title: The D-lineage MADS-box gene OsMADS13 controls ovule identity in rice.
abstract: Genes that control ovule identity were first identified in Petunia. Co-suppression of both FLORAL BINDING PROTEIN 7 (FBP7) and FBP11, two D-lineage genes, resulted in the homeotic transformation of ovules into carpelloid structures. Later in Arabidopsis it was shown that three genes, SHATTERPROOF1 (SHP1), SHP2, and SEEDSTICK (STK), redundantly control ovule identity, because in the stk shp1 shp2 triple mutant ovules lose identity and are transformed into carpel and leaf-like structures. Of these three Arabidopsis genes STK is the only D-lineage gene, and its expression, like FBP7 and FBP11, is restricted to ovules. OsMADS13 is the rice ortholog of STK, FBP7, and FBP11. Its amino acid sequence is similar to the Arabidopsis and Petunia proteins, and its expression is also restricted to ovules. We show that the osmads13 mutant is female sterile and that ovules are converted into carpelloid structures. Furthermore, making carpels inside carpels, the osmads13 flower is indeterminate, showing that OsMADS13 also has a function in floral meristem determinacy. OsMADS21 is most likely to be a paralog of OsMADS13, although its expression is not restricted to ovules. Interestingly, the osmads21 mutant did not show any obvious phenotype. Furthermore, combining the osmads13 and the osmads21 mutants did not result in any additive ovule defect, indicating that osmads21 does not control ovule identity. These results suggest that during evolution the D-lineage gene OsMADS21 has lost its ability to determine ovule identity.
authors: Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy.
authors: Ludovico
authors: L
authors: Dreni
authors: Sara
authors: S
authors: Jacchia
authors: Fabio
authors: F
authors: Fornara
authors: Monica
authors: M
authors: Fornari
authors: Pieter B F
authors: PB
authors: Ouwerkerk
authors: Gynheung
authors: G
authors: An
authors: Lucia
authors: L
authors: Colombo
authors: Martin M
authors: MM
authors: Kater
mesh_terms: D000595:Amino Acid Sequence; D015152:Blotting, Northern; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D017403:In Situ Hybridization; D026161:MADS Domain Proteins / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins