Research Projects in the Department of Molecular Ecology

Julia Bing

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Research Description:

I am working on the interaction between N. attenuata with its pollinator community which consists of hummingbirds, hawkmoths and bees. These pollinators are known to be differently attracted by floral traits such as scent and nectar. N. attenuata genotypes vary in these important traits and certain genotypes attract pollinators differently and thus influence the types of conspecific pollen they receive on their stigmas in nature. As a result, floral traits such as nectar and scent influence which pollen genotypes are delivered to stigmas and hence are available for post-pollination, pre-zygotic mate selection. In my project I am combining both pollinator attraction and mate selection in plants with the aim to find out if there are pollinators that transfer the particular pollen genotypes that match the sporophyte´s mate selection preferences.


Dechang Cao

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Research Description:

My research is focused on the ecological significance and mechanisms of seed germination and dormancy. With assistance from the analytical platform, I am currently working on a project to identify active compounds in smoke that promote N. attenuata’s seed germination to better understand how the plant uses smoke to colonize post-fire environments.


Lucas Cortes Llorca

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Research Description:

My main project aims to identify regulatory genes that lie at the crossroads between the circadian clock and the auxin signaling pathway; two networks that are tightly interwoven and regulate multiple developmental processes. I am also exploring the function of JA-mediated epigenetic modifications in the regulation of defense responses to herbivory. Specifically, how JA-induced changes in the methylome, triggered by the RNA-directed DNA methylation pathway, influence intergenerational responses to JA and other phytohormones. I approach scientific questions with creative thinking and I have an intrinsic curiosity for all scientific fields, especially neurobiology.


Junfu Dong

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Research Description:

In China, I worked on ecosystem responses to global climate change, in particular the response grassland ecosystems and the role of arbuscular mycorrhizal fungi (AMF) in climate change responses. Here in Jena, I’m helping with many projects to broaden my skill set and scientific experience, and am currently working with a transgenic line of N. attenuata that is impaired in its interactions with AMF (irCCaMK) to better understand how AMF associations influence plant performance.


Han Guo

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Research Description:

Sperm cells of flowering plants are non-motile and thus require assistance from the pollen tube to be transported to the egg apparatus to execute the double fertilization that results in seed production. During the growth of the pollen tube from the stigma to the eggs, various post-pollination and pre-zygotic reproductive barriers result in non-random mate selection by influencing the ability of pollen tubes to deliver sperm to the eggs. I’m interested in the mate selection process, by which the styles of self-compatible N. attenuata flowers select certain genotypes of pollen over others after mixed genotype pollinations. The molecular mechanism of this type of mate selection is not clear. Based on genomic and tissue-specific transcriptome data, I am trying to identify gene candidates that mediate this mate selection process and plan to alter their transcription in vivo by transformation (virus induce gene silencing, VIGS, as well as stable transgenic lines) to test whether there is a relationship between the transcriptional abundance of candidates gene and the mate selection phenotype. By integrating comparative genomics, molecular biology and genetics, I am trying to uncover the nature of this interesting intra-specific reproductive behavior of N. attenuata.


Rayko Halitschke

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Research Description:

As the coordinator of the analytical platform, I am responsible for the development and optimization of analytical tools in the Department of Molecular Ecology. My major research focus is the development of high throughput methods for the metabolic characterization of large populations of recombinant inbred lines (RILs). With a combination of targeted and untargeted metabolomics analysis and ecological phenotyping we are trying to identify important chemical traits mediating biotic interactions and the underlying genetic background regulating them. I am also a member of the Sonderforschungsbereich (SFB) ChemBioSys, which is funded by the German Science Foundation.


Jun He

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Research Description:

 I am interested in how N. attenuata mediates its interactions between herbivores and their predators. Currently, I focus on the function of linalool emissions in indirect and direct defense against Manduca sexta. A single QTL was identified to control emissions of linalool from RIL lines constructed from two accesses collected from Utah (Ut) and Arizona (Az). Ectopic overexpression of (+)/(-) linalool synthase genes in both Ut and Az genotypes are being used to reveal the influence of emitted or internal pools of linalool on caterpillar growth and oviposition behavior of the moth.


Sven Heiling

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Research Description:

My objective is to elucidate the ecological function of 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs) in N. attenuata when the plant is attacked by herbivores, such as M. sexta. To this end, I am using comparative metabolomics and transient/stable RNAi approaches to identify and functionally characterized novel glucosyl-, rhamnosyl- and malonyl transferases that participate in the biosynthesis of HGL-DTGs in N. attenuata plants, which will allow me to evaluate the impact of each individual compound class in insect resistance and to understand the connectivity of HGL-DTG metabolism with other branches of the plant’s herbivory-regulated metabolism. I am also studying the impact of the phytotoxic aglycone, 17-HGL, in N. attenuata and additionally establishing a FrassOmics platform as a tool to study the importance of post-ingestive rearrangements of a plant’s specialized metabolites in insects.


Youngsung Joo

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Research Description:

N. attenuata plants face biotic and abiotic stresses that vary widely over temporal and spatial scales and this stress heterogeneity often increases a plant’s phenotypic plasticity. I am interested in the context-dependence of a plant’s responses to ecological interactions and understanding if these spatio-temporal plastic responses are adaptive under ecologically relevant circumstances. My main research focus is the role of the circadian clock in time-dependent photosynthesis and responses to herbivore attack and I have also investigated the ecological consequence of tissue-specific defenses. JA-mediated systemic signaling plays a central role in mediating these spatio-temporal plastic responses to herbivore attack, and I’m currently examining the ecological consequences (e.g., herbivore community, plant resistance, etc.) of these JA-mediated systemic defense responses.


Elham Karimi Dorchey

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Research Description:

 Plants use an array of metabolites to defend themselves against harmful organisms and to attract others that are beneficial. For example, it has been widely documented for root-rhizobial and root-mycorrhizal interactions that roots secrete secondary metabolites that attract Rhizobium and AMF. My research elucidates how changes in metabolite pathways affect root exudates and consequently influence root-associated bacteria. I am using stable isotope probing (SIP) to identify the active bacterial species in synthetic bacterial communities which originate from the roots of healthy N. attenuata plants grown in their natural habitats. I am establishing glasshouse bioassays to compare the population dynamics of synthetic bacterial communities colonizing different transgenic lines with those of wild type (WT) plants. By comparing the metabolic profiles of root exudates collected from transgenic lines that differ in their ability to support the growth of synthetic bacterial communities, I hope to identify those metabolites that are secreted by roots to recruit root-associated bacteria and to understand the role that the recruited bacteria play in ecological interactions and traits important for plant fitness.


Gundega Lapina

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Research Description:

 I manage small- and large-scale research and management projects with the aim to optimize existing procedures and protocols. Improving the procedures and protocols can be achieved by finding innovative solutions, enhancing communication, cooperations and finding synergies among researchers and the permanent staff of the Department. Being a professional teacher of project and innovation management in business university environment, I’m enjoying finding ways of applying my skills to the scientific environment of the Department. Another essential part of my activities is related to Utah field station management - planning and organization of field projects, carrying out research experiments and providing technical support for all activities at the Utah field station.

 

 


Gisuk Lee

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Research Description:

Research in plant-herbivore interactions has mainly focused on the visible interactions, namely with leaf-feeding folivores, but little is known about the less-visible stem-feeding herbivores. The larvae of stem-boring weevil, Trichobaris mucorea, feed only on the pith of their host plants and a single larva spends its entire life inside the stem of a single plant until pupating and becoming an adult. I have investigated the effects of plant secondary metabolites on larval performance and adult oviposition preferences and how the plant increases resistance in response to the feeding damage of this stem-boring herbivore. Given their confined feeding location, it’s not surprising that larvae frequently come into contact with their frass and even eat it (coprophagy) and use it to construct pupation chambers. I am currently trying to understand the role of frass-associated microbes in this endophytic interaction between the plant stem and the stem-boring herbivore.


Dapeng Li

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Research Description:

I use computational metabolomics to analyze N. attenuata’s responses to multi-layered biotic interactions. My research interests are to characterize the structure of diverse small molecules using mass spectrometry and investigate the expression patterns of secondary metabolites under different conditions such as herbivory elicitation in a time scale and from different tissues and ontogeny. Furthermore, my research involves the characterization of the regulatory basis of the secondary metabolites by applying integrative analysis of transcriptome and metabolome and bioinformatics.


Jiancai Li

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Research Description:

My research focuses on one class of abundant second metabolites in N. attenuata, 17-hydroxygernallinalool diterpene glucosides (HGL-DTGs). The major three directions of my research are: how do plants synthesize HGL-DTGs? What is the effect of HGL-DTGs on a plant’s physiology? What is the effect of HGL-DTGs on a plant’s herbivore defense.  My research will illuminate how these abundant metabolites help N. attenuata defend itself against herbivores in nature.


Ran Li

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Research Description:

I study the role of jasmonate (JA) signaling in N. attenuata-herbivore interactions. JA signaling is important for many developmental processes as well as a plant’s response to stresses (Li et al., 2017 JIPB). Jasmonate ZIM domain (JAZ) proteins, the suppressors of JA signaling, play a central role in JA signaling by directly suppressing JA-responsive transcription factors. By RNA-sequencing, we found the expression of JAZs to be highly tissue-specific, implying that the function of individual JAZs differ in different tissues (Li et al., 2017, PNAS).  These different sectors of JA signaling may explain the multiple roles played by this universal phytohormone. Using analytical tools (metabolomics, pyhtohormone analysis), molecular tools (gene silencing, transcriptomics, protein-protein interaction) and ecological tools (insect bioassay, field work), I hope to better understand these novel sectors of JA signaling.


Suhua Li

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Research Description:

The physiological function of strigolactone (SL) and karrikin (KAR) signaling in plants has been well-studied, while their ecological function remains to be explored. By using well-established molecular, analytical and ecological tools, I plan to investigate the function of SL and KAR signaling in plant defense in N. attenuata and reveal their associated molecular mechanisms.


Erica Mc Gale

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Research Description:

My research explores the functional effects of a key gene that controls a water-wasting phenotype in N. attenuata plants: mitogen-activated protein kinase 4 (MPK4). I use plants stably silenced in MPK4 expression (irMPK4) and by growing these plants with EV (empty vector, Wt-like) plants in pairs, populations, and communities at different abundances, I examine the productivity of each population’s individuals as well as the population as a whole. My research focuses on the performance of these populations under drought stress, and/or while interacting with arbscular mycorrhizal fungi (AMF). I'm interested in the effect of MPK4 on how a plant responds to drought tolerance and recovery through changes in photosynthetic rates, efficiencies, and structures, as well as through metabolomic accumulation in leaves, branches and roots. Below ground interactions between plants, facilitated by a fungus such as AMF, are key to how irMPK4 plants can affect community drought response and recovery, and I seek to define some of the responsible mechanisms.


Maitree Pradhan

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Research Description:

When plants are attacked by pathogens or herbivores, they reconfigure their transcriptomes to combat these stresses and maximize their fittness. How these transcriptional responses, which include the reprogramming of phytohomone signals, defense metabolites and the master transcription factors, are regulated is poorly understood. Rapid changes in gene expression may be modulated by regulatory small-RNAs (smRNAs), such as the microRNAs and small-interfering RNAs (miRNAs, siRNAs). When N. attenuata plants are attacked by herbivores, a smRNA-pathway mediated by RNA-directed RNA polymerase 1 (RdR1) and Dicer-like proteins 3 and 4 (DCL3 and 4) is recruited. The effectors of the smRNA pathways are the family of Argonaute (AGO) proteins and these are the focus of my research. Which AGO proteins are recruited during elicitation of a herbivory-specific smRNA pathway remains unknown, and I hope to identify herbivory-specific AGO effectors that would enable the construction of smRNA pathways tailored to regulate a plant’s induced-defense responses. In addition, I hope to elucidate the roles of AGOs in mediating the plant’s responses to phytopathogens.


Martin Schäfer

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Research Description:

I investigate the role of small molecules in the interactions between N. attenuata and its biotic interaction partners. Currently, my research focus is in the systemic changes that occur in the plant after establishing a symbiosis with arbuscular mycorrhizal fungi (AMF). Additionally, I have a long-standing interest in the interaction of growth and defense related phytohormones (e.g., cytokinins, jasmonates, strigolactones) and their roles in the adaptation of plants to their environment. In my research, I combine molecular tools, such as genetic manipulations and transcript analysis, with analytical tools, in particular mass spectrometry.


Meredith Schuman

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Research Description:

 The functional characterization of genes is often done in controlled laboratory environments and I am especially interested in the community-level effects of genetic diversity. What is the consequence for ecological communities of variation in the expression or allele frequency of single functional genes? How much of the effects generally attributable to biodiversity can we observe in the interactions of ecological communities with a plant species monoculture, by genetically manipulating the diversity of ecologically important plant traits? Herbivore-induced plant volatiles (HIPVs) are arguably an example of a collection of traits whose functions can best be revealed by studying plants in populations and communities. HIPVs are emitted by plants within minutes to days after an herbivore begins to feed and can provide spatiotemporal information about an herbivore’s identity and presence to its predators and parasitoids – who may indirectly defend the plant by preying on the herbivore – but also to neighboring plants, and other community members. How does the chemical landscape emitted and exuded by plants affect – or mediate – ecological interactions? How do plants regulate these emissions, and monitor emissions from neighbors? How diverse are these chemical landscapes, and what are the consequences of that diversity?

As the coordinator of the ecological platform, I am responsible for the development and optimization of the field work in the Department of Molecular Ecology. I am also a member of the German Center for Integrative Biodiversity Research (iDiv) and of the Sonderforschungsbereich (SFB) ChemBioSys, both funded by the German Science Foundation.


Henrique Valim

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Research Description:

From the timing of photosynthesis to the timing defense responses against herbivore attack, N. attenuata’s circadian clock is intimately involved in orchestrating stress responses with daily rhythms. However, the clock also functions in developmental responses to stresses such as water limitation and heat stress, which gradually become acute as N. attenuata’s growing season progresses in its natural environment, the Great Basin Desert. Despite these whole-plant functions of the circadian clock, circadian mechanisms may vary from tissue to tissue, and recent evidence suggests that the clock functions differently in roots and shoots. My research focuses on understanding the role of the circadian clock in these developmental responses, as well as in understanding the interplay between the root and shoot clock in response to abiotic stress. As the circadian clock gene, TIMING OF CAB EXPRESSION 1 (TOC1), is mechanistically linked to drought responses via abscisic acid (ABA) signaling, it provides a clear target for an exploration of the clock’s function in roots and shoots. My ultimate goal is to utilize N. attenuata’s extensive transgenic toolbox as well as various native accessions to elucidate the functional consequences for plant fitness of TOC1 in roots and shoots in response to drought stress.


Ming Wang

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Research Description:

Full establishment of arbuscular mycorrhizal fungal (AMF) symbioses, which occurs between more than 80% of all land plants and fungi of the Glomeromycota, is thought to be largely controlled by phytohormones. Evidence for a role for jasmonates (JA) in AMF colonization with Medicago truncatula, tomato and rice, has been confounded by the use of various mutants in JA biosynthesis and signaling and has produced inconsistent results. Clearly a need for a systematic examination of JA biosynthesis or signaling in AMF colonization in a single native host plant that does not have a long history of artificial selection is required for a clearer understanding of this important natural symbiosis.


Yong Zou

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Research Description:

Light serves not only as an important environmental factor for plant growth and development, but also as a modulator of shade avoidance and plant defense. In plants, several photoreceptors, including cryptochromes (CRYs), phytochromes (PHYs), phototropin (PHOT), UV-B resistance 8 (UVR8), and ZEITLUPE (ZTL) are employed to accurately perceive the dynamics of environmental light. My research interest focuses on how N. attenuata’s photoreceptors help it to survive in nature.