Xia Yan, Shi Min, Chen Weiwei, Hu Ruoqian, Jing Danlong, Wu Di, Wang Shuming, Li Qingfen, Deng Honghong, Guo Qigao, Liang Guolu
Key Laboratory of Horticulture Science for Southern Mountains Regions of Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, Chongqing, China.
State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences of Southwest University, Chongqing, China.
Front Plant Sci. 2020 Jan 17;10:1685. doi: 10.3389/fpls.2019.01685. eCollection 2019.
Double-flower , of which one phenotype is homeotic transformation of sepals into petals, is a new germplasm for revealing the molecular mechanisms underlying the floral organ transformation. Herein, we analyzed the sequence, expression pattern and functional characterization of , which encoded a B-class floral homeotic protein referred to as ortholog, from genetically cognate single-flower and double-flower . Phylogenetic analysis suggested that the gene was assigned to the rosids PI/GLO lineage. Analysis of protein sequence alignments showed that EjPI has typical domains of M, I, K, and C, and includes a distinctive PI motif at the C-terminal region. Compared with asterids PI/GLO lineage, the K1 and K3 subdomains of EjPI both contain a single amino acid difference. Subcellular localization of EjPI was determined to be in the nucleus. Expression pattern analysis revealed that expressed not only in petals, filament, and anther in single-flower , but also in petaloid sepals in double-flower . Meanwhile, there were high correlation between transcript level and petaloid area within a sepal. Furthermore, 35S:: transgenic wild-type Arabidopsis caused the homeotic transformation of the first whorl sepals into petaloid sepals. Ectopic expression of in transgenic mutant Arabidopsis rescued normal petals and stamens. These results suggest expression pattern of is associated with the formation of petaloid sepal. Our study provides the potential application of for biotechnical engineering to create petaloid sepals or regulate floral organ identity in angiosperms.
重瓣花，其一种表型是萼片向花瓣的同源异型转变，是揭示花器官转变潜在分子机制的一种新种质。在此，我们分析了来自遗传同源的单瓣花和重瓣花中编码一种B类花同源异型蛋白（称为EjPI直系同源物）的EjPI的序列、表达模式和功能特性。系统发育分析表明，EjPI基因属于蔷薇分支的PI/GLO谱系。蛋白质序列比对分析表明，EjPI具有典型的M、I、K和C结构域，并且在C末端区域包含一个独特的PI基序。与菊分支的PI/GLO谱系相比，EjPI的K1和K3亚结构域均含有一个单氨基酸差异。EjPI的亚细胞定位确定在细胞核中。表达模式分析表明，EjPI不仅在单瓣花的花瓣、花丝和花药中表达，而且在重瓣花的瓣化萼片中也表达。同时，EjPI转录水平与萼片中瓣化面积之间存在高度相关性。此外，35S::EjPI转基因野生型拟南芥导致第一轮萼片向瓣化萼片的同源异型转变。EjPI在转基因AP2突变体拟南芥中的异位表达挽救了正常的花瓣和雄蕊。这些结果表明EjPI的表达模式与瓣化萼片的形成有关。我们的研究为生物技术工程在被子植物中创造瓣化萼片或调节花器官特征提供了EjPI的潜在应用。
