title: Initiation of spontaneous tumors in radish (Raphanus sativus): Cellular, molecular and physiological events.
abstract: In plant meristems, the balance of cell proliferation and differentiation is maintained by phytohormones, specifically auxin and cytokinin, as well as transcription factors. Changing of the cytokinin/auxin balance in plants may lead to developmental abnormalities, and in particular, to the formation of tumors. The examples of spontaneous tumor formation in plants include tumors formed on the roots of radish (Raphanus sativus) inbred lines. Previously, it was found that the cytokinin/auxin ratio is altered in radish tumors. In this study, a detailed histological analysis of spontaneous radish tumors was performed, revealing a possible mechanism of tumor formation, namely abnormal cambial activity. The analysis of cell proliferation patterns revealed meristematic foci in radish tumors. By using a fusion of an auxin-responsive promoter (DR5) and a reporter gene, the involvement of auxin in developmental processes in tumors was shown. In addition, the expression of the root meristem-specific WUSCHEL-related homeobox 5 (WOX5) gene was observed in cells adjacent to meristematic foci. Taken together, the results of the present study show that tumor tissues share some characteristics with root apical meristems, including the presence of auxin-response maxima in meristematic foci with adjacent cells expressing WOX5.
authors.affiliation: Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia. Electronic address: mary_osipova@mail.ru.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Lebedeva Osipova
authors.affiliation: Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia. Electronic address: krubaza@mail.ru.
authors.forename: Varvara E
authors.initials: VE
authors.lastname: Tvorogova
authors.affiliation: Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia. Electronic address: alena_08_93@mail.ru.
authors.forename: Alena P
authors.initials: AP
authors.lastname: Vinogradova
authors.affiliation: Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia. Electronic address: vaiagan@mail.ru.
authors.forename: Maria S
authors.initials: MS
authors.lastname: Gancheva
authors.affiliation: Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia. Electronic address: mahboobeazarakhsh@gmail.com.
authors.forename: Mahboobeh
authors.initials: M
authors.lastname: Azarakhsh
authors.affiliation: Komarov Botanical Institute, Russian Academy of Sciences, Laboratory of Anatomy and Morphology, Prof. Popov Street 2, 197376 Saint-Petersburg, Russia. Electronic address: substrat@yandex.ru.
authors.forename: Elena L
authors.initials: EL
authors.lastname: Ilina
authors.affiliation: Komarov Botanical Institute, Russian Academy of Sciences, Laboratory of Anatomy and Morphology, Prof. Popov Street 2, 197376 Saint-Petersburg, Russia. Electronic address: sardonio@yandex.ru.
authors.forename: Kirill N
authors.initials: KN
authors.lastname: Demchenko
authors.affiliation: Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia. Electronic address: wildtype@yandex.ru.
authors.forename: Irina E
authors.initials: IE
authors.lastname: Dodueva
authors.affiliation: Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034 Saint-Petersburg, Russia. Electronic address: la.lutova@gmail.com.
authors.forename: Lyudmila A
authors.initials: LA
authors.lastname: Lutova
mesh_terms: D000595:Amino Acid Sequence; D058506:Cambium / Q000166:cytology / Q000235:genetics / Q000502:physiology; D002454:Cell Differentiation; D049109:Cell Proliferation; D003583:Cytokinins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D018519:Meristem / Q000166:cytology / Q000235:genetics / Q000502:physiology; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000502:physiology; D010941:Plant Tumors; D011401:Promoter Regions, Genetic / Q000235:genetics; D031224:Raphanus / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment
chemical_list: D003583:Cytokinins; D018398:Homeodomain Proteins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins
keywords: Auxin; Cambium; Plant tumors; Radish; WOX5