Explanting Of Candidate Genes For Maize Gray Leaf Spot Resistance Based On Transcriptome Sequencing

Gray leaf spot(GLS)is one of the most serious maize leaf diseases in the world.At present,the most effective method to prevent and control maize GLS is exploring the disease-resistant maize materials and selecting the disease-resistant genes for breeding disease-resistant maize varieties.In this study,chromosome fragment replacement lines(R)qi319 with disease-resistant fragments,and infected materials for recurrent parent ye478(S)were selected as the targrt materials,and the transcriptome sequencing and bioinformatics analysis were done.Combinating with the results of the fine mapping of q GLS1.02,a series of analyses of the candidate genes were performed,and the main conclusions are as follows:1.A total of 536,328,566 clean reads were obtained by transcriptome sequencing,and the reads sequences of all samples were compared with the B73 genome reference sequence.The analyses of differentially expressed genes(DEGs)revealed that the number of DEGs was the least after inoculation with 0h resistant materials.DEGs were the most at 0h after inoculation of ye478 and 65 d after inoculation.GO analysis showed that DEGs were enriched in metabolism,signal transduction,cell transport and other processes.The KEGG analysis showed that the metabolic pathway of plant-pathogen interaction was significantly enriched,indicating that Ca2+ played an important role in signal transmission of maize defensing fungus infection after the inoculation of corn gray spot pathogen.RIN4,a disease-resistant material,was involved in the early resistance reaction of corn gray spot in ETI.2.Combined with the results of fine mapping interval and gene differential multiples of transcriptome sequencing data,GRMZM2G153920 was predicted to be the candidate gene and named as gls1 gene.Through the analyses of CDS sequences,17 base mutations and 9 base deletions were found in S_gls1 sequence.The expression level of candidate genes was determined,indicating that the relative expression level of R was significantly up-regulated in 82 hpi,as well as 82 h was an important period of anti-gray spot disease in maize.3.Bioinformatics analysis of the candidate genes showed that 9 amino acid mutations and 3 amino acid deletions were found in the S_gls1 amino acid sequence.gls1 gene encoding protein belongs to the Sugar transport superfamily.The protein was composed of 524 amino acids with molecular weight of 55.9 kda and theoretical isoelectric point of 8.31.R_gls1 and S_gls1 have two active sites.The prediction of protein subcellular localization indicated that the protein localization in the chloroplast thylakoid membrane had the maximum confidence value.Both R_gls1 and S_gls1 have 9 transmembrane domains,but their locations are different.R_gls1 and S_gls1 encoding proteins had significant differences in 3d predicted structures.The protein is mainly related to putative polyol transporter protein and its similarity is 91.37%.