Christoph Böttcher

Quantifying biochemical quality parameters in carrots (Daucus carota L.) - FT-Raman spectroscopy as efficient tool for rapid metabolite profiling.

Application of FT-Raman spectroscopy for simultaneous quantification of carotenoids, carbohydrates, polyacetylenes and phenylpropanoids with high bioactive potential was investigated in storage roots of Daucus carota. Within single FT-Raman experiment carbohydrates, carotenoids, and polyacetylenes could be reliably quantified with high coefficients of determination of R(2)>0.91. The most abundant individual representatives of each compound class could be quantified with comparably high quality resulting in R(2)=0.97 and 0.96 for α-carotene and β-carotene, in R(2)=0.90 for falcarindiol (FaDOH), R(2)=0.99, 0.98 and 0.96 for fructose, glucose and sucrose. In contrast, application of FT-Raman spectroscopy for quantification of two laserine-type phenylpropanoids was investigated but failed due to low concentration and Raman response. Furthermore, evaluation of metabolic profiles by principle component analysis (PCA) revealed metabolic variety of carrot root composition depending on root color and botanical relationship.

Nicht zielgerichtetes Metabolom-Profiling von grünenBlütenknospen bei Raps: Screening auf Resistenz gegen den Rapsglanzkäfer

Recent studies on endophytic Kosakonia radicincitans DSM 16656T demonstrated a wide plant growth-promoting activity. The application of this Gram-negative bacterium as a biofertilizer is limited due to the lack of adequate formulation that protects the cells during drying and storage and supports plant colonization. Here we set out to elucidate the compatible solutes accumulation influence of K. radicincitans triggered by osmotic stress on its capacity as an endophyte in radish plants. We found that physiological modifications by osmotic stress treatments and accumulation of compatible solutes during cultivation, improve the capability of K. radicincitans formulated in dry beads to colonize and to promote radish growth. Thus, pre-conditioning of cells with NaCl 4% and by adding compatible solutes such as hydroxyectoine during cultivation induced a positive effect on relative gene expression response, enhancing significantly the ability to colonize plant tissue up to 10 fold. Additionally, when this osmolyte was added, either dry matter of tuber or leaves increased by 3 % and 13.59 %, respectively in comparison to beads without the bacterium. These first results indicate that a systematic approach to cultivation and formulation may increase the endophytic capacity of this bacterium.