WOX (WUSCHEL-RELATED HOMEOBOX) is a family of homeodomain-containing transcription factors in plants. WOX proteins maintain the activity of different types of meristems and regulate the formation of plant organs, controlling cell proliferation and differentiation. Study of the WOX family is important for the development of plant transformation and genome editing techniques. Here we review the functions of the WOX transcription factors as well as their targets, partners, and regulators. The WOX family can be divided into three phylogenetically distinct clades: so-called ancient, intermediate, and WUS clade; each clade is covered in a separate section. The WOX genes of Arabidopsis thaliana are described most comprehensively, with their orthologs in other plant species also considered. Summary tables with the described targets, regulators and partners of WOX family members are provided.

Radish (Raphanus sativus L.) is a widespread agricultural plant forming storage root due to extensive secondary growth which involves cambium proliferation and differentiation of secondary conductive tissues. Closely related to the model object Arabidopsis thaliana, radish is a suitable model for studying processes of secondary growth and storage root development. CLE peptides are a group of peptide phytohormones which play important role in the regulation of primary meristems such as SAM, RAM, and procambium, as well as secondary meristems. However, the role of CLE peptides in lateral growth of root during storage root formation has not been studied to date. In present work we studied the role of CLE peptides in the development of storage root in radish. We have identified 18 CLE genes of radish (RsCLEs) and measured their expression in various plant organs and also at different stages of root development in R. sativus and Raphanus raphanistrum—its close relative which does not form storage root. We observed significant decline of expression levels for genes RsCLE1, 2, 11, 13, and 16, and also multifold increase of expression levels for genes RsCLE19, and 41 during secondary root growth in R. sativus but not in R. raphanistrum. Expression of RsCLE 2, 19, and 41 in R. sativus root was confined to certain types of tissues while RsCLE1, 11, 13, and 16 expressed throughout the root. Experiments on overexpression of RsCLE2, 19 and 41 or treatment of radish plants with synthetic CLE peptides revealed that CLE19 and CLE2 increase the number of xylem elements, and CLE41 induces the formation of extra cambium foci in secondary xylem. Expression levels of RsCLE2 and 19 strongly decrease in response to exogenous cytokinin, while auxin causes dramatic increase of RsCLE19 expression level and decrease of RsCLE41 expression. Our data allow us to hypothesize about the role of RsCLE2, 19 and 41 genes in the development of storage root of Raphanus sativus, e.g. RsCLE19 may play a role in auxin-dependent processes of xylem differentiation and RsCLE41 stimulates cambium activity.

Comparative analysis of WOX and PIN genes expression in the ovules and during somatic embryogenesis in Medicago truncatula was performed. It was shown that some WOX and PINgenes with high expression...

WOX (WUSCHEL-RELATED HOMEOBOX) – это семейство гомеодоменсодержащих транскрипционных факторов растений. Белки WOX поддерживают активность меристем различного типа, а также регулируют формирование органов растений, влияя на пролиферацию и дифференцировку клеток в различных тканях. Изучение семейства WOX может оказаться полезным для разработки методик трансформации и редактирования генома растений. В настоящем обзоре рассмотрены функции и механизмы работы транскрипционных факторов WOX, их мишени, партнеры и регуляторы. Семейство WOX можно разделить на три филогенетически обособленные клады: так называемую древнюю, промежуточную и кладу WUS. Каждой из ветвей семейства посвящен отдельный раздел обзора. Наиболее подробно рассмотрены гены WOX Arabidopsis thaliana, описаны также их ортологи у других видов растений. Приведены сводные таблицы с известными мишенями, регуляторами и партнерами членов семейства WOX.