Isolation of a differentially spliced C-type flower specific AG-like MADS-box gene from Crocus sativus and characterization of its expression

Abstract

We have cloned and characterized the expression of Crocus sativus AGAMOUS1 (CsAG1), a putative C-type MADS-box gene homologous to AGAMOUS (AG) from a triploid monocot species crocus (Crocus sativus L.). The typical domain structure of MIKC-type plant MADS proteins was identified. Phylogenetic analysis of the deduced amino acid sequence indicated that the isolated gene forms a clade with the AGAMOUS homologs from the monocots Hyacinthus orientalis and Phalaenopsis equestris. A differential splicing event altering the amino acid sequence at the C terminus was identified, leading to the formation of two mRNAs differing ten nucleotides in size. The presence of both differentially spliced transcripts was restricted only to mature crocus flowers and particularly to stamens and carpels.