Earthworm excreta as a natural defense booster: enhancing tomato resistance against Botrytis cinérea [Dataset]

Soil and its biota play fundamental roles in plant development and ecosystem functioning by regulating nutrient cycling, organic matter decomposition, and soil structure. Among them, earthworms (EWs) act as ecosystem engineers, enhancing soil aeration, nutrient availability, and microbial activity, with potential benefits for plant growth and pest control. Their coelomic extract (CEx) contains bioactive compounds that may induce plant defense responses; however, the mechanisms behind these effects remain poorly understood. This study evaluated the impact of EWs and their CEx on Solanum lycopersicum (tomato), assessing growth, nutrient content, and defense against the foliar fungal pathogen Botrytis cinerea. Plants were exposed to EWs, CEx, or water (control) and inoculated with B. cinerea after two weeks. Plant defense was monitored via expression of key defense-related genes at 24- and 48-hours post-inoculation (hpi), while growth, nutrient content, and fungal abundance and damage were assessed at 72 hpi. EWs enhanced aerial biomass, while both EWs and CEx reduced root dry weight, suggesting resource reallocation to aboveground growth. CEx significantly reduced B. cinerea-induced leaf damage and increased flavonol levels, a known marker of induced resistance. Both EWs and CEx activated the jasmonic acid signaling pathway, with CEx specifically upregulating genes involved in fungal pathogen defense and sustaining their expression over time. These results highlight the potential of EWs and their secretions to promote plant immunity and resilience, reinforcing their value in sustainable agriculture and the role of soil biodiversity in crop protection strategies.

The CSIC i-coop+ 2018 grant (COOPA20231) and Instituto de Estudios Riojanos (IER), Government of La Rioja, Spain, ref. 8/2020, December 29th 2020. MC was supported by the mobility program stablished by the CSIC i-coop+ 2018 grant (COOPA20231). IVD is supported by FPI-UR (2021) fellowship from the University of La Rioja (Spain). RBP is supported by the contract Juan de la Cierva (JDC2022-048978-I) from the “European Union NextGenerationEU/PRTR” and MCIN/AEI/10.13039/501100011033. JDH is supported by the Programa Investigo from the Government of La Rioja and the “European Union NextGenerationEU/PRTR.

Peer reviewed