title: Correlation of toxicity with lead content in root tip cells (Allium cepa L.).
abstract: The present study determines lead content in onion root tip cells (Allium cepa L.), correlating it with its toxicity. The treatment was carried at 25 +/- 0.5 degrees C using aqueous solutions of lead chloride at 0.1, 0.25, 0.50, 0.75, and 1 ppm for 12, 24, 48, and 72 h. For each treatment, a control where the lead solution was substituted by distilled water was included. After treatment, the meristems were fixed with a mixture of alcohol-acetic acid (3:1) and colored according to the technique of Feulgen. Lead content was quantified by graphite furnace absorption atomic spectrometry. The lead content in the roots ranged from 3.25 to 244.72 microg/g dry weight, with a direct relation with the concentration and time of exposure. A significant negative correlation was presented (r = -0.3629; p < 0.01) among lead content and root growth increment, and a positive correlation (r = 0.7750; p < 0.01) with the induction of chromosomic aberrations. In conclusion, lead is able to induce a toxic effect in the exposed roots, correlated with its content.
authors.affiliation: Departamento de Biología, Facultad Experimental de Ciencias, Universidad del Zulia, Maracaibo, Estado Zulia, Venezuela. yncarr24@hotmail.com
authors.forename: Ingrid
authors.initials: I
authors.lastname: Carruyo
authors.forename: Yusmary
authors.initials: Y
authors.lastname: Fernández
authors.forename: Letty
authors.initials: L
authors.lastname: Marcano
authors.forename: Xiomara
authors.initials: X
authors.lastname: Montiel
authors.forename: Zaida
authors.initials: Z
authors.lastname: Torrealba
mesh_terms: D002869:Chromosome Aberrations / Q000139:chemically induced; D007854:Lead / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity*; D018519:Meristem / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects*; D008940:Mitotic Index; D019697:Onions / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D007854:Lead; C029891:lead chloride