*Article* **Genome-Wide Analysis of the MADS-Box Transcription Factor Family in** *Solanum lycopersicum*

**Yunshu Wang 1,**† **, Jianling Zhang 1,**† **, Zongli Hu <sup>1</sup> , Xuhu Guo <sup>1</sup> , Shibing Tian <sup>2</sup> and Guoping Chen 1,\***


Received: 10 May 2019; Accepted: 15 June 2019; Published: 18 June 2019

**Abstract:** MADS-box family genes encode transcription factors that are involved in multiple developmental processes in plants, especially in floral organ specification, fruit development, and ripening. However, a comprehensive analysis of tomato MADS-box family genes, which is an important model plant to study flower fruit development and ripening, remains obscure. To gain insight into the MADS-box genes in tomato, 131 tomato MADS-box genes were identified. These genes could be divided into five groups (Mα, Mβ, Mγ, Mδ, and MIKC) and were found to be located on all 12 chromosomes. We further analyzed the phylogenetic relationships among Arabidopsis and tomato, as well as the protein motif structure and exon–intron organization, to better understand the tomato MADS-box gene family. Additionally, owing to the role of MADS-box genes in floral organ identification and fruit development, the constitutive expression patterns of MADS-box genes at different stages in tomato development were identified. We analyzed 15 tomato MADS-box genes involved in floral organ identification and five tomato MADS-box genes related to fruit development by qRT-PCR. Collectively, our study provides a comprehensive and systematic analysis of the tomato MADS-box genes and would be valuable for the further functional characterization of some important members of the MADS-box gene family.

**Keywords:** tomato; MADS-box; genome-wide analysis; floral organ; fruit development
