Study On Sex Reversal Mechanism Of Taxus Cuspidata

Taxus cuspidate is the only rare species of Taxus（4 species and 1 variety）distributed in Northeast China,and its conservation value,ornamental value and market value are among the top plants.Although some scholars have studied this species from different perspectives,the understanding of sex reversal phenomenon,which frequently occurred in Taxus cuspidate population is almost blank,and no one has conducted systematic investigation and studied its mechanism.This project proposed the following four questions and designed corresponding experiments to study the sexual reversal phenomenon of Taxus cuspidate:1)The relationship between the frequency of sexual reversal and habitat,tree age and varieties in wild and cultivated populations of Taxus cuspidate.2)Is sex reversal caused by changes in hormone levels in plants?3)How to screen out differential genes based on transcriptome sequencing and track their functions?4)Can sex reversal of Taxus cuspidata be induced artificially?Through the above research will figure out the frequency of the Taxus cuspidata sex reversal phenomenon,cause sex reversal of habitat conditions and tree age and the influence of the varieties,reveals the relationship between the endogenous hormone level changes and sex reversal,and then discusses how hormone induced sex-linked gene expression pathwayopens,lays the foundation for understanding the molecular mechanism of sex reversal phenomenon.The main conclusions are as follows:（1）The results of field investigation on sex reversal of Taxus cuspidata are as follows:the frequency of sex reversal of plants over 30 years old is much higher than that of plants over 10-30 years old;The cultivated type is slightly more than the wild type,and the male to female is more than the female to male.（2）The contents of IAA,GA₃,ABA and TZ in male and female branches of Ta xus cuspidata without sexual reversal over 30 years were higher than those of male and female branches of plants without sexual reversal in 10 years,and the contents of IA A,GA₃,ABA and TZ in X→C were higher than those of plants without variation i n 30 years.It can be seen that Taxus cuspidata realized branch gender variation by incre asing its own IAA,GA₃,ABA and TZ contents;And more than 30 years old,the e ndogenous hormone of Taxus cuspidata reached a high level,which provided basic co nditions for sexual reversal.（3）It is speculated that the genes rpn11 and abcb13 negatively regulate the IAA co ntent of female branches in X→C Taxus,so that the IAA content of female branches is lower than that of male branches,resulting in sexual reversal;It is speculated that g enes cdc14a and CDC48 negatively regulate the ABA content of female branches in X→C Taxus,so that the ABA content of female branches is lower than that of male bra nches,resulting in sexual reversal;It is speculated that RGA1 gene negatively regulate s the GA₃content of female branches in X→C Taxus,so that the GA₃ content of fem ale branches is lower than that of male branches,resulting in sexual reversal.