Genetics of barley hooded suppression

Area of Science:

• Plant genetics
• Molecular biology
• Crop science

Background:

• The barley Hooded (K) mutant arises from a 305 bp duplication in intron IV of the Bkn3 homeobox gene.
• Understanding Bkn3 gene regulation is crucial for barley development.

Purpose of the Study:

• To identify genetic factors involved in Bkn3 intron-mediated gene regulation.
• To characterize suppressors of the K allele's hooded awn phenotype.

Main Methods:

• Chemical mutagenesis of barley KK seeds.
• Identification and complementation testing of suppressor of K (suK) mutants.
• Bulked segregant analysis with AFLP markers for genetic mapping.

Main Results:

• Identified 41 suK recessive mutants, defining five suK loci.
• suKB, suKE, and suKF map to chromosome 7H; suKD maps to 5H.
• suK mutants exhibit a short-awn phenotype, independent of hood formation control.

Conclusions:

• suK loci are candidate participants in regulating Bkn3 expression.
• The short-awn phenotype results from a dominant function of the K allele.
• These findings provide insights into barley awn development regulation.