Molecular Evolution Of Terpene Synthase Gene Family In Angiosperms

Terpenoids(terpenoids)are compounds that are widely found in all living organisms and function as phytohormones,modification reagents for proteins,antioxidants and so on.Terpene synthases(TPS)are enzymes that catalyze the synthesis of terpenoids and play an important role in plant growth and resistance regulation.In order to study the evolutionary history of TPS gene family and explore the evolutionary characteristics and functions of TPS gene in different plants,this study analyzed the molecular evolution,gene structure and gene expression of TPS gene family.The main results are as follows.1.To investigate the distribution of TPS gene families in plant systems,a total of 1199 TPS gene protein sequences were identified using 34 representative plant genomic data.The results of phylogenetic analysis showed that the TPS gene family in plant systems was mainly divided into 10 subfamilies,the The results showed that the TPS gene family in plants was divided into 10 subfamilies,namely TPS-a,TPS-b,and TPS-g,TPS-d,TPS-e,TPS-f,TPS-h,TPS-c,TPS-new1,TPS-new2.Among them,TPS-a,TPS-b and TPS-g is endemic to angiosperms,TPS-d is specific to gymnosperms,TPS-h is endemic to early land plants.In addition,two new subclades TPS-new1 and TPS-new2 were identified in angiosperms.2.To investigate the distribution and evolutionary relationships of the TPS gene subfamilies in angiosperms,a phylogenetic tree was constructed by sequence alignment.The results indicate that TPS-a has only one branch in angiosperms,but the number of member copies is high.The The TPS-b subfamily had at least one replication event in angiosperms,and the two branches were labeled as TPS-b1 and TPS-b2.TPS-g subfamily had a replication event in angiosperms,and two branches were labeled as TPS-g1 and TPS-g2,respectively.Compared with the TPS-a/b/g subfamilies,the TPS-e/f subfamily is relatively conservative in its expansion,consisting of only one member for each species from early terrestrial plants to angiosperms.TPS-c subfamily is an ancestral evolutionary branch,which is most widely distributed in 10 subfamilies.In addition,new subfamilies TPS-new1 and TPS-new2 were found in Asparagus officinalis,Calamus simplicifolius and Ananas comosus,while Phalaenopsis equestris and Amborella trichopoda were found separately in the former,and Cinnamomum kanehirae and Elaeis guineensis were only found in the latter.3.To investigate the relationship between the conserved motif and gene composition structure of TPS proteins and the taxonomic and phylogenetic evolution of TPS gene family in angiosperms,the conserved motifs distribution and gene structure of TPS protein were analyzed from the protein sequence level.It was found that the motif and intron phase composition of each subfamily protein were basically the same but the motif deletion may occur in the evolution process,resulting in different subfamilies containing conserved motifs and intron phases are not exactly the same,thus forming different subfamilies.The conserved motifs of TPS-new1 and TPS-new2 were basically consistent with those of TPS-e/f subfamily,which was consistent with their phylogenetic results in the phylogenetic tree.In addition,the results of the repeat gene type screen for TPS genes showed that the largest proportion of dispersed repeat gene types contributed significantly to the expansion of the TPS gene family.4.To investigate the functions of TPS genes related to different tissues or developmental periods in plants,gene expression analysis of four species,Arabidopsis thaliana,Oryza sativa,Solanum lycopersicum and Glycine max,revealed that the TPS-a subfamily is essential for plant reproductive growth and development,with significant expression in most tissues of Arabidopsis thaliana,higher expression in Oryza sativa shoots and post-flowering spikes,and higher expression in fruit,root,and leaf tissues of Solanum lycopersicum.The TPS-b,TPS-c,TPS-e/f,and TPS-g subfamilies had less effect on plant growth and development compared to the TPS-a subfamily,and were only highly expressed in specific tissue periods,which was closely related to the copy number of the family members.The results of TPS gene expression data in soybean leaf tissues under different stress treatments indicated that all subfamilies were associated with resistance in soybean,and in particular,significant expression of 7,10,and 14 TPS genes was observed only in leaf tissues under drought stress,flooding stress,or control,respectively.Analysis of the cis-regulatory elements(CREs)of the TPS gene family revealed that the TPS gene family had the largest number of light-responsive elements and most of them were distributed in the TPS-a subfamily.Most of the remaining CREs belonged to the phytohormone response class and less to the plant growth and development class.In this study,we describe the evolutionary history and expansion mechanism of the TPS gene family in angiosperms,specifically analyze the evolution of each subfamily in angiosperms,and propose new insights.We identified two TPS-new1 and TPS-new2 subfamilies,which are consistent with the conserved motifs of TPS-e/f subfamily.The results of the conserved motif and gene structure analysis showed that the protein motif and intron phase composition of the subfamilies were generally consistent with the TPS gene family phylogenetic tree affinity.The TPS-a subfamily plays an important role in plant reproductive growth and development.This study lays some research foundation for further understanding the biological functions of TPS gene family,and has important theoretical implications for the application of TPS gene family in realistic genetic transformation or domestication breeding.