Isoflavone production in hairy root cultures and plantlets of Trifolium pratense

International audienc

Metabolite profiling and cytotoxic activity of Andean potatoes: polyamines and glycoalkaloids as potential anticancer agents in human neuroblastoma cells in vitro

Andean potatoes (Solanum tuberosum L. ssp. andigena) are a good source of dietary antioxidant polyphenols. We have previously demonstrated that polyphenol extracts from Andean potato tubers exerted a dose-dependent cytotoxic effect in human neuroblastoma SH-SY5Y cells, being skin extracts more potent than flesh ones. In order to gain insight into the bioactivities of potato phenolics, we investigated the composition and the in vitro cytotoxic activity of total extracts and fractions of skin and flesh tubers of three Andean potato cultivars (Santa María, Waicha, and Moradita). Potato total extracts were subjected to liquid-liquid fractionation using ethyl acetate solvent in organic and aqueous fractions. We analyzed both fractions by HPLC-DAD, HPLC-ESI-MS/MS, and HPLC-HRMS. Results corroborated the expected composition of each fraction. Organic fractions were rich in hydroxycinnamic acids (principally chlorogenic acid isomers), whereas aqueous fractions contained mainly polyamines conjugated with phenolic acids, glycoalkaloids, and flavonoids. Organic fractions were not cytotoxic against SH-SY5Y cells, and indeed, some increased cellular metabolism compared to controls. Aqueous fractions were cytotoxic and even more potent than their respective total extracts. Treatment with a combination of both fractions showed a similar cytotoxic response to the corresponding extract. According to correlation studies, it is tempting to speculate that polyamines and glycoalkaloids are crucial in inducing cell death. Our findings indicate that the activity of Andean potato extracts is a combination of various compounds and contribute to the revalorization of potato as a functional food.Fil: Lanteri, Maria Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Silveyra, María Ximena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Morán, Mónica Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Boutet Mercey, Stéphanie. Centre National de la Recherche Scientifique; Francia. l'Institut national de recherche pour l'agriculture, l'alimentation et l'environnement; FranciaFil: Solis Gozar, Deyvis Dante. Centre National de la Recherche Scientifique; Francia. l'Institut national de recherche pour l'agriculture, l'alimentation et l'environnement; FranciaFil: Perreau, François. Centre National de la Recherche Scientifique; Francia. l'Institut national de recherche pour l'agriculture, l'alimentation et l'environnement; FranciaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin

The Arabidopsis thaliana lectin receptor kinase LecRK-I.9 is required for full resistance to Pseudomonas syringae and affects jasmonate signalling

On microbial attack, plants can detect invaders and activate plant innate immunity. For the detection of pathogen molecules or cell wall damage, plants employ receptors that trigger the activation of defence responses. Cell surface proteins that belong to large families of lectin receptor kinases are candidates to function as immune receptors. Here, the function of LecRK-I.9 (At5g60300), a legume-type lectin receptor kinase involved in cell wall-plasma membrane contacts and in extracellular ATP (eATP) perception, was studied through biochemical, gene expression and reverse genetics approaches. In Arabidopsis thaliana, LecRK-I.9 expression is rapidly, highly and locally induced on inoculation with avirulent strains of Pseudomonas syringae pv. tomato (Pst). Two allelic lecrk-I.9 knock-out mutants showed decreased resistance to Pst. Conversely, over-expression of LecRK-I.9 led to increased resistance to Pst. The analysis of defence gene expression suggests an alteration of both the salicylic acid (SA) and jasmonic acid (JA) signalling pathways. In particular, LecRK-I.9 expression during plant-pathogen interaction was dependent on COI1 (CORONATINE INSENSITIVE 1) and JAR1 (JASMONATE RESISTANT 1) components, and JA-responsive transcription factors (TFs) showed altered levels of expression in plants over-expressing LecRK-I.9. A similar misregulation of these TFs was obtained by JA treatment. This study identified LecRK-I.9 as necessary for full resistance to Pst and demonstrated its involvement in the control of defence against pathogens through a regulation of JA signalling components. The role of LecRK-I.9 is discussed with regard to the potential molecular mechanisms linking JA signalling to cell wall damage and/or eATP perception.</p

Supercritical fluid chromatography coupled to mass spectrometry for lipidomics

International audienceSupercritical fluid chromatography (SFC) has experienced a particular revival in recent years thanks to the development of robust and efficient commercial systems. Because of its physico-chemical properties, supercritical carbon dioxide (CO2 ) mixed with cosolvents and additives is particularly suitable for SFC to allow the elution of compounds of different polarities and more particularly complex lipids. Hyphenation with mass spectrometry (MS) is increasingly described in the literature but still requires many further developments in order to be as user-friendly as coupling with liquid chromatography. The basic concepts of SFC and MS hyphenation will be first considered. Then a representative example of method development in lipidomics will be introduced. In conclusion, the challenges and future needs in this field of research will be discussed

Supercritical fluid chromatography coupled to mass spectrometry for lipidomics

International audienceSupercritical fluid chromatography (SFC) has experienced a particular revival in recent years thanks to the development of robust and efficient commercial systems. Because of its physico-chemical properties, supercritical carbon dioxide (CO2 ) mixed with cosolvents and additives is particularly suitable for SFC to allow the elution of compounds of different polarities and more particularly complex lipids. Hyphenation with mass spectrometry (MS) is increasingly described in the literature but still requires many further developments in order to be as user-friendly as coupling with liquid chromatography. The basic concepts of SFC and MS hyphenation will be first considered. Then a representative example of method development in lipidomics will be introduced. In conclusion, the challenges and future needs in this field of research will be discussed

Overexpression of a Cytochrome P450 Monooxygenase Involved in Orobanchol Biosynthesis Increases Susceptibility to Fusarium Head Blight

International audienceFusarium Head Blight (FHB) is a cereal disease caused primarily by the ascomycete fungus Fusarium graminearum with public health issues due to the production of mycotoxins including deoxynivalenol (DON). Genetic resistance is an efficient protection means and numerous quantitative trait loci have been identified, some of them related to the production of resistance metabolites. In this study, we have functionally characterized the Brachypodium distachyon BdCYP711A29 gene encoding a cytochrome P450 monooxygenase (CYP). We showed that BdCYP711A29 belongs to an oligogenic family of five members. However, following infection by F. graminearum , BdCYP711A29 is the only copy strongly transcriptionally induced in a DON-dependent manner. The BdCYP711A29 protein is homologous to the Arabidopsis thaliana MAX1 and Oryza sativa MAX1-like CYPs representing key components of the strigolactone biosynthesis. We show that BdCYP711A29 is likely involved in orobanchol biosynthesis. Alteration of the BdCYP711A29 sequence or expression alone does not modify plant architecture, most likely because of functional redundancy with the other copies. B. distachyon lines overexpressing BdCYP711A29 exhibit an increased susceptibility to F. graminearum , although no significant changes in defense gene expression were detected. We demonstrate that both orobanchol and exudates of Bd711A29 overexpressing lines stimulate the germination of F. graminearum macroconidia. We therefore hypothesize that orobanchol is a susceptibility factor to FHB

The <i>lif2</i> mutants are less susceptible to <i>P. syringae</i> infection.

<p>(A) Bacterial growth of the virulent DC3000 strain in wild-type (WT) and <i>lif2-1</i> rosette leaves at 24 hours post-inoculation (hpi). (B) Rosette leaves imaged 5 days post-inoculation (dpi) with the virulent DC3000 strain. The <i>lif2-1</i> and <i>lif2-3</i> plants had similar responses, whereas the complemented <i>lif2-1</i> mutant (<i>lif2-c</i>) behaved similarly to WT plants. Four independent experiments were performed with similar results. (C) Bacterial growth of the avirulent DC3000 <i>avrRpm1</i> strain in rosette leaves at 24 hpi. For bacterial growth experiments, each data point represents the mean value from at least thirty leaves. Similar results were obtained in two independent experiments. The bars represent standard deviation. (Student's t-test, * p<0,05).</p