Newest publications
Reintroduction strategies for rare arable weeds in agricultural practice and their influence on yield
(2024) Schumacher, Matthias; Witty, Rosa; Gerhards, Roland; Schumacher, Matthias; Department of Weed Science, Institute of Phytomedicine (360), University of Hohenheim, Stuttgart, Germany; Witty, Rosa; Department of Weed Science, Institute of Phytomedicine (360), University of Hohenheim, Stuttgart, Germany; Gerhards, Roland; Department of Weed Science, Institute of Phytomedicine (360), University of Hohenheim, Stuttgart, Germany
Agricultural intensification and changing landscape structure led to decreasing numbers of arable flora and fauna during the last decades. To counteract these declines, arable plant diversity needs to be restored. It is important to promote regional plant communities including endangered species to ensure adaption to agricultural landscapes. Therefore, this study examines the development of arable plant diversity, crop yield and the reintroduction success of rare arable plants (RAPs) under different practical farming strategies in cereals from 2019 to 2021 in southwestern Germany. Farming strategies varied regarding weed control intensity (none, mechanical, herbicide with and without efficiency gap), fertilisation (mineral and none) and row spacing (12.5 cm and 20 cm). Additionally, two different seed mixtures containing RAP and common species were used for reintroduction: one commercially available and another self‐composed. Reintroduction success was quite high with more than 80% establishment rate. Species numbers doubled in all treatments over time, except the one with herbicide application, with on average 8–10 species emerging from the soil seed bank. Reintroduction of RAP increased arable plant species richness further up to 37 species. The site‐adapted mixture showed in the end a site‐typical weed community. Yield was significantly lower in treatments with reintroduction via sown mixtures and no weed control, losing on average 65% yield. The reintroduction of RAP was successful and accompanied by an increasing floral diversity, however, with a simultaneous yield loss. Financial incentives or subsidies are therefore still necessary to compensate yield loss for reintroduction and conservation efforts.
Influence of different storage atmospheres in packaging on color stability of beef
(2024) Krell, Johannes; Poveda‐Arteaga, Alejandro; Weiss, Jochen; Witte, Franziska; Terjung, Nino; Gibis, Monika; Krell, Johannes; Department of Food Material Science, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany; Poveda‐Arteaga, Alejandro; DIL, German Institute of Food Technology, Quakenbrück, Germany; Weiss, Jochen; Department of Food Material Science, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany; Witte, Franziska; DIL, German Institute of Food Technology, Quakenbrück, Germany; Terjung, Nino; DIL, German Institute of Food Technology, Quakenbrück, Germany; Gibis, Monika; Department of Food Material Science, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany
The influence of storage atmosphere on the color development and myoglobin (Mb) redox state of beef was investigated. Beef samples were packaged in 6 different atmospheres including different degrees of vacuum, levels of oxygen, nitrogen, and a mixture with 20% CO2 and stored at 2°C for 14 days. Over this time, color and reflection of the packaged samples were measured. The used method allows quick, easy, and non‐invasive measurement of the packaged samples, without using time consuming chemical assays. The method could be implemented in beef production lines, with potential for automatization. The data was used to illustrate the L*a*b* values for insights regarding qualitative color changes. Quantitative color changes were analyzed by calculation of color difference ΔE2000. Additionally, the relative levels of the deoxymyoglobin (DMb), oxymyoglobin (OMb) and metmyoglobin (MMb) were calculated from reflection spectra. The most important findings are: there is a strong correlation (rsp = 0.80 to 0.99 with one exception at rsp = 0.69 (high vacuum), p ≤ 0.05) between a* values and relative OMb levels. Storage atmospheres containing high oxygen concentrations lead to an attractive meat color, but a decreased overall color and Mb stability (ΔE = 5.02 (synthetic air) and ΔE = 2.23 (high oxygen) after 14 days of storage). Vacuum packaged samples are most stable in regards of color and Mb stability (ΔE = 1.79 (high vacuum) and ΔE = 1.63 (low vacuum) after 14 days of storage), but lack in the vibrant red color desired for sale. The experiments showed that color measurement can be a fast, non‐invasive marker for meat quality.Practical ApplicationIn this research article, six different storage atmospheres are compared regarding their influence on color stability and color quality of beef during storage in packaging. The results suggest which atmospheres to use in various sales‐related scenarios. The method described can easily be applied in the meat industry to quickly monitor changes during storage and wet‐aging without damaging the meat or opening the meat packages.
Nonadditive gene expression contributing to heterosis in partially heterozygous maize hybrids is predominantly regulated from heterozygous regions
(2025) Pitz, Marion; Baldauf, Jutta A.; Piepho, Hans‐Peter; Hochholdinger, Frank; Pitz, Marion; Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn, Germany; Baldauf, Jutta A.; Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn, Germany; Piepho, Hans‐Peter; Biostatistics Unit, Institute of Crop Science, University of Hohenheim, Stuttgart, Germany; Hochholdinger, Frank; Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn, Germany
Hybrids often perform better than their homozygous parents, a phenomenon that is commonly referred to as heterosis. Heterosis is widely utilized in modern agriculture, although its molecular basis is not very well understood. In this study, we backcrossed an intermated recombinant inbred line population of maize ( Zea mays L.) with its parental inbred lines B73 and Mo17. The resulting hybrids exhibited different degrees of heterozygosity and heterosis. We identified nonadditively expressed genes, which are expressed differently from their mid‐parental level. In addition, we surveyed their regulation by investigating expression quantitative trait loci (eQTL). Nonadditively expressed genes explain up to 27% of heterotic variance in the backcross hybrids. Furthermore, nonadditively expressed genes are regulated almost exclusively from heterozygous regions of the genome. We observed that nonadditive expression patterns are distinctly regulated depending on the genetic origin of the higher expressed parent. As a consequence, these regulatory regimes lead to higher gene activity in most nonadditively expressed genes in the hybrids. We demonstrated that nonadditive expression patterns contribute to heterosis and their mode of regulation might translate phylogenetic distance into vigorous hybrids. Based on our results, we hypothesize that diverging regulatory preferences in inbred lines are beneficial for selecting parental combinations for hybrid breeding.
Human-mediated migration of plants, their pathogens and parasites
(2024) Miedaner, Thomas; Garbelotto, Matteo M.; Miedaner, Thomas; State Plant Breeding Institute, University of Hohenheim, Fruwirthstr. 21, 70599, Stuttgart, Germany; Garbelotto, Matteo M.; Department of Environmental Science, Policy and Management, University of California-Berkeley, 94720, Berkeley, CA, USA
The adoption of agriculture in several parts of the world during the early Neolithic period led to a fundamental change in human migration. By introducing newly domesticated crops into new environments, pathogens and parasites were also inadvertently transferred from their regions of origin and underwent a considerable population growth. In the newly settled regions, some pests of indigenous plants adapted to new crops by host switching. This review is limited to three basic migration events and mainly to agricultural crops of the temperate zone: (1) the migration of the first farmers from SE Asia to Europe, (2) European expansion from the 16th century onward, (3) modern globalization since the 20th century. Molecular analyses offer the opportunity to study the evolutionary history of pest populations, their origin and dynamics and their spread around the world. Cereals’ rusts and powdery mildew, storage insects were the first to spread with wheat species, barley, and pulses from the Levant across Eurasia. The Columbian exchange of crops to and from the Americas brought entirely new pests to Europe while old world pathogens spread to the Americas and subsequently to all other regions colonized by Europeans. Modern globalization further facilitated the spread of pathogens and insects worldwide, as previously inconceivable amounts of agricultural products, business travelers, and maybe tourists have elevated global accessibility. This is illustrated by case studies based on fungi and insects. In the near future, pests will have colonized all crops in all countries where they can exist according to their agro-climatic requirements.
Genetic code expansion for controlled surfactin production in a high cell-density Bacillus subtilis strain
(2025) Hermann, Alexander; Hiller, Eric; Hubel, Philipp; Biermann, Lennart; Benatto Perino, Elvio Henrique; Kuipers, Oscar Paul; Hausmann, Rudolf; Lilge, Lars; Hermann, Alexander; Department of Bioprocess Engineering, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (A.H.); (E.H.); (L.B.); (E.H.B.P.); (R.H.); Hiller, Eric; Department of Bioprocess Engineering, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (A.H.); (E.H.); (L.B.); (E.H.B.P.); (R.H.); Hubel, Philipp; Core Facility Hohenheim, Mass Spectrometry Core Facility, University of Hohenheim, 70599 Stuttgart, Germany;; Biermann, Lennart; Department of Bioprocess Engineering, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (A.H.); (E.H.); (L.B.); (E.H.B.P.); (R.H.); Benatto Perino, Elvio Henrique; Department of Bioprocess Engineering, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (A.H.); (E.H.); (L.B.); (E.H.B.P.); (R.H.); Kuipers, Oscar Paul; Department of Molecular Genetics, University of Groningen, 9747 AG Groningen, The Netherlands;; Hausmann, Rudolf; Department of Bioprocess Engineering, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (A.H.); (E.H.); (L.B.); (E.H.B.P.); (R.H.); Lilge, Lars; Department of Bioprocess Engineering, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (A.H.); (E.H.); (L.B.); (E.H.B.P.); (R.H.); Fouillaud, Mireille
Background: In biotechnology, B. subtilis is established for heterologous protein production. In addition, the species provides a variety of bioactive metabolites, including the non-ribosomally produced surfactin lipopeptide. However, to control the formation of the target product-forming enzyme, different expression systems could be introduced, including the principle of genetic code expansion by the incorporation of externally supplied non-canonical amino acids. Methods: Integration of an amber stop codon into the srfA operon and additional chromosomal integration of an aminoacyl-tRNA synthetase/tRNA mutant pair from Methanococcus jannaschii enabled site-directed incorporation of the non-canonical amino acid O-methyl-L-tyrosine (OMeY). In different fed-batch bioreactor approaches, OMeY-associated surfactin production was quantified by high-performance thin-layer chromatography (HPTLC). Physiological adaptations of the B. subtilis production strain were analyzed by mass spectrometric proteomics. Results: Using a surfactin-forming B. subtilis production strain, which enables high cell density fermentation processes, the principle of genetic code expansion was introduced. Accordingly, the biosynthesis of the surfactin-forming non-ribosomal peptide synthetase (NRPS) was linked to the addition of the non-canonical amino acid OMeY. In OMeY-associated fed-batch bioreactor fermentation processes, a maximum surfactin titre of 10.8 g/L was achieved. In addition, the effect of surfactin induction was investigated by mass spectrometric proteome analyses. Among other things, adaptations in the B. subtilis motility towards a more sessile state and increased abundances of surfactin precursor-producing enzymes were detected. Conclusions: The principle of genetic code expansion enabled a precise control of the surfactin bioproduction as a representative of bioactive secondary metabolites in B. subtilis . This allowed the establishment of inducer-associated regulation at the post-transcriptional level with simultaneous use of the native promoter system. In this way, inductor-dependent control of the production of the target metabolite-forming enzyme could be achieved.