New papers from Poppenberger lab.
Cold stress signaling in female reproductive tissues.
Plant Cell Environ 2018 Jul 25.
Pablo Albertos, Konstantin Wagner, and Brigitte Poppenberger
Cold stress is a significant threat for plant productivity and impacts on plantdistribution and crop production, particularly so when it occurs during the growthphase. A developmental stage at risk is that of flowering, since a single stress eventduring sensitive stages, such as the full?bloom stage of fruit trees can be fatal forreproductive success. Although pollen development and fertilization are widelyviewed as the most critical reproductive phases, the development and function offemale reproductive tissues, which in Angiosperms are embedded in the gynoecium,are also affected by cold stress. Today however, we have essentially no understandingof the cold stress response pathways that act during floral organogenesis. In thisreview, we briefly summarize our current knowledge of cold stress signalling modulesactive in vegetative tissues that may provide a framework of general principles alsotransferable to female reproductive tissues. We then align these signalling cascadeswith those that govern gynoecium development to identify factors that may act inboth processes and could thereby contribute to cold stress responses in femalereproductive tissues.Cold stress is a significant threat for plant productivity and impacts on plantdistribution and crop production, particularly so when it occurs during the growthphase. A developmental stage at risk is that of flowering, since a single stress eventduring sensitive stages, such as the full?bloom stage of fruit trees can be fatal forreproductive success. Although pollen development and fertilization are widelyviewed as the most critical reproductive phases, the development and function offemale reproductive tissues, which in Angiosperms are embedded in the gynoecium,are also affected by cold stress. Today however, we have essentially no understandingof the cold stress response pathways that act during floral organogenesis. In thisreview, we briefly summarize our current knowledge of cold stress signalling modulesactive in vegetative tissues that may provide a framework of general principles alsotransferable to female reproductive tissues. We then align these signalling cascadeswith those that govern gynoecium development to identify factors that may act inboth processes and could thereby contribute to cold stress responses in femalereproductive tissues. Cold stress is a significant threat for plant productivity and impacts on plantdistribution and crop production, particularly so when it occurs during the growthphase. A developmental stage at risk is that of flowering, since a single stress eventduring sensitive stages, such as the full?bloom stage of fruit trees can be fatal forreproductive success. Although pollen development and fertilization are widelyviewed as the most critical reproductive phases, the development and function offemale reproductive tissues, which in Angiosperms are embedded in the gynoecium,are also affected by cold stress. Today however, we have essentially no understandingof the cold stress response pathways that act during floral organogenesis. In thisreview, we briefly summarize our current knowledge of cold stress signalling modulesactive in vegetative tissues that may provide a framework of general principles alsotransferable to female reproductive tissues. We then align these signalling cascadeswith those that govern gynoecium development to identify factors that may act inboth processes and could thereby contribute to cold stress responses in femalereproductive tissues.
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Quantification of Glutamate and Aspartate by Ultra-High Performance Liquid Chromatography.
Molecules, 23(6), 1389
Carlos Agius, Sabine von Tucher, Brigitte Poppenberger, and Wilfried Rozhon
Glutamic and aspartic acid fulfil numerous functions in organisms. They are proteinogenic amino acids, they function as neurotransmitters, and glutamic acid links the citrate cycle with amino acid metabolism. In addition, glutamic acid is a precursor for many bioactive molecules like ?-aminobutyric acid (GABA). In tomatoes, glutamic acid accumulates in ripening fruits. Here we present a simple and rapid method for quantification of glutamate and aspartate in tomatoes. A cleared extract is prepared and 2-aminoadipic acid added as internal standard. Subsequently, the amino acids are derivatised with 2,4-dinitro-1-fluorobenzene under alkaline conditions. The derivatives are separated by ultra-high performance liquid chromatography using a phenyl-hexyl column and 50 mM N-methylmorpholine/acetate buffer pH 7.4 containing 12% acetonitrile as eluent and detected by UV absorption at 363 nm. The whole analysis time including separation and column equilibration takes less than 2.8 min with a flow rate of 1 mL/min and less than 1.6 min with a flow rate of 2 mL/min, making this method suitable for high-throughput applications. The method shows excellent reproducibility with intra- and inter-day SDs of approximately 4% for both aspartic and glutamic acid. Using this method we show that the glutamate/aspartate ratio changes significantly during fruit ripening.
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Quantification of sugars and organic acids in tomato fruits.
MethodsX 5, 537-550
Carlos Agius, Sabine von Tucher, Brigitte Poppenberger, and Wilfried Rozhon
Sugar and organic acid contents are major factors for tomato fruit flavour and are important breeding traits. Here we provide an improved protocol for accurate quantification of the main sugars, glucose and fructose, and the organic acids, citric acid and malic acid, present in tomato. The tomato extract is spiked with lactose and tricarballylic acid as internal standards and loaded onto a NH2 solid phase extraction (SPE) column. The sugars appear in the flow-through and are subsequently analysed by HPLC using a Nucleodur NH2 column and a refractive index detector. The organic acids bind to the SPE column and are eluted with 400?mM phosphoric acid. For analysis, the organic acids are separated by HPLC using a Nucleodur C18ec column and detected by UV absorption at 210?nm. The method shows excellent inter-day and intra-day reproducibility for glucose, fructose and citric acid with standard deviations of 1–5%. Quantification of citric acid by HPLC and GC–MS showed perfect agreement with a deviation of less than 3%.
