A serine/threonine protein kinase encoding gene KERNEL NUMBER PER ROW6 regulates maize grain yield

Area of Science:

• Plant genetics
• Agricultural science
• Maize breeding

Background:

• Global demand for maize (Zea mays L.) necessitates increased grain yield for food, feed, and fuel.
• Maize breeding strategies have focused on enhancing ear size, but the underlying genetic loci are not fully understood.

Purpose of the Study:

• To identify genetic factors controlling pistillate floret number and ear length in maize.
• To explore the potential of specific genes for enhancing maize grain yield.

Main Methods:

• Gene expression analysis to identify candidate genes.
• Genetic modification (overexpression and introgression of specific alleles) to assess gene function.
• In vitro biochemical assays to investigate protein interactions.

Main Results:

• Identified KERNEL NUMBER PER ROW6 (KNR6), a serine/threonine protein kinase gene, as a key determinant of pistillate floret number and ear length.
• Overexpression of KNR6 or using KNR6 alleles with specific regulatory region modifications significantly increased maize grain yield.
• Demonstrated in vitro that KNR6 interacts with an Arf GTPase-activating protein (AGAP), suggesting a regulatory mechanism for ear development.

Conclusions:

• KNR6 plays a critical role in regulating maize ear morphology and kernel number.
• Targeting KNR6 offers a promising avenue for developing high-yielding maize hybrids.
• Understanding KNR6's interaction with AGAP provides insights into the genetic control of maize yield potential.