The MADS-box gene family encodes a type of transcription factor, and plays a key role in the growth and development of plants. Here, we identified 62 MADS-box genes in the melon (Cucumis melo) genome using bioinformatics methods. These genes were divided into type I Mα, Mγ, and Mδ subfamilies (26 members) and type II MIKCC subfamilies (36 members) by phylogenetic analysis. There were no genes in type II AGL12, BS, TM8, and MIKC* subfamilies, and type I Mβ subfamilies. Conserved motif analysis showed that all motifs had a subfamily-specific distribution except the M domain. The expression analysis of the MADS-box genes showed different expression characteristics. In summary, this study is the first to identify melon MADS-box genes and analyze their gene structures, subfamily distribution, and expression characteristics. These results provide a foundation for investigating the functions of the melon MADS-box genes.
Xin Hao, Yu Fu, Wei Zhao, Lifei Liu, Rengui Bade, Agula Hasi and Jinfeng Hao
Na Liu, Baoli Zhou, Xin Zhao, Bo Lu, Yixiu Li and Jing Hao
Verticillium wilt (caused by Verticillium dahliae), a soilborne disease, often causes significant reductions of yield in eggplant (Solanum melongena L.) production where crop rotation is limited. Rootstock replacement through grafting is considered an effective method to control this disease. This 2-year study investigated the eggplant yield, resistance to verticillium wilt, and allelochemicals in root exudates of eggplant grafted onto a tomato rootstock. Both disease incidence and disease severity on grafted eggplant were markedly lower than those of nongrafted eggplants. Fifteen days after V. dahliae inoculation, grafted eggplants did not exhibit any infection, whereas the disease incidence and disease severity index of the nongrafted eggplants were 68.3% and 37.8% in 2006 and 66.7% and 36.3% in 2007, respectively. Twenty-five days after inoculation, disease incidences on grafted eggplants were only 8.1% and 9.5% in 2006 and 2007, respectively, but those of the nongrafted eggplants increased to 100%. As a result, early yield, total yield, and average fruit weight were significantly increased by grafting when inoculated with V. dahliae in 2006 and 2007. Mycelium growth of V. dahliae was inhibited by the root exudates of grafted eggplants. In contrast, the root exudates of nongrafted eggplants enhanced the mycelium growth. The gas chromatography–mass spectrometry analysis revealed that the composition in the root exudates released by grafted eggplants differed not only from the nongrafted eggplants, but also from the tomato rootstock plants. Ten chemical classes were isolated and identified in root exudates of grafted eggplants. Carbazoles, amines, azulene, and fluorene were only detected in the grafted eggplants. The relative contents of ester compounds were the highest in the root exudates from the grafted eggplant followed by derivatives of benzene, whereas the relative contents of benzene derivatives were much higher than that of the ester compounds in the root exudates from the nongrafted eggplant and tomato rootstock.