PH09 Plant Ecotoxicology
Exhibit Hall
8:00 AM - Thursday
(PH119) An assessment of genetic stability in cadmium-treated Lactuca sativa L. by flow cytometry and microsatellite analysis.
Monteiro, MS1, Lopes, T1, Loureiro, J1, Mann, RM1, Santos, C1, Santos, AMVM1, 1 Biology Department, Aveiro University, Aveiro, Aveiro, Portugal
ABSTRACT- The development of new technologies has increased the opportunities to evaluate the effect of genetic instability in toxicological studies. Analyses of changes in DNA by flow cytometry (e.g. ploidy level, DNA content and cell cycle) and by microsatellite instability (MSI) are among those techniques. Five week old lettuce plants (Lactuca sativa L.) grown in a modified Hoagland medium were exposed for a further 14 days to medium containing 100 
M Cd(NO3)2. After 7 and 14 days of exposure leaves and roots were removed from plants in order to evaluate genetic stability using a flow cytometer (Beckman-Coulter EPICS-XL) and by MSI. Nuclear DNA content and the number of nuclei in the phase G2 of the cellular cycle in leaves and roots of treated plants presented similar values to those presented by control plants, suggesting that the genomic characteristics analysed by flow cytometry were not affected by the cadmium genotoxic exposure. Mutagenic effects of cadmium on microsatellite DNA loci were assessed and results will be discussed in respect to genetic instability. This work was funded through a research grant from the Portuguese Foundation for Science & Technology (FCT/POCTI/BSE/48757/2002); Aveiro University supported the fellowships of Marta Monteiro (TCF/P-RP Reitoria) and FCT supported the fellowships of João Loureiro (FCT/SFRH/BD/9003/2002) and Tina Lopes (FCT/SFRH/BPD/6012/2001).
Key words: cadmium, Lactuca sativa, flow cytometry, microsatellites instability