Identification And Expression Analysis Of The E2F/DP Genes Under Salt Stress In Medicago Truncatula

Growth and development of a multicellular organism relies on cell division, which is accurately regulated by cell cycle. The process of cell cycle is controlled by the complex of cyclin and cyclin dependent kinase, cell cycle control in plants converges on the Rb/E2F/DP pathway.Plants can moderate the cell cycle under salt stress to benefit their growth and development. However, the mechanism underlying cell cycle control under salt stress is still unclear. Here, we identified five predicted E2F/DP genes in the Medicago truncatula genome, including three E2Fs, one DP, and one DEL. The conserved domains of the E2F/DP proteins were relatively well conserved with those of Arabidopsis thaliana and Oryza sativa. Intron/exon organization analyses indicated that Medtr;E2Fc and Medtr;DPa gained/lost introns in the conserved domains during recent evolutionary process. Furthermore, an expression analysis showed that these genes were expressed with varied transcription levels in all of the tissues tested. Contrasting gene expression changes in response to salt treatment in salt-tolerant genotype versus salt-sensitive genotype indicated that Medtr;DPa might be a candidate gene underlying the salt tolerance. This study will contribute to the understanding of the E2F/DP transcription factors in M. truncatula and the mechanism organizing cell cycle regulation under salt stress.