A plant natriuretic peptide GhEG45 plays a significant role in regulating resistance to Verticillium dahliae

Abstract Background Plant natriuretic peptides (PNPs) are a class of peptide hormones that regulate plant responses to salt stress, water balance, and pathogen attacks. However, the precise underlying role of PNPs in plant defense mechanisms remains poorly understood. Results In this study, we investigated the role of the cotton gene GhEG45 in plant response to Verticillium dahliae infection. GhEG45 overexpression in cotton ( Gossypium hirsutum ) enhanced resistance to V. dahliae by increasing the expression levels of salicylic acid (SA)-related defense genes and upregulating antioxidant activities. GhEG45 expression was significantly induced by both V. dahliae infection and exogenous treatments with SA, hydrogen peroxide (H 2 O 2 ), and other stress signals, which indicates its potential involvement in modulating plant defense mechanisms via SA signaling, oxidative stress pathways, and cell wall-based defenses. Transcriptomic analysis showed that GhEG45 regulates SA signaling and reactive oxygen species (ROS) metabolism. GhEG45 silencing via virus-induced gene silencing (VIGS) increased susceptibility to V. dahliae , impaired SA signaling, and disrupted ROS regulation. Conclusions This study provides evidences that GhEG45 plays a pivotal role in defense against V. dahliae infection in cotton, primarily by regulating SA signaling and ROS metabolism. Although GhEG45 shares some functional characteristics with PNPs, further structural and biochemical studies are needed to comprehensively categorize GhEG45 as a natriuretic peptide. Our findings suggest that GhEG45 enhances cotton resistance to V. dahliae by potentiating defense responses.