Reference "The D-lineage MADS-box gene OsMADS13 controls ovule identity in rice"

Reference ID

11683

Title

The D-lineage MADS-box gene OsMADS13 controls ovule identity in rice

Source

The Plant journal : for cell and molecular biology, 2007, vol. 52, pp. 690-699

Authors (8)

Dreni-L	Jacchia-S
Fornara-F	Fornari-M
Ouwerkerk-P-B	An-G
Colombo-L	Kater-M-M

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.