Effects of <i>SvAPETALA1-5</i> gene on floral organ development in <i>Senecio vulgaris</i>.

Asteraceae is a large class of eudicots with complex capitulum, and little is known regarding the molecular regulation mechanism of flower development. <i>APETALA1</i>(<i>AP1</i>) belongs to the MADS-box gene family and plays a key role in plant floral induction and floral organ development. In this study, the bioinformatics and tissue-specific expression of <i>AP1</i> homologous gene <i>SvAP1-5</i> in <i>Senecio vulgaris</i> were analyzed. Based on VIGS technology, <i>SvAP1-5</i> gene silencing plants were created, and <i>SvAP1-5</i> was overexpressed in <i>Solanum nigrum</i>. The results of bioinformatics analysis showed that <i>SvAP1-5</i> gene had typical MADS-box and K-box structure, and contains FUL motif and paleoAP1 motif at the C-terminal. <i>SvAP1-5</i> belongs to the euFUL branch of <i>AP1</i> gene. qRT-PCR results showed that <i>SvAP1-5</i> was expressed in bracts, petals and carpels, and was highly expressed in carpels. Compared with the control group, <i>SvAP1-5</i> gene silencing resulted in irregular petal dehiscence, increased stigma division, and carpel dysplasia. The fruit development of <i>SvAP1-5</i> overexpressing <i>S.nigrum</i> plants was abnormal, and the hyperplastic tissue similar to fruit appeared. In summary, <i>SvAP1-5</i> gene may be involved in the development of petals and carpels and plays an important role during the development of <i>S.vulgaris</i>.