Characterization of wheat Bell1-type homeobox genes in floral organs of alloplasmic lines with Aegilops crassa cytoplasm.

Background: Alloplasmic wheat lines with Aegilops crassa cytoplasm often show homeotic conversion of stamens into pistils under long-day conditions. In the pistillody-exhibiting florets, an ectopic ovule is formed within the transformed stamens, and female sterility is also observed because of abnormal integument development.

Results: In this study, four wheat Bell1-like homeobox (BLH) genes were isolated and named WBLH1 to WBLH4.

The spatial expression patterns of DROOPING LEAF orthologs suggest a conserved function in grasses.

The DROOPING LEAF (DL) gene regulates carpel specification in the flower and midrib formation in the leaf in Oryza sativa (rice). Loss-of-function mutations in the dl locus cause homeotic transformation of carpels into stamens and lack of midrib, resulting in the drooping leaf phenotype. DL is a member of the YABBY gene family and is closely related to the CRABS CLAW (CRC) gene in Arabidopsis thaliana.

Class D and B(sister) MADS-box genes are associated with ectopic ovule formation in the pistil-like stamens of alloplasmic wheat (Triticum aestivum L.).

Homeotic transformation of stamens into pistil-like structures (pistillody) has been reported in cytoplasmic substitution (alloplasmic) lines of bread wheat (Triticum aestivum L.) that have the cytoplasm of a related wild species, Aegilops crassa. An ectopic ovule differentiates in the pistil-like stamen in the alloplasmic wheat.

Altered expression of wheat AINTEGUMENTA homolog, WANT-1, in pistil and pistil-like transformed stamen of an alloplasmic line with Aegilops crassa cytoplasm.

Homeotic transformation of stamens into pistil-like structures, called pistillody, has been reported in some alloplasmic common wheat lines with Aegilops crassa cytoplasm. An alloplasmic line of Chinese Spring ditelosomic 7BS (CSdt7BS) with Ae. crassa cytoplasm lacking the long arm of the chromosome 7B shows pistillody, and the pistils and transformed stamens are sterile due to abnormal ovule development.

Genetic and epigenetic alteration among three homoeologous genes of a class E MADS box gene in hexaploid wheat.

Bread wheat (Triticum aestivum) is a hexaploid species with A, B, and D ancestral genomes. Most bread wheat genes are present in the genome as triplicated homoeologous genes (homoeologs) derived from the ancestral species. Here, we report that both genetic and epigenetic alterations have occurred in the homoeologs of a wheat class E MADS box gene.