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Romance and Irony
(2017)
3D geovisualization systems (3DGeoVSs) that use 3D geovirtual environments as a conceptual and technical framework are increasingly used for various applications. They facilitate obtaining insights from ubiquitous geodata by exploiting human abilities that other methods cannot provide. 3DGeoVSs are often complex and evolving systems required to be adaptable and to leverage distributed resources. Designing a 3DGeoVS based on service-oriented architectures, standards, and image-based representations (SSI) facilitates resource sharing and the agile and efficient construction and change of interoperable systems. In particular, exploiting image-based representations (IReps) of 3D views on geodata supports taking full advantage of the potential of such system designs by providing an efficient, decoupled, interoperable, and increasingly applied representation.
However, there is insufficient knowledge on how to build service-oriented, standards-based 3DGeoVSs that exploit IReps. This insufficiency is substantially due to technology and interoperability gaps between the geovisualization domain and further domains that such systems rely on.
This work presents a coherent framework of contributions that support designing the software architectures of targeted systems and exploiting IReps for providing, styling, and interacting with geodata. The contributions uniquely integrate existing concepts from multiple domains and novel contributions for identified limitations. The proposed software reference architecture (SRA) for 3DGeoVSs based on SSI facilitates designing concrete software architectures of such systems. The SRA describes the decomposition of 3DGeoVSs into a network of services and integrates the following contributions to facilitate exploiting IReps effectively and efficiently. The proposed generalized visualization pipeline model generalizes the prevalent visualization pipeline model and overcomes its expressiveness limitations with respect to transforming IReps. The proposed approach for image-based provisioning enables generating and supplying service consumers with image-based views (IViews). IViews act as first-class data entities in the communication between services and provide a suitable IRep and encoding of geodata. The proposed approach for image-based styling separates concerns of styling from image generation and enables styling geodata uniformly represented as IViews specified as algebraic compositions of high-level styling operators. The proposed approach for interactive image-based novel view generation enables generating new IViews from existing IViews in response to interactive manipulations of the viewing camera and includes an architectural pattern that generalizes common novel view generation. The proposed interactive assisting, constrained 3D navigation technique demonstrates how a navigation technique can be built that supports users in navigating multiscale virtual 3D city models, operates in 3DGeoVSs based on SSI as an application of the SRA, can exploit IReps, and can support collaborating services in exploiting IReps.
The validity of the contributions is supported by proof-of-concept prototype implementations and applications and effectiveness and efficiency studies including a user study. Results suggest that this work promises to support designing 3DGeoVSs based on SSI that are more effective and efficient and that can exploit IReps effectively and efficiently. This work presents a template software architecture and key building blocks for building novel IT solutions and applications for geodata, e.g., as components of spatial data infrastructures.
Extreme weather events like heatwaves and floods severely affect societies with impacts ranging from economic damages to losses in human lifes. Global warming caused by anthropogenic greenhouse gas emissions is expected to increase their frequency and intensity, particularly in the warm season. Next to these thermodynamic changes, climate change might also impact the large scale atmospheric circulation.Such dynamic changes might additionally act on the occurence of extreme weather events, but involved mechanisms are often highly non-linear. Therefore, large uncertainty exists on the exact nature of these changes and the related risks to society. Particularly in the densely populated mid-latitudes weather patterns are governed by the large scale circulation like the jet-streams and storm tracks. Extreme weather in this region is often related to persistent weather systems associated with a strongly meandering jet-stream. Such meanders are called Rossby waves. Under specific conditions they can become slow moving, stretched around the entire hemisphere and generate simultaneaous heat- and rainfall extremes in far-away regions.
This thesis aims at enhancing the understanding of synoptic-scale, circumglobal Rossby waves and the associated risks of dynamical changes to society. More specific, the analyses investigate their relation to extreme weather, regions at risk, under which conditions they are generated, and the influence of anthropogenic climate change on those conditions now, in the past and in the future.
I find that circumglobal Rossby waves promoted simultaneous occuring weather extremes across the northern hemisphere in several recent summers. Further, I present evidence that they are often linked to quasiresonant-amplification of planetary waves. These events include the 2003 European heatwave and the Moscow heatwave of 2010. This non-linear mechanism acts on the upper level flow through trapping and amplification of stationary synoptic scale waves. I show that this resonance mechanism acts in both hemispheres and is related to extreme weather. A main finding is that circumglobal Rossby waves primarily occur as two specific teleconnection patterns associated with a wave 5 and wave 7 pattern in the northern hemisphere, likely due to the favourable longitudinal distance of prominent mountain ridges here. Furthermore, I identify those regions which are particularly at risk: The central United States, western Europe and the Ukraine/Russian region. Moreover, I present evidence that the wave 7 pattern has and extreme weather in these regions. My results suggest that the increase in frequency can be linked to favourable changes in large scale temperature gradients, which I show to be largely underestimated by model simulations. Using surface temperature fingerprint as proxy for investigating historic and future model ensembles, evidence is presented that anthropogenic warming has likely increased the probability for the occurence of circumglobal Rossby waves. Further it is shown that this might lead to a doubling of such events until the end of the century under a high-emission scenario.
Overall, this thesis establishes several atmosphere-dynamical pathways by which changes in large scale temperature gradients might link to persistent boreal summer weather. It highlights the societal risks associated with the increasing occurence of a newly discovered Rossby wave teleconnection pattern, which has the potential to cause simultaneaous heat-extremes in the mid-latitudinal bread-basket regions. In addition, it provides further evidence that the traditional picture by which quasi-stationary Rossby waves occur only in the low wavenumber regime, should be reconsidered.
This thesis investigates the processing and representation of (ir-)regularity in inflectional verb morphology in German and English. The focus lies on the predictions from models of morphological processing about the production of subtypes of irregular verbs which are usually subsumed under the category `irregular verbs'. Thus, this dissertation presents three journal articles investigating the language production of healthy speakers and speakers with agrammatic aphasia in order to fill a gap both for the availability of language production data and systematically tested patterns of irregularity. The second Chapter set out to investigate whether regularity of a verb or its phonological complexity (measured in number of phonemes) better predict the production accuracies of German speakers with agrammatic aphasia. While regular verbs were significantly more often correct than mixed and irregular verbs, production accuracies of irregular and mixed verbs for impaired participants did not differ. Thus, no influence of phonological complexity was observed. Chapter 3 aimed at teasing apart the influence of stem changes and affix type on the production accuracies of English speaking individuals with agrammatic aphasia. The analyses revealed that the presence of stem changes but not the type of affix had a significant effect on the production accuracies. Moreover, as four different verb types were tested, results showed that production accuracies did not conform to a regular-irregular distinction but that accuracies differed by the degree of regularity. In Chapter 4, long-lag primed picture naming design was used to study if the differences found in the production accuracies of Chapter 3 were also associated with differences in production latencies of non-brain damaged speakers. A morphological priming effect was found, however, in neither experiment the effect differed of the three verb types tested. In addition to standard frequentist analysis, Bayesian analysis were performed. In this way the absence of a difference of the morphological priming effect between verb types was interpreted as actual evidence for the lack of such a difference. Hence, this thesis presents diverging results on the production of subtypes of irregular verbs in healthy and impaired adult speakers. However, at the same time these results provided evidence that the conventional regular-irregular distinction is not adequate for testing models of morphological processing.
Conformational transition of peptide-functionalized cryogels enabling shape-memory capability
(2017)
Seizing long-term growth opportunities is both a key goal of and a challenge for companies at the same time. Saturated markets and shorter product lifecycles have changed market dynamics over the past decades, in such a way that competition on price or quality leadership has receded into the background. Instead, firms increasingly depend on the successful development of new business fields and strong brands to retain customers and spur growth. Thus, the two pillars of business development and brand management have become core strategic functions.
By focusing on innovation – a key dimension of business development – this book analyzes the interrelations between innovation and brand management and the ways in which both functions can benefit from each other. Innovations are considered crucial for building brand equity and revitalizing brand images in the long term, while vice versa, branding could facilitate consumer adoption of a newly launched innovative product or service. Since a brand is a first quality signal, it could act as a vehicle for consumers to reduce the risks and uncertainty associated with a novel product from a consumer's perspective and encourage product trial.
This book empirically investigates whether such interdependencies exist and how managers can make use of them to best leverage their company’s innovation and branding efforts. In particular, the author examines the interplay between innovation and brand management by analyzing (1) how innovations impact consumer attitudes towards the (parent) brand and its brand images, (2) how branding an innovation facilitates its market success, and (3) how building brand equity can serve as a buffer against impacts from adverse events such as a product scandal.
Its findings are highly relevant from a managerial and a theoretical perspective. They provide managers with guidance on two key aspects of business development and innovation management: One, how is innovation employed in order to best enhance a brand's equity (e.g., to revitalize its brand image)? Two, how to choose whether to leverage an existing brand or to develop a new brand in order to facilitate consumer adoption of a new innovation?
Hintergrund: Die Untersuchung von Ernährungsmustern als komplementärer Ansatz zu der Untersuchung einzelner Lebensmittel nimmt stetig zu. Generell können drei verschiedene Ansätze unterschieden werden um Ernährungsmuster herzuleiten: A priori Indizes, welche das Wissen über gesundheitsförderliche und –schädliche Eigenschaften eines Lebensmittels für einen gewissen Endpunkt nutzen; A posteriori (exploratorische) Ernährungsmuster, welche die populationsspezifischen vorliegenden Daten ohne eine vorangegangene Hypothese nutzen; gemischte Methoden, die das Wissen über bestimmte Nährstoffe oder Biomarker, welche in der Krankheitsentstehung eine Rolle spielen, nutzen und mit einer exploratorischen Methode kombinieren um krankheitsrelevante Ernährungsmuster zu generieren. Vorangegangene systematische Übersichtsarbeiten, welche die Evidenz der Assoziation zwischen Ernährungsmustern und Diabetes mellitus Typ 2 zusammenfassten, waren entweder beschränkt auf eine Mustermethode oder kombinierten die Muster verschiedener Methoden, ohne die Zusammensetzung der Ernährungsmuster zu berücksichtigen.
Ziel: Das Ziel dieser Dissertation war eine umfassende Untersuchung der Assoziation von Ernährungsmustern mit Diabetes mellitus Typ 2. Das erste Teilprojekt zielte auf die Erstellung einer systematischen Übersichtsarbeit von prospektiven Studien ab, unter der Berücksichtigung der verschiedenen Methoden zur Herleitung von Ernährungsmustern in der meta-analytischen Zusammenfassung, was in vorangegangen Übersichtsarbeiten eine Limitation darstellte. Das zweite Teilprojekt hatte die Untersuchung der Assoziation mit Diabetes mellitus Typ 2 von exploratorischen Ernährungsmustern, welche mit der Hauptkomponentenanalyse in einer multi-zentrischen europäischen Fall-Kohorten Studie hergeleitet wurden, zum Ziel. Des Weiteren wurde der eingeschränkten Anwendbarkeit von exploratorischen Mustern in anderen Studienpopulationen mit Methoden der Replikation dieser Ernährungsmuster begegnet.
Methoden: Im ersten Teilprojekt wurde eine systematische Literatursuche in den Datenbanken MEDLINE und Web of Science vorgenommen, sowie ein dreistufiger Screeningprozess. Die identifizierten Studien wurden nach den jeweiligen Methoden zur Erstellung von Ernährungsmustern zusammengefasst und Meta-Analysen nur für diejenigen Ernährungsmuster mit vergleichbarer Zusammensetzung vorgenommen. Im zweiten Teilprojekt wurden länderspezifische Ernährungsmuster mittels Hauptkomponentenanalyse aus 36 standardisierten Lebensmittelgruppen hergeleitet. Die Assoziation mit Diabetes mellitus Typ 2 Risiko wurde mit verschieden adjustierten Cox Regressionsmodellen zur Berechnung von Hazardratenverhältnissen untersucht. Die Ernährungsmuster, welche eine signifikante Assoziation mit dem Diabetesrisiko aufzeigten, wurden anschließend über alle Länder in der EPIC-InterAct Studie repliziert: Entweder wurden Summenscores ungewichteter standardisierter Lebensmittelgruppen berechnet (wenn die Korrelation mit dem originalen Ernährungsmuster r ≥ 0.90 war) oder Summenscores der Produkte von standardisierten Scoringkoeffizienten mit standardisierten Lebensmittelgruppen (wenn die Korrelation mit dem originalen Ernährungsmuster r < 0.90). Die resultierenden Scores wurden standardisiert nach der Verteilung der gesamten EPIC-InterAct Subkohorte, dann in jedem Land angewendet und die Assoziation mit Diabetes mellitus Typ 2 anhand der Cox Regressionsmodelle berechnet. Anschließend wurden Meta-Analysen zur Berechnung der gepoolten Schätzer durchgeführt.
Ergebnisse: Im ersten Teilprojekt ergab die Literatursuche 48 Artikel, welche 16 Kohorten umfassten. Die Einhaltung der Mediterranen Diät (relatives Risiko (RR) für den Vergleich der extremen Quantile: 0,87; 95%-Konfidenzintervall (KI): 0,82, 0,93), der DASH Diät (RR: 0,81; 95%-KI: 0,72, 0,92) und des Alternative Healthy Eating Index (AHEI) (RR: 0,79; 95%-KI: 0,69, 0,90) war mit einer signifikanten Reduzierung des Diabetesrisikos assoziiert. Exploratorische Ernährungsmuster, charakterisiert durch rotes und verarbeitetes Fleisch, prozessiertes Getreide, hochfette Milchprodukte, Eier und frittierte Produkte, waren positiv mit dem Diabetesrisiko assoziiert (RR: 1,44; 95%-KI: 1,27, 1,62), während Ernährungs-muster, charakterisiert durch Gemüse, Hülsenfrüchte, Obst, Geflügel und Fisch, invers mit dem Diabetesrisiko assoziiert waren (RR: 0,84; 95%-KI: 0,77, 0,91). Ernährungsmuster, welche mit reduzierter Rangregression hergeleitet wurden und charakterisiert waren durch eine hohe Aufnahme von prozessiertem Getreide, zuckergesüßten Getränken und verarbeitetem Fleisch und einen niedrigen Weinkonsum, waren alle signifikant mit dem Diabetesrisiko assoziiert. Im zweiten Teilprojekt konnten zwei wesentliche Ernährungsmuster in jedem Land mit der Hauptkomponentenanalyse hergeleitet werden. Ein Ernährungsmuster, welches in Frankreich hergeleitet wurde und charakterisiert war durch Nüsse, andere Früchte, verarbeitetes Fleisch, Fisch, Eier, Kuchen und Kekse, Kaffee und andere alkoholische Getränke, war signifikant assoziiert mit einem erniedrigten Diabetesrisiko. Drei andere Ernährungsmuster, hergeleitet in Spanien, Norfolk und Oxford, welche sich erheblich in ihrer Zusammensetzung unterschieden, waren mit einem erhöhten Diabetesrisiko assoziiert. Keine der Replikationen dieser vier Ernährungsmuster konnte die signifikante Assoziation mit Diabetes mellitus Typ 2 über andere Länder bestätigen.
Schlussfolgerung: Aus der systematischen Übersichtsarbeit ließ sich schlussfolgern, dass Ernährungsweisen gemäß der Mediterranen Diät, DASH und AHEI ein starkes Potenzial zur Prävention von Diabetes mellitus Typ 2 zu haben, obwohl sie sich in einigen Komponenten unterscheiden. Exploratorische Ernährungsmuster wurden basierend auf konkordanten Lebensmitteln gruppiert und waren signifikant mit dem Diabetesrisiko assoziiert, auch wenn die Untersuchungen einzelner Lebensmittel eher begrenzte Evidenz für einen Zusammenhang aufwiesen. Trotzdem bleiben sie populationsspezifische Beobachtungen. Das wurde auch in dem zweiten Teilprojekt unterstrichen, als länderspezifische Ernährungsmuster generiert wurden und keines der Ernährungsmuster, welches signifikant mit dem Diabetesrisiko assoziiert war, durch Simplifizierung oder Replikation der Musterstruktur des Originalmusters über alle Länder bestätigt werden konnte. Für drei RRR-Muster konnten konsistente positive Assoziationen mit dem Diabetesrisiko über verschiedene Studienpopulationen beobachtet werden.
Chloroplast membranes have a unique composition characterized by very high contents of the galactolipids, MGDG and DGDG. Many studies on constitutive, galactolipid-deficient mutants revealed conflicting results about potential functions of galactolipids in photosynthetic membranes. Likely, this was caused by pleiotropic effects such as starvation artefacts because of impaired photosynthesis from early developmental stages of the plants onward. Therefore, an ethanol inducible RNAi-approach has been taken to suppress two key enzymes of galactolipid biosynthesis in the chloroplast, MGD1 and DGD1. Plants were allowed to develop fully functional source leaves prior to induction, which then could support plant growth. Then, after the ethanol induction, both young and mature leaves were investigated over time.
Our studies revealed similar changes in both MGDG- and DGDG-deficient lines, however young and mature leaves of transgenic lines showed a different response to galactolipid deficiency. While no changes of photosynthetic parameters and minor changes in lipid content were observed in mature leaves of transgenic lines, strong reductions in total chlorophyll content and in the accumulation of all photosynthetic complexes and significant changes in contents of various lipid groups occurred in young leaves. Microscopy studies revealed an appearance of lipid droplets in the cytosol of young leaves in all transgenic lines which correlates with significantly higher levels of TAGs. Since in young leaves the production of membrane lipids is lowered, the excess of fatty acids is used for storage lipids production, resulting in the accumulation of TAGs.
Our data indicate that both investigated galactolipids serve as structural lipids since changes in photosynthetic parameters were mainly the result of reduced amounts of all photosynthetic constituents. In response to restricted galactolipid synthesis, thylakoid biogenesis is precisely readjusted to keep the proper stoichiometry and functionality of the photosynthetic apparatus. Ultimately, the data revealed that downregulation of one galactolipid triggers changes not only in chloroplasts but also in the nucleus as shown by downregulation of nuclear encoded subunits of the photosynthetic complexes.
Plastid protein biosynthesis occurs on bacterial-type 70S ribosomes consisting of a large (50S) and a small (30S) subunit. However, since many steps of ribosome biogenesis are not thermodynamically favorable at biological conditions, it requires many assembly factors. One group of assembly factors, circularly permuted GTPases, was implicated in 30S subunit maturation in E. coli, by a protein RsgA. RsgA orthologues are present in bacteria and plastid-containing species and in silico analysis revealed presence of a RsgA-like protein in Arabidopsis thaliana. To functionally characterize the Arabidopsis orthologue, two AtRsgA T-DNA insertion lines were analyzed in this study. The exon line (rsgA-e) led to embryo lethality, while the intron line (rsgA-i) caused severe dwarf, pale green phenotype. Further investigation of rsgA-i mutant line revealed defects in chloroplast biogenesis which led to increased number of chloroplasts, decreased chloroplast size, decreased air space between mesophyll cells and smaller shoot apical meristems, which showed unusual proplastid accumulation. Moreover, rsgA-i plants showed reduction in chlorophyll A and B content, decreased electron transport rate and photosynthetic efficiency. Further analyses revealed that the protein is involved in chloroplast 30S subunit maturation. Interestingly, we observed that while chloroplast-targeted and chloroplast-encoded proteins are generally downregulated in the mutant, a contrasting upregulation of the corresponding transcripts is observed, indicating an elaborate compensatory mechanism. To conclude, the study presented here reveals a ribosome assembly factor and a compensatory mechanism activated during impaired chloroplast function.
Rubisco catalyses the first step of CO2 assimilation into plant biomass. Despite its crucial role, it is notorious for its low catalytic rate and its tendency to fix O2 instead of CO2, giving rise to a toxic product that needs to be recycled in a process known as photorespiration. Since almost all our food supply relies on Rubisco, even small improvements in its specificity for CO2 could lead to an improvement of photosynthesis and ultimately, crop yield. In this work, we attempted to improve photosynthesis by decreasing photorespiration with an artificial CCM based on a fusion between Rubisco and a carbonic anhydrase (CA).
A preliminary set of plants contained fusions between one of two CAs, bCA1 and CAH3, and the N- or C-terminus of RbcL connected by a small flexible linker of 5 amino acids. Subsequently, further fusion proteins were created between RbcL C-terminus and bCA1/CAH3 with linkers of 14, 23, 32, and 41 amino acids. The transplastomic tobacco plants carrying fusions with bCA1 were able to grow autotrophically even with the shortest linkers, albeit at a low rate, and accumulated very low levels of the fusion protein. On the other hand, plants carrying fusions with CAH3 were autotrophic only with the longer linkers. The longest linker permitted nearly wild-type like growth of the plants carrying fusions with CAH3 and increased the levels of fusion protein, but also of smaller degradation products.
The fusion of catalytically inactive CAs to RbcL did not cause a different phenotype from the fusions with catalytically active CAs, suggesting that the selected CAs were not active in the fusion with RbcL or their activity did not have an effect on CO2 assimilation. However, fusions to RbcL did not abolish RbcL catalytic activity, as shown by the autotrophic growth, gas exchange and in vitro activity measurements. Furthermore, Rubisco carboxylation rate and specificity for CO2 was not altered in some of the fusion proteins, suggesting that despite the defect in RbcL folding or assembly caused by the fusions, the addition of 60-150 amino acids to RbcL does not affect its catalytic properties. On the contrary, most growth defects of the plants carrying RbcL-CA fusions are related to their reduced Rubisco content, likely caused by impaired RbcL folding or assembly. Finally, we found that fusions with RbcL C-terminus were better tolerated than with the N-terminus, and increasing the length of the linker relieved the growth impairment imposed by the fusion to RbcL. Together, the results of this work constitute considerable relevant findings for future Rubisco engineering.
Plant cells host two important organelles: mitochondria, known as the cell’s ‘powerhouse’, which act by converting oxygen and nutrients into ATP, and plastids, which perform photosynthesis. These organelles contain their own genomes that encode proteins required for gene expression and energy metabolism. Transformation technologies offer great potential for investigating all aspects of the physiology and gene expression of these organelles in vivo. In addition, organelle transformation can be a valuable tool for biotechnology and molecular plant breeding. Plastid transformation systems are well-developed for a few higher plants, however, mitochondrial transformation has so far only been reported for Saccharomyces cerevisiae and the unicellular alga Chlamydomonas reinhardtii.
Development of an efficient new selection marker for plastid transformation is important for several reasons, including facilitating supertransformation of the plastid genome for metabolic engineering purposes and for producing multiple knock-outs or site-directed mutagenesis of two unlinked genes. In this work, we developed a novel selection system for Nicotiana tabacum (tobacco) chloroplast transformation with an alternative marker. The marker gene, aac(6′)-Ie/aph(2′′)-Ia, was cloned into different plastid transformation vectors and several candidate aminoglycoside antibiotics were investigated as selection agents. Generally, the efficiency of selection and the transformation efficiency with aac(6′)-Ie/aph(2′′)-Ia as selectable marker in combination with the aminoglycoside antibiotic tobramycin was similarly high as that with the standard marker gene aadA and spectinomycin selection. Furthermore, our new selection system may be useful for the development of plastid transformation for new species, including cereals, the world’s most important food crops, and could also be helpful for the establishment of a selection system for mitochondrial transformation.
To date, all attempts to achieve mitochondrial transformation for higher plants have been unsuccessful. A mitochondrial transformation system for higher plants would not only provide a potential for studying mitochondrial physiology but could also provide a method to introduce cytoplasmic male sterility into crops to produce hybrid seeds. Establishing a stable mitochondrial transformation system in higher plants requires several steps including delivery of foreign DNA, stable integration of the foreign sequences into the mitochondrial genome, efficient expression of the transgene, a highly regenerable tissue culture system that allows regeneration of the transformed cells into plants, and finally, a suitable selection system to identify cells with transformed mitochondrial genomes. Among all these requirements, finding a good selection is perhaps the most important obstacle towards the development of a mitochondrial transformation system for higher plants. In this work, two selection systems were tested for mitochondrial transformation: kanamycin as a selection system in combination with the antibiotic-inactivating marker gene nptII, and sulfadiazine as a selection agent that inhibits the folic acid biosynthesis pathway residing in plant mitochondria in combination with the sul gene encoding an enzyme that is insensitive to inhibition by sulfadiazine. Nuclear transformation experiments were considered as proof of the specificity of the sulfadiazine selection system for mitochondria. We showed that an optimized sulfadiazine selection system, with the Sul protein targeted to mitochondria, is much more efficient than the previous sulfadiazine selection system, in which the Sul protein was targeted to the chloroplast. We also showed by systematic experiments that the efficiency of selection and nuclear transformation of the optimized sulfadiazine selection was higher compared to the standard kanamycin selection system. Finally, we also investigated the suitability of this selection system for nuclear transformation of the model alga Chlamydomonas reinhardtii, obtaining promising results. Although we designed several mitochondrial transformation vectors with different expression elements and integration sites in the mitochondrial genome based on the sulfadiazine system, and different tissue culture condition were also considered, we were not able to obtain mitochondrial transformation with this system. Nonetheless, establishing the sul gene as an efficient and specific selection marker for mitochondria addresses one of the major bottlenecks and may pave the way to achieve mitochondrial transformation in higher plants.