Function Analysis Of Quinoa PEBP Family Gene And Seed Dormancy Related Genes

Chenopodium quinoa is a stress-resistant crop with high nutritional value,but its seed vigor is high.If it encounters a high temperature and rainy environment in the later stage of maturity,ear germination is prone to occur,which seriously influences the yield,quality and processing performance of the crop.Flowering means the transition of plants from the vegetative growth stage to the reproductive growth stage.The degree of seed dormancy determines the time for germination,both of which can regulate the growth of plants in a suitable environment.Therefore,it is of great practical significance to study the regulation of quinoa flowering time and seed germination and dormancy.A lot of studies have shown that among the three subfamilies of the plant PEBP gene family,FLOWERING LOCUS T(FT)and TERMINAL FLOWER 1(TFL1)regulate the flowering time of Arabidopsis thaliana,FT promotes early flowering of plants,while TFL1 acts as a flowering suppressor gene to maintain plant vegetative growth.MOTHER OF FT AND TFL1(MFT)is considered the ancestor of FT and TFL1,but its function in regulating flowering time is redundant,and it may play a role in regulating seed dormancy and germination.This study systematically analyzed the characteristics of quinoa PEBP gene family and tissue expression patterns,and heterologously expressed some PEBP family genes and seed dormancy-related genes Cq SDR4,Cq QSD1 and Cq TCP14 in Arabidopsis to verify their functions.In addition,we evaluated the transformation efficiency of five Agrobacterium strains GV2260,LBA4404,AGL1,EHA105 and GV3101 to infect Quinoa.The main results obtained in this study are as follows:1.Quinoa PEBP family gene contains 19 genes,which can be divided into 3subfamilies: MFT-Like,FT-Like and TFL1-Like.2.Quinoa PEBP family gene structure is highly conserved,most of the genes contain4 exons and 3 introns.The protein sequence of quinoa PEBP family gene is highly conserved.3.Using RT-PCR,the expression patterns of Cq MFT-981,Cq MFT-509,Cq MFT-749,Cq FT,Cq TFL1,Cq SDR4,Cq QSD1-705,Cq TCP14-478 and Cq TCP14-571 in different tissues of quinoa were analyzed and the expression of Cq MFT-981,Cq MFT-509,Cq MFT-749,Cq SDR4 and Cq QSD1-705 in different periods of quinoa seed germination.It was found that the expression levels of these genes in various tissues were different.Among them,the expression levels of genes related to seed dormancy were different in faster-germinating varieties and slower-germinating varieties.4.Transgenic Arabidopsis seed germination profiling analysis showed that overexpression of Cq MFT-981,Cq MFT-509 and Cq SDR4 genes inhibited Arabidopsis seed germination to a certain extent;Cq MFT-749 gene may not regulate seed dormancy.5.Analysis of flowering phenotype of transgenic Arabidopsis thaliana showed that overexpression Cq FT-053 gene promote flowering of Arabidopsis thaliana,and Cq TFL1-689 gene delays flowering of Arabidopsis thaliana.The two genes function antagonistically in regulating flowering time.Cq MFT may not participate in the regulation of plant flowering.6.Among the five Agrobacterium strains,GV3101 infects quinoa cotyledons with the highest transformation efficiency.