Dendrobium officinale, a herb with highly medicinal and ornamental value, is widely distributed in China. MADS-box genes encode transcription factors that regulate various growth and developmental processes in plants, particular in flowering. However, the MADS-box genes in D. officinale are largely unknown. In our study, expression profiling analyses of selected MADS-box genes in D. officinale were performed. In total, 16 DnMADS-box genes with full-length ORF were identified and named according to their phylogenetic relationships with model plants. The transient expression of eight selected MADS-box genes in the epidermal cells of tobacco leaves showed that these DnMADS-box proteins localized to the nucleus. Tissue-specific expression analysis pointed out eight flower-specific expressed MADS-box genes in D. officinale. Furthermore, expression patterns of DnMADS-box genes were investigated during the floral transition process. DnMADS3, DnMADS8 and DnMADS22 were significantly up-regulated in the reproductive phase compared with the vegetative phase, suggesting putative roles of these DnMADS-box genes in flowering. Our data showed that the expressions of MADS-box genes in D. officinale were controlled by diverse exogenous phytohormones. Together, these findings will facilitate further studies of MADS-box genes in Orchids and broaden our understanding of the genetics of flowering.

中文翻译：

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铁皮石斛 MADS-box 家族基因的鉴定和表达谱

铁皮石斛是一种具有很高药用和观赏价值的草本植物，在我国广泛分布。MADS-box 基因编码转录因子，调节植物的各种生长和发育过程，特别是在开花过程中。然而，D. officinale 中的 MADS-box 基因在很大程度上是未知的。在我们的研究中，对铁皮草中选定的 MADS-box 基因进行了表达谱分析。根据与模式植物的系统发育关系，共鉴定并命名了 16 个具有全长 ORF 的 DnMADS-box 基因。烟草叶表皮细胞中八个选定的 MADS-box 基因的瞬时表达表明这些 DnMADS-box 蛋白定位于细胞核。组织特异性表达分析指出了铁皮石斛中八个花特异性表达的 MADS-box 基因。此外，在花转化过程中研究了 DnMADS-box 基因的表达模式。与营养期相比，DnMADS3、DnMADS8 和 DnMADS22 在生殖期显着上调，表明这些 DnMADS-box 基因在开花中的假定作用。我们的数据表明，麦冬中 MADS-box 基因的表达受多种外源植物激素控制。总之，这些发现将有助于进一步研究兰花中的 MADS-box 基因，并拓宽我们对开花遗传学的理解。我们的数据表明，麦冬中 MADS-box 基因的表达受多种外源植物激素控制。总之，这些发现将有助于进一步研究兰花中的 MADS-box 基因，并拓宽我们对开花遗传学的理解。我们的数据表明，麦冬中 MADS-box 基因的表达受多种外源植物激素控制。总之，这些发现将有助于进一步研究兰花中的 MADS-box 基因，并拓宽我们对开花遗传学的理解。