Sequencing trait-associated mutations to clone wheat rust-resistance gene YrNAM

Area of Science:

• Plant genetics
• Crop science
• Molecular biology

Background:

• Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), poses a significant threat to global wheat production.
• Cloning wheat resistance genes is crucial for developing cultivars with enhanced Pst resistance.
• While Yr10CG has been identified, additional resistance genes near the Yr10 locus are suspected.

Purpose of the Study:

• To clone and characterize novel Pst resistance genes located in the Yr10 region.
• To investigate the function and domains of the identified resistance gene.
• To assess the potential of the cloned gene for breeding rust-resistant wheat.

Main Methods:

• Sequencing Trait-Associated Mutations (STAM) was employed to identify the resistance gene.
• Functional analysis of the gene's domains (NAM and ZnF-BED) was performed.
• Transgenic wheat lines expressing the YrNAM gene were generated and tested.

Main Results:

• The Pst resistance gene YrNAM was successfully cloned from the Yr10 region.
• YrNAM encodes a non-canonical resistance protein requiring both NAM and ZnF-BED domains for function.
• Transgenic wheat expressing YrNAM demonstrated resistance to Pst races CYR32 and CYR33.

Conclusions:

• YrNAM represents a novel stripe rust resistance gene in wheat.
• The gene's ancient origin and presence in wild relatives, coupled with its absence in many cultivars, highlight its significant breeding value.
• YrNAM offers a promising genetic resource for developing durable stripe rust resistance in wheat.