Guardians of wheat: Unleashing transgenerational immune priming with Trichoderma against spot blotch

Plants encounter various biotic stresses in their natural habitat, prompting the exploration of innovative protective measures to bolster their immune defences against pathogens. An effective strategy involves priming plant immunity, conferring enduring and comprehensive protection. Defence priming, characterized by heightened responsiveness to attackers following prior stress exposure, intriguingly manifests transgenerationally, transmitting the memory of priming to subsequent plant generations. In our investigation, we delved into the phenomenon of transgenerational immune priming (TGIP) in wheat facilitated by Trichoderma, spanning from the parental generation (G0) to the grand progeny (G2) generation. Successful establishment of transgenerational priming in the G2 generation was achieved by initially priming the G0 generation of wheat with Trichoderma. To assess priming inheritance, seeds from the G1 generation were collected, and both primed and non-primed wheat plants' grand progeny (G2 generation) were cultivated in soil. Subsequent evaluation encompassed the disease phenotype, biochemical parameters, and yield-related traits of the G2 generation wheat when confronted with Bipolaris sorokiniana, the causal agent of spot blotch disease. Our analysis revealed that the G2 generation of primed wheat displayed superior protection against spot blotch compared to non-primed wheat. Biochemical studies indicated no activation of defensive responses in the absence of disease pressure in G2 wheat plants. However, upon pathogen challenge, the grand progeny of primed wheat exhibited a robust defence response, surpassing that of non-primed wheat. This targeted defence response enabled efficient resource utilization and mitigated yield penalties. Furthermore, under biotic stress conditions, the grand progeny of primed wheat exhibited enhanced yield parameters compared to non-primed wheat. Our findings provide conclusive evidence that Trichoderma-mediated priming against B. sorokiniana can be inherited successfully from the parental (G0) generation to the grand progeny (G2) generation of wheat. This study represents the initial documentation of Trichoderma-mediated TGIP in wheat against B. sorokiniana, holding significant promise for sustainable agriculture by offering an environmentally friendly alternative to chemical pesticides.