TaACTIN7-D regulates plant height and grain shape in bread wheat

Area of Science:

• Plant genetics
• Molecular biology
• Crop science

Background:

• Improving crop yield through molecular breeding requires understanding genes controlling traits like plant height and grain characteristics.
• Identifying novel genetic resources is crucial for developing high-yielding wheat varieties.

Purpose of the Study:

• To identify and characterize a novel gene influencing plant architecture and grain morphology in wheat.
• To elucidate the molecular mechanism by which this gene affects plant development and hormone signaling.

Main Methods:

• Ethylmethanesulfonate mutagenesis to create mutants.
• Bulked segregant RNA-sequencing (RNA-seq) and map-based cloning to identify the causal gene.
• Analysis of actin polymerization and phytohormone response.

Main Results:

• A wheat mutant (mu-597) exhibiting semi-dwarfism and round grain shape was identified.
• A single-base mutation in TaACTIN7-D (Glycine to Serine at residue 65, G65S) was found to cause these traits.
• The G65S mutation impairs actin polymerization and reduces sensitivity to brassinosteroids, auxin, and gibberellin.

Conclusions:

• TaACTIN7-D is a novel gene for semi-dwarfing and grain shape modification in bread wheat.
• Actin structure modulation is directly linked to phytohormone signal transduction in wheat.
• This discovery provides a new resource for molecular breeding of wheat with desired plant architecture and grain characteristics.