ZmPRX38 is required for improving stalk strength and yield in maize

Area of Science:

• Plant Genetics
• Agricultural Science
• Molecular Biology

Background:

• Stalk lodging significantly reduces maize yield due to insufficient stalk strength.
• Improving maize lodging resistance requires understanding the genetic factors controlling stalk strength.

Purpose of the Study:

• To identify quantitative trait loci (QTLs) associated with maize stalk strength.
• To clone and characterize the gene responsible for a major QTL hotspot influencing stalk strength.
• To investigate the role of ZmPRX38 in lignin biosynthesis and its impact on stalk mechanical properties.

Main Methods:

• Genome-wide association study to identify QTLs for stalk strength.
• Gene cloning and expression analysis of candidate genes.
• Gene knockout and overexpression experiments in maize.
• Analysis of lignin composition and content.
• Haplotype analysis of ZmPRX38 in natural maize populations.

Main Results:

• 31 QTLs for maize stalk strength were identified.
• ZmPRX38 was cloned and found to be responsible for a hotspot QTL.
• ZmPRX38 knockout decreased stalk strength, while overexpression increased it.
• ZmPRX38 is involved in the biosynthesis of multiple lignin types.
• A favorable ZmPRX38 haplotype enhancing stalk strength was identified.

Conclusions:

• ZmPRX38 plays a critical role in determining maize stalk strength and yield.
• Targeted editing of unfavorable ZmPRX38 haplotypes offers a strategy to improve maize lodging resistance.
• Understanding ZmPRX38's function provides insights for breeding stronger maize varieties.