Emerging Strategies for Aflatoxin Resistance in Peanuts via Precision Breeding

Area of Science:

• Plant breeding and genetics
• Food safety
• Agricultural biotechnology

Background:

• Aflatoxin contamination by Aspergillus flavus significantly impacts peanut production, food safety, and trade.
• Developing durable resistance in peanuts is difficult due to the polygenic and environmentally sensitive nature of resistance traits.
• Existing resistance mechanisms offer limited protection and are highly influenced by genotype-environment interactions.

Purpose of the Study:

• To review recent advances in peanut aflatoxin resistance research, focusing on susceptibility gene targeting and genome editing.
• To highlight the potential of disrupting host susceptibility genes for broad-spectrum, durable aflatoxin resistance in peanuts.
• To outline an integrated pipeline for accelerating the development of aflatoxin-resistant peanut cultivars.

Main Methods:

• Phenotyping diverse peanut germplasm under stress conditions.
• Mapping resistance loci using Quantitative Trait Loci (QTL) and Genome-Wide Association Studies (GWAS).
• Utilizing multi-omics platforms to identify candidate susceptibility genes.
• Functional validation of candidate genes via CRISPR/Cas9, Cas12a, base editing, and prime editing.
• Introgression of validated genes into elite peanut lines using marker-assisted and genomic selection.

Main Results:

• Identification of promising susceptibility (S) gene candidates, such as AhS5H1/2 and ABR1, which influence peanut's interaction with Aspergillus flavus.
• Demonstration that disrupting these S genes can confer broad-spectrum resistance.
• Advancement in genome editing technologies enables precise targeting of these genes for resistance breeding.

Conclusions:

• Targeting host susceptibility genes represents a paradigm shift in developing durable aflatoxin resistance in peanuts.
• Genome editing technologies offer precise tools for manipulating these genes to enhance resistance.
• Integrating conventional breeding with multi-omics and precision biotechnology is crucial for developing aflatoxin-free peanut cultivars.