Vincent Coral A, Carpenter Rosemary, Coen Enrico S
John Innes Centre, Colney Lane, Norwich NR4 7UH, UK.
Plant J. 2003 Feb;33(4):765-74. doi: 10.1046/j.1365-313x.2003.01666.x.
The DEFICIENS (DEF) gene is required for establishing petal and stamen identity in Antirrhinum and is expressed in all three layers of the floral meristem in whorls 2 and 3. Expression of DEF in a subset of meristem layers gives rise to organs with characteristic shapes and cell types, reflecting altered patterns and levels of DEF gene activity. To determine how the contributions of layers and gene activity interact, we exploited a DEF allele which carries a transposon insertion in the MADS box region to generate periclinal chimeras expressing alleles with different activities. By comparing the phenotype, development and expression patterns of these chimeras we show that expression of DEF in L1 makes a major contribution to morphology in whorl 2, irrespective of the allele. By contrast L1 expression is largely unable to rescue whorl 3, possibly because of a non-autonomous inhibitor of DEF activity in this whorl.
DEFICIENS（DEF）基因对于金鱼草花瓣和雄蕊特征的建立是必需的，并且在第二轮和第三轮花分生组织的所有三层中均有表达。DEF在分生组织层的一个子集中表达会产生具有特征形状和细胞类型的器官，这反映了DEF基因活性模式和水平的改变。为了确定层的贡献与基因活性如何相互作用，我们利用了一个DEF等位基因，该等位基因在MADS盒区域携带转座子插入，以产生表达具有不同活性等位基因的周缘嵌合体。通过比较这些嵌合体的表型、发育和表达模式，我们发现L1层中DEF的表达对第二轮的形态有主要贡献，而与等位基因无关。相比之下，L1层的表达在很大程度上无法挽救第三轮，这可能是因为该轮中存在DEF活性的非自主抑制剂。
