Molecular characterizations of the B-class MADS-box Genes in Physalis floridana. A, The exon-intron structure of the B-class MADS-box genes. Five B-class MADS-box genes were obtained. Boxes stand for the exons. Black boxes represent the coding regions, while the empty boxes represent untranslated regions. The lines represent introns. The length of each gene and the size of each intragenic region are given in base pairs. The digit above the box indicates the length of the corresponding exon, while the digits under the line indicate the length of the corresponding intron. For PFminDEF, two alternative splicing transcripts, a and b, are shown. B, Relative expression of the B-class MADS-box genes. Expression of PFGLO1, PFGLO2, PFDEF, PFTM6, and PFminDEF from left to right was investigated via qRT-PCR. PFACTIN was used as an internal control. The experiments were repeated three times using three independent biological samples. Mean expression values and sd are presented.