Domestication Reduces Plant Immune Receptor Gene Repertoires Across Lineages.

Abstract

Plant domestication is sometimes associated with a reduction in the diversity of immune receptor genes (IRGs), critical for pathogen recognition and defence. Yet, the extent and evolutionary forces driving this pattern remain unclear. Using a comparative genomics framework, we analysed the IRG repertoires of 15 domesticated crop species and their wild relatives, representing nine plant families. We examined both cell-surface pattern recognition receptors (PRRs) and intracellular nucleotide-binding leucine-rich repeat receptors (NLRs). Our results show that five crops-grapes, mandarins, rice, barley and yellow sarson-exhibited significantly reduced IRG repertoires compared to their wild counterparts; however, the overall rate of IRG loss reflected the background rate of gene loss. Despite this, there is a positive association between domestication duration and IRG loss. Together these results suggest that domestication imposes a subtle, cumulative pressure, consistent with relaxed selection rather than a strong cost-of-resistance effect. This study provides insights into how domestication impacts plant immunity, with implications for future crop breeding strategies to enhance disease resistance.