Unravelling the Interplay of Nitrogen Nutrition and theBotrytis cinereapectin lyase BcPNL1 in ModulatingArabidopsis thalianaSusceptibility

Abstract

AbstractIn this study, we investigated the intricate interplay between nitrogen nutrition, and the dynamics of pectin degradation during plant-pathogen interactions, usingArabidopsis thalianaandBotrytis cinereaas a model pathosystem. Our findings revealed a noteworthy impact of nitrogen availability on the pectin degrading activity of theB. cinereapectin lyase 1 (PNL) for which the mutant strains presented a reduced pathogenicity restored by complementation. More precisely, infected nitrogen-sufficient (high N) plants exhibited an increased release of PNL-derived oligogalacturonides compared to infected nitrogen-deficient (low N) plants. This correlated with an elevated expression of jasmonic acid repressor genes in high N plants, rendering them more susceptible toB. cinerea. UsingΔBcpnl1deletion mutants, we demonstrated that the increased production of BcPNL1 -derived oligogalacturonides under high N conditions was responsible for the increased expression of jasmonic acid repressor genes, significantly contributing to the higher susceptibility of high N plantstoB. cinerea.In conclusion, we demonstrated that BcPNL1 is a major pathogenicity factor duringB. cinereainteraction that is affected by the plant’s N nutrition conditions.