Uptake and distribution of iodine in rice plants.

Inst. for Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212, Japan.
Journal of Environmental Quality (Impact Factor: 2.35). 01/2008; 37(6):2243-7. DOI: 10.2134/jeq2008.0010
Source: PubMed

ABSTRACT Rice (Oryza sativa L.) plants were cultivated in an experimental field and separated at harvest into different components, including polished rice, rice bran, hull, straw, and root. The contents of iodine in these components and the soil were determined by inductively coupled plasma-mass spectrometry and radiochemical neutron activation analysis, respectively. Iodine content varied by more than three orders of magnitude among the plant components. Mean concentration of iodine in the entire plants was 20 mg kg(-1) dry weight, and the concentration of iodine in the surface soil (0-20 cm depth) was 48 mg kg(-1). The highest concentration of iodine (53 mg kg(-1) dry weight) was measured in root and the lowest concentration (0.034 mg kg(-1) dry weight) in polished rice. While the edible component (polished rice) accounted for 32% of the total dry weight, it contained only 0.055% of iodine found in the entire rice plants. Atmospheric gaseous iodine (5.9 ng m(-3)) was estimated to contribute <0.2% of the total iodine content in the biomass of rice plants; therefore nearly all of the iodine in the rice plants was a result of the uptake of iodine from the soil. The content of iodine in the aboveground part of rice plants was 16 mg kg(-1) dry weight and the percentage of iodine transferred per cropping from the soil into the aboveground biomass corresponded to 0.27% (20 mg m(-2)) of the upper soil layer content.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We hypothesize that amylose is an important in planta sink for iodine. Moreover, starch with greater amylose content could be capable of sequestering higher levels of this important micronutrient. Diets low in iodine can result in goitre, cretinism and a host of other serious medical conditions. Since nearly two billion people worldwide still receive insufficient dietary iodine despite salt iodisation programmes, iodine deficiency disorders (IDD) constitute a serious global health issue in need of innovative solutions strengthened by interdisciplinary systems approaches (Bouis & Welch, 2010; World Health Organisation, 2007). Iodine can be sequestered within the helical V-amylose component of starch in the form of polyiodide chains (Yu, Houtman, & Atalla, 1996). We argue that stable iodine complexation in high-amylose staple crops could contribute an invaluable and critical biofortification tactic to prevent IDD.
    Trends in Food Science & Technology 06/2011; 22(6):335-340. · 4.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A non-destructive analysis method for total bromine (Br) and iodine (I) contents in soil was established using polarizing energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The matrix-corrected intensity of Br and I Kα X-rays from pressed pellets of soil powder samples was calibrated with their contents measured by inductively coupled plasma (ICP)-mass spectrometry after pyrohydrolysis preparation. The calibration curves for Br and I were successfully obtained in the concentration ranges 3.8–223 mg kg−1 and 0.91–54 mg kg−1 respectively. Repeated analyses of the same sample with polarizing EDXRF spectrometry within one day and after approximately 1.5 years showed good reproducibility of the measurement results. The lower limits of detection for Br and I were 0.14 mg kg−1and 0.34 mg kg−1 respectively. The established analytical method for total Br and I contents in soil is non-destructive, simple and rapid, and is suitable for routine analysis. Trace elements such as rubidium (Rb), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb), cadmium (Cd), tin (Sn), antimony (Sb), caesium (Cs), barium (Ba), light rare earth elements and lead (Pb) were also measurable simultaneously under the identical operational conditions as those for Br and I measurements.
    Soil Science and Plant Nutrition 02/2011; 57(1):19-28. · 0.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Iodine, as one of the essential trace elements for human body, is very important for the proper function of thyroid gland. In some regions, people are still suffering from iodine deficiency disorder (IDD). How to provide an effective and cost-efficient iodine supplementation has been a public health issue for many countries. In this review, a novel iodine supplementation approach is introduced. Different from traditional iodine salt supplement, this approach innovatively uses cultivated iodine-rich phytogenic food as the supplement. These foods are cultivated using alga-based organic iodine fertilizer. The feasibility, mechanics of iodine absorption of plants from soil and the bioavailability of iodine-rich phytogenic food are further discussed.
    Environmental Geochemistry and Health 02/2014; · 2.08 Impact Factor