title: Ectopic expression of a Catalpa bungei (Bignoniaceae) PISTILLATA homologue rescues the petal and stamen identities in Arabidopsis pi-1 mutant.
abstract: PISTILLATA (PI) plays crucial roles in Arabidopsis flower development by specifying petal and stamen identities. To investigate the molecular mechanisms underlying organ development of woody angiosperm in Catalpa, we isolated and identified a PI homologue, referred to as CabuPI (C. bungei PISTILLATA), from two genetically cognate C. bungei (Bignoniaceae) bearing single and double flowers. Sequence and phylogenetic analyses revealed that the gene is closest related to the eudicot PI homologues. Moreover, a highly conserved PI-motif is found in the C-terminal regions of CabuPI. Semi-quantitative and quantitative real time PCR analyses showed that the expression of CabuPI was restricted to petals and stamens. However, CabuPI expression in the petals and stamens persisted throughout all floral development stages, but the expression levels were different. In 35S::CabuPI transgenic homozygous pi-1 mutant Arabidopsis, the second and the third whorl floral organs produced normal petals and a different number of stamens, respectively. Furthermore, ectopic expression of the CabuPI in transgenic wild-type or heterozygote pi-1 mutant Arabidopsis caused the first whorl sepal partially converted into a petal-like structure. These results clearly reveal the functional conservation of PI homologues between C. bungei and Arabidopsis.
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, PR China. Electronic address: jingdanlong110@126.com.
authors.forename: Danlong
authors.initials: D
authors.lastname: Jing
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, PR China. Electronic address: xia_y@outlook.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Biotechnology Research Center, China Three Gorges University, Yichang City 443002, Hubei Province, PR China. Electronic address: chenfj616@163.com.
authors.forename: Faju
authors.initials: F
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, PR China. Electronic address: wangzhi6666@126.com.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, PR China. Electronic address: shougong.zhang@caf.ac.cn.
authors.forename: Shougong
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, PR China. Electronic address: wangjh@caf.ac.cn.
authors.forename: Junhui
authors.initials: J
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D029402:Bignoniaceae / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D026161:MADS Domain Proteins; C090225:PISTILLATA protein, Arabidopsis
keywords: B-class MADS box gene; Catalpa bungei; Ectopic expression; Flower development; Functional conservation; PISTILLATA