Genome-wide investigation of the TIFY transcription factors in alfalfa (Medicago sativa L.): identification, analysis, and expression

Background Alfalfa (Medicago sativa L.) is an essential leguminous forage with high nutrition and strong adaptability. The TIFY family is a plant-specific transcription factor identified in many plants. However, few reports have been reported on the phylogenetic analysis and gene expression profiling of TIFY family genes in alfalfa. ResultA total of 84 TIFY genes belonging to 4 categories were identified in alfalfa, including 58 MsJAZs, 18 MsZMLs, 4 MsTIFYs and 4 MsPPDs, respectively. qRT-PCR data from 8 genes in different tissues revealed that most MsTIFY genes were highly expressed in roots. The expression of MsTIFY14 was up-regulated after different times in both thrips-resistant and susceptible alfalfa after thrips feeding, and the expression of the remaining MsTIFYs had a strong correlation with the time of thrips feeding. Different abiotic stresses, including drought, salt, and cold, could induce or inhibit the expression of MsTIFY genes to varying degrees. In addition, the eight genes were all significantly up-regulated by JA and/or SA. Interestingly, MsTIFY77 was induced considerably by all the biotic, abiotic, or plant hormones (JA or SA) except ABA. Conclusion Our study identified members of the TIFY gene family in alfalfa and analyzed their structures and possible functions. It laid the foundation for further research on the molecular functions of TIFYs in alfalfa.