On May 1, 2006 all the Chemistry Department imaging programs transferred
to the BNL Medical Department, however all programmatic material herein
remains unchanged.
Exploring Root Physiology in Relation to Uptake of Groundwater
Pollutants
A long-standing challenge to plant biologists has been to find
the physiological basis for whole-plant responses to environment. Plants
have evolved with mechanisms that coordinate the changing vascular transport
of nutrients between foliage and roots as the plant grows, under wide
ranging environmental stresses - shortage of water and nutrients, attack by
herbivores and pathogens, pollution of soil and air. The transport
mechanisms and defense responses are key to management of plants and
ecosystems, but have been elusive to study, particularly as there have been
no non-invasive techniques to observe the nutrient transport within intact
plants. Short-lived positron-emitting radioisotopes provide that
opportunity, allowing repeated measurement within a plant over time, with
high temporal and spatial resolution. By radio-labeling pollutants we can
also probe the interplay of pollutant transport and plant metabolism. We are
combining Positron Emission Tomography (PET) and Phosphor-Plate Imaging to
investigate the impacts of nutrient, water and pollutants on plant growth
processes, and on pollution using the short-lived isotopes 11C
and 13N.
Phytoremediation: Groundwater contamination by organic and chlorocarbon
compounds presents a direct health risk and also contributes to atmospheric
pollution with further risks to health. We are studying the interaction of
plant metabolism and pollutant uptake and emissions with a view to reducing
volatile emissions. For example carbon tetrachloride entering plants via
the roots was found to be metabolized in leaves into less volatile
compounds. This metabolism places a new demand for plant carbon resources
that we are investigating by imaging the distribution of [11C]carbohydrate.
This program is supported by a Laboratory-Directed
Research and Development Grant (LDRD).
We acknowledge Brookhaven National Laboratory for this support.

Last Modified: June 28, 2012
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