title: Copper-induced root growth inhibition of Allium cepa var. agrogarum L. involves disturbances in cell division and DNA damage.
abstract: Copper (Cu) is considered to be an indispensable microelement for plants. Excessive Cu, however, is toxic and disturbs several processes in the plant. The present study addressed the effects of ionic Cu (2.0 µM and 8.0 µM) on mitosis, the microtubule cytoskeleton, and DNA in root tip cells of Allium cepa var. agrogarum L. to better understand Cu toxicity on plant root systems. The results indicated that Cu accumulated in roots and that root growth was inhibited dramatically in Cu treatment groups. Chromosomal aberrations (for example, C-mitosis, chromosome bridges, chromosome stickiness, and micronucleus) were observed, and the mitotic index decreased during Cu treatments at different concentrations. Microtubules were one of the target sites of Cu toxicity in root tip meristematic cells, and Cu exposure substantially impaired microtubule arrangements. The content of α-tubulin decreased following 36 h of exposure to 2.0 µM or 8.0 µM of Cu in comparison with the control group. Copper increased DNA damage and suppressed cell cycle progression. The above toxic effects became more serious with increasing Cu concentration and prolonged exposure time.
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou, China.
authors: Rong
authors: R
authors: Qin
authors: Congyue
authors: C
authors: Wang
authors: Da
authors: D
authors: Chen
authors: Lars O
authors: LO
authors: Björn
authors: Shaoshan
authors: S
authors: Li
mesh_terms: D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002869:Chromosome Aberrations; D020552:Comet Assay; D003300:Copper / Q000737:chemistry / Q000633:toxicity*; D003599:Cytoskeleton / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D018519:Meristem / Q000166:cytology / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D008938:Mitosis / Q000187:drug effects; D008940:Mitotic Index; D019697:Onions / Q000254:growth & development* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects; D014404:Tubulin / Q000378:metabolism
chemical_list: D014404:Tubulin; D003300:Copper
keywords: Copper; DNA damage; DNA synthesis; Microtubule; Mitosis