Decreasing Arsenic Concentration In Rice Grain Through Safener-Elicited Glutathione Sequestration
Date
2022-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
Arsenic accumulation in rice grain poses major problems for human safety,
global food security, and the future of nutrition, especially in the developing world. In
an effort to investigate feasible and effective strategies to prevent arsenic
accumulation in rice grain, this study investigates a potential pathway to reduce
arsenic accumulation in rice grains through involving glutathione sequestration. I
hypothesized that exogenous applications of solutions called safeners, which are
similar to herbicides but lack a key functional group that give xenobiotic capabilities,
could elicit a defense response in rice plants that leads to increased production of
glutathione. Glutathione has the capability to bind with arsenic sequester it into the
vacuole of plants, thus offering a potential avenue to sequester arsenic in non-grain
tissue which prevents the arsenic from reaching the grain. The effects of 4 safeners
were investigated: fenclorim, isoxadifen-ethyl, dimepiperate, and dichlormid. A
greenhouse pot study was done to establish comparisons of glutathione concentrations
in various plant parts and glutathione defense pathway gene regulation of safener
treated plants as compared to untreated controls. Overall, there were no statistically
significant differences between the concentrations of reduced or oxidized glutathione
in the nodes, leaves, or flag leaves of safener treated plants in comparison to untreated
controls. There was some evidence for a localization effect of reduced glutathione to
the nodes of plants treated with fenclorim, but this result was not statistically
significant. Likewise, there was no significant increase in expression of genes related
to glutathione biosynthesis or transport in plants treated with safeners as compared to
untreated controls. The lack of significant data suggests there is room to understanding
potential avenues for arsenic sequestration in rice. Additionally, further analysis could
be necessary to test the efficacy of safener uptake after exogenous application.
Description
Keywords
Rice, Arsenic, Nutrition, Safener