Journal
NEW PHYTOLOGIST
Volume 192, Issue 1, Pages 87-98Publisher
WILEY
DOI: 10.1111/j.1469-8137.2011.03789.x
Keywords
arsenic; grain filling; phloem; rice; translocation
Categories
Funding
- Biotechnology and Biological Sciences Research Council
- National Institute of Environmental Health Sciences [P42 ES007373-14]
- National Science Foundation - Earth Sciences [EAR-0622171]
- Department of Energy - Geosciences [DE-FG02-94ER14466, DE-FG02-92ER14244]
- US Department of Energy, Office of Science, Office of Basic Energy Science [DE-AC02-06CH11357]
- DOE - Office of Biological and Environmental Research, Environmental Remediation Sciences Div. [DE-FC09-96-SR18546]
- DOE [DE-AC02-98CH10886]
- US Environmental Protection Agency, through its Office of Research and Development
- NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES [P20ES018175, P42ES007373] Funding Source: NIH RePORTER
Ask authors/readers for more resources
Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was investigated. Arsenic species were delivered through cut flag leaves during grain fill. Spatial unloading within grains was investigated using synchrotron X-ray fluorescence (SXRF) microtomography. Additionally, the effect of germanic acid (a silicic acid analog) on grain As accumulation in arsenite-treated panicles was examined. Dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were extremely efficiently retranslocated from flag leaves to rice grain; arsenate was poorly retranslocated, and was rapidly reduced to arsenite within flag leaves; arsenite displayed no retranslocation. Within grains, DMA rapidly dispersed while MMA and inorganic As remained close to the entry point. Germanic acid addition did not affect grain As in arsenite-treated panicles. Three-dimensional SXRF microtomography gave further information on arsenite localization in the ovular vascular trace (OVT) of rice grains. These results demonstrate that inorganic As is poorly remobilized, while organic species are readily remobilized, from leaves to grain. Stem translocation of inorganic As may not rely solely on silicic acid transporters.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available