Abstract Accumulating scientific insights reveal the ecological and evolutionary implications of phenotypic plant plasticity in response to biotic and abiotic stress factors. This study confirms that root-knot nematode infection leads to intergenerational acquired resistance (IAR) in rice offspring. Genome-wide and targeted gene expression analyses demonstrated that offspring of nematode-infected rice plants are better prepared to fight against such attack through ‘spring loading’ of hormone-related plant defense genes. These genes are suppressed under basal conditions in IAR plants but show a more dramatic induction upon nematode attack. Here, ChIP-sequencing was executed on the offspring of IAR versus naive plants to investigate if histone modifications could be involved in the spring-loaded expression pattern. This revealed enrichment of H3K4me3 on defence related genes and H3K27me3 on development-related genes in roots of IAR plants. Detailed bio-informatic analyses pointed towards significant epigenetic changes to the ABA, ET and MAPK signalling pathways in the offspring of nematode-infected plants. A rice line with reduced activity for OsMPK5 was found to be deficient in defense spring loading and the IAR phenotype. Transmitting a memory of encountered stress factors to one’s offspring is arguably an important asset for the adaptation of sessile plant communities to hostile environments.
Atighi et al. (2026) studied this question.