Study On The Function And Mechanism Of MADS-box Protein MtSOC1 In Regulating The Growth And Development Of Medicago Truncatula

Medicago truncatula is a typical economic legume forage with high nutritional value.In addition,it has been widely studied as a model plant of legumes,which is of great significance for improving alfalfa yield and forage quality.SOC1(SUPPRESSOR OF OVEREXPRESSION OF CO 1)belongs to MIKC-like branch members of MADS-box transcription factor family,and plays a key pivotal role in regulating plant growth and development.It not only regulates flowering,but also affects seed development and responds to abiotic stress.Therefore,it is of great significance to study the function of MtSOC1 protein for the innovation of new strains with short maturity and high yield in Medicago truncatula.In order to further explore the function and regulatory mechanism of MtSOC1 protein in the growth and development of Medicago truncatula,this paper took The MtSOC1 of Medicago truncatula as the research object,and found that the amino acid sequence encoded by three MtSOC1 gene is highly similar to AtSOC1 through bioinformation analysis,and MtSOC1 protein was closely related to AtSOC1 protein,suggesting that MtSOC1 c was evolutionarily conserved.Then,the phenotypes of 35S:MtSOC1 c transgenic plants were analyzed,and it was found that the flowering period,internode length,seed size and seed germination rate of transgenic plants were significantly changed,which proved that MtSOC1 c not only has conserved function in regulating plant flowering,but also has new functions such as regulating seed development.At the same time,subcellular localization experiments and Yeast two-hybrid and fluorescence complementary experiments were used to verify that MtSOC1 c could interact with MtAGL15 and MtAGL16 proteins,which might be an important way for MtSOC1 c to regulate flowering and seed development.In conclusion,our work improves the role of MtSOC1 in regulating the flowering,which is beneficial to promote the understanding of the gene regulatory network of the flowering in Medicago truncatula,and reveals the new function of MtSOC1 differentiation during seed development.It also provides a new experimental basis for improving the yield and quality and molecular breeding in Medicago truncatula.