Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Engineering Research Center of Landscape Environment of Ministry of Education, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, 100083, China.
Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Engineering Research Center of Landscape Environment of Ministry of Education, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China.
Plant Physiol Biochem. 2019 Sep;142:510-518. doi: 10.1016/j.plaphy.2019.08.012. Epub 2019 Aug 16.
As one of the most popular woody species that blooms in summer, Lagerstroemia speciosa has been used abundantly in urban landscape for its excellent floral beauty. For the first time, we discovered a double-flower variant with all petaloid stamens. To understand the molecular basis of this variation, we contrasted the transcriptomes of single- and double-flower buds at three stamen development stages. In total, 73,536 unigenes were mapped and 30,714 differently expressed genes (DEGs) were identified in the tissues. We focused on the DEGs expressing in both phenotypes and investigated the association of their expression profiles with their functions in transcription pathways. Furthermore, we performed WGCNA and identified co-expressed genes with four floral homeotic genes as hubs (MADS16, Unigene0026169; AP2, Unigene0042732; SOC1, Unigene0046314; AG, Unigene0056437). The expression of these hub genes has been conserved across the three developmental stages but significantly different between the two floral phenotypes. As a result, the robust transcriptional regulation of stamen petaloidy in double flowers was deduced. These findings will help to unravel the regulatory mechanisms of several specific genes, thereby providing a basis to study double-flower molecular breeding in L. speciosa.
作为夏季开花的最受欢迎的木本植物之一，紫薇因其极好的花朵美丽而被大量用于城市景观。我们首次发现了一种具有全瓣化雄蕊的重瓣花变种。为了了解这种变异的分子基础，我们在三个雄蕊发育阶段对比了单瓣和重瓣花蕾的转录组。总共映射了 73536 个基因，在组织中鉴定了 30714 个差异表达基因（DEGs）。我们重点关注在两种表型中都表达的 DEGs，并研究了它们的表达谱与其在转录途径中的功能的关联。此外，我们进行了 WGCNA，并鉴定了与四个花同源基因作为枢纽（MADS16、Unigene0026169；AP2、Unigene0042732；SOC1、Unigene0046314；AG、Unigene0056437）共表达的基因。这些枢纽基因的表达在三个发育阶段都保持保守，但在两种花表型之间差异显著。因此，推断出重瓣花中雄蕊瓣化的稳健转录调控。这些发现将有助于揭示几个特定基因的调控机制，从而为研究紫薇重瓣花的分子育种提供基础。
