title: Thymoquinone causes multiple effects, including cell death, on dividing plant cells.
abstract: Thymoquinone (TQ) is a major constituent of Nigella sativa oil with reported anti-oxidative activity and anti-inflammatory activity in animal cells. It also inhibits proliferation and induces programmed cell death (apoptosis) in human skin cancer cells. The present study sought to detect the influence of TQ on dividing cells of three plant systems and on expression of Bcl2-associated athanogene-like (BAG-like) genes that might be involved during the process of cell death. BAG genes are known for the regulation of diverse physiological processes in animals, including apoptosis, tumorigenesis, stress responses, and cell division. Synthetic TQ at 0.1mg/mL greatly reduced wheat seed germination rate, whereas 0.2mg/mL completely inhibited germination. An Evans blue assay revealed moderate cell death in the meristematic zone of Glycine max roots after 1h of TQ treatment (0.2mg/mL), with severe cell death occurring in this zone after 2h of treatment. Light microscopy of TQ-treated (0.2mg/mL) onion hairy root tips for 1h revealed anti-mitotic activity and also cell death-associated changes, including nuclear membrane disruption and nuclear fragmentation. Transmission electron microscopy of TQ-treated cells (0.2mg/mL) for 1h revealed shrinkage of the plasma membrane, leakage of cell lysate, degradation of cell walls, enlargement of vacuoles and condensation of nuclei. Expression of one BAG-like gene, previously associated with cell death, was induced 20 min after TQ treatment in Glycine max root tip cells. Thus, TQ has multiple effects, including cell death, on dividing plant cells and plants may serve as a useful system to further investigate the mechanisms underlying the response of eukaryotic cells to TQ.
authors.affiliation: Bioinformatics Department, Agricultural Genetic Engineering Research Institute (AGERI), Agriculture Research Center (ARC), Giza, Egypt; College of Biotechnology, Misr University for Science and Technology (MUST), 6th October city, Egypt.
authors.forename: Sameh E
authors.initials: SE
authors.lastname: Hassanien
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Ramadan
authors.forename: Ahmed Z Abdel
authors.initials: AZ
authors.lastname: Azeiz
authors.forename: Rasha A
authors.initials: RA
authors.lastname: Mohammed
authors.forename: Sabah M
authors.initials: SM
authors.lastname: Hassan
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Shokry
authors.forename: Ahmed
authors.initials: A
authors.lastname: Atef
authors.forename: Khalid B H
authors.initials: KB
authors.lastname: Kamal
authors.forename: Samar
authors.initials: S
authors.lastname: Rabah
authors.forename: Jamal S M
authors.initials: JS
authors.lastname: Sabir
authors.forename: Osama A
authors.initials: OA
authors.lastname: Abuzinadah
authors.forename: Fotouh M
authors.initials: FM
authors.lastname: El-Domyati
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Martin
authors.forename: Ahmed
authors.initials: A
authors.lastname: Bahieldin
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis / Q000187:drug effects; D029681:Arabidopsis Proteins / Q000378:metabolism; D016227:Benzoquinones / Q000633:toxicity*; D016923:Cell Death / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects*; D017931:DNA Primers; D018525:Germination; D018551:Solanum lycopersicum; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D019697:Onions / Q000254:growth & development; D059828:Plant Cells / Q000187:drug effects*; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D060888:Real-Time Polymerase Chain Reaction; D013025:Glycine max; D014026:Nicotiana; D014908:Triticum / Q000254:growth & development
chemical_list: D029681:Arabidopsis Proteins; D016227:Benzoquinones; D017931:DNA Primers; C003466:thymoquinone
keywords: BAG domain; Bcl2-associated athanogene-like family; Cell death; IQ motif; Root tips; Stress response