Katharina Hobrak
Adviser
Biography
I have a masters degree in plant biology (2020) from the Norwegian University of Life Sciences (NMBU)
My work mainly consists of:
- Coordinating the GHG accounting for LULUCF on municipality level
- Different subjects revolving the national GHG accounting for LULUCF.
- Peat extraction
- Settlements
- Grassland
- Climate mitigation in forestry
Authors
Marte Ragnhild Owren Ingvild Byskov Britta Maria Hoem Julien Jabot Hans H. Kolshus Kathrine Loe Bjønness Jakob Sandven Trude Melby Bothner Mona Irene Andersen Engedal Eirik Knutsen Lene Skyrudsmoen Berit Storbråten Kristina Vikesund Hart Evan Christian Wilhelm Mohr Gry Alfredsen Ana Aza Johannes Breidenbach Lise Dalsgaard Rune Eriksen Katharina Hobrak Christophe Moni Gunnhild SøgaardEditors
Ingeborg RønningAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Camilo Chiang Marcos Viejo Oda Toresdatter Aas Katharina Hobrak Christian Bianchi Strømme Inger Sundheim Fløistad Jorunn Elisabeth OlsenAbstract
Light and temperature are crucial factors for the annual growth rhythm of tree seedlings of the boreal and temperate zone. Dormant, vegetative winter buds are formed under short days (SD) and altered light quality. In the conifer Norway spruce, expression of FTL2 increases and PaCOL1-2 and PaSOC1 decrease under light regimes, inducing bud set. Although temperature is known to modulate the timing of bud set, information about combined effects of light climate and temperature on bud phenology and gene expression is limited. We studied the interactive effects of temperature (18, 22/24 °C) and day extension with blue (B), red (R) or far-red (FR) light or different R:FR ratios compared to SD on growth–dormancy cycling and expression of FTL2, PaCOL1-2 and PaSOC1 in Norway spruce seedlings. Day-extension with B light and all treatments involving FR light sustained shoot elongation, with increased growth at higher temperature. The R light treatment resulted in delayed/prevented bud set compared to SD, with more delay/prevented bud set at 24 °C than 18 °C. This was associated with lower PaFTL2-transcript levels at 24 °C and more rapid subsequent bud burst. For the growth-sustaining treatments (long days, FR and B light), the PaFTL2-transcript levels were generally lower and those of PaCO1-2 and PaSOC1 higher compared with SD and R light. In conclusion, our results demonstrate more reduced/prevented bud set and faster bud burst with increased temperature under day extension with R light, indicating less deep dormancy than at lower temperature. Also, sustained shoot elongation under the B light treatment (27 µmol m−2 s−1) in contrast to the lower B light-irradiances tested previously (≤13 µmol m−2 s−1), demonstrates an irradiance-dependent effect of day extension with B light.