Supplementary data for the article: Pavlovic, J.; Samardzic, J.; Kostic, L.; Laursen, K. H.; Natic, M.; Timotijevic, G.; Schjoerring, J. K.; Nikolic, M. Silicon Enhances Leaf Remobilization of Iron in Cucumber under Limited Iron Conditions. Annals of Botany 2016, 118 (2), 271–280. https://doi.org/10.1093/aob/mcw105

Supplementary material for: [https://doi.org/10.1093/aob/mcw105]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2305

Silicon enhances leaf remobilization of iron in cucumber under limited iron conditions

Background and Aims Retranslocation of iron (Fe) from source tissues enhances plant tolerance to Fe deficiency. Previous work has shown that silicon (Si) can alleviate Fe deficiency by enhancing acquisition and root to shoot translocation of Fe. Here the role of Si in Fe mobilization in older leaves and the subsequent retranslocation of Fe to young leaves of cucumber (Cucumis sativus) plants growing under Fe-limiting conditions was investigated. Methods Iron (Fe-57 or naturally occurring isotopes) was measured in leaves at different positions on plants hydroponically growing with or without Si supply. In parallel, the concentration of the Fe chelator nicotianamine (NA) along with the expression of nicotianamine synthase (NAS) involved in its biosynthesis and the expression of yellow stripe-like (YSL) transcripts mediating Fe-NA transport were also determined. Key Results In plants not receiving Si, approximately half of the total Fe content remained in the oldest leaf. In contrast, Si-treated plants showed an almost even Fe distribution among leaves with four different developmental stages, thus providing evidence of enhanced Fe remobilization from source leaves. This Si-stimulated Fe export was paralleled by an increased NA accumulation and expression of the YSL1 transporter for phloem loading/unloading of the Fe-NA complex. Conclusions The results suggest that Si enhances remobilization of Fe from older to younger leaves by a more efficient NA-mediated Fe transport via the phloem. In addition, from this and previous work, a model is proposed of how Si acts to improve Fe homeostasis under Fe deficiency in cucumber

The OrgTrace project: Content, Bioavailability and Health Effects of Trace Elements and Bioactive Components of Food Products Cultivated in Organic and Conventional Agricultural Systems

Trace elements, bioactive secondary metabolites and vitamins are among the most important quality parameters in plants. Yet, very little information is available on their content, bioavailability and health effects in organically grown plant food products. The main objective of OrgTrace is to study the impact of different agricultural management practices relevant for organic farming on the ability of cereal and vegetable crops to absorb trace elements from the soil and to synthesize bioactive compounds (secondary metabolites, antioxidant vitamins and phytates) with health promoting effects. Based on different plant products produced in OrgTrace, diets were composed and the bioavailabilities of health promoting substances were analyzed in a human intervention study. Moreover, various health effects such as immune system responses were studied using rats as model organisms. OrgTrace is the first study, which follows selected elements and bioactive compounds all the way from the plant and soil system to absorption in the human body. All experimental studies have now been finalized and we are able to draw final conclusions

Supplementary data for the article: Pavlovic, J.; Samardzic, J.; Kostic, L.; Laursen, K. H.; Natic, M.; Timotijevic, G.; Schjoerring, J. K.; Nikolic, M. Silicon Enhances Leaf Remobilization of Iron in Cucumber under Limited Iron Conditions. Annals of Botany 2016, 118 (2), 271–280. https://doi.org/10.1093/aob/mcw105

Supplementary material for: [https://doi.org/10.1093/aob/mcw105]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2305

Can agricultural cultivation methods influence the healthfulness of crops for foods

The aim of the current study was to investigate if there are any health effects of long-term consumption of organically grown crops using a rat model. Crops were retrieved over two years from along-term field trial at three different locations in Denmark, using three different cultivation systems(OA, organic based on livestock manure; OB, organic based on green manure; and C, conventional with mineral fertilizers and pesticides)with two field replicates. The cultivation system had an impact on the nutritional quality, affecting γ-tocopherol, some amino acids, and fatty acid composition. Additionally, the nutritional quality was affected by harvest year and location. However, harvest year and location rather than cultivation system affected the measured health biomarkers. In conclusion, the differences in dietary treatments composed of ingredients from different cultivation systems did not lead to significant differences in the measured health biomarkers, except for a significant difference in plasma IgGl evels