How climate change influences the growing season length of woody plants
The biannually awarded Eduard Strasburger Prize will go to Dr. Constantin Mario Zohner this year. To measure the responses of plants to climate change, Dr. Zohner analysed how temperatures and day length influence spring leaf-out of temperate woody plants. If trees and shrubs start into the season too early, they are likely to experience frost damage and have to start building leaves all over again – given that they have sufficient energy reserves left. In his doctoral thesis, Zohner shows that woody plants from Asia strongly react to rising air temperatures and thus will unfold their leaves ever earlier in the future, even when grown in Europe or North America. In contrast, woody plants from Europe and North America are less sensitive to rising temperatures, probably as a result of adaptation to historically more unstable climates in these areas. In his work, carried out at Prof. Dr. Susanne S. Renner’s chair of Systematic Botany and Mycology at the Ludwig Maximilian University Munich, Germany, Zohner also showed for the first time that every leaf bud has sensors, allowing buds to react independently to light and temperature cues, even when located only few centimetres apart. To demonstrate this phenomenon in mature trees, the plant ecologist who now works with a fellowship at ETH Zurich, Switzerland, kept the leaf buds of adult trees under short day conditions for 187 consecutive days during winter/spring by covering them with light-tight bags. On the awarding ceremony on 18th September, where he receives the price endowed with 2,500 Euros, he will not only introduce the above-mentioned research results on spring leaf-out but also show new findings on how climate change affects autumn leaf coloration and drop in temperate trees. Climate-change induced changes in spring leaf-out and autumn leaf drop will alter forest productivity in temperate and boreal regions, which needs to be accurately integrated into climate change models.
How a manipulative protein helps to analyse highly dynamic plastid extensions
Dr. Jessica Lee Erickson will receive DBG’s Wilhelm Pfeffer Award for her novel approach to the analysis of the highly dynamic tubules that extend from plastids in living plant cells under stress. Although they are known for more than 100 years the function and formation of these plastid’s tubules (called stromules) was largely unknown. Many plant species make stromules, and so it seems as though they are important to plant survivability. To elucidate why and how stromules are made, Dr. Erickson combined knowledge and methods from biophysics, bioinformatics, genetics, biochemistry and cell biology in her doctoral thesis. She employed a new approach at the Institute of Plant Physiology at Martin-Luther-Universität Halle-Wittenberg, Germany, in Dr. Martin Hartmut Schattat's lab. She used so called 'effector proteins' from a plant pathogen responsible for causing disease in tomato and pepper plants as a tool to manipulate and study plastid shape in tobacco plants (Nicotiana benthamiana). Effector proteins are typically used by plant pathogens to manipulate host plants for the pathogen’s benefit. In her thesis she describes, how these proteins could be used to understand the plastid-shaping processes that unfold within minutes. In the meantime, other scientists outside Germany apply her new method. Dr. Erickson will receive the award endowed with 2,500 Euros from the president of the Wilhelm Pfeffer Foundation, Prof. Dr. Christian Wilhelm, in Rostock, Germany. In her talk on 17th September, she will speak about the fundamental aspects of shaping a plastid and will also tell us about how she used plant pathogen effectors proteins to study plastid shape changes.
Flower populations that have better chances to survive climate change
Dr. Moisés Expósito Alonso will receive DBG’s second Wilhelm Pfeffer Award. In his PhD, he showed that the subpopulations of Eurasian thale cresses (Arabidopsis thaliana) from central Europe have lower chances to survive droughts than populations from the Southern and Northern borders of their native geographic range. He combined field studies with populations’ genetics, greenhouse experiments and a self-developed algorithm in his studies. First, he chooses genetically distinct plant specimens from the Arabidopsis Genomes Project, representing more than 500 natural populations, reared them and put them under severe drought in the greenhouse and in two different climate locations: Tübingen (Germany) and Madrid (Spain). Plant varieties that originated from the borders of the natural range of Arabidopsis from Sweden and Spain survived the simulated extreme droughts. He argues that populations from the geographical borders had faced more extreme weather periods and thus accumulated more survival-related mutations in the past than populations in the more “cozy” middle of the geographical range. Moreover, by creating a machine-learning algorithm he projected that, based on their weaker mutations, specimens in central Europe, would be exposed to the highest threat of extinction – if rainfall suddenly decreases in the future. Expósito Alonso conducted his studies at Eberhard Karls Universität and Max Planck Institute for Developmental Biology at Tübingen, Germany, with Professor Dr. Detlef Weigel, Prof. Dr. Oliver Bossdorf and Prof. Dr. Hernán Burbano. In the meantime, he moved to a Principal Investigator and Assistant Professor position to start his laboratory on climate change genetics at the Carnegie Institution for Science at Stanford University. He will receive the price endowed with 2,500 Euros from the president of DBG’s Wilhelm Pfeffer Foundation, Prof. Dr. Christian Wilhelm.
Factors that induce phloem formation
Dr. Eva-Sophie Wallner will receive DBG’s Horst Wiehe Award for this year. In her doctoral thesis, she identified so far uncharacterized proteins as essential factors regulating early steps in forming the sugar-transporting plant tissue, known as phloem. The phloem part of the vascular system transports sugars from leaves into fruits for storage and into new organs that require energy to grow. At the Centre for Organismal Studies (COS) at Heidelberg University in the lab of Prof. Dr. Thomas Greb, Dr. Wallner identified that these new proteins called SMXL3, SMXL4 and SMXL5 are essential for regulating early stages of phloem development. Although other members of the SMXL-family are susceptible to a distinct hormone, SMXL3/4/5 proteins are insensitive to this hormone. This unresponsiveness is potentially crucial for forming robust phloem tissues and viable plants. By genetic studies using the model organism Arabidopsis thaliana, Dr. Wallner showed that SMXL3/4/5 interact with other proteins to form complexes that could fulfil important roles in gene regulation. While eliminating the activity of these complexes leads to termination of plant growth and death, increasing their concentrations could improve crop yields in the future. Thanks to her persistence and creativity, the results will not only open new doors for basic research in plant vascular development but also in applied research. Dr. Wallner will receive the award endowed with 2,000 Euros from DBG’s president Prof. Dr. Karl-Josef Dietz in Rostock, coming from the USA, were she now holds a postdoc position at Stanford University, to present her talk on 16th September.