Molecular and Applied Plant Sciences majorTopics and lecturers
Heidelberg is home to a very active community of plant researchers that are based at the Centre for Organismal Studies (COS). All researchers involved in MAPS are world renowned leaders in their fields and addresses the global challenges of food security, green technology and climate change. The range of topics studied is wide: sulfur biochemistry, cell wall biology, cellular transport and trafficking systems, stem cell behaviour, root development and plant defences. In this research environment, MAPS has developed into an internationally distinguished master program that provides students from around the world with a high-level education at one of the leading universities in Germany. The MAPS curriculum covers a broad spectrum of topics and is integrally taught in English. The program is focused on intensive stays in the labs. Already by the second semester students spend most of their time actively doing research. The lectures and practical allow students to study the biochemistry, cell biology, physiology or developmental biology of plants using advanced equipment for high-end microscopy, genomics, transcriptomics and metabolomics. A key strength of the program is the international network of academic and industrial host labs that the program has built over the years. This offers many opportunities to our students to discover an even wider range of topics and methodologies.
Regulation of flavonoid synthesis in grapevine
Grapevine (Vitis vinifera L.) represents economically the most important fruit globally, covering up to 8 million ha worldwide. The biosynthesis of natural product determining the quality of the grape berry and wine and biotic/abiotic factors limiting growth and yield of the crop are research topic in the AG Bogs. Hereby, flavonoids and monoterpenes play important roles for grape berries and wine contributing substantially to their taste, aroma quality and nutrition. Therefore, transcriptional regulation of the flavonoid and monoterpene pathways of grapevine in respect to the developmental stage and environmental factors is studied in this group. The lack of natural resistance against most fungal diseases of V. vinifera and sensitivity against freezing damages causes high financial and environmental costs. Accordingly, another priority of the group is to identify the sources of natural resistance to fungal diseases and frost damages and the understanding of the underlying mechanisms of grapevine resistance.
Growth and Cell Fate Regulation
How are cellular properties coordinated during growth and development to generate functional organs and whole bodies? In our lab we use lateral growth of plant shoots as an example to address this fundamental question. Lateral growth is based on the tissue-forming properties of a group of stem cells called the cambium, the activity of which leads to the production of secondary vascular tissue (wood and bast). Considering its function as a stem cell niche that is essential for the constant production of new tissues in a highly differentiated cellular environment, the cambium represents an ideal model for addressing questions concerning the regulation of cell identity and how growth processes are aligned with endogenous and exogenous requirements.
Molecular biology of plants
Our work aims at the understanding of how plants work under different environmental conditions. In project 1 the availability of nutrients is investigated at the whole plant level. The assimilation of sulfate and its interaction with iron metabolism are analysed with respect to metabolites, gene expression, protein biochemistry and cell biology.
Project 2 discovers the functions of N-alpha-terminal acetylation of proteins. This usually co-translational process is the most common modification of soluble proteins in plants and animals and operates in protein stability and many other functions and contributes to stress resistance.
Changing environmental conditions trigger diverse metabolic and developmental adaptation reactions in plants. These adaptation mechanisms involve cellular changes in the levels of Ca2+ and H+ but also changes in hormones, metabolites and cellular redox state. Fluorescent indicators are ideally suited to monitor dynamic changes of various molecules associated with signaling or metabolism. We employ different fluorescent indicators techniques to study physiological and cellular processes in living plant cells. This helps us to get new insight into signaling, physiology and metabolism in plant cells.
Biodiversity and plant systematics
Evolutionary and biodiversity research in our department is focusing on various levels of biological variation - from molecules to landscapes. In our department we are addressing questions on 1) systematics and phylogenetic relationships among plant species, 2) phylobiogeography (the distribution of genetic variation in space and time), 3) the evolution of molecular marker systems (from single genes and regions to whole genomes), 4) adaptation processes and character trait evolution, 5) genome evolution, 6) speciation processes, breeding system evolution and differentiation on the population level, 7) developmental-molecular processes responsible for maintaining plant cell identity, and 8) structure, morphology and evolution of angiosperm flowers. For many of the projects we are focusing on cruciferous plants (mustard family, Brassicaceae). Our aim is to develop this group of more than 3700 species into one of the most important model systems on the family level and below.
Stem cell biology
Work in the department of Stem Cell Biology is focused on the regulatory programs governing shoot meristem function and the control of stem cell number in the reference plant Arabidopsis thaliana. To this end we employ an integrated approach of advanced genetic, genomic, and molecular methods together with computational analysis to determine how hard-wired genetic circuits underlying stem cell control are orchestrated and integrated with environmental signals.
Regulation of plant morphogenesis
Work in my laboratory focuses on understanding how plant organs, in particular roots, are shaped. This morphogenesis results from the combined action of the plant genes controlling cell identity, the mechanical interactions between cells and tissues, and the physical environment in which development takes place. However, very little is known about the perception of environmental inputs and their impact on morphogenesis. Our focus is to understand how temperature and water availability alter this process. Our work is based on an integrated approach of cell biology, molecular genetics, advanced microscopy, and biochemical methods together with computational analysis to advance our physical and biological understanding of how biological shapes arise.
Plants use sunlight to turn carbon dioxide and water into the sugars we eat and the oxygen we breathe. Land plants form microscopic “breathing” pores on their leaves, the so-called stomata, to balance carbon dioxide uptake with water vapour loss. The grass family that includes the three major food crops rice, maize and wheat, form particularly efficient stomata; Grasses add lateral “helper cells” or subsidiary cells to the central guard cells, which makes the four-celled grass stomata faster to open and close and thus more water-efficient. We study how subsidiary cells are formed and how they functionally support guard cells using genetics and gene editing, (time-lapse) confocal microscopy and methods to measure actual gas exchange between the plant and the atmosphere.
Plant sexual and asexual reproduction through seeds
Plant seeds are an essential source of energy for human and animal nutrition. In order to form seeds, plants have adopted different strategies including sexual and asexual (apomictic) reproduction through seeds. Apomixis has a great potential for agricultural applications, as it results in a full fixation of the maternal genotype and thus leads to clonality of all offspring. Thus, high yielding hybrid genotypes can be conserved in subsequent generations. As apomixis is not represented in major crop species, engineering of apomixis into these species is a longstanding aim. However, despite the high interest in apomixis shared by scientists and plant breeders, the knowledge about the genetic pathways regulating apomixis and their evolution is still limited.
By a combination of cell type-specific transcriptome analysis and the investigation of mutants, the importance of RNA helicases for plant reproduction was recently uncovered in the model plant Arabidopsis thaliana (Schmidt et al., PLoS BIOL 2011; doi: 10.1371). Importantly, in plants carrying a mutant allele of the RNA helicase MNEME features of apomixis were observed. The aim of my research is to gain insights into the genetic basis of apomixis, in particular the role of RNA helicases and aspects of their evolution.
Plant developmental biology
Due to their sessile lifestyle, plants need to efficiently adapt their metabolic and developmental program to changing and often unfavourable environmental conditions. Adaptation often involves considerable fluctuations of metabolite and ion concentrations between tissues, cells and organelles that are mediated either by membrane transport or vesicular trafficking. Our lab has shown that in the model plant Arabidopis the V-ATPase, a highly conserved eikaryotic proton-pumps, does not only fuel secondary active transport processes but also plays anl important role in the regulation of endocytic and secretory trafficking.
Current research aims at understanding the regulatory networks that control V-ATPase activity as well as the identification of the biological interactions that depend on the activity of this complex proton-pump. Using Arabidopsis as our main model system, we employ genetics and cell biology as well as biochemistry and physiology to provide knowledge that could eventually lead to novel strategies for improved crop yield under stress conditions.