My lab investigates plant cell wall biosynthesis and carbohydrate metabolism in Arabidopsis, aspen and Norway spruce. We are interested in the molecular mechanisms responsible for sucrose transport to secondary cell wall forming cells, and the subsequent production of cell wall polymer precursors.
Transcriptional regulation plays an important role in these processes, and we are applying different genomics tools to identify transcription factors involved in woody biomass accumulation. We also work on carbohydrate active enzymes involved in the biosynthesis of arabinogalactan proteins (AGPs), which form a diverse group of cell surface- and wall-associated glycoproteins. We are interested in AGP’s role in cell wall biosynthesis, and the relationship between AGP glycosylation and AGP functionality.
A) Light microscopy picture of aspen wood fibers and vessels; B) Cross section of Arabidopsis stem. Lignified cell walls are shown in red and non-lignified in blue; C) Cross section of aspen stem; D) Siliques of wild type Arabidopsis and opnr-1 showing the seed abortion phenotype (left). Elongated zygotes of wild type and opnr-1 (middle). Confocal microscopy images showing the dual localisation of OPNR in nuclear envelope and mitochondria labelled with PHB3-mCherry (right).
In addition to wood biology we also explore novel fundamental cellular processes. One third of the genes in the model plant Arabidopsis remain of unknown function. Our ambition is to push new inroads to this unknown gene space. We are interested in identifying essential genes, which are indispensable for the function of a plant cell and constitute the minimum gene set required for cellular life.
Siliques of wild type Arabidopsis and opnr-1 showing the seed abortion phenotype (left). Elongated zygotes of wild type and opnr-1 (middle). Confocal microscopy images showing the dual localisation of OPNR in nuclear envelope and mitochondria labelled with PHB3-mCherry (right)
Our approach is to investigate evolutionarily-conserved single copy Arabidopsis genes of unknown function with predominant expression in meristematic cells. Evolutionarily-conserved single copy genes in flowering plants have been shown to be enriched in essential housekeeping functions. This exploratory project has led us to new areas of cell biology, and provide an adventure for those who do not fear the unknown.
Recently we identified an essential gene named OPENER (OPNR) in this project. opnr mutants show zygotic lethality and endosperm arrest, and intriguingly OPNR localizes to both nuclear envelope and mitochondria pointing to an uncharacterized essential process occurring in both nucleus and mitochondria in dividing plant cells.
Mahboubi A, Linden P, Hedenström M, Moritz T, Niittylä T (2015). Carbon-13 tracking after 13CO2 supply revealed diurnal patterns of wood formation in aspen. Plant Physiology 168: 478-489.
Gerber L, Zhang B, Roach M, Rende U, Gorzsás A, Kumar M, Burgert I, Niittylä T and Sundberg B (2014). Deficient sucrose synthase activity in developing wood does not specifically affect cellulose biosynthesis, but causes an overall decrease in cell wall polymers. New Phytologist 203: 1220 – 1230.
Mahboubi A, Ratke C, Gorzsás A, Kumar M, Mellerowicz EJ, Niittylä T (2013). Aspen SUCROSE TRANSPORTER 3 allocates carbon into wood fibers. Plant Physiology 163, 1729-1740.
Nystedt et al. (2013). The Norway spruce genome sequence gives insights into conifer genome evolution. Nature, 497, 579-584.
Roach M, Gerber L, Sandquist D, Gorzsas A, Hedenström M, Kumar M, Steinhauser MC, Feil R, Daniel G, Stitt M, Sundberg B and Niittylä T (2012). Fructokinase is required for carbon partitioning to cellulose in aspen wood. Plant Journal, 70, 967 – 977.
Two-step derivatization for determination of sugar phosphates in plants by combined reversed phase chromatography/tandem mass spectrometry
Plant Methods 2019, 15(127)
Isolation and characterization of cellulose nanofibers from aspen wood using derivatizing and non-derivatizing pretreatments
Cellulose 2019, First Online October 3
Genome-Wide Association Study (GWAS) identified novel candidate loci affecting wood formation in Norway spruce
Plant J. 2019, July Early access
OPENER Is a Nuclear Envelope and Mitochondria Localized Protein Required for Cell Cycle Progression in Arabidopsis
Plant Cell 2019, 31(7):1446-1465
High Spatial Resolution Profiling in Tree Species
Annual Plant Reviews Online 2019
Cellulose synthase stoichiometry in aspen differs from Arabidopsis and Norway spruce
Plant Physiology 2018, 177 (3):1096-1107
Sucrose transport and carbon fluxes during wood formation
Physiologia Plantarum 2018, 164(1):67-81
Two Complementary Mechanisms Underpin Cell Wall Patterning during Xylem Vessel Development
Plant Cell. 2017, 29 (10):2433-2449
AspWood: High-spatial-resolution transcriptome profiles reveal uncharacterized modularity of wood formation in Populus tremula
Plant Cell. 2017, 29 (7):1585-1604
Spatially resolved metabolic analysis reveals a central role for transcriptional control in carbon allocation to wood
J Exp Bot 2017, 68 (13):3529-3539
Laser Capture Microdissection Protocol for Xylem Tissues of Woody Plants
Front. Plant Sci., 04 January 2017
Cytosolic invertase contributes to the supply of substrate for cellulose biosynthesis in developing wood
New Phytol. 2017, 214(2):796-807
Carbon-13 tracking after 13CO2 supply revealed diurnal patterns of wood formation in aspen
Plant Physiol. 2015; 168(2):478-489
Deficient sucrose synthase activity in developing wood does not specifically affect cellulose biosynthesis, but causes an overall decrease in cell wall polymers
New Phytol. 2014, 203(4):1220-1230
Aspen SUCROSE TRANSPORTER 3 allocates carbon into wood fibers
Plant Physiology 2013; 163(4):1729-1740
The Norway spruce genome sequence and conifer genome evolution
Nature 2013; 497(7451):579-584
Xue W, Ruprecht C, Street N, Hematy K, Chang C, Frommer WB, Persson S, Niittylä T
Paramutation-Like Interaction of T-DNA Loci in Arabidopsis
PLoS ONE 2012 7(12): e51651
Roach M, Gerber L, Sandquist D, Gorzsás A, Hedenström M, Kumar M, Steinhauser MC, Feil R, Daniel G, Stitt M, Sundberg B, Niittylä T
Fructokinase is required for carbon partitioning to cellulose in aspen wood
Plant Journal, 2012, 70(6):967 – 977
Niittylä T, Chauduri B, Sauer U and Frommer WB
Comparison of quantitative metabolite imaging tools and carbon-13 techniques for fluxomics
Methods Mol Biol, 2009, 553:355-372
Niittylä T, Fuglsang AT, Palmgren MG, Frommer WB, Schulze WX
Temporal analysis of sucrose-induced phosphorylation changes in plasma membrane proteins of Arabidopsis
Mol Cell Proteomics, 2007,6:1711-1726
Chaudhuri B, Niittylä T, Hörmann F, Frommer WB
Fluxomics with ratiometric metabolite dyes
Plant Signal Behav. 2007, 2(2):120-2
Niittylä T, Comparot-Moss S, Lue W-L, Messerli G, Trevisan M, Seymour MD, Gatehouse JA, Villadsen D, Smith SM, Chen J, Zeeman SC, Smith AM
Similar protein phosphatases control starch metabolism in plants and glycogen metabolism in mammals
J. Biol. Chem. 2006, 281:11815-11818
Niittylä T, Messerli G, Trevisan M, Chen J, Smith AM, Zeeman SC
A previously unknown maltose transporter essential for starch degradation in leaves
Science 2004, 303:87-89
Smith AM, Zeeman SC, Niittylä T, Kofler H, Thorneycroft D, Smith SM
Starch degradation in leaves
J. Appl. Glycosci. 2003, 50:173-176
Zabela MD, Fernandez-Delmond I, Niittylä T, Sanchez P, Grant M
Differential expression of genes encoding Arabidopsis phospholipases after challenge with virulent or avirulent Pseudomonas isolates
Mol. Plant Microbe Interact. 2002, 15:808-816