Müller K J, Romano N, Gerstner O, Garcia-Maroto F, Pozzi C, Salamini F, Rohde W
MPI für Züchtungsforschung, Köln, Germany.
Nature. 1995 Apr 20;374(6524):727-30. doi: 10.1038/374727a0.
In barley (Hordeum vulgare L.) the unit of inflorescence is the spikelet, which bears a fertile bract, the lemma, and the floret consisting of palea, two lodicules, three stamens and the pistil. The Hooded mutation causes the appearance of an extra flower of inverse polarity on the lemma. This phenotype is governed by the single dominant genetic locus K3. Here we show that the homeobox gene Knox3 represents this locus. Ectopic Knox3 gene expression in the primordium of the extra floret is caused by a 305-base pair duplication in intron 4, and phenocopies of the mutation are obtained in the heterologous tobacco system by Knox3 overexpression. It is concluded that homeotic genes of the Knox gene family are involved in floral evocation. Furthermore, the study of polarity of reproductive organs in K and related mutants can now focus on homeobox genes.
在大麦（Hordeum vulgare L.）中，花序单位是小穗，小穗带有一枚可育苞片、外稃，以及由内稃、两枚浆片、三枚雄蕊和雌蕊组成的小花。“头巾状”突变导致在外稃上出现一朵极性相反的额外小花。这种表型由单一显性遗传位点K3控制。我们在此表明，同源异型盒基因Knox3代表该位点。额外小花原基中异位的Knox3基因表达是由内含子4中一段305个碱基对的重复所引起的，并且通过Knox3的过表达在异源烟草系统中获得了该突变的拟表型。得出的结论是，Knox基因家族的同源异型基因参与了花的诱导。此外，对K及其相关突变体中生殖器官极性的研究现在可以聚焦于同源异型盒基因。
