Publication: Unveiling how potato cyst nematodes break through potato resistance

A group of researchers from NEM-EMERGE, led by Wageningen University & Research, has recently published an article in the journal New Phytologist, in which they explore the genetic basis of the breakdown of a major potato resistance by the potato cyst nematode Globodera pallida.

Potatoes and nematodes are in a constant battle in which nematodes try to invade potatoes to withdraw essential nutrients from the plant. Potatoes, in turn, try to defend themself against the nematodes with resistances that aim at restricting nematode development. To escape resistance, the nematodes try to evade and suppress this defence response.

In this study, the NEM-EMERGE researchers discovered that all Dutch potato varieties rely on the same resistance for G. pallida resistance. The repeated use of the same resistance puts a selection pressure on the nematode populations that can eventually lead to the breakdown of a resistance. Over the last decade, resistance-breaking G. pallida populations (so-called virulent populations) have become a matter of great concern. However, the genetic basis and molecular mechanisms underlying nematode virulence are still poorly understood.

The NEM-EMERGE researchers aimed to identify the genetic basis of G. pallida virulence in field populations. By whole-genome sequencing of nematodes from five generations of selection on resistant potato varieties, they found that a single genomic locus is involved in the breakdown of resistance. Silencing of a prime candidate gene, Gp-pat-1, in juvenile nematodes significantly increased virulence on resistant potatoes, confirming a role in the breakdown of potato resistance. “These findings help improve the understanding of the evolutionary dynamics of nematode adaptation in the field and open avenues to develop molecular diagnostic tools to monitor G. pallida virulence”, stated researchers.