion strain, mainly due to increased Pseudomonadales abundance
Intriguingly, this virulence contribution was not observed in the absence of a host-associated microbiota, suggesting that microbiota manipulation is the genuine virulence function of the Av2 effector
June 16, 2025 at 1:28 PM
Intriguingly, this virulence contribution was not observed in the absence of a host-associated microbiota, suggesting that microbiota manipulation is the genuine virulence function of the Av2 effector
Tomato inoculations with wild-type V. dahliae and an Av2 deletion strain revealed that Av2 contributes to virulence during host colonisation
June 16, 2025 at 1:27 PM
Tomato inoculations with wild-type V. dahliae and an Av2 deletion strain revealed that Av2 contributes to virulence during host colonisation
To test antimicrobial activity of the Av2 effector, which occurs in two allelic variants in the Verticillium dahliae population, both variants were produecd in E. coli and tested in antimicrobial activity assays, revealing sective antimicrobial activity
June 16, 2025 at 1:27 PM
To test antimicrobial activity of the Av2 effector, which occurs in two allelic variants in the Verticillium dahliae population, both variants were produecd in E. coli and tested in antimicrobial activity assays, revealing sective antimicrobial activity
Excited to have @metalichen.bsky.social as seminar speaker today on the fascinating (effector) biology of the sunburst lichen Xanthoria
June 4, 2025 at 8:13 AM
Excited to have @metalichen.bsky.social as seminar speaker today on the fascinating (effector) biology of the sunburst lichen Xanthoria
Generally, PNPs can induce stomatal opening. Also Ave1, but not Ave1L2, can open stomates, and thus affect host physiology. Thus, beyond its antimicrobial function, Ave1 may contribute to virulence through manipulation of host physiology.
April 4, 2025 at 2:20 PM
Generally, PNPs can induce stomatal opening. Also Ave1, but not Ave1L2, can open stomates, and thus affect host physiology. Thus, beyond its antimicrobial function, Ave1 may contribute to virulence through manipulation of host physiology.
Intriguingly, Ave1 clearly contributes to virulence also in absence of a host-associated microbiota, suggesting that it modulates (a) host virulence target(s) besides manipulation of host-associated microbiota
April 4, 2025 at 2:17 PM
Intriguingly, Ave1 clearly contributes to virulence also in absence of a host-associated microbiota, suggesting that it modulates (a) host virulence target(s) besides manipulation of host-associated microbiota
Interestingly, Ave1L2 only contributed to virulence on plants that carry an associated microbiota, and not on plants grown on sterilized substrate, suggesting that this effector does not have additional virulence targets in the plant
April 4, 2025 at 2:13 PM
Interestingly, Ave1L2 only contributed to virulence on plants that carry an associated microbiota, and not on plants grown on sterilized substrate, suggesting that this effector does not have additional virulence targets in the plant
Interestingly, a SynCom composed of 26 isolates from the culture collection seemed to reduce the impact of Verticillium dahliae infection on tomato plants
April 4, 2025 at 2:08 PM
Interestingly, a SynCom composed of 26 isolates from the culture collection seemed to reduce the impact of Verticillium dahliae infection on tomato plants
To enable reconstitution experiments on tomato plants using host-associated bacteria, we generated a bacterial culture collection of tomato-associated bacteria, resulting in 132 unique bacterial isolates, 75 of which sequenced completely.
April 4, 2025 at 2:07 PM
To enable reconstitution experiments on tomato plants using host-associated bacteria, we generated a bacterial culture collection of tomato-associated bacteria, resulting in 132 unique bacterial isolates, 75 of which sequenced completely.
However, we can employ the system for infections on other host plants too: Arabidopsis thaliana and Lotus japonicus
April 4, 2025 at 2:06 PM
However, we can employ the system for infections on other host plants too: Arabidopsis thaliana and Lotus japonicus
We show that our gnotobiotic “Flowpot” system can be used to accommodate interactions of Verticillium dahliae on tomato; clear impact of Verticillium wilt disease is observed in absence and presence of a plant-associated microbiota.
April 4, 2025 at 2:05 PM
We show that our gnotobiotic “Flowpot” system can be used to accommodate interactions of Verticillium dahliae on tomato; clear impact of Verticillium wilt disease is observed in absence and presence of a plant-associated microbiota.
Pathogen-secreted effectors can target host plant physiology, plant-associated microbiota, or both. To distinguish between these possibilities, we now developed a gnotobiotic plant system that allows infections with Verticillium dahliae in presence or absence of defined microbiota
April 4, 2025 at 2:04 PM
Pathogen-secreted effectors can target host plant physiology, plant-associated microbiota, or both. To distinguish between these possibilities, we now developed a gnotobiotic plant system that allows infections with Verticillium dahliae in presence or absence of defined microbiota
Terrific MSc thesis defense by Zoe on her research carried out in the lab of @luckystrike1984.bsky.social; next stage will be her PhD research in the framework of @mibinet.bsky.social under the guidance of @hroevenich.bsky.social
March 22, 2025 at 8:34 AM
Terrific MSc thesis defense by Zoe on her research carried out in the lab of @luckystrike1984.bsky.social; next stage will be her PhD research in the framework of @mibinet.bsky.social under the guidance of @hroevenich.bsky.social
Had an amazing time at #FABI today, diving deep into microbiota profiling data to uncover how an antimicrobial effector protein influences plant-associated microbiota. Brilliant students and enthusiastic PIs, lively discussions, and thorough engagement. Loved every minute of it!
March 12, 2025 at 7:10 PM
Had an amazing time at #FABI today, diving deep into microbiota profiling data to uncover how an antimicrobial effector protein influences plant-associated microbiota. Brilliant students and enthusiastic PIs, lively discussions, and thorough engagement. Loved every minute of it!