Transcriptome Analysis of Developing Wheat Grains at Rapid Expanding Phase Reveals Dynamic Gene Expression Patterns.

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Wheat grain development is critical for crop yield and quality.
• The early grain expanding phase involves rapid morphological changes and the initiation of grain filling.
• The molecular mechanisms governing this crucial stage remain largely unexplored.

Purpose of the Study:

• To provide a comprehensive time-series transcriptome profile of developing wheat grain during the early grain expanding phase.
• To identify differentially expressed genes, transcription factors, and key regulatory pathways involved in wheat grain development.
• To elucidate the role of hormone metabolism and homoeolog expression in early grain development.

Main Methods:

• Time-series transcriptome profiling of wheat grains at multiple time points post-pollination (0-10 days).
• Differential gene expression analysis to identify significant gene changes between time points.
• Co-expression cluster analysis and Gene Ontology enrichment to understand functional gene networks.
• Analysis of gene expression patterns in homoeologous triads, focusing on hormone metabolism genes.

Main Results:

• Identified 26,892 differentially expressed genes, including 1468 transcription factors, across adjacent time points.
• Revealed dynamic expression of genes related to cell division and starch biosynthesis.
• Observed diverse and drastic expression trends in hormone metabolism-related genes.
• ~30% of gene triads exhibited unbalanced expression, enriched in pivotal metabolic pathways.
• Identified specific hormone metabolism genes (e.g., YUC10, AOS2, CYP90D2, CKX1) predominantly contributed by A or D homoeologs.

Conclusions:

• This study offers a systematic view of transcriptional regulation during the early wheat grain expanding phase.
• The findings deepen the understanding of wheat grain development at the molecular level.
• Insights into gene expression dynamics and homoeolog contributions provide a foundation for strategies to improve wheat yield.