Identification,Expression And Functional Analysis Of The Expansin Gene Family In Foxtail Millet During Germination

This study based on whole genome system identify the foxtail millet SiEXP gene families,combined with bioinformatics and tissue specific expression patterns analysis of the expression patterns of SiEXP gene family members in the process of seed germination of the and its response to different factors such as drought,hormone,identification and cloning of candidate genes involved in the expansion of the corn seed germination protein,and through transgenic arabidopsis further analysis on the functional verification research of extension protein gene in the growth and development of foxtail millet and the regulatory role of germination,which provide theoretical basis for further study the improvement of corn seed germination ability and its resistance,and lay a foundation for the subsequent utilization of SiEXP gene in foxtail millet.The efficient method of extracting RNA from Storage period foxtail millet was studied,it provides the basis for the following experiments such as reverse transcription and gene cloning.The research results show that:In this study,26 expansin genes were identifed in the foxtail millet genome,distributed on 6 chromosomes,belonged to the EXPA and EXPB subfamilies.Phylogenetic analysis of expansin genes in Arabidopsis,rice and foxtail millet classifed these genes into 4 subgroups.Members of the same subfamily and subgroup shared conserved gene structure and motif compositions.Further analysis of SiEXP gene promoter regions uncovered various growth,development and stress-responsive cis-acting elements.Expression analysis revealed that SiEXPs had diferent expression patterns in different tissues at various developmental stages.SiEXPA1 was highly expressed in the ear of grain,SiEXPA12 was significantly expressed in root,and the expression of SiEXPA8 and SiEXPB5 varied with time in different organizations.Trend of relative expression level of expanain gene family during the germination are same,it firstly increased and then decreased(except SiEXPA2,SiEXPA5 and SiEXPB1).PEG,ABA and PAC inhibit foxtail millet germination.SiEXPA5 does not respond to any treatment;the expression of SiEXPB5 was 3.01 times higher than that of the control group under drought conditions,and it did not change much under ABA stress,so it was speculated that this gene was mainly response to drought stress during seed germination and this response is independent of ABA,the expression of SiEXPB7 was 4.49 times higher than that of the control group under ABA stress,So this gene was mainly response to ABA sress.SiEXPB5 transgenic arabidopsis thaliana is insignificantly different from the wild type under normal conditions,while SiEXPB7 transgenic arabidopsis thaliana is taller and have larger leaves than the wild type.The germination rate and root length of SiEXPB5 transgenic arabidopsis thaliana are higher than that control group only under drought conditions,and the gene expression is increased,and other conditions don’t change much.The germination rate and root length of SiEXPB7 genotype arabidopsis thaliana under ABA treatment were significantly different from control.Therefore,SiEXPB5 has obvious drought-resistant effect,and SiEXPB7 can promote the growth of arabidopsis thaliana,and be regulated by ABA.High-quality,well-completed RNA can be obtained from foxtail millet seed the modified RNAiso Plus method.The isolated RNA was suitable for subsequent molecular manipulations,such as c DNA synthesis and gene clone.