Effect Of The Deletion Of PFS Gene On The Pollen Development Of Rice

Polyploidization is an important approach for rice breeding,but the low seed setting rate caused by meiotic disturbances has always been a bottleneck restricting the breeding of polyploid rice.The successful breeding of PMeS,a meiotic stable strain,broke through the difficulties of low seed setting rate.Previous studies confirmed that pollen fertility of PMeS was normal and had high seed setting rate.Comparative proteomic analysis of meiotic PMeS and non-PMeS anther proteins was performed,and the ABC1 family member PFS(Pollen Fertility Stability)was significantly expressed in PMeS.The pollen fertility of pfs decreased significantly,meiosis and abnormal pollen appeared early.The specific mechanism of PFS on pollen development needs to be further studied.In this experiment,T-DNA insertion mutants 9007,9025,CG93,wild-type Nipponbare and Zhonghua 11 were used as research materials.The main findings were as follows:(1)Bioinformatics analysis showed that the PFS gene was located on rice chromosome 11,and the CDS sequence was 1146 bp in length.This gene was translated into an open reading frame to obtain a protein sequence of 381 amino acids in length.Bioinformatics software predictive analysis found that the relative molecular mass of the protein is 44138.5、the theoretical isoelectric point PI is 9.17 and the first 60 amino acids may form a transmembrane structure.In addition,the protein contains a typical ABC1 family domain and AarF domain.Its tertiary structure predicts that the protein is composed of 9 alpha helices and 4 beta strands.(2)Analysis of PFS gene expression pattern showed that the gene was expressed in anthers and ovary tissues but not in roots and leaves of vegetative tissues.The gene has strong expression in early,middle and late stages of microspore development.In the early ovary 3 days and 5 days after flowering,the gene was predominantly expressed in the embryo.With the advancement of the development stage,in addition to the obvious expression of the site of the embryo,some cells of the endosperm began to express the gene.(3)Mutant and replenishment analysis showed that the pollen fertility and seed setting rate of pps were significantly decreased,meiosis and early pollen were abnormal.And the gene function returned to normal after compensation.It shows that there is a significant positive correlation between the level of PFS expression and pollen development.(4)Subcellular localization analysis showed that the protein encoded by the PFS gene is mainly located in the cell membrane,indicating that the protein is likely to be a transmembrane protein involved in transmembrane transport and energy metabolism.(5)In transcriptome analysis,pfs and wild-type meiotic transcripts were analyzed by transcriptome sequencing.The results showed that pfs were up-regulated and down-regulated in wild-type genes were 235 and 45,respectively,which up-regulated the expression of genes It mainly focuses on catabolism,stress response,extracellular components and hydrolase activity.Its involved metabolic pathways are mainly concentrated in the process of phenylpropanoid biosynthesis and phenylalanine metabolism,and down-regulate the function of expressed genes.It mainly focuses on the process of protein catabolism,carbohydrate metabolism and macromolecular biosynthesis.The metabolic pathways involved are mainly concentrated on ubiquitin-regulated proteolysis and processing of proteins in the endoplasmic reticulum.