TY - JOUR A1 - Witzel, Katja A1 - Strehmel, Nadine A1 - Baldermann, Susanne A1 - Neugart, Susanne A1 - Becker, Yvonne A1 - Becker, Matthias A1 - Berger, Beatrice A1 - Scheel, Dierk A1 - Grosch, Rita A1 - Schreiner, Monika A1 - Ruppel, Silke T1 - Arabidopsis thaliana root and root exudate metabolism is altered by the growth-promoting bacterium Kosakonia radicincitans DSM 16656(T) JF - Plant and soil N2 - 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. KW - Arabidopsis KW - Carotenoids KW - Glucosinolates KW - Plant growth promoting bacteria KW - Phenylpropanoids KW - Root exudates Y1 - 2017 U6 - https://doi.org/10.1007/s11104-017-3371-1 SN - 0032-079X SN - 1573-5036 VL - 419 SP - 557 EP - 573 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Neugart, Susanne A1 - Baldermann, Susanne A1 - Ngwene, Benard A1 - Wesonga, John A1 - Schreiner, Monika T1 - Indigenous leafy vegetables of Eastern Africa - A source of extraordinary secondary plant metabolites JF - Food research international N2 - 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. KW - Indigenous African leafy vegetables KW - Flavonoid glycosides KW - Hydroxycinnamic acids KW - Carotenoids KW - Glucosinolates Y1 - 2017 U6 - https://doi.org/10.1016/j.foodres.2017.02.014 SN - 0963-9969 SN - 1873-7145 VL - 100 SP - 411 EP - 422 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ngwene, Benard A1 - Neugart, Susanne A1 - Baldermann, Susanne A1 - Ravi, Beena A1 - Schreiner, Monika T1 - Intercropping Induces Changes in Specific Secondary Metabolite Concentration in Ethiopian Kale (Brassica carinata) and African Nightshade (Solanum scabrum) under Controlled Conditions JF - Frontiers in plant science N2 - 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. KW - intercropping KW - indigenous leafy vegetables KW - nutrition security KW - secondary plant metabolites KW - Brassica carinata KW - Solanum scabrum Y1 - 2017 U6 - https://doi.org/10.3389/fpls.2017.01700 SN - 1664-462X VL - 8 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Wiesner-Reinhold, Melanie A1 - Schreiner, Monika A1 - Baldermann, Susanne A1 - Schwarz, Dietmar A1 - Hanschen, Franziska S. A1 - Kipp, Anna Patricia A1 - Rowan, Daryl D. A1 - Bentley-Hewitt, Kerry L. A1 - McKenzie, Marian J. T1 - Mechanisms of Selenium Enrichment and Measurement in Brassicaceous Vegetables, and Their Application to Human Health JF - Frontiers in plant science N2 - Selenium (Se) is an essential micronutrient for human health. Se deficiency affects hundreds of millions of people worldwide, particularly in developing countries, and there is increasing awareness that suboptimal supply of Se can also negatively affect human health. Selenium enters the diet primarily through the ingestion of plant and animal products. Although, plants are not dependent on Se they take it up from the soil through the sulphur (S) uptake and assimilation pathways. Therefore, geographic differences in the availability of soil Se and agricultural practices have a profound influence on the Se content of many foods, and there are increasing efforts to biofortify crop plants with Se. Plants from the Brassicales are of particular interest as they accumulate and synthesize Se into forms with additional health benefits, such as methylselenocysteine (MeSeCys). The Brassicaceae are also well-known to produce the glucosinolates; S-containing compounds with demonstrated human health value. Furthermore, the recent discovery of the selenoglucosinolates in the Brassicaceae raises questions regarding their potential bioefficacy. In this review we focus on Se uptake and metabolism in the Brassicaceae in the context of human health, particularly cancer prevention and immunity. We investigate the close relationship between Se and S metabolism in this plant family, with particular emphasis on the selenoglucosinolates, and consider the methodologies available for identifying and quantifying further novel Se-containing compounds in plants. Finally, we summarize the research of multiple groups investigating biofortification of the Brassicaceae and discuss which approaches might be most successful for supplying Se deficient populations in the future. KW - Brassica vegetables KW - selenium KW - biofortification KW - glucosinolates KW - human health KW - immune system KW - cancer KW - analytical methods Y1 - 2017 U6 - https://doi.org/10.3389/fpls.2017.01365 SN - 1664-462X VL - 8 PB - Frontiers Research Foundation CY - Lausanne ER -