Preliminary Analysis On Expression Characteristics And Function Of TAC2 Gene In Salix Psammophila

The study of plant branch development is a key issue in plant architecture construction,which is of great significance in plant function and habitat adaptation.Salix psammophila is an important tree species for shelterbelt and erosion control in northwest China.The study on genetic mechanism related to its branching of S.psammophila is conducive to understanding the molecular mechanism of spatial structure formation and subsequent molecular breeding.In this thesis,SpsTAC2 gene expression localization and its overexpressed 84 K poplar phenotypic and transcriptome analysis are the main contents,and the results are as follows:(1)Subcellular localization showed that SpsTAC2 protein was expressed in both cell membrane and nucleus;RNA in situ hybridization showed that SpsTAC2 gene was mainly expressed in immature xylem.(2)33 transgenic lines with 84 K overexpression of SpsTAC2 were identified,and 12 of them had high expression of SpsTAC2.At the seedling stage,compared with non-transgenic 84 K poplar,the plant height of each line decreased significantly,and the plants with relatively high expression level presented double branches.Anatomical structure analysis showed that the xylem thickness of double-branched plants increased significantly and the gelatinous layer appeared.(3)Transcriptome sequencing analysis was used to screen several differentially expressed genes,which were mainly enriched in plant hormones,photosynthesis and carbohydrate metabolism.These results indicate that SpsTAC2 gene has a certain effect on lateral branch differentiation,xylem development and plant height change.The conclusion is that SpsTAC2 gene may combine with Aux/IAA,AP2 and other transcription factors to regulate the auxin and ethylene pathways of plant hormones,and then change plant architecture.The expression level of SpsTAC2 gene is likely to be the main factor affecting its function.This thesis further enriched the molecular function research of IGT gene family,and laid a foundation for the subsequent research and utilization of SpsTAC2 gene function.