Invited Speakers

University of Goettingen

What the genome does not tell - Searching for the function of Gretchen Hagen 3 enzymes

GRETCHEN HAGEN 3 (GH3) enzymes form a group of adenylating enzymes that were initially identified as auxin responsive genes. The dicot model Arabidopsis thaliana harbors a total of 19 GH3 enzymes in its genome and so far important contributions to phytohormone-driven signaling for auxin, jasmonates and also SA have been described. While at least eight genes conjugate auxin with different amino acids and thereby inactivating the hormone, JAR1 is the main JA-Ile-forming enzyme in Arabidopsis which activates jasmonates, while PBS3 is involved in salicylate biosynthesis. Further analysis of this Brassicales specific clade of 11 GH3 enzymes from Arabidopsis revealed the discovery of novel substrate groups such as polyunsaturated fatty acids (PUFAs) and their oxidized derivatives. These data are currently been compared with the situation in bryophytes, since Marchantia polymorpha and Physcomitrium have only two genes each. Together these data will be the basis for further studies on the emergence of novel enzyme activities.

Anhalt University of Applied Sciences

Can biodiversity shape the evolution of phenotypic plasticity? Insights from a long-term biodiversity experiment

The growing concern about global biodiversity loss has led to numerous studies manipulating plant species diversity to investigate its effects on ecosystem functioning. These studies have consistently shown that decreasing species diversity reduces both the amount and the stability of community biomass production, while at the species level, changes in plant diversity and the associated abiotic and biotic environment also generate substantial phenotypic variation. Functional traits play a central role in determining plant phenotype, performance under different environmental conditions, and coexistence with other species. Phenotypic responses can arise from genetic differences or from phenotypic plasticity, the ability of a single genotype to express different phenotypes in different environments without genetic change. While phenotypic plasticity enables plants to cope with environmental variation, plasticity itself can also evolve under different selective pressures. In this talk, we will explore how differences in plant community diversity can shape both adaptive trait evolution and transgenerational phenotypic plasticity.

By combining field observations with a two-generation common garden experiment using clonal lineages of Taraxacum officinale, originating from a 17-year-old grassland biodiversity experiment (the Jena Experiment), we disentangled the effects of evolutionary history from environmental plasticity. By exposing plants to contrasting light environments, we tested whether populations with different plant diversity backgrounds differed in their ability to adjust growth, reproduction, and leaf traits, and whether these responses were transmitted across generations.

Our results show that while most measured traits adjusted to their current light environment through phenotypic plasticity, selection in plant communities of different diversity altered patterns of transgenerational plasticity. These findings suggest that biodiversity shapes not only plant performance, but also the capacity of plant populations to respond to future environmental change across generations.

Finally, we will discuss the implications of these findings for understanding the interplay between ecological and evolutionary processes, and the role of biodiversity in shaping evolutionary trajectories.

Swedish University of Agricultural Sciences (SLU), Sweden

Phenotypic Plasticity in Plants: The Norm of Reaction as a Breeder's Best Friend

Phenotypic plasticity is the ability of a single genotype to produce different phenotypes in response to environmental variation. This ability is particularly important in plants because, as sessile organisms, they cannot escape unfavorable conditions and must adjust their physiology, metabolism, growth, and development to survive. Environmental factors such as drought, temperature, salinity, and nutrient availability can trigger complex responses involving environmental perception, hormonal and molecular signaling, gene regulation, and developmental changes.

This presentation explores the mechanisms and evolutionary importance of phenotypic plasticity, with a special focus on genotype × environment (G × E) interactions, the immense usefulness of the norm of reaction, and the genetic basis of environmental responses. This paper analyzes how approaches such as QTL mapping, genome-wide association studies (GWAS), and plasticity QTLs (pQTLs) can identify genomic regions associated with differences in plant responses to various environments. Understanding these genetic mechanisms establishes an important link between molecular biology, ecology, evolution, and plant breeding. A key focus will be the potential of incorporating plasticity into crop improvement. Finally, I will present some of my own research, illustrating how these concepts can be applied experimentally to understand the genetic basis of phenotypic plasticity and its potential relevance for developing more resilient crops.

Molecular Systems Biology Lab (MOSYS), Department of Functional and Evolutionary Ecology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria

Vienna Metabolomics Center (VIME), University of Vienna, Vienna, Austria

Research Center Artificial Intelligence in Personalized Nutrition (AIPN), University of Vienna, Vienna, Austria

Environment and Climate Research Hub, University of Vienna, Vienna, Austria

Research Network Health in Society, University of Vienna, Vienna, Austria

 

Plant Plasticity and Natural Variation in the Holobiont-Panomics Era

This lecture explores how plant plasticity and natural variation form the biological foundation for climate‑resilient agriculture, and how modern PANOMICS technologies transform our ability to understand, predict, and utilize this variation. Drawing on evidence from global germplasm collections—Arabidopsis, wheat, chickpea, pearl millet, and other underutilized crops—the presentation demonstrates that genomics alone explains only 10–40% of phenotypic variance, leaving the majority of adaptive traits encoded in dynamic layers of the proteome, metabolome, microbiome, and environmental interactions [1,2,3]. It will be demonstrated that phenotypes and plasticity emerge from multi‑layered causal molecular networks, not static DNA sequences [1].

Plant plasticity—the capacity of plants to adjust physiology, metabolism, and development across microhabitats—is illustrated through examples such as Clusia, which exhibits a continuum from C3 to CAM photosynthesis [4], and through genotype‑dependent drought responses in chickpea and wheat root exudate metabolomes [5,6]. These cases highlight how local environments sculpt unique phenotypes, implying that locally adapted cultivars outperform globally distributed seed stocks.

The lecture introduces the holobiont concept, emphasizing that plant performance is inseparable from its associated microbiome [7]. Natural variation in root exudates, BNI (Biological Nitrification Inhibition) activity, and soil microbiome function demonstrates that plants actively engineer their ecological niche [6]. It is demonstrated that metabolomic diversity in root exudates drives soil nitrogen cycling, microbial community structure, and ultimately yield and sustainability.

Together, these insights establish a new paradigm: breeding must shift from genome‑centric approaches to panome‑centric, holobiont‑aware strategies [7]. PANOMICS, machine learning, and genome‑scale metabolic modeling enable causal inference across biological layers, revealing metabolic control points and actionable targets for breeding climate‑smart crops [2,3]. Natural variation—across genomes, proteomes, metabolomes, and microbiomes—provides the raw material for designing resilient agroecosystems that support both human and planetary health [7].

References

[1] Weckwerth W. Green systems biology - From single genomes, proteomes and metabolomes to ecosystems research and biotechnology. J Proteomics. 2011;75(1):284-305. Epub 20110723. doi: 10.1016/j.jprot.2011.07.010. PubMed PMID: 21802534.

[2] Weckwerth W, Ghatak A, Bellaire A, Chaturvedi P, Varshney RK. PANOMICS meets germplasm. Plant Biotechnol J. 2020;18(7):1507-25 doi: 10.1111/pbi.13372. PubMed PMID: 32163658; PubMed Central PMCID: PMCPMC7292548.

[3] Ghatak A, Chaturvedi P, Waldherr S, Subbarao GV, Weckwerth W. PANOMICS at the interface of root-soil microbiome and BNI. Trends Plant Sci. 2023;28(1):106-22. Epub 20221010. doi: 10.1016/j.tplants.2022.08.016. PubMed PMID: 36229336.

[4] Kramml HM, Herpell JB, Priemer C, Wessely Z, Schindler F, Berger A, et al. Clusia genomes shed light on the evolution and diversity of crassulacean acid metabolism physiotypes. Nat Commun. 2026;17(1). Epub 20260505. doi: 10.1038/s41467-026-71958-z. PubMed PMID: 42086566; PubMed Central PMCID: PMCPMC13144421.

[5] Chaturvedi P, Pierides I, Lopez-Hidalgo C, Garg V, Zhang S, Barmukh R, et al. Natural variation in the chickpea metabolome under drought stress. Plant Biotechnol J. 2024;22(12):3278-94. Epub 20241016. doi: 10.1111/pbi.14447. PubMed PMID: 39411896; PubMed Central PMCID: PMCPMC11606430.

[6] Ghatak A, Kanellopoulos AE, Lopez-Hidalgo C, Malits A, Meng Y, Schindler F, et al. Natural variation of the wheat root exudate metabolome and its influence on biological nitrification inhibition activity. Plant Biotechnol J. 2025;23(11):4755-72. Epub 20250721. doi: 10.1111/pbi.70248. PubMed PMID: 40692297; PubMed Central PMCID: PMCPMC12576471.

[7]Weckwerth W, Chaturvedi P, Ghatak A, Kerou M, Garg V, Bohra A, et al. Natural variation of the holobiont for sustainable agroecosystems. Trends Plant Sci. 2025;30(9):972-9. Epub 20250627. doi: 10.1016/j.tplants.2025.05.006. PubMed PMID: 40579258.

University of Sheffield, UK

Understanding leaf humidity and ABA responses at the cellular level

The escalating frequency of ‘flash droughts’, rapid farmland desiccation due to soaring temperatures and arid climates, threatens global food security. Understanding plant stress responses is critical if we are to generate new crops that can both withstand stress but also continue to thrive and deliver optimal yields. Plant responses to drought and low humidity are controlled by the plant hormone, abscisic acid (ABA), which accumulates under stress, rebalancing plant hydraulics to reduce water loss.

To understand how ABA regulates stress responses and achieve our vision of stress resilient crops, we must be able to determine in which cells ABA is made and how ABA levels change during stress. Despite nearly 60 years of research, these key questions remained difficult to answer, until recently. I developed genetically encoded tools allowing us to see and quantify ABA concentrations in living plants. This major innovation resulted in surprising and illuminating results. We found that different types of stress elicited different patterns of ABA accumulation. Now, we are investigating the functional relevance of each of these context-dependent, spatially defined hormone accumulations - to understand how ABA functions in stomata and non stomatal responses, to allow plants to survive stress.