Gene Localization and Transcriptome Analysis of Maize (Zea mays) Glume Development Mutants
ZHAO Xing-Chen1, SHAN Da-Peng2, LIU Xue3,*, ZHANG Lin1,*
1 College of Agronomy, Northeast Agricultural University (NEAU),Haerbin 150030, China; 2 Suihua Branch, Heilongjiang Academy of Agricultural Sciences, Suihua 152052, China; 3 Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China
Abstract：Modern cultivated maize (Zea mays) exhibits significant differences in glume morphology compared to its wild ancestor, teosinte (Z. mays ssp. parviglumis), with glume traits being subjected to strong artificial selection during domestication. In natural environments, glumes are recognized to effectively prevent pathogen invasion caused by rainy conditions and confer insect resistance.The Eg1 mutant was identified as displaying elongated ear glumes. Phenotypic observations revealed that the Eg1 mutant showed significantly longer ear glumes compared to the wild type, while no obvious differences were observed in tassel glumes. Cytological analysis indicated that glume elongation in Eg1 resulted from an increased cell number rather than cell expansion in ear glumes. Genetic analysis demonstrated that the Eg1 mutant phenotype was controlled by a dominant gene. Using map-based cloning, the EG1 gene was preliminarily mapped to an 80 kb interval on maize chromosome 7, which contained 8 candidate genes. Among these, a Harbinger transposon insertion was identified 567 bp upstream of the promoter of Zm00001eb330490 (ZmERF58), leading to upregulated expression of this gene. ZmERF58 was classified as a member of the AP2/ERF family, functioning as a nuclear-localized transcription factor with autonomous activation activity.To further investigate EG1, transcriptome sequencing analysis was performed on 10 cm ear glumes from both wild-type and Eg1 mutants. A total of 3 264 differentially expressed genes (DEGs) were identified, including 1 266 upregulated and 1 998 downregulated genes. Gene Ontology (GO) enrichment analysis revealed that these DEGs were primarily involved in DNA-dependent transcription regulation, protein phosphorylation, and cell cycle processes. KEGG pathway analysis showed significant enrichment in plant hormone signal transduction, MAPK signaling pathways, and biosynthesis of secondary metabolites. This study aims to provide a theoretical foundation for subsequent functional characterization of the EG1 gene.
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