Characterization and Transcriptome Analysis of Maize Small-Kernel Mutant smk7a in Different Development Stages

Area of Science:

• Plant Biology
• Genetics
• Agricultural Science

Background:

• Maize kernel development is crucial for crop yield and quality.
• Understanding kernel development mechanisms is vital for improving maize production.

Purpose of the Study:

• To characterize a small-kernel mutant (smk7a) in maize.
• To investigate the underlying causes of defective kernel development in smk7a.

Main Methods:

• Cytological observation of kernel development.
• Biochemical analysis of starch, zein protein, and indole-3-acetic acid (IAA) content.
• Transcriptome analysis of kernel gene expression.
• Genetic mapping to identify the responsible gene.

Main Results:

• The smk7a mutant showed arrested endosperm and embryo development.
• Significantly lower starch, zein protein, and IAA content in smk7a compared to wild-type.
• Downregulation of starch, zein, and auxin biosynthesis genes in smk7a.
• Identified a recessive gene on chromosome 2 controlling the mutant phenotype.

Conclusions:

• Disrupted nutrition accumulation and auxin synthesis are key factors in smk7a's defective kernel development.
• The smk7a mutation provides insights into maize kernel development regulation.
• This study highlights the importance of starch, zein, and auxin pathways in maize kernel formation.