Isolation and characterization of a MADS-box gene in cucumber (Cucumis sativus L) that affects flowering time and leaf morphology in transgenic Arabidopsis

The MADS-box family genes are important transcription factors that play essential roles in plant growth and development. In this study, a MADS-box gene, CsMADS02, was identified and functionally characterized in cucumber (Cucumis sativus L.). CsMADS02 encoded a typical SEP MADS-box protein which contained a MADS-box, a K-box, an I region and a C region, as well as two short conserved SEP motifs. Sequence alignment and phylogenetic analysis showed that the CsMADS02 protein belonged to the SEP3 subfamily and was highly homologous to other published plant SEP proteins. Expression analyses revealed that CsMADS02 was primarily expressed in flowers and ovaries, and differentially expressed during the development of male and female flowers. Ectopic overexpression of CsMADS02 caused earlier flowering of Arabidopsis. In addition, morphological changes were also observed in transgenic plants, including curled and fewer rosette leaves. These findings suggest that CsMADS02 is a potential regulator of the flowering time and leaf morphology in cucumber.