SHORT AND CROOKED AWN, encoding the epigenetic regulator EMF1, promotes barley awn development

Area of Science:

• Plant genetics
• Molecular biology
• Agricultural science

Background:

• Barley awns are vital for grain yield and quality via photosynthesis.
• Awn development mechanisms are poorly understood, despite available morphological mutants.

Purpose of the Study:

• Identify the gene responsible for the short and crooked awn (sca) mutant phenotype in barley.
• Elucidate the molecular mechanisms underlying SCA's role in awn development.

Main Methods:

• Map-based cloning and sequencing to identify the causative gene.
• RNA sequencing to analyze gene expression changes in sca mutants.
• Histone modification analysis (H3K27me3) to investigate regulatory pathways.

Main Results:

• The SCA gene, encoding EMBRYONIC FLOWER 1, was identified as causative for the sca mutant.
• SCA promotes cell proliferation, elongation, and cell wall synthesis during awn development.
• SCA regulates genes involved in awn development and represses key floral organ transcription factors, including MADS-box genes, via histone modification.

Conclusions:

• SCA plays a critical role in barley awn development by regulating cell growth and gene expression.
• SCA-mediated gene regulation, involving histone modification, represents a novel pathway in controlling awn morphology and potentially impacting crop yield.