Peter Marhavý at the confocal microscope

Marhavý, Peter - Short distance communication in response to wound stress

Research

Peter Marhavy at the confocal microscopePhoto: Fredrik Larsson

In my group, we are studying the mechanisms involved in short distance cell-to-cell communication in response to localized wound stress in plant roots using plant parasitic nematodes and state-of-the-art laser ablation approach.

Plants are able to recognize biotic, abiotic and physical stressors and orchestrate different signaling pathways accordingly. Although defensive stress response signals have been intensively studied and documented, the exact mechanisms by which these signals are perceived by cells and how the signal is further transmitted from one cell to another are still largely unknown. Our research will provide insights into molecular mechanisms of cell-to-cell communication to underlying early responses to wounding in plant roots.

  
Real-time monitoring of calcium wave propagation after cortex cell ablation using an R-GECO1 reporter line. Laser ablation of cortex cells leads to signal increases a few seconds after ablation at the ablated root side (indicated by white arrow). In non-ablated control roots, no changes of signal intensity were observed.
Arabidopsis root expressing SCR::SCR-YFP (green) in endodermis and stained with cell-wall fluorescence dye propidium iodide (red). Time lapse demonstrate single cell laser ablation in root meristem. White arrow indicates ablated cell.
Real-time monitoring (xyt) of cyst nematodes (Heterodera schachtii) during infection in 5-day-old roots of Arabidopsis thaliana stained with propidium iodide (red). Video demonstrate nematode progression between epidermal cells.
Portrait photo of Petra Marhava standing in an in vitro growth room fetching a square plate with green Arabidopsis seedlings

Marhava, Petra - Plant acclimation to heat and cold stress

Research

Portrait photo of Petra Marhava standing in an in vitro growth room fetching a square plate with green Arabidopsis seedlingsPhoto: Andreas Palmén

Temperatures below or above the physiological optimum for plant growth induce temperature stress, which can cause detrimental and irreversible damage to plant growth and development. While most of the studies to date have focused on big-picture elements of plant responses to climate change, our research will provide insights into the molecular and cellular responses, to improve our mechanistic understanding of plant acclimation to heat and cold stress.

Even though studies on the underlying mechanisms of plant acclimation to high/low temperature are making steady progress, many questions remain unanswered. In particular, the role of the plant root system during acclimation to temperature stress has received little attention, though temperature stress at the root level can strongly affect the function of the whole plant and decrease crop productivity. In addition, despite knowing that plants show organ-specific transcriptome responses to temperature stress, we still tend to generalize findings based on shoot tissues. In my group, we combine state-of-the-art techniques for exploring root tissue to understand how roots sense and modulate their growth in response to fluctuating temperatures.

Torgeir Rhoden Hvidsten, Professor at the Norwegian University of Life Sciences

Hvidsten, Torgeir R. – Evolutionary analysis of gene regulatory networks

Research

Torgeir Rhoden Hvidsten, Professor at the Norwegian University of Life SciencesPhoto: Håkon Sparre/NMBU

In my research group, we use machine learning methods and large-scale genomics datasets to model how genes interact in regulatory networks, how regulatory networks evolve and how they give rise to complex properties characteristic to individuals and species.

Our main project aims to understand the process of wood formation in angiosperm and gymnosperm tree species by modelling the regulatory networks orchestrating the differentiation of stem cells into woody tissues. To this end, we are integrating large-scale multi-omics data to infer regulatory networks for several species and comparing these networks across species to identify regulatory mechanisms explaining the evolution of trees.

Network of different colored dots that are connected with lines Regulatory network of aspen wood formation

In another project, we work to understand how gene regulation evolves after whole genome duplication and to reveal to what degree these events, which play major roles in plant evolution, spark new regulatory innovations. To this end, we are developing phylogenetic methods for comparative analysis of omics data across multiple species.

In collaboration with Nathaniel Street, we are developing a number of online tools for facilitating comparative network analysis in plants. ComPlEx, available through the PlantGenIE portal (http://plantgenie.org), allows Comparative analysis of Plant Expression networks. AspWood (http://aspwood.popgenie.org) and NorWood (http://norwood.congenie.org) offer dedicated tools to analyze high-resolution gene expression data across wood formation in aspen and Norway spruce.

Read more about Torgeir Hvidsten's research here

 

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