Carbon allocation is a fundamental physiological process in tree growth. Carbon allocation at tree level cascades across scales to ecosystems and global carbon cycle. In my group we investigate the genetic, biochemical and physiological processes linking metabolism and carbon allocation in trees.
We apply a combination of genomics, metabolomics and fluxomics tools to identify genes, enzymes and pathways which are central in carbon allocation to woody biomass. We use aspen as a model in most of our tree work, while Arabidopsis is used to address fundamental questions linked to metabolism and cell wall biosynthesis. Our Arabidopsis work has recently focused on starch and sucrose metabolism as well as carbohydrate active enzymes involved in the biosynthesis of arabinogalactan proteins (AGPs), and the relationship between AGP glycosylation and cellulose biosynthesis.
In addition to the cell wall and metabolism centric work on carbon allocation, we also explore overlooked fundamental processes in plant growth. 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 particularly interested in identifying essential genes, which are indispensable in dividing and growing plant cells.
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.
Our current focus is on understanding the function of an essential gene we named OPENER (OPNR). opnr mutants show zygotic lethality and endosperm arrest, and intriguingly OPNR localizes to both nuclear envelope and mitochondria pointing to an essential process occurring on both nucleus and mitochondria in dividing plant cells.
Recent Key Publications
- Wang W, Talide L, Viljamaa S, Niittylä T (2022). Aspen growth is not limited by starch reserves. Current Biology, 32(16): 3619-3627 doi.org/10.1016/j.cub.2022.06.056
- Fünfgeld MMFF, Wang W, Ishihara H, Arrivault S, Feil R, Smith AM, Stitt M, Lunn JE, Niittylä T. (2022). Sucrose synthases are not involved in starch synthesis in Arabidopsis Nature Plants, 8(5): 574–582. doi.org/10.1038/s41477-022-01140-y
- Dominquez PG, Evgeniy D, Derba-Maceluch M, Bünder A, Hedenström M, Tomášková I, Mellerowicz EJ, Niittylä T (2021). Sucrose synthase determines carbon allocation in developing wood and alters carbon flow at the whole tree level in aspen. New Phytologist, 229: 186-198. https://doi.org/10.1111/nph.16721
- Nibbering P, Petersen BL, Mohammed SM, Jørgensen B, Ulvskov P, Niittylä T (2020). Golgi-localized exo-β1,3-galactosidases involved in cell expansion and root growth in Arabidopsis. Journal of Biological Chemistry, 295: 10581-10592. https://doi.org/10.1074/jbc.ra120.013878
- Wang W, Zhang X, Niittylä T (2019). OPENER Is a Nuclear Envelope and Mitochondria Localized Protein Required for Cell Cycle Progression in Arabidopsis. Plant Cell, 31:1446-1465. https://doi.org/10.1105/tpc.19.00033
- Since 2015: Associate Professor, Swedish University of Agricultural Sciences
- 2009 – 2014 Assistant Professor, Swedish University of Agricultural Sciences
- 2005 – 2008 Post Doc, Carnegie Institution for Science, California, USA
- 2004 PhD John Innes Centre, University of East Anglia, UK
- 2000 MSc University of Helsinki
Skogsråvaran är en förnybar resurs som blir allt viktigare i framtiden när vi övergår från fossila till mer hållbara resurser. Utvecklingen mot biobaserad ekonomi kräver optimerad produktion från skogsbruk och trädplantager. Vårt mål är att utveckla genetiska verktyg för att öka kolallokering till ved.
I de flesta trädslag byggs vedbiomassan upp från sackaros som importeras från fotosyntetiska vävnader. Vi undersöker mekanismerna för kol allokering, sackaros transport och metabolism i ved och dess betydelse för cellväggbiosyntes. Vi fokuserar särskilt på cellulosabiosyntes. Informationen kan sedan användas i skogsträdsförädling. Vår vision är att förädling av träd kommer att ge underlag för framtida bioraffinaderi industrier och minskar utnyttjande trycket på orörda skogar.