Iron is an essential element in plant nutrition and the determination of its concentration, location and chemical form is of paramount relevance to study Fe homeostasis in plants. Assessing the mechanisms of Fe uptake, transport and storage by plants is critical to overcome nutrition deficiencies for cultivated plants and to improve the nutritional value of food crops. For such studies, researchers need to visualize where iron is located at the level of the whole plant, the individual cell and the organelle. This requires a μm or sub-μm spatial resolution and a ppm or sub ppm detection sensitivity. Fe is not easy to analyze in plant materials because of its highly heterogeneous distribution with large differences in concentration, ranging from sub ppm to %, depending to its location. Especially the lower concentrations are hardly detectable with normal laboratory equipments (e.g., Electron Probe Micro Analysis, Proton Induced X-ray Emission). In this study, intact freeze dried leaves and roots of model plants such as tomato and cucumber have been studied for Fe distribution by scanning SXRF and confocal SXRF, without the need of sectioning. Quantification has been reached by using Fundamental Parameter algorithms coupled with standards analysis. With such an approach Fe distribution maps could be obtained with concentrations ranging from 100 ppb to 0,1%, with an accuracy of 2%. Such accurate distribution maps can be extremely useful to compare Fe allocation and concentration between plants altered with respect to the genes they express and/or the environmental conditions under which they are grown.
SPATIALLY RESOLVED QUANTITATIVE DETERMINATION OF IRON (FE) IN PLANTS BY MEANS OF SYNCHROTRON MICRO X-RAY FLUORESCENCE
TERZANO, ROBERTO;
2012-01-01
Abstract
Iron is an essential element in plant nutrition and the determination of its concentration, location and chemical form is of paramount relevance to study Fe homeostasis in plants. Assessing the mechanisms of Fe uptake, transport and storage by plants is critical to overcome nutrition deficiencies for cultivated plants and to improve the nutritional value of food crops. For such studies, researchers need to visualize where iron is located at the level of the whole plant, the individual cell and the organelle. This requires a μm or sub-μm spatial resolution and a ppm or sub ppm detection sensitivity. Fe is not easy to analyze in plant materials because of its highly heterogeneous distribution with large differences in concentration, ranging from sub ppm to %, depending to its location. Especially the lower concentrations are hardly detectable with normal laboratory equipments (e.g., Electron Probe Micro Analysis, Proton Induced X-ray Emission). In this study, intact freeze dried leaves and roots of model plants such as tomato and cucumber have been studied for Fe distribution by scanning SXRF and confocal SXRF, without the need of sectioning. Quantification has been reached by using Fundamental Parameter algorithms coupled with standards analysis. With such an approach Fe distribution maps could be obtained with concentrations ranging from 100 ppb to 0,1%, with an accuracy of 2%. Such accurate distribution maps can be extremely useful to compare Fe allocation and concentration between plants altered with respect to the genes they express and/or the environmental conditions under which they are grown.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
