Reference "The barley Hooded mutation caused by a duplication in a homeobox gene intron"

Reference ID

8678

Title

The barley Hooded mutation caused by a duplication in a homeobox gene intron

Source

Nature, 1995, vol. 374, pp. 727-730

Authors (7)

Muller-K-J	Romano-N
Gerstner-O	Garcia-Maroto-F
Pozzi-C	Salamini-F
Rohde-W

Abstract

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.