61 documents found

Dissertation
CC BY 4.0
2020

Determining the context and scale at which functional traits increase Nicotiana...

At least 10,000 years ago, humans began domesticating crop plants into consistent, high-yielding food sources. Plants continue to provide 90% of human food energy intake worldwide. However, as human populations increase and arable land becomes scarce or unproductive due to climate instability, plant...
Dissertation
All rights reserved
2019

Understanding the regulatory basis of defence signaling in plants : the role o ...

Plants display extensive transcriptional and phenotypic plasticity to adapt to unforeseen challenges and maximize their fitness. Such massive reprogramming requires an efficient reprogramming of gene expression in tissue and time-specific manner. At the same time, plants contain numerous non-coding small...
Dissertation
All rights reserved
2018

A hidden mystery : root adaptive responses to environmental factors in Nicotia ...

As one of well-established plant model systems, Nicotiana attenuata has been intensively researched in plant resistance/tolerance, plant physiology and interactions with other environmental components in the last two decades. Although root systems, hidden belowground, are much harder to study than other...
Dissertation
CC BY 3.0
2018

Cytokinins shape plant-herbivore interactions in Nicotiana attenuata

Cytokinins (CK), a group of plant hormones, are well known for their functions in growth and development as well as in environmental interactions. Except for some prominent examples like green islands and leafgalls caused by endophytic insects via CK, only little is known about the function of CK in...
Dissertation
CC BY 3.0
2018

Coping with variable herbivore community : ecological consequences of temporal ...

Environmental heterogeneity is ubiquitous in nature and generates different ecological niches. Plants require evolving plastic responses over time and space to cope with the variable environment. Indeed, the ecological interactions between environmental factors and the plant depend largely on their temporal...
Dissertation
All rights reserved
2017

About sisters and starlets : Bsister and MIKC*-type MADS-box genes in rice dev ...

I investigate the function and evolution of different rice MIKC-type MADS-box genes, which due to their high variety and significance in plant development are excellent objects to study the outcome of gene duplications. Bsister MADS-box genes are known for their predominant role in plant female organ...
Dissertation
All rights reserved
2017

Molekulare Physiologie und Genetik der Homothallie bei Zygomyceten

Pilze können in Bezug auf sexuelle Entwicklung homo- oder heterothallisch sein. Während die sexuelle Interaktion in heterothallischen Pilzen zwischen zwei zueinander kompatiblen Kreuzungspartnern stattfindet, entwickeln sich in homothallischen Pilzen sexuelle Strukturen im selben Individuum. Die genetische...
Dissertation
All rights reserved
2017

Spatio-temporal expression of nuclear-encoded proteins associated to the...

The development of functional chloroplasts originating from undifferentiated proplastids is a complex process that depends on the proper function of the plastid-encoded RNA polymerase (PEP). The PEP complex comprises the plastid-encoded bacteria-like core-proteins αββ ʹβʺ and 12 tightly associated, nuclear-encoded...
Dissertation
All rights reserved
2016

Nicotiana attenuata microbiome characterization and plant-bacterial interactions...

Plants rely on soil microbes for beneficial interactions i.e., growth promotion, nutrient availability and disease suppression. Biotic and abiotic factors shaping the root microbiome are still largely unknown. Furthermore, why and how plants acquire soil microbes during germination and their ecological...
Dissertation
All rights reserved
2016

The role of soluble sugars and starch in plant-herbivore interactions

Insect attack leads to a strong reconfiguration of plant metabolome, which influences the performance of the attacker. While the causes and consequences of induced changes in plant secondary metabolites are well studied, less is known about primary metabolites. To contribute to filling this gap of knowledge,...
Dissertation
2015-12-01

Stress in the interaction of the endophytic fungus Piriformospora indica...

Piriformospora indica is an endophytic fungus and belongs to Sebacinales. It colonizes the roots of many plant species. This results in better plant performance and biotic and abiotic stress toler-ance. Furthermore, the fungus enhances the biomass and seed yield. The symbiotic interaction of P. indica...
Dissertation
2015-09-09

The beneficial fungus Piriformospora indica confers benefits to plants...

P. indica, a root endophytic fungus, lives in beneficial relationship with plants and protects them from biotic and abiotic stresses. Despite its positive impact on the host, little is known about the genes involved in stress tolerance. In Arabidopsis, a whole cascade of genes participates in abiot-ic...
Dissertation
2015-03-16

The beneficial fungus Piriformospora indica confers tolerance to plants...

P. indica is a beneficial root endophytic fungus which promotes plant growth and induces resistance against abiotic and biotic stress. The wide host range also provides the possibility for investigating the role of multiple functions in symbiosis. In my research, the following 3 aspects were investigated. 1....
Dissertation
2015-01-28

Integrating below- and above-ground signaling in Nicotiana attenuata

In this thesis, I investigate the role of the roots in processes which have so far mostly described within leaves. I manipulate gene function in the roots, and ask whether root gene function affects plant responses to above-ground herbivore attack and above-ground herbivore preference. I establish an...
Dissertation
2014-11-25

Manipulation of the plant microbiome : antimicrobial peptide expression in nic ...

Endophytic bacteria are believed to be important for plant growth, plant health and plant resistance. But the exploration of these roles in nature is difficult. To be able to manipulate endophytic bacteria of Nicotiana attenuata, I made 11 different genotypes for the constitutive expression of antimicrobial...
Dissertation
2014-11-21

The roles of plant sesquiterpenes in defense against biotic and abiotic...

Plants emit a substantial portion of their fixed carbon back into the atmosphere in the form of volatile organic compounds (VOCs). This process costs plants a large portion of fixed energy that could otherwise be allocated for growth, development and reproduction. However, VOCs have been implicated in...
Dissertation
2014-09-25

The role of cytosolic calcium signaling in beneficial and pathogenic interactions...

Perception of beneficial microbes and pathogens, and their associated molecular patterns (bMAMP, PAMP) leads to changes in cytosolic calcium concentration ([Ca2+]cyt). The model plant Arabidopsis thaliana, expressing the bioluminescent Ca2+ reporter apoaequorin in the cytosol, was used to elucidate the...
Dissertation
2014-06-05

Die funktionelle Charakterisierung des Augenfleckproteins SOUL3 in Chlamydomonas...

Die Familie der SOUL/HBPs sind Häm-bindende Proteine, über deren biologische Funktion relativ wenig bekannt ist. Sie kommen z. Bsp. in Cyanobakterien, Pflanzen und Wirbeltieren vor. In der Grünalge Chlamydomonas reinhardtii war im Proteom des Augenflecks, einem primitiven visuellen System, das Protein...
Dissertation
2014-02-12

Mutualistic plant-microbe interactions in Nicotiana attenuata : from bacterial ...

Endosphere-inhabiting mutualistic bacteria establish intimate relationships with their host plant and often provide services like plant growth-promotion (PGP) or disease protection. How plants select for these microbes and which mechanism of PGP are employed remain mostly elusive. I assessed the relevance...
Dissertation
All rights reserved
2013-08-29

Molecular response of nicotiana attenuata to herbivory and solar UVB

Plants have coexisted with insects for approximately 400 million years. During this time, the interactions between flora and fauna have driven coevolutionary and reciprocal changes, resulting in a complex mosaic of plant defenses and insect counter-defenses. In addition, abiotic stress such as UVB radiation...