Regulation Mechanism Of AtMUD1 In The Synthesis Of Seed Coat Mucilage Mucopolysaccharides In Arabidopsis Thaliana And Identification Of Seed-specific Candidate Genes From Peanut

Cell wall is the basic structure of plant cells and plays an important role in maintaining cell morphology,controlling cell growth,intercellular substance transport and signal transduction.In our previous study,we found that a gene which was encoded by a C3HC4 zinc finger protein,we named this gene as MUD1(MUCILAGE DEFICIENT 1).This study systematically studied the MUD1 gene expression pattern,seed mucilage phenotype,polysaccharide composition and structure,and regulatory network of Arabidopsis thaliana.or study the regulation mechanism of polysaccharide in seed coat of Arabidopsis thaliana,we try to use existing transcriptome and genomic data for mining seed or seed coat specific expressed genes.In this study,we used transcriptome data of specific expression in peanut seeds to mine specific expression genes of seeds.According comparative analysis of two samples("seeds at different stages after flowering" and "mixed samples of roots,stems and leaves"),we found many seed specific genes.This will lay a foundation for the excavation of specific gene expression and the analysis of specific promoter.finally,the main results of our research are as follows:(1)The mutants of MUD1 gene were identified and the mutants were found to have thinner seed coat pectin layer,indicating that the genes affected the synthesis or modification of seed coat mucilage pectin.The total amount of monosaccharide extracted from mutants was decreased.Immunolabeling analysis found that fluorescence signals of low-value HG,high-methylated HG and unmethylated HG were all weakened,which proved that the content of HG in mutant was reduced,and it was implying that this gene mainly affected the synthesis of HG.The MUD1 gene was most expressed in the pod on the seventh day after flowering(the critical period of pectin and city was 1-13 days after flowering),which indicated that MUD1 was expressed in the critical period of pectin synthesis.22 genes related to cell wall function were predicted by GENEVESTIGATOR online software,qRT-PCR analysis found that these genes are expressed decreased in MUD1 mutant,indicating that MUD1 preliminary gene may be a positive regulation of transcription factors.according screening from the yeast two-essay library,About 100 interacting genes,including 10 transcription factor genes and 8 cell wall polysaccharide synthesis-related genes,were obtained.The overexpression vector of MUD 1 gene,the subcellular localization vector,and the promoter GUS gene vector were constructed.High expression genes and their promoters during seed development were identified and analyzed.This sets the foundation for further functional research of MUD1 gene.(2)comparing analysis of transcriptome data between peanut seed sample and non-seed samples,a total of 337 seeds high expression or specific expression genes were obtained.The first 108 gene expression was increased with more than 2 times,expression pattern analysis shows that 108 SSCG genes were specifically expressed in seed or high expression.Expression pattern analysis showed that 108 SSCG genes were specifically expressed or highly expressed in seeds.Through the analysis of Gene Ontology(GO),it was found that most of these genes were related to seed development,allergen,seed storage protein and fatty acid metabolism.The cis-acting elements RY repeat and GCN4 elements of SSPs were distributed in 108 SSCGs promoters.In addition,the promoter of SSCG29 was cloned from cultivated peanut and predicted.Combined with the previous identification results of SSCG5 heterozygous gene SSP in cultivated peanuts,the SSCG identification method proposed in this study is feasible and accurate.The SSCGs found in this work can be widely used in SSP cloning.In addition,this study identified a low-cost,high-throughput method for the exploration of tissue-specific genes in other crop species.