In vivoXANES measuring technique for studying the arsenic uptake in cucumber plants

Abstract

New in vivo X-ray absorption near edge structure measuring technique was developed by using liquid nitrogen steam flow for cooling cucumber samples keeping them under cryogenic conditions during the measurement in order to preserve the original chemical states of arsenic species in the hypocotyl. The aim of this study was to determine the As oxidation state in order to identify the possible metabolic processes during the nutrient uptake in cucumber (Cucumis sativus L. cv Joker) as model plant. The plants were grown in Hoagland's modified nutrient solution. The ratio of the quantity of two As species was determined in the hypocotyls of the cucumber samples: arsenite, As(III) and arsenate, As(V). The ultimate biological goal of the in vivo experiments was to investigate the applicability of the X-ray absorption near edge structure technique under cryogenic conditions and to specify the resistance level of the plants to arsenic toxicity when different chemical forms of iron, FeCl3 and Fe-ascorbate were supplied in the nutrient solution. We have examined the influence of the intense synchrotron radiation beam on the transformation of the oxidation number of both As species when the effect of the reactive oxygen forms was eliminated by the presence of ascorbate. Copyright © 2016 John Wiley & Sons, Ltd.