NEWS FROM
PHYSIOLOGIA PLANTARUM
 |
 |
Published monthly on behalf of SPPS by Wiley-Blackwell.
 |
|
|
|
 |
Using photosynthesis as a thermometer
|
Plants need to respond to changes in the temperature as part of cold acclimation. In a special issue on cold and abiotic stress, scientists from University of Western Ontario, Canada review how photosynthesis seems to be key to sensing the low temperature signal. Photosynthesis consists of temperature independent photochemical reactions leading to charge separation, and temperature dependent biochemical reactions where this redox potential energy is converted to stable reducing power. When the temperature drops, this leads to an energy imbalance that causes an increase in the free pool of reduced plastoquinone in the electron transport. Being the primary energy sensor, these changes transduce into biochemical signals that regulate transcription of genes involved in cold acclimation.
Read full article free: Ensminger et al (January 2006) Physiologia Plantarum 126: 28-44
|
|
NEWS IN BRIEF
FROM OTHER JOURNALS
|
|
Scaling small and large plants
|
|
Source: Reich et al (26 January 2006) Nature 439: 457-461
|
|
|
|
Feeding on military explosives
|
|
Source: Rylott et al (22 January 2006) Nature Biotechnology 24: 216-219
|
|
|
|
|
|
|
Scandinavian research institute:
Norwegian University of Life Sciences (UMB), Oslo
|
| |
|
|
The former Agricultural University is beautifully situated outside Oslo. Photo courtesy of Christiaan van der Schoot.
|
|
|
Founded in 1859 as Norges Landbrukshøgskole (NLH or Agricultural University of Norway), the Norwegian University of Life Sciences emerged in 2005 after a reorganization that gave it recognition as a real, research based university. Its historic roots attached in agriculture, the research at Universitetet for Miljø- og Biovetenskap (UMB) - as it is called in the local language - focuses on quality, technology and environmental friendliness of agri- and aquaculture.
With a total of approximately 900 employees and 2800 students of which about 248 are PhD students, UMB is a relatively small university. It is divided into 8 institutes and 5 centres, with most experimental plant research located in the Institute for Plant and Environmental Sciences (Institutt for plante- og miljøvitenskap, IPM). IPM is loosely organized into 9 sections that cover a broad range of plant related sciences:- Agroecology
- Genetics & Plant Biology
- Geology
- Urban Horticulture and Urban Greening
- Hydrology & Limnology
- Soil Biochemistry & Plant Nutrition
- Food Plants
- Environmental Chemistry
- Plant Protection and Plant Health
A total of 125 people, excluding students, work at IPM, making it the largest institute at UMB. They include 30 professors, 25 associate professors, 25 researchers, 40 PhD students, 35 technicians, and 20 persons in the administration.
| |
|
|
In addition to plant sciences, IPM covers soil, water and environmental sciences. Photo by Lillian Øygarden.
|
|
|
The section of Genetics & Plant Biology is the largest at the institute and contributes the majority of basic plant research within genetics and physiology at IPM and UMB. The activities are divided into small groups working in several different areas. The major workgroups include:- Christiaan van der Schoot
- Basic plant physiology and developmental biology - Åsmund Bjørnstad
- Breeding - Hilde-Gunn Opsahl Sorteberg
- Genetics - Roar Moe
- Applied plant physiology and horticulture - Hans-Ragnar Gislerød
- Floriculture
Christiaan van der Schoot and his colleagues focus on how plants respond to environmental cues. This can e.g. be adaptive defence responses to biotic and abiotic stress or developmental responses to changes in the temperature.
| |
|
|
Professor Christiaan van der Schoot in the electrophysiology lab. Photo courtesy of Christiaan van der Schoot.
|
|
|
In a recent study published in Plant Journal, they show that typical symptoms of viral infection can actually be caused by the plants own defence response rather than the virus. Transgenic tobacco plants expressing the NSM viral movement protein of tomato spotted wilt virus got characteristic symptoms including chlorotic leaves that failed to expand.
Using a combination of techniques, the researchers were able to show, that this was caused by obstruction of mesophyll plasmodesmata due to defence related deposition of glucan and callose. By closing plasmodesmata, the plant can restrict virus movement but apparently this defence system also leads to self-inflicted viral symptoms.
| |
|
|
Probing with fluorescent dye visualizes diffusion pathways in birch apical meristem after bud dormancy. Photo courtesy of Christiaan van der Schoot.
|
|
|
Another line of research by Christiaan van der Schoot addresses the patterning activity of the shoot apical meristem. Injecting fluorescent dyes into the meristem reveals symplasmic communication. Changes in the patterns of communication reflect the switching of the meristem between active and dormant states. Using model plants like Arabidopsis, birch, poplar and Norway spruce, such an approach can lead to understanding of how plants respond to changes in the environment.
In the genetics group, Hilde-Gunn Opsahl-Sorteberg is studying barley endosperm. She has previously published a study where dissection of a non-specific lipid transfer protein gene promoter led to identification of the ds-sequence within a 49-bp fragment. The sequence confers aleurone specific expression and might be useful for producing pharmaceutically important compounds in the grain of transgenic crops.
| |
|
|
The aleurone layer of barley grain secretes hydrolases that mobilize endosperm. Photo from www.umb.no.
|
|
|
In a recent publication Hilde-Gunn Opsahl-Sorteberg have addressed endosperm and embryo development using Arabidopsis as a model plant. T-DNA tagging of the DEK1 gene revealed its importance in regular mitotic divisions in the embryo proper and suspensor as well as a general positional clue for appropriate developmental of plant tissues.
Ten researchers from UMB (5 of them from IPM) as well as researchers from Skogforsk (Norwegian Forest Research Institute) and Bioforsk participate in a Strategic University Program, Climatree(Adaptive and Developmental Changes of Forest Trees to Climate Change) led by Christiaan van der Schoot. Climatree aims to understand climatic adaptation at the molecular, physiological and whole plant level and is divided into 6 subprojects:- Photoperiod sensing (Øystein Johnsen & Harald Kvaalen)
- Growth, dormancy and wood characteristics (Aksel Granhus & Gunnhild Søgaard)
- Meristem transitions in dormancy cycling and flowering (Chris van der Schoot, Päivi Rinne & Sissel Torre)
- Molecular regulation of dormancy breaking (Chris van der Schoot, Päivi Rinne, Jihong Liu-Clarke & Sonja Klemsdal)
- Defence proteins (Carl Gunnar Fossdal, Nina Elisabeth Nagy & Øystein Johnsen)
- Functional genomics of plant stress (Johannes Einset)
The programme runs from 2003-2007 and is funded by a budget of NOK 18.4 million (€2.3 million) from The Research Council of Norway (NRF, Norges Forskningsråd). Whereas most research at IPM and UMB is fragmented and addresses short-term practical projects, Climatree is a long-term project addressing fundamental problems that can only be solved through extensive cooperation of several scientists. In this way, the funding policy of NRF might direct research at UMB onto a more unified and rigorous path.
You can find more information about UMB on its official website.
|
|
