Structure and evolution of the rp1 complex conferring rust resistance in maize

Area of Science:

• Plant genetics
• Molecular biology
• Agricultural science

Background:

• The rp1 locus in maize is crucial for rust resistance.
• Understanding genetic diversity at rp1 is key for crop improvement.

Purpose of the Study:

• To investigate the role of recombination in generating genetic diversity at the maize rp1 locus.
• To identify novel rp1 genes and their functions.

Main Methods:

• Genetic analysis of the rp1 rust resistance complex in maize.
• Meiotic analysis to study gene pairing and recombination.

Main Results:

• Recombination is central to rp1 genetic diversity, driven by high intragenic recombination rates and meiotic mispairing.
• Novel rp1 genes identified include those with new race-specificities and lesion mimic phenotypes.
• Recombinants conferring partial, non-race-specific resistance were found, potentially useful for durable rust control.

Conclusions:

• Recombination is a primary driver of genetic variation at the maize rp1 locus.
• The identified novel rp1 genes and resistance mechanisms offer new avenues for breeding rust-resistant maize.
• Partial, non-race-specific resistance from rp1 recombinants shows promise for sustainable disease management in maize.