@article{WitzelStrehmelBaldermannetal.2017, author = {Witzel, Katja and Strehmel, Nadine and Baldermann, Susanne and Neugart, Susanne and Becker, Yvonne and Becker, Matthias and Berger, Beatrice and Scheel, Dierk and Grosch, Rita and Schreiner, Monika and Ruppel, Silke}, title = {Arabidopsis thaliana root and root exudate metabolism is altered by the growth-promoting bacterium Kosakonia radicincitans DSM 16656(T)}, series = {Plant and soil}, volume = {419}, journal = {Plant and soil}, publisher = {Springer}, address = {Dordrecht}, issn = {0032-079X}, doi = {10.1007/s11104-017-3371-1}, pages = {557 -- 573}, year = {2017}, abstract = {Plant growth-promoting bacteria (PGPB) affect host physiological processes in various ways. This study aims at elucidating the dependence of bacterial-induced growth promotion on the plant genotype and characterizing plant metabolic adaptations to PGPB. Eighteen Arabidopsis thaliana accessions were inoculated with the PGPB strain Kosakonia radicincitans DSM 16656(T). Colonisation pattern was assessed by enhanced green fluorescent protein (eGFP)-tagged K. radicincitans in three A. thaliana accessions differing in their growth response. Metabolic impact of bacterial colonisation was determined for the best responding accession by profiling distinct classes of plant secondary metabolites and root exudates. Inoculation of 18 A. thaliana accessions resulted in a wide range of growth responses, from repression to enhancement. Testing the bacterial colonisation of three accessions did not reveal a differential pattern. Profiling of plant secondary metabolites showed a differential accumulation of glucosinolates, phenylpropanoids and carotenoids in roots. Analysis of root exudates demonstrated that primary and secondary metabolites were predominantly differentially depleted by bacterial inoculation. The plant genotype controls the bacterial growth promoting traits. Levels of lutein and beta-carotene were elevated in inoculated roots. Supplementing a bacterial suspension with beta-carotene increased bacterial growth, while this was not the case when lutein was applied, indicating that beta-carotene could be a positive regulator of plant growth promotion.}, language = {en} } @article{NeugartBaldermannNgweneetal.2017, author = {Neugart, Susanne and Baldermann, Susanne and Ngwene, Benard and Wesonga, John and Schreiner, Monika}, title = {Indigenous leafy vegetables of Eastern Africa - A source of extraordinary secondary plant metabolites}, series = {Food research international}, volume = {100}, journal = {Food research international}, publisher = {Elsevier}, address = {Amsterdam}, organization = {The e-ASTROGAM Collaboration}, issn = {0963-9969}, doi = {10.1016/j.foodres.2017.02.014}, pages = {411 -- 422}, year = {2017}, abstract = {Indigenous African leafy vegetables vary enormously in their secondary plant metabolites whereat genus and the species have a great impact. In African nightshade (Solanum scabrum), spiderplant (Cleome gynandra), amaranth (Amaranthus cruentus), cowpea (Vigna unguiculata), Ethiopian kale (Brassica carinata) and common kale (Brassica oleracea) the specific secondary metabolite profile was elucidated and gained detailed data about carotenoids, chlorophylls, glucosinolates and phenolic compounds all having an appropriate contribution to health beneficial properties of indigenous African leafy vegetables. Exemplarily, various quercetin glycosides such as quercetin-3-rutinoside occur in high concentrations in African nightshade, spiderplant, and amaranth between similar to 1400-3300 mu g/g DW. Additionally the extraordinary hydroxydnnamic acid derivatives such as glucaric isomers and isocitric acid isomers are found especially in amaranth (up to similar to 1250 mu g/g DW) and spiderplant (up to 120 mu g/g DW). Carotenoids concentrations are high in amaranth (up to 101.7 mu g/g DW) and spiderplants (up to 64.7 mu g/g DW) showing high concentrations of beta-carotene, the pro-vitamin A. In contrast to the ubiquitous occurring phenolics and carotenoids, glucosinolates are only present in the Brassicales species Ethiopian kale, common kale and spiderplant characterized by diverse glucosinolate profiles. Generally, the consumption of a variety of these indigenous African leafy vegetables can be recommended to contribute to different benefits such as antioxidant activity, increase pro-vitamin A and anticancerogenic compounds in a healthy diet. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{NgweneNeugartBaldermannetal.2017, author = {Ngwene, Benard and Neugart, Susanne and Baldermann, Susanne and Ravi, Beena and Schreiner, Monika}, title = {Intercropping Induces Changes in Specific Secondary Metabolite Concentration in Ethiopian Kale (Brassica carinata) and African Nightshade (Solanum scabrum) under Controlled Conditions}, series = {Frontiers in plant science}, volume = {8}, journal = {Frontiers in plant science}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-462X}, doi = {10.3389/fpls.2017.01700}, pages = {12}, year = {2017}, abstract = {Intercropping is widespread in small-holder farming systems in tropical regions and is also practiced in the cultivation of indigenous vegetables, to alleviate the multiple burdens of malnutrition. Due to interspecific competition and/or complementation between intercrops, intercropping may lead to changes in plants accumulation of minerals and secondary metabolites and hence, alter nutritional quality for consumers. Intercropping aims to intensify land productivity, while ensuring that nutritional quality is not compromised. This study aimed to investigate changes in minerals and secondary plant metabolites in intercropped Brassica carinata and Solanum scabrum, two important African indigenous vegetables, and evaluated the suitability of this combination for dryer areas. B. carinata and S. scabrum were grown for 6 weeks under controlled conditions in a greenhouse trial. Large rootboxes (8000 cm(3) volume) were specifically designed for this experiment. Each rootbox was planted with two plants, either of the same plant species (mono) or one of each plant species (mixed). A quartz sand/soil substrate was used and fertilized adequately for optimal plant growth. During the last 4 weeks of the experiment, the plants were either supplied with optimal (65\% WHC) or low (30\% WHC) irrigation, to test the effect of a late-season drought. Intercropping increased total glucosinolate content in B. carinata, while maintaining biomass production and the contents of other health related minerals in both B. carinata and S. scabrum. Moreover, low irrigation led to an increase in carotene accumulation in both mono and intercropped S. scabrum, but not in B. carinata, while the majority of kaempferol glycosides and hydroxycinnamic acid derivatives of both species were decreased by intercropping and drought treatment. This study indicates that some health-related phytochemicals can be modified by intercropping or late-season drought, but field validation of these results is necessary before definite recommendation can be made to stakeholders.}, language = {en} }