NEWS FROM
PHYSIOLOGIA PLANTARUM
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Published monthly on behalf of SPPS by Wiley-Blackwell.
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Shedding light in the canopy
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Since plants get most of their light from above, photosynthetic activity is highest in the upper part of the canopy. Applying light directly into the canopy might, accordingly, contribute to a more uniform photosynthetic profile and could potentially increase overall photosynthesis leading to higher yield of crops. This hypothesis has now been tested by Dutch researchers from Wageningen University in the Netherlands. They supplied cucumber plants grown in the greenhouse with 38% of their light from LEDs within the canopy and compared them with controls that got all the light from above. Light from within the canopy significantly increased photosynthesis in the lower leaf layers, however, this was not followed by a concomitant increase in overall biomass and fruit yield. This was apparently caused by a more stunted growth when less light came from above and because the LEDs seemingly caused the leaves to curl and thus reduced light interception.
Read full article free: Trouwborst et al (March 2010) Physiologia Plantarum 138: 289Ð300
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NEWS IN BRIEF
FROM OTHER JOURNALS
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Male olives have access to more females
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Source: Saumitou-Laprade et al (26 March 2010) Science 327: 1648-1650
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Lowering atmospheric with algae may contaminate ocean
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Source: Trick et al (15 March 2010) PNAS doi:10.1073/pnas.0910579107
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Scandinavian research institute:
Department of Botany, Stockholm University, Sweden
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The Department of Botany is situated in green surroundings in Lilla Frescati in central Stockholm. From www.su.se
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Plant biology has a very prominent position at Stockholm University where around 100 scientist are engaged at the Department of Botany. The department is situated in what used to be King Karl XI's royal game park and the area - now known as Lilla Frescati named after the Italian city of Frascati - is still an urban park. The first plant scientists moved in in 1964 and have since expanded their activities considerably.
The department is now divided into three research areas each of which is headed by a responsible professor: - Plant ecology - Prof. Johan Ehrlén
- Plant physiology - Prof. Birgitta Bergman
- Plant systematics - Prof. Birgitta Bremer
Within these three research areas a large number of projects have been established, but still the overall focus is kept tight so coherence and synergy is ensured.
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The Swedish scientists at Department of Botany also studies epiphytic mosses in subtropical Ethiopia. From nuthatch.typepad.com
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Research in plant ecology covers almost everything that lives in the in the sky, on the ground and in the water. The responsible professor Johan Ehrlén studies promarily the interaction of plants and animals in e.g. pollination and seed predation in the understorey. Some of the other scientists focus on the interaction of species in various ecological settings including costal areas, cultivated fields, and forests of Northern Sweden as well as subtropical Ethiopia. The two latter projects are carried out by Kristoffer Hylander. In 2008 he found that epiphytic rainforest bryophytes thrive in Ethiopian home coffee gardens and that these ecological niches can have a higher epiphyte/bryophyte biodiversity than in the forest.
Another kind of epiphytes, marine micro- and macroalgae, is studied by Lena Kautsky. One of her projects is concerned about how biomass and diversity of the algal species is regulated by nutrient supply and grazing. In a study from 2008 she found that the two opposing factors depended on each other, so that e.g. microalgal diversity was reduced by addition of nutrients only in the absence of efficient grazers, but that the presence of specialist grazers prevented a reduction in the biodiversity. Lena Kautsky is also taking a chemical approach looking at the accumulation of substances related to brominated flame retardants in red alga and cyanobacteria from the Baltic Sea. In a study from 2009, she was the first to show that these anthropogenic substances are present in red algae but also suggested that they were probably of natural origin.
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Maria Israelsson Nordström has shown how carbonic anhydrases are involved in regulation of stomatal movements. From www.nature.com
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Work on cyanobacteria is carried on into the plant physiology research area where responsible professor Birgitta Bergman, Ulla Rasmussen and Rehab El-Shehawy are looking at e.g. their ability to form nitrogen-fixing diazocytes and to produce various toxins. John Rowley, on the other hand, studies the early development of pollen grains and spores with emphasis on how material is transported through microchannels in the exine, i.e. the outer layer of the mature pollen grain. Another central research area is signal transduction. In two review articles earlier this year Sylvia Lindberg has emphasized the role of cytosolic calcium and pH signaling and how this system might serve as a platform for auxin perception. Following a related line of research Sophia Ekengren is looking at the pathogen response of tomato. Very recently she used bacterial expression and virus induced gene silencing to demonstrate the role of various isoforms of phosphatidylinositol-specific phospholipase-C in the resistance response of tomato to Cladosporium fulvum.
Among the noteworthy achievements within the area of plant physiology was when Maria Israelsson Nordström managed to get her results published in the prestiges journal Nature Cell Biology in January 2010. Together with colleagues from University of California San Diego and University of Zürich she was able to gain insight into the mechanisms by which atmospheric CO2 regulates stomatal opening. It turned out that the process is regulated by carbonic anhydrases and that manipulation of their activities influenced movement of stomata.
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Uncaria is a member of the coffee family, Rubiaceae, that is being studied by Birgitta Bremer. From www.bergianska.se
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The research area of plant systematics was expanded three years ago when the scientific staff from the nearby Bergius Botanical Garden moved to the Department of Botany. The garden is named after the brothers Bengt and Peter Jonas Bergius who established it in 1791. To their honor, the Bergius Foundation was founded and it has appointed a professorship to Birgitta Bremer, who is responsible for the research area. She is a plant molecular biologist and uses DNA sequence data to study the phylogenetic relationship and character evolution within the coffee family, Rubiaceae. This large family - the fifth largest flowering plant familiy with over 13.000 species - is also the focus of study for Sylvain G. Razafimandimbison and Torsten Eriksson (who is also studying Rosaceae), while Jenny E. E. Smedmark is looking into the phylogeny of Urophylleae and Lasiantheae.
A somewhat different approach is taken by Per Ola Karis who is concerned with the diversification and evolution of of members of the large flowering plant family Asteraceae in arid and semi-arid southern Africa. Instead of using DNA sequence data he is mainly studying anatomical and morphological features. Scanning electron microscope pictures of the endothecium of the anthers in subtribe Gorteriinae have e.g. shown that longitudinally striate hairs can distinguish the Gorteria clade from other members of the subtribe.
You can find more information about Department of Botany at the official homepage.
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