Kasajima Ichiro, Ohtsubo Norihiro, Sasaki Katsutomo
Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Ibaraki 305-8519, Japan.
Hortic Res. 2017 Mar 22;4:17008. doi: 10.1038/hortres.2017.8. eCollection 2017.
Although chimeric repressors such as the Arabidopsis TCP3 repressor are known to have significant effects on flower morphology and color, their cellular-level effects on flower petals are not understood. The promoter sequences of the genes expressed in the flowers of cyclamen, a representative potted flower grown during the winter season, are also unknown. Here, we isolated eight promoters from cyclamen genes that are reportedly expressed in the petals. These promoters were then fused to four chimeric repressors and introduced into the model flower torenia to screen for effective combinations of promoters and repressors for flower breeding. As expected, some of the constructs altered flower phenotypes upon transformation. We further analyzed the effects of chimeric repressors at the cellular level. We observed that complicated petal and leaf serrations were accompanied by excessive vascular branching. Dichromatism in purple anthocyanin was inferred to result in bluish flowers, and imbalanced cell proliferation appeared to result in epinastic flowers. Thus, the genetic constructs and phenotypic changes described in this report will benefit the future breeding and characterization of ornamental flowers.
尽管已知诸如拟南芥TCP3阻遏物之类的嵌合阻遏物对花的形态和颜色有显著影响，但其在细胞水平上对花瓣的影响尚不清楚。仙客来是一种在冬季生长的代表性盆栽花卉，其花中表达的基因的启动子序列也未知。在这里，我们从据报道在花瓣中表达的仙客来基因中分离出了八个启动子。然后将这些启动子与四种嵌合阻遏物融合，并导入模式花蓝猪耳中，以筛选用于花卉育种的启动子和阻遏物的有效组合。正如预期的那样，一些构建体在转化后改变了花的表型。我们进一步在细胞水平上分析了嵌合阻遏物的作用。我们观察到复杂的花瓣和叶片锯齿伴随着过多的维管束分支。紫色花青素的二色性被推断导致花朵呈蓝色，而细胞增殖失衡似乎导致花朵向下弯曲。因此，本报告中描述的基因构建体和表型变化将有利于未来观赏花卉的育种和特性鉴定。
