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. 💛🖤
Finally, a crystal structure was solved for the f. sp. vasinfectum homolog by X-ray crystallography at 1.5 Å resolution, revealing a novel effector fold 💠
February 14, 2026 at 11:19 AM
Finally, a crystal structure was solved for the f. sp. vasinfectum homolog by X-ray crystallography at 1.5 Å resolution, revealing a novel effector fold 💠
Fusarium D homologs from f. sp. vasinfectum (infects cotton) and radicis-cucumerinum Iinfects cucurbits) induce wilting on cotton and on cucurbit plants
February 14, 2026 at 11:18 AM
Fusarium D homologs from f. sp. vasinfectum (infects cotton) and radicis-cucumerinum Iinfects cucurbits) induce wilting on cotton and on cucurbit plants
D homologs occur in V. alfalfae and V. longisporum, but not other Verticillium spp. Beyond, homologs solely occur in some Fusarium spp; a pattern that suggests horizontal gene transfer. Surprise: the Verticillium D gene occurs on Ar1h2 haplotype Starships! 🚀 😱
February 14, 2026 at 11:17 AM
D homologs occur in V. alfalfae and V. longisporum, but not other Verticillium spp. Beyond, homologs solely occur in some Fusarium spp; a pattern that suggests horizontal gene transfer. Surprise: the Verticillium D gene occurs on Ar1h2 haplotype Starships! 🚀 😱
While D pathotype strains carry identical D homologs, diverged D-like homologs occur throughout the V. dahliae population with 91% to 82% amino acid similarity that do not seem to cause defoliation
February 14, 2026 at 11:15 AM
While D pathotype strains carry identical D homologs, diverged D-like homologs occur throughout the V. dahliae population with 91% to 82% amino acid similarity that do not seem to cause defoliation
The D effector also mediated aggressiveness on hosts that do not respond to defoliation, such as benthamiana and Arabidopsis
February 14, 2026 at 11:15 AM
The D effector also mediated aggressiveness on hosts that do not respond to defoliation, such as benthamiana and Arabidopsis
Olive-defoliating V. dahliae strains also carry the D gene. Deleting both D copies in the olive-defoliating strain V150I nearly abolished disease, showing D is essential for olive defoliation
February 14, 2026 at 11:14 AM
Olive-defoliating V. dahliae strains also carry the D gene. Deleting both D copies in the olive-defoliating strain V150I nearly abolished disease, showing D is essential for olive defoliation
⚠️ Treatment of cotton seedlings with purified D protein led to progressive chlorosis and defoliation. Thus, the D effector protein, rather than fungal colonization, is sufficient to cause defoliation symptoms ‼️
February 14, 2026 at 11:14 AM
⚠️ Treatment of cotton seedlings with purified D protein led to progressive chlorosis and defoliation. Thus, the D effector protein, rather than fungal colonization, is sufficient to cause defoliation symptoms ‼️
Introduction of D into the ND pathotype strain JR2 causing severe stunting and defoliation
February 14, 2026 at 11:12 AM
Introduction of D into the ND pathotype strain JR2 causing severe stunting and defoliation
Targeted deletion of D in V. dahliae CQ2 shows its role in cotton disease: single ΔD mutants had reduced aggressiveness, double ΔΔD mutants lost pathogenicity entirely, and complementation restored virulence
February 14, 2026 at 11:12 AM
Targeted deletion of D in V. dahliae CQ2 shows its role in cotton disease: single ΔD mutants had reduced aggressiveness, double ΔΔD mutants lost pathogenicity entirely, and complementation restored virulence
Transcriptome analysis during cotton infection showed high expression of only two of these genes, encoding two 100% identical secreted effectors that originate from a segmental duplication
February 14, 2026 at 11:11 AM
Transcriptome analysis during cotton infection showed high expression of only two of these genes, encoding two 100% identical secreted effectors that originate from a segmental duplication
Comparative genomics identified 200 kb of D-specific sequence. To narrow this region down further strains were sought. Strain BGI_32 clustered outside D and ND groups, but turned out ND, reducing the D-specific interval to ~24 kb with only 7 genes
February 14, 2026 at 11:10 AM
Comparative genomics identified 200 kb of D-specific sequence. To narrow this region down further strains were sought. Strain BGI_32 clustered outside D and ND groups, but turned out ND, reducing the D-specific interval to ~24 kb with only 7 genes
To address this knowledge gap, we pursued a comparative genomics approach making use of a collection of 18 Verticillium strains that were first phenotyped to separate defoliating from non-defoliating strains
February 14, 2026 at 11:09 AM
To address this knowledge gap, we pursued a comparative genomics approach making use of a collection of 18 Verticillium strains that were first phenotyped to separate defoliating from non-defoliating strains
...and thank you Thomas Kroj for the nice seminar and acting as Gabriella's examiner!
January 27, 2026 at 3:27 PM
...and thank you Thomas Kroj for the nice seminar and acting as Gabriella's examiner!
🎉 Yesterday we enjoyed the glorious defence of @gabriellapetti.bsky.social of her @unicologne.bsky.social PhD thesis on "Homologous antimicrobial proteins in plants and fungi: conserved mechanisms shaping the plant microbiota" #proudPI #PhDone ..mind the crown modeled after the Ave1 NMR structure!😍
January 27, 2026 at 3:25 PM
🎉 Yesterday we enjoyed the glorious defence of @gabriellapetti.bsky.social of her @unicologne.bsky.social PhD thesis on "Homologous antimicrobial proteins in plants and fungi: conserved mechanisms shaping the plant microbiota" #proudPI #PhDone ..mind the crown modeled after the Ave1 NMR structure!😍
You were right @suaybuestuen.bsky.social ! Amazing….
December 24, 2025 at 8:15 AM
You were right @suaybuestuen.bsky.social ! Amazing….
📣 Major milestone achieved! First @teamthomma.bsky.social @unicologne.bsky.social PhD student graduated 🎉! Congratulations to @wolki95.bsky.social for a stellar defence of a thesis on antimicrobial effectors of Verticillium dahliae that drive niche adaptation #proudPI #PhDone
December 12, 2025 at 12:39 PM
📣 Major milestone achieved! First @teamthomma.bsky.social @unicologne.bsky.social PhD student graduated 🎉! Congratulations to @wolki95.bsky.social for a stellar defence of a thesis on antimicrobial effectors of Verticillium dahliae that drive niche adaptation #proudPI #PhDone
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!