Eleni Stravrinidou in a lab looking on plants

Stavrinidou, Eleni – Plant Bioelectronics

Research

Eleni Stravrinidou in a lab looking on plantsPhoto: Thor Balkhed

The research in my group focuses on developing bioelectronic technologies for real time monitoring and dynamic modulation of plant physiology. Bioelectronics devices are very promising for interfacing with biology. Bioelectronic sensors can translate complex biological inputs to electronic readout signals while bioelectronic actuators can modulate biological networks via electronic addressing. Our aim is to develop bioelectronic technologies that overcome limitations of conventional methods and establish bioelectronics in plant biology. Focus is given on understanding and enhancing plant responses to environmental stress.

Recently we developed sensors based on the organic electrochemical transistor for monitoring sugar concentration in in-vitro and in-vivo plant systems. OECTs can operate in complex biological environment and directly detect analytes upon functionalization with biological recognition elements such as enzymes. OECTs also offer signal amplification and fast response times. In a first example we developed OECT glucose sensors and measured quantitively and in real-time the export of glucose from isolated chloroplasts1. Glucose was detected only from chloroplasts isolated in night-time in agreement with our understanding of starch degradation in plants. With the OECT sensors we achieved a temporal resolution of 1min that surpass conventional methods. In another work we developed implantable OECT sugar sensors for in-vivo, real time monitoring of sugar transport in trees2. Glucose and Sucrose sensors were implanted into the stem of Populus tremula x tremuloides (Hybrid Aspen tree) and could monitor sugar variations for 48h in the mature xylem tissue. The sensors revealed diurnal fluctuation in sucrose concentration while glucose concentration remained constant, something that was not observed before.

Collage of three images illustrating the principle of organic electrochemical transistor sensor measurement of sugar concentrations in plantsFigure 1: A. OECT-sensors for real time monitoring of sugars in trees. B. Photograph of the sensor implanted in the stem of Hybrid Aspen tree. C. Diurnal variation of sucrose concentration in xylem sap.

Furthermore, we developed a capillary based organic electronic ion pump (c-OEIP) for electronically controlled delivery of phytohormones. The OEIP is an electrophoretic delivery device that converts the electronic addressing signal into ionic fluxes allowing precise and dynamic delivery of ions and charged biomolecules with high spatiotemporal resolution. With the c-OEIP we could efficiently deliver the phytohormone Abscisic Acid, in the leaf apoplast of intact Nicotiana tabacum plants and induced stomata closure3. Our work revealed kinetics of ABA signal propagation in the leaf that were unknown.

Collage of three images illustrating the principle of capillary based organic electronic ion pumps delivering plant hormones in intact plants Figure 2: OEIP for controlled and local delivery of phytohormones in intact plants. B. Micrograph of c-OEIP implanted in the leaf of tobacco plant. C. Temporal evolution of stomatal aperture upon ABA delivery with c-OEIP

Our proof-of-concept studies so far have shown that with bioelectronic devices, both sensors and actuators, we revealed biological processes that were not observed previously with conventional methods, highlighting the potential of bioelectronics for plant science.

Read more about Eleni Stavrinidou's research

References

  1. “Real-Time Monitoring of Glucose Export from Isolated Chloroplasts Using an Organic Electrochemical Transistor” C. Diacci, J. W. Lee, P. Janson, G. Dufil, G. Méhes, M. Berggren*, D. T. Simon, E. Stavrinidou* Advanced Materials Technologies, 1900262 (2019)
  2. "Diurnal in vivo xylem sap glucose and sucrose monitoring using implantable organic electrochemical transistor sensors” C. Diacci, T. Abedi, J. W. Lee, E. O. Gabrielsson, M. Berggren, D.T. Simon, T. Niittylä,* and E. Stavrinidou* iScience, 24, 101966 (2021)
  3. “Implantable Organic Electronic Ion Pump Enables ABA Hormone Delivery for Control of Stomata in an Intact Tobacco Plant” I. Bernacka-Wojcik, M. Huerta, K. Tybrandt, M. Karady, Y. Mulla, D. J. Poxson, E. O. Gabrielsson, K. Ljung, D. T. Simon, M. Berggren, and E. Stavrinidou* Small, 1902189 (2019)
 
Portrait photo of Sandra Jämtgård in a forest

Jämtgård, Sandra – Plant Nitrogen Availability

Research

Portrait photo of Sandra Jämtgård in a forestPhoto: Andreas Palmén

My group’s research revolves around understanding the mechanisms governing plant nitrogen availability at the root-soil interface. A key tool in our research is the sampling technique microdialysis.
Our main aim is to develop microdialysis as a tool for root simulation, investigating key aspects of root physiology and plant-microbial interactions and how that influence plant nitrogen availability at the root surface, in a root growing in undisturbed soil.

In many ecosystems, nitrogen availability is limiting plant growth. Nitrogen is therefore applied to increase yields. Further insight into the plant perspective of nitrogen availability could lead to identifying ways to increase nitrogen use efficiency and decrease nitrogen pollution in managed environments. Critical in this seems to be the sampling methods used. Microdialysis is an approach for seeing nitrogen availability from a roots perspective.

We use microdialysis for measuring induced diffusive fluxes of foremost nitrogen, simulating what a plant root would experience in the field. An important factor in mirroring plant nitrogen availability at the root surface, particularly for the organic forms, in soil, is that this tool enables sampling with very little disturbance of the soil and that it allows continuous sampling. Due these sampling benefits, this technique has unveiled that in unfertilized soil, plant roots has access to a larger proportion of organic nitrogen than previously detected.

In a recent study, we used microdialysis to simulate root exudation by retrodialysis and its effect on nitrogen availability. Our study revealed that in a short-term perspective, nitrogen availability decreased, rather than increased most likely due to microbial immobilization.

Microdialysis allows repeated sampling, in situ in a small scale. This has led us to develop the application of this technique in additional directions. This includes sampling low molecular weight organic carbon compounds, enzymes and signalling molecules involved in plant-mycorrhiza interactions.

Our close collaboration with the Swedish Metabolomics Centre (SMC) enables our work on organic nitrogen in analysis of amino acids LC-MS (QQQ) and dipeptides and LC-MS (qTOF) quantification of isotopically labelled amino acids and metabolomic screening with GC-MS. This collaboration led to a recent study highlighting how critical the analysis is for evaluating the importance of plant uptake of organic nitrogen.

Close up of two hands setting in a microdialysis device into forest soilsMicrodialysis probe inserted into the soil organic layer in the boreal forest (photo: Sandra Jämtgård)

Read more about Sandra Jämtgård's research

Key publications

  • Buckley S, Brackin R, Näsholm T, Schmidt S, Jämtgård S. 2022. The influence of sucrose on soil nitrogen availability–A root exudate simulation using microdialysis. Geoderma 409, 115645. https://doi.org/10.1016/j.geoderma.2021.115645
  • Svennerstam H, Jämtgård S. 2022. Timing is everything–obtaining accurate measures of plant uptake of amino acids. New Phytologist 234: 311-318. https://doi.org/10.1111/nph.17964
  • Plett K, Buckley S, Plett J, Anderson I, Lundberg-Felten J, Jämtgård S. 2021. Novel microdialysis technique reveals a dramatic shift in metabolite secretion during the early stages of the interaction between the ectomycorrhizal fungus Pisolithus microcarpus and its host Eucalyptus grandis. Microorganisms 9: 1817. https://doi.org/10.3390/microorganisms9091817
  • Buckley S, Brackin R, Jämtgård S, Näsholm T, Schmidt S, 2020. Microdialysis in soil environments: Current practice and future perspectives. Soil Biology & Biochemistry 143: 107743. https://doi.org/10.1016/j.soilbio.2020.107743
  • Buckley S, Brackin R, Näsholm T, Schmidt S, Jämtgård S. 2017. Improving in situ recovery of soil nitrogen using the microdialysis technique. Soil Biology & Biochemistry 114:93-103. https://doi.org/10.1016/j.soilbio.2017.07.009
  • Ganeteg U, Ahmad I, Jämtgård S, Aguetoni Cambui C, Inselsbacher E, Svennerstam H, Schmidt S and Näsholm T. 2017. Amino acid transporter mutants of Arabidopsis provides evidence that a non-mycorrhizal plant acquires organic nitrogen from agricultural soil. Plant Cell and Environment 40: 413-423. https://doi.org/10.1111/pce.12881
  • Jämtgård S, Näsholm T and Huss-Danell K. 2010. Nitrogen compounds in soil solutions of agricultural land. Soil Biology & Biochemistry 42: 2325-2330. https://doi.org/10.1016/j.soilbio.2010.09.011
Xiao-Ru Wang inspecting a pine tree

Wang, Xiao-Ru - Ecological Genomics of Speciation and Adaptation

Research

Xiao-Ru Wang inspecting a pine treePhoto: Mattias Pettersson

The ability of a species to sustain environmental change is primarily determined by its genetic reservoir, which is shaped over the course of history through demography and selection. We apply ecological and genomics tools to understand the origin and distribution of genetic diversity across landscapes in Eurasian conifer species. We use seed orchards as a study system to evaluate the impact of abiotic and biotic factors and management practices on genetic diversity and breeding gain in seed crops, and the adaptability of the regenerated production forests to future climate.

Ecological genomics

Local adaptation in which local genotypes have a fitness advantage than foreign genotypes is well known among long-lived tree species. Rapid climate change can break this genetic-environmental association much faster than trees’ ability to evolve in situ or migrate, thus creating a mismatch between genetic adaptation to altered environmental conditions. Inferences of genotype-environment associations due to polygenic nature of adaptive traits and the complexity of adaptive and dispersal-demographic factors that contribute to genetic differentiation across species range. Using landscape genomics approaches, we interrogate genome-wide variation across landscapes for understanding the extent to which evolutionary forces, e.g. demographic events, gene flow, introgression and selection, shape past and contemporary populations’ genetic structure, and identify those populations that may be most at risk under climate change. This research is conducted for major conifer species in Eurasia, e.g. Pinus sylvestris, Pinus tabuliformis, Pinus yunnanensis, Pinus densata and Picea abies.

Collage of four images showing a tree top on the left upper corner, a section of a map of China coloured in different colours and colour intensities on the top right corner, a coloured map of Scandinavia and upper Europe with dark blue colour in the North that gradiently goes over to magenta end to yellow in the South on the bottom left corner and horticultural tunnels with pine trees on the bottom right.A) Pinus densata on the Tibetan Plateau; B) Spatial structure of genomic diversity in P. densata; C) Hardiness variation in Scots pine; D) Controlled mating experiment in a Scots pine seed orchard

Seed orchards and adaptability of production forests

Efficient use of breeding resources requires a good understanding of the genetic composition of the founder materials for predicting the gain and diversity in future generations. For conifer trees, seed orchard is the link between tree breeding and the production forest. Well-functioning seed orchard is the most cost efficient and realistic way to increase timber production from forestland during the coming century. Our research in this area focuses on: 1) the assessment of diversity and coancestry in breeding populations of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies); 2) the mating system in seed orchards of the two species, and pedigree structure and diversity in seed crops; and 3) the adaptation of orchard crops to different climate zones and thus formulating site-specific seedlot selection system for reforestation. These activities are in close collaboration with Skogforsk.

Read more about Xiao-Ru Wang's research on the homepage of Umeå University


Key publications

  • Hall, D., Olsson, J., Zhao, W., Kroon, J., Wennström, U., Wang, X-R. 2021. Divergent patterns between phenotypic and genetic variation in Scots pine. Plant Communications，2:100139.
  • Zhao, W., Sun, Y-Q., Pan, J., Sullivan, A., Arnold, M.L., Mao, J-F., Wang, X-R. 2020. Effects of landscapes and range expansion on population structure and local adaptation. New Phytologist. 228: 330-343.
  • Sullivan, A.R., Schiffthaler, B., Thompson, S.L., Street, N.R., Wang, X-R. 2017. Interspecific plastome recombination reflects ancient reticulate evolution in Picea (Pinaceae). Molecular Biology and Evolution 34:1689-1701.
  • Funda, T., Wennström, U., Almqvist, C., Andersson Gull, B., Wang, X-R. 2016. Mating dynamics of Scots pine in isolation tents. Tree Genetics & Genomes 12:112.
  • Wang, B., Mao, J-F., Gao, J. Zhao, W., Wang, X-R. 2011. Colonization of the Tibetan Plateau by the homoploid hybrid pine Pinus densata. Molecular Ecology 20: 3796-3811.

Torgny Näsholm standing in front of a spruce tree

Näsholm, Torgny - Ecophysiology and Molecular Biology of Plant Organic N Nutrition

Research

Torgny Näsholm standing in front of a spruce tree

Plant nitrogen (N) nutrition is a topic that challenges the researcher with a number of problems not encountered in other areas of plant mineral nutrition research. The diversity of N forms present in the soil, their interconversions, their different chemical and physical characteristics and not the least the multitude of adaptations and acclimatisations that plants display to optimize acquisition of various N forms all contribute to the complexity of plant N nutrition.

Thus, plants can use a wide array of chemical N forms, ranging from the simple inorganic N compounds such as NH4+ and NO3- as well as polymeric N forms such as proteins. My research deals with plant N physiology, particularly N acquisition and metabolism of forest plants. This research spans from detailed studies of uptake processes to forest fertilization and environmental effects of N.

Small tree seedlings growing in a nursery are seen on the left image, on the right side thale cress seedlings grown on a round agar plate that is divided in four parts is seenLeft: Tests with arginine based fertilizer in a seedling nursery Rotorua, New Zeeland. Right: Selection on D-amino acids.

We have studied uptake of various N forms and demonstrated how field-grown plants acquire different organic N compounds. These studies have stimulated us to characterize the molecular mechanisms underpinning plant organic N nutrition, specifically the specific transporters mediating uptake of various amino acids as well as metabolism of absorbed organic compounds.

We have discovered that plants have a well-developed capacity for using the common L-enantiomers of amino acids but a very restricted capacity to metabolise their D-counterparts. We have also shown how transgenic plants expressing genes encoding D-amino acid metabolising enzymes can detoxify and grow on D-amino acids. This finding has formed the basis for the development of a new selectable marker in plant biotechnology, now commercialized under the tradename SELDA. Basic L-amino acids, and in particular L-arginine, are absorbed at high rates by many plants and we have shown that such N forms have specific advantages for cultivation of woody plants such as conifer seedlings.

This finding forms the basis for the development of a new fertilizer – arGrow®, which is now commercialized by the company SweTree Technologies.

Read more about Torgny Näsholm's research here


Key Publications

  • Näsholm, T., Kielland, K. & Ganeteg, U. (2009). Uptake of organic nitrogen by plants. Tansley Review New Phytologist, 182: 31- 48.
  • Svennerstam, H., Ganeteg, U., Bellini, C. & Näsholm, T. (2007). Comprehensive screening of Arabidopsis mutants suggests the Lysine Histidine Tranporter 1 to be involved in root uptake of amino acids. Plant Physiology 143: 1-8
  • Erikson, O., Hertzberg, M. & Näsholm, T. (2004). A conditional marker gene allowing both positive and negative selection in plants. Nature Biotechnology, 22: 455-458.
  • Lipson, D. and Näsholm, T. (2001). The unexpected versatility of plants: Organic Nitrogen Use and Availability in Terrestrial Ecosystems. Commissioned review. Oecologia 128: 305-316
  • Näsholm, T., Ekblad, A., Nordin, A., Giesler, R., Högberg, M. and Högberg, P. (1998). Boreal forest plants take up organic nitrogen. Nature 392, 914-916, 1998.

 

Markus Schmid sitting at his desk in his office

Schmid, Markus - Regulation of Plant Growth & Development by the Environment

Research

Markus Schmid sitting at his desk in his officePhoto: Fredrik Larsson

A fundamental difference between the development of plants and most animals is that the former maintains the potential to form new organs throughout their life. This capacity not only endows plants with the ability for continued growth, but also provides them with the means to rapidly and flexibly adjust to changes in their environment, resulting in a high degree of phenotypic plasticity. The aim of our research is to understand the molecular mechanisms that controls plant development, in particular the transition from vegetative to reproductive growth, in response to both endogenous and environmental stimuli.

Ambient temperature & alternative pre-mRNA splicing

An environmental signal that can have pronounced effects on plant growth and development is ambient temperature. We have recently identified a mutant in the plant model Arabidopsis thaliana that displays strong pleiotropic developmental defects in the shoot meristem and lateral organs specifically at low ambient temperature. The mutated gene, PORCUPINE, encodes a putative splice factor, suggesting that alternative splicing of pre-mRNA might be involved in modulating growth and development in response to changes in ambient temperature and might contribute to establish phenotypic plasticity in plants.

Illustration of the research done in Markus Schmid's groupAlternative splicing in the porcupine mutant

We are currently performing a number of experiments to:

  • identify the molecular mechanisms underlying the temperature-specific phenotype of the porcupine mutant
  • study the general effect of temperature on (alternative) pre-mRNA splicing and its consequences for plant growth and development
  • isolate and characterize new temperature-specific alleles affecting plant development

Regulation of flowering time & flower development

A trait that is in part controlled by ambient temperature is the induction of flowering. The transition from vegetative growth to flowering is a central event in the life cycle of plants, which requires correct timing to ensure reproductive success. In most plants flowering time is not fully deterministic but allows for some degree of phenotypic plasticity. Given that the decision to initiate flowering is made in a small number of cells in the leaf vasculature and the shoot meristem, any results obtained from complex tissues can be misleading as they likely mask tissue-specific regulatory processes. To overcome these limitations, we have adopted technologies such as INTACT and FACS to isolate nuclei from specific tissues for subsequent (epi-)genome and transcriptome analyses.

Regulation of flowering in ArabidopsisGenomics in the flower primordia

In collaboration with our colleagues at UPSC, Karin Ljung, Johannes Hanson and Ove Nilsson, we are:

  • investigating the dynamic changes of the epigenome, transcriptome, translatome, and metabolome during the switch to flowering in A. thaliana and hybrid aspen
  • isolating and characterizing novel flowering time regulators in A. thaliana
  • establishing methods for tissue- and cell-type specific “-omics” approaches in hybrid aspen

One of the first steps once plants are committed to flowering is the induction of the plant-specific transcription factor LEAFY in the incipient flower primordia. In collaboration with our colleagues Ove Nilsson (UPSC) and François Parcy (Grenoble) we are investigating how the LEAFY protein contributes to specifying the four different floral organs.

Trehalose 6 phosphate & SnRK1 signaling

The transition to flowering and subsequent seed filling are highly energy demanding processes. Thus, it is not surprising that the time of flowering is influenced by carbohydrate availability. Of particular importance in this regard is the phospho-disaccharide trehalose 6-phosphate (T6P), which plays a crucial role in carbohydrate signaling. T6P signals at least in part through the evolutionary conserved heterotrimeric kinase complex SUCROSE NON-FERMENTING1 RELATED KINASE 1 (SnRK1). We are studying how the T6P pathway and SnRK1 complex are integrated into the canonical network that regulates flowering.

Key publications:

  • Capovilla, G, Delhomme, N, Collani, S, Shutava, I, Bezrukov, I, Symeonidi, E, de Francisco Amorim, M, Laubinger, S, Schmid, M (2018) PORCUPINE regulates development in response to temperature through alternative splicing. Nature Plants 4: 534-539. doi: 10.1038/s41477-018-0176-z
  • You, Y, Sawikowska, A, Neumann, M, Posé, D, Capovilla, G, Langenecker, T, Neher, RA, Krajewski, P, Schmid, M (2017) Temporal dynamics of gene expression and histone marks at the Arabidopsis shoot meristem during flowering. Nature Communications 8: 15120, doi: 10.1038/ncomms15120
  • Posé D, Verhage L, Ott F, Yant L, Mathieu J, Angenent GC, Immink RGH and Schmid M (2013). Temperature-dependent regulation of flowering by antagonistic FLM variants. Nature 503: 414-417.
  • Wahl V, Ponnu P, Schlereth A, Arrivault S, Langenecker T, Franke A, Feil R, Lunn JE, Stitt M and Schmid M (2013). Regulation of flowering by trehalose-6-phosphate signaling in Arabidopsis thaliana. Science 339: 704-707.
  • Mathieu J, Warthmann N, Küttner F and Schmid M (2007). Export of FT protein from phloem companion cells is sufficient for floral induction in Arabidopsis. Current Biology 17: 1055-1060.
Thomas Moritz in front of a mass spectrometer

Moritz, Thomas - Metabolomic Control of Shoot Elongation and Wood Formation

Research

Thomas Moritz in front of a mass spectrometer

The aim of my research is to understand the mechanisms of metabolic control of shoot elongation and wood formation in the model plant Populus. We want to understand how plant hormones and other metabolites are involved in the control of plant development, and how different environmental cues, such as photoperiod, affect the metabolic control of growth and development. The metabolic control of growth and development are studied by using both targeted and untargeted metabolomics approaches.

Gibberellins (GAs) are a group of tetracyclic diterpenes, some of which are essential endogenous regulators that influence growth and development events throughout the life cycle of a plant, e.g. shoot elongation, expansion and shape of leaves, flowering and seed germination. Our project is concerned with the role of GAs in plant development, and daylength responses, focusing on the tree hybrid aspen (Populus tremula x P. tremuloides) as a model system. Our approach for studying the role of GAs in trees is to study endogenous expression of GA biosynthetic and signalling genes and to transform Populus with genes encoding those genes.

Populus transformed with the AtGA20ox1 under the control of the 35S promoter shows elongated internodes, longer petioles and larger leaves, reduced root formation and increased shoot biomass.We have also char- acterized the GA receptor, GID1 in Populus. Four orthologs of GID1 have been identified in Populus tremula x P. tremuloides (PttGID1.1 to 1.4). When PttGID1.1 and PttGID1.3 were overexpressed in Populus with a 35S promoter, overexpressors shared several similar phenotypic traits with previously described 35S:AtGA20ox1 overexpressors, including rapid growth and increased elongation.

Three photos showing parts of a mass spectrometer instrument that is used to measure metabolites

We are also studying the role of GAs and other signaling compounds in wood formation. The role of GAs is done by both using transgenic Populus with increased levels of GAs and signalling and by predicting where GAs are formed and perceived during wood formation. For example, we have quantified GAs and analyzed the expression of GA biosynthesis genes and genes with predicted roles in GA signalling in tangential sections across the cambial region of aspen trees (Populus tremula). The results show, for example inter alia, that the bioactive GA and GA 14 predominantly occur in the zone of expansion of xylem cells.

Studies with transgenic Populus overexpressing AtGA20ox1 or PttGID1 with 35S or a xylem-specific promoter, suggest that GAs are required for two distinct processes in wood formation with tissue-specific signalling pathways: xylogenesis, mediated by GA signalling in the cambium, and fibre elongation in developing xylem.

By using a metabolomics approach we are also studying how specific patterns of metabolites, including signalling compounds, are vary in different regions of the wood-forming zone in Populus. From the data we can conclude that cambial activity, cell expansion and secondary cell wall thickening are tightly coupled processes, Many of these patterns can be explained on the basis of the developmental processes taking place within these regions, e.g. in the cambium.

Many woody species with indeterminate growth show complete cessation of elongation growth after only a few weeks in short photoperiods. In hybrid aspen transformed with the oat PHYA gene, the dwarf phenotype is correlated with a reduction in GA levels, but in short photoperiods there is no further reduction in GA contents, in marked contrast to the pattern in wild-type plants. These observations imply that GAs have an important role as signals in the photoperiodic regulation of shoot elongation. We have also been studying transgenic GA plants to elucidate how changes in GA levels and signalling affect photoperiodic growth. Studies in PHYA and GA biosynthesis/signalling overexpressors are used with transcriptomic and metabolomic approaches to elucidate the early signalling pathways in short-day induced growth cessation, including identification of new putative signalling compounds.

Key Publications

  • Davoine, C., Abreu, I. N. Khajeh, K., Blomberg, J., Kidd, B. N., Kazan, K., Schenk, P. M., Gerber, L., Nilsson, O., Moritz, T. , Bjorklund, S. 2017. Functional metabolomics as a tool to analyze mediator function and structure in plants. Plos One 12(6).
  • Lindén, P., Keech, O., Stenlund, H., Gardeström, P., Moritz, T. 2016 Reduced mitochondrial malate dehydrogenase activity has a strong effect on photorespiratory metabolism as revealed by 13C-labelling. J. Exp. Bot., 67: 3123-3135
  • Eriksson, M.E., Hoffman, D., Kaduk, M., Mauriat, M., Moritz, T. 2015 Transgenic hybrid aspen trees with increased gibberellin (GA) concentrations suggest that GA acts in parallel with FLOWERING LOCUS T2 to control shoot elongation. New Phytologist, 205, 1288-1295.
  • Mauriat M., Sandberg L., Moritz T. 2011 Proper gibberellin localization in vascular tissue is required to control auxin dependent leaf development and bud outgrowth in hybrid aspen. Plant J. 67: 805-816.
  • Mauriat M., Moritz T. 2009 Analyses of GA20ox- and GID1-overexpressing Populus suggest gibberellins play two distinct roles in wood formation. Plant J. 58: 989-1003.
  • Israelsson M., Sundberg B., Moritz T. 2005 Tissue-specific localisation of gibberellins in wood-forming tissues in aspen. Plant J. 44: 494-504.
  • Jonsson P., Johansson A., Gullberg J., Trygg J., A J., Grung B., Marklund S., Sjöström M., Antti H., Moritz T. 2005 High through-put data analysis for detecting and identifying differences between samples in GC/MS-based metabolomic analyses Anal. Chem. 77: 5635-5642.
  • Eriksson M., Israelsson M., Olsson O., Moritz T. 2000. Increased gibberellin biosynthesis in transgenic trees promotes growth, biomass production and xylem fibre length. Nature Biotech. 784-788.