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Xanthomonas campestris pv. campestris (Xcc) is a significant phytopathogen causing black rot disease in crucifers. Its virulence relies heavily on the type III secretion system (T3SS), facilitating effector translocation into plant cells. The type III effectors (T3Es) disrupt cellular processes, promoting pathogen proliferation. However, only a few T3Es from Xcc have been thoroughly characterized. In this study, we further investigated two effectors using the T3Es-deficient mutant and the Arabidopsis protoplast system. XopE2Xcc triggers Arabidopsis immune responses via an unidentified activator of the salicylic acid (SA) signaling pathway, whereas XopLXcc suppresses the expression of genes associated with patterns-triggered immunity (PTI) and the SA signaling pathway. These two effectors exert opposing effects on Arabidopsis immune responses. Additionally, we examined the relationship between the specific domains and functions of these two effector proteins. Our findings demonstrate that the N-myristoylation motif and N-terminal domain are essential for the subcellular localization and virulence of XopE2Xcc and XopLXcc, respectively. These novel insights enhance our understanding of the pathogenic mechanisms of T3Es and contribute to developing effective strategies for controlling bacterial disease. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of chlorogenic acid (CGA) treatment on induction of resistance against pathogens in peach fruit. Treatment with CGA at 25–150 mg L −1 was effective at reducing lesion diameter and decay index of peach fruit during storage at 25 °C after Penicillium expansum infection. CGA treatment had also significant beneficial effects on fruit quality parameters including firmness, soluble solids contents, pH value, and titratable acidity. Activities of main defense-related enzymes and expression of key genes involved in the salicylic acid (SA) signaling pathway, such as PAL , ICS , WRKY , NPR1 , PR1 , CHI , GLU , PR5 , and POD , were enhanced by CGA treatment. These findings suggest that CGA treatment is a promising approach to controlling postharvest blue mold rot in peach fruit, and activation of the SA signaling pathway may play a potential role in mechanisms involving CGA-induced plant disease resistance. [ABSTRACT FROM AUTHOR]

(E)-2-Hexenal is one of the most prevalent and abundant volatile substances in fruits. Many researchers have attempted fumigation with (E)-2-hexenal to control fungal diseases with poor or no results; the key is the inability to maintain an effective concentration for a long time. Therefore, a new starch-based antifungal coating with (E)-2-hexenal microcapsules was prepared. The obtained results showed that the microcapsule embedding rate reached 78.95% by orthogonal optimization experiments and that the (E)-2-hexenal-based coating was effective at reducing the lesion diameter of apple fruit during storage at 25 °C after Penicillium expansum infection, and in other fruits; it also achieved a good antifungal effect. Moreover, the activities of the main defense-related enzymes and the expression of key genes involved in the salicylic acid (SA) signaling pathway, such as CHI, GLU, PAL , NPR1 , and PR1 , were enhanced by (E)-2-hexenal-based coating treatment. These findings suggest that the (E)-2-hexenal-based coating has the dual effect of direct antifungal and induction of apple system resistance. E2H-based coating is a promising approach to control postharvest Penicillium expansum in fruit. • E2H-based coating effectively inhibiting the growth of Penicillium expansum in apple. • E2H-based coating antifungal effect is widespread in fruits. • E2H-based coating initiates the SA signaling pathway. • E2H-based coating induces an increase in the resistance-related genes and enzymes in apple. [ABSTRACT FROM AUTHOR]

Verticillium wilt (VW) is caused by Verticillium dahliae and significantly impacts cotton yield and quality. Breeding of resistant varieties is the most effective strategy for controlling VW. Therefore, it is important to identify VW resistance genes. The diploid wild cotton species Gossypium australe is highly resistant to VW. This study identified 33 CC-NBS-LRR (CNL) genes in the G. australe genome. GauCNL expression pattern (EP) analyses showed that EP1 cluster which included four of the 33 genes, were significantly up-regulated after V. dahliae inoculation. The EP1 cluster genes were then introduced into Arabidopsis thaliana wild type Col-0, respectively. The results showed GauCNL18 overexpression significantly increased V. dahliae resistance, indicating the functional importance of GauCNL18. GauCNL18 promotes V. dahliae resistance by activating the salicylic acid signaling pathway to mediate up-regulating pathogenesis-related genes and reactive oxygen species accumulation. This study identified a CNL resistance gene, GauCNL18 , and revealed its resistance mechanism to V. dahliae. • Verticillium wilt is caused by Verticillium dahliae and significantly impacts cotton yield and quality. • The diploid wild cotton species Gossypium australe is highly resistant to Verticillium wilt. • GauCNL18 overexpression significantly increased Verticillium dahliae resistance in Arabidopsis thaliana. • GauCNL18 promotes Verticillium dahliae resistance by activating the salicylic acid signaling pathway to mediate up-regulated pathogenesis-related genes and reactive oxygen species accumulation. [ABSTRACT FROM AUTHOR]