Analysis Of Expression Characteristics Of TCTP Gene And Screening Of Its Interacting Proteins In Medicago Truncatula

The symbiotic relationship between legumes and rhizobia is beneficial to both agricultural development and ecological protection.Studies on the function of genes related to the symbiosis of leguminous plants can make better use of this mutually beneficial relationship to promote the development of healthy ecological agriculture.In this study,the function of TCTP gene in Medicago truncatula was researched to further reveal the molecular mechanisms of TCTP in symbiotic nodulation.Translationally controlled tumor protein?TCTP?is a protein family that is widely existed and highly conserved in eukaryotes and plays major roles in regulation of plant growth and development.Previous studies on the subcellular localization,RNAi and gene overexpression of a homologous gene of TCTP,MTR₁g083380,have confirmed its role in the symbiotic interaction between Medicago truncatula and rhizobia.In order to further understand the function of TCTP gene in symbiotic nodulation of legumes,the spatiotemporal expression and the tissue-specific expression of MTR₁g083380 gene were analyzed;and its possible interacting proteins were explored by yeast two-hybrid assay and bimolecular fluorescence complementation experiment.The results of spatiotemporal expression analysis indicated that MTR₁g083380 gene was expressed at different developmental stages,and the highest expression level of the inoculated roots is the 18 th day,while the 28 th day was the highest expression level in uninoculated roots.The relative expression levels in different tissues showed that the expression level in the nodules was higher than that roots with nodules removed.The analysis of tissue-specific expression indicated that the expression of the target gene was started from the stele of root,and then expressed in the cortex and epidermis,regardless of the inoculation or uninoculation.In the longitudinal direction of the root,the target gene are expressed in the elongation zone and maturation zone,but not expressed in root tips and root hairs.In the new lateral roots,MTR₁g083380 was not expressed at the root tip,but expressed at the origin of lateral roots.In the nodule,MTR₁g083380 was expressed in the other parts except the meristematic area in the early stage;and expressed in the whole nodule with the prolonging of time.The results of yeast two-hybrid experiment and the bimolecular fluorescence complementation experiment revealed that there is an interaction between TCTP and ethylene receptor?MTR₁g079790?.We refer that MTR₁g083380 regulates the nodulation process through ethylene signaling pathway.