Functional Characterization of Accessible Chromatin in Common Wheat

Area of Science:

• Plant molecular biology
• Epigenetics
• Wheat genetics

Background:

• Gene transcription in eukaryotes relies on cis-regulatory elements (CREs) and trans-acting factors.
• The specific roles of CREs and epigenetic marks in regulating homoeolog bias expression in wheat remain largely unexplored.

Purpose of the Study:

• To comprehensively characterize open chromatin and DNA methylation in wheat seedling and spikelet tissues.
• To investigate the function of CREs in regulating tissue-specific gene expression and homoeolog bias.
• To identify the impact of epigenetic modifications and sequence variations on gene expression and agronomic traits.

Main Methods:

• Genome-wide characterization of open chromatin using ATAC-seq or similar techniques.
• Analysis of DNA methylation patterns (e.g., whole-genome bisulfite sequencing).
• Integration of chromatin accessibility, methylation data, and gene expression profiles.

Main Results:

• Differential chromatin openness was observed between wheat seedling and spikelet tissues, influencing tissue development.
• CHH methylation was identified as a key factor in differential transcription factor binding and target gene expression.
• Sequence variations within MNase hypersensitive sites (MHSs) were linked to differential expression of genes controlling agronomic traits.

Conclusions:

• CREs play crucial roles in regulating tissue-specific and homoeolog bias expression in wheat.
• Epigenetic marks, particularly CHH methylation, and sequence variations in CREs are critical for controlling gene expression and agronomic traits.
• The study identifies potential CREs for genetic and epigenetic manipulation to enhance desirable traits in wheat breeding.