A single gene change turns susceptible peas into fusarium wilt fighters

Fusarium wilt, caused by Fusarium oxysporum f. sp. pisi (Fop), is a devastating disease affecting pea‑growing regions globally, with yield losses frequently exceeding 30% and sometimes reaching total crop failure.

While resistant cultivars offer the most effective control strategy, known resistance genes are limited, and pathogens can evolve to overcome single‑gene resistance. Based on these challenges, there is an urgent need to identify new resistance genes and broaden the genetic resources available for pea breeding programs.

New plant gene linked to Fusarium wilt resistance

Researchers from the Chinese Academy of Agricultural Sciences and the Liaoning Academy of Agricultural Sciences report their findings, in Horticulture Research. The team discovered that a single dominant gene, PsFwC9, confers resistance to Fop race 5 in the pea line Chengwan 9‑8. Through whole‑genome resequencing and fine mapping, they pinpointed the candidate gene Psat4g213640 on chromosome 4 and validated its function using hairy root transformation experiments.

The research team employed bulked segregant analysis sequencing (BSA‑seq) to rapidly identify genomic regions associated with resistance. By sequencing DNA pools from resistant and susceptible plants, they narrowed the candidate region to an 817.06 kb interval on chromosome 4, with four markers showing complete co‑segregation with the resistance trait.

Haplotype analysis of 218 pea accessions revealed that a single “G/A” single‑nucleotide polymorphism (SNP) within the candidate gene Psat4g213640 was the only variant consistently associated with resistance. This SNP changes the amino acid from threonine to alanine, altering the protein’s predicted structure. Notably, the protein localizes to the endoplasmic reticulum (ER)—a cellular compartment increasingly recognized for its role in plant immune responses.

When the resistant version of the gene was overexpressed in susceptible plants using Agrobacterium rhizogenes‑mediated hairy root transformation, the plants gained significant resistance, delaying wilting symptoms by nearly two weeks. Conversely, silencing the gene in resistant plants compromised their defense, confirming its essential role in Fusarium wilt resistance.

Selectively breeding resitant strains

“The identification of PsFwC9 adds a valuable new tool to the pea breeder’s toolbox,” the authors said. “What makes this particularly exciting is that this gene sits on a different chromosome from previously known resistance genes and appears to work through a distinct mechanism—one that doesn’t involve the typical NB‑ARC domains found in many classic resistance proteins. This opens up new possibilities for understanding how peas defend themselves against Fusarium wilt and for stacking resistance genes to create more durable protection.”

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The diagnostic marker developed in this study, A016615, enables precise identification of the resistance allele in breeding programs. With this marker, breeders can efficiently screen germplasm and select resistant individuals without time‑consuming disease assays. The discovery also provides a foundation for gene pyramiding—combining multiple resistance genes in a single variety to enhance durability and reduce the risk of pathogen breakdown. As Fusarium wilt continues to threaten pea production worldwide, PsFwC9 offers a promising new line of defense for this important food legume.