Identification And Expression Analysis Of AGO Gene Family Of Bupleurum Chinense DC

Bupleurum chinense DC is a commonly used bulk medicinal material.It has the functions of antipyretic and anti-inflammatory,sedative and analgesic,protecting liver and gallbladder,regulating intestines and intestines,and enhancing immunity.The quality of bupleurum bupleurum is affected by many factors in the process of growth and development.AGO(Argonaute)gene plays an important role in regulating plant growth and development and responding to stress.In this study,the members of AGO gene family in Bupleurum were screened and identified,and the physiological indexes and the relative expression of AGO gene family in different tissues,different growth stages and different stress conditions were investigated to explore the possible regulatory function of AGO gene in the growth and development of Bupleurum and its response to stress.Key findings were as follows:1.A total of 9 AGO genes were identified by analysis of Bupleurum,which belonged to 3subfamilies,which were consistent with the taxonomic relationship of Arabidopsis AGO gene family.The domain,conserved motif,secondary and tertiary structure of each gene were highly similar,and AGO was a relatively conserved gene in evolution.Physicochemical analysis showed that the proteins encoded by AGO gene were all basic hydrophilic unstable proteins,among which BcAGO1 A,BcAGO1 B,BcAGO2,BcAGO5,BcAGO7,BcAGO10 proteins had complete DDH/H catalytic residues,which may be responsible for catalytic cleavage.2.The relative expression levels of BcAGOs were different in different growth stages of Bupleurum.The expression of BcAGO5 was significantly higher in the stem than in the root and leaf of Bupleurum,while the expression of the other 8 genes was the highest in the leaf.BcAGO1 A,BcAGO1 B,BcAGO2,BcAGO4,BcAGO5,BcAGO7,BcAGO9,and BcAGO10 are abundantly expressed in the elongation and growth stages of roots and stems and play a role in the elongation and growth of roots and stems.BcAGO1 A,BcAGO2,BcAGO7,BcAGO10,BcAGO1 B,BcAGO4,BcAGO6,and BcAGO9 play a role in the growth and development of Bupleurum leaves.There was a synergistic effect of BcAGOs on the growth and development of Bupleurum.3.The activities of SOD(superoxide dismutase)and POD(peroxidase),the content of MDA(malondialdehyde),and the relative expression of BcAGOs were measured after water submergence,20%PEG-Hoagland’s simulated drought stress,and 38° high temperature stress.The results of correlation analysis showed that there was a significant correlation.Among them,BcAGO1 A,BcAGO2,BcAGO4,BcAGO5,BcAGO7,BcAGO9,BcAGO10,BcAGO1 B showed positive regulatory effects under drought stress.BcAGO1 A,BcAGO7 and BcAGO10 showed positive regulation under flooding stress,and BcAGO1 A,BcAGO1 B,BcAGO2,BcAGO4,BcAGO5,BcAGO7,BcAGO9 and BcAGO10 showed positive regulation under high temperature stress.BcAGO5 and BcAGO6 function as negative regulators in response to high temperature and flooding stress.The AGO gene family of bupleurum showed different regulatory effects in different parts of bupleurum,at different periods and under different stress treatments.The results could provide a theoretical basis for stress resistance breeding and variety improvement of bupleurum.