Identification of Potential Candidate Dwarf Genes in Maize by BSA-Seq and Transcriptomic Analyses

Area of Science:

• Plant genetics
• Crop science
• Molecular biology

Background:

• Maize (Zea mays L.) is a vital global crop.
• Understanding genes controlling plant height is crucial for improving maize architecture and lodging resistance.

Purpose of the Study:

• To identify and map the gene responsible for dwarfism in a newly generated maize mutant (CM17-2).
• To investigate the genetic inheritance and physiological response to gibberellin (GA3) in the dwarf mutant.
• To pinpoint candidate genes associated with maize dwarfism using transcriptomic and genetic mapping data.

Main Methods:

• Induced mutagenesis using carbon ion beam irradiation to create the dwarf mutant CM17-2.
• Segregation analysis in F2 populations to determine inheritance patterns (monogenic recessive).
• Bulked segregant analysis sequencing (BSA-seq) and transcriptomic analysis following GA3 treatment to map the causal locus and identify differentially expressed genes.

Main Results:

• The dwarf mutant CM17-2 displayed significantly reduced plant height, internode length, and ear height.
• Monogenic recessive inheritance was confirmed with a 3:1 segregation ratio.
• GA3 treatment rescued the dwarf phenotype, indicating GA sensitivity.
• BSA-seq mapped the locus to chromosomes 2, 4, and 5. Transcriptomic analysis revealed 3292 differentially expressed genes, with 1664 enriched in hormone signaling pathways.
• Integration of data identified 18 candidate genes on chromosome 4, with four potential dwarfism-associated genes.

Conclusions:

• A novel maize dwarf mutant CM17-2 was characterized, showing monogenic recessive inheritance and GA sensitivity.
• The study successfully mapped the dwarfism locus and identified potential candidate genes.
• These findings provide a foundation for future functional validation and mechanistic studies of maize dwarfism.