Genome-wide Identification And Analysis Of The TIFY Family In Walnut

Walnut(Juglans regia)is an important woody oil tree species in China.In practical production,abiotic stress such as drought,high temperature,and high salinity have a certain impact on the normal growth of walnut.The TIFY gene family is a unique and important gene family in plants,which plays an important role in plant growth and development,physiological metabolism,and stress resistance.In this study,the TIFY gene family was identified in walnut,its close relative Carya illinoinensis(also known as pecan),and the model plant Arabidopsis thaliana(used as a reference).The distribution and evolutionary relationship of the TIFY gene family in the genomes of the three species were analyzed.The protein-protein interaction(PPI)network of the walnut TIFY family was explored,and it was found that the PPI network of the TIFY protein family is involved in regulating plant signal pathways such as jasmonic acid,ethylene,and MAPK,as well as signal transduction,stress resistance,and photomorphogenesis,playing an important role in plant growth and development and response to stress.The main research results obtained are as follows:1.We identified 21,22,and 17 members of the TIFY gene family in walnut,hickory,and Arabidopsis,respectively.It was found that the TIFY gene family was divided into 8 branches in the evolutionary tree,and the structure of the subfamily members of the same branch was highly similar.The number of JAZ subfamilies in the TIFY gene family is significantly greater than other subfamilies.The gene structure,conserved domain and cis acting elements of walnut TIFY gene family members were also identified.2.By analyzing the expression of JrTIFYs gene family under different patterns,it was found that the members of the TIFY gene family mainly responded to salt stress,followed by heat stress,and the expression of JrTIFYs under drought stress had relatively little change.In addition,the results showed that JrTIFY01 and JrTIFY09 had higher expression levels in early ripening and late ripening of walnut fruit.JrTIFY04 expression level was higher only in early ripening of fruit.The expressions of JrTIFY03,JrTIFY14,JrTIFY18 and JrTIFY20 decreased first and then increased during fruit ripening,suggesting that the physiological metabolism of walnut fruit in early and late ripening requires the participation of these JrTIFYs gene family members.3.It is found that there are many collinearity gene pairs(9 and 11 pairs,respectively)in walnut and pecan,indicating that the TIFY gene family in both species has undergone a largescale expansion.Moreover,there are a large number of collinearity gene pairs in the TIFY gene family between the two species;The number of collinearity gene pairs belonging to the TIFY gene family in both species has reached an astonishing 33 pairs(some genes have a collinearity relationship with multiple genes).This indicates that the expansion event of the TIFY gene family occurred before the differentiation of these two species,and there was no large-scale variation and expansion of the TIFY gene family after the species differentiation.4.The protein and protein interaction network(PPI)of JrTIFY was predicted and analyzed.A total of 53 interacting proteins were found in the PPI network,which play an important role in various physiological functions of plants.Among them,JrTIFY08 and a transcription factor with a MYC domain have a major regulatory role in the PPI network.The interaction between two important proteins in the PPI network was successfully verified through Yeast Two-Hybrid Assay.Through the identification and analysis of the TIFY gene family in walnut,this study laid a foundation for the in-depth exploration of the resistance mechanism and the discovery of resistance genes in walnut.