Fusarium verticillioides, F. proliferatum, and F. meridionale were identified as the predominant fungi among 116 Fusarium isolates causing maize ear and kernel rot, a destructive disease in Chongqing areas, China. The toxigenic capability and genotype were determined by molecular amplification and toxin assay. The results showed that the key toxigenic gene FUM1 was detected in 47 F. verticillioides and 19 F. proliferatum isolates. Among these, F. verticillioides and F. proliferatum isolates mainly produced fumonisin B₁, ranging from 3.17 to 1566.44, and 97.74 to 11,100.99 µg/g for each gram of dry hyphal weight, with the averages of 263.94 and 3632.88 µg/g, respectively, indicating the F. proliferatum isolates on average produced about an order of magnitude more fumonisins than F. verticillioides did in these areas, in vitro. Only NIV genotype was detected among 16 F. meridionale and three F. asiaticum isolates. Among these, 11 F. meridionale isolates produced NIV, varying from 17.40 to 2597.34 µg/g. ZEA and DON toxins were detected in 11 and 4 F. meridionale isolates, with the toxin production range of 8.35–78.57 and 3.38–33.41 µg/g, respectively. Three F. asiaticum isolates produced almost no mycotoxins, except that one isolate produced a small amount of DON. The findings provide us with insight into the risk of the main pathogenic Fusarium species and a guide for resistance breeding in these areas.

Exploring the mechanism of plant resistance has become the basis for selection of resistance varieties but reports on revealing resistant mechanism in Brassica napus against Plasmodiophora brassicae are rare. In this study, RNA-seq was conducted in the clubroot-resistant B. napus breeding line ZHE-226 and in the clubroot-susceptible rapeseed cultivar Zhongshuang 11 at 0, 3, 6, 9, and 12 days after inoculation. Strong alteration was detected specifically in ZHE-226 as soon as the root hair infection happened, and significant promotion was found in ZHE-226 on cell division or cell cycle, DNA repair and synthesis, protein synthesis, signaling, antioxidation, and secondary metabolites. Combining results from physiological, biochemical, and histochemical assays, our study highlights an effective signaling in ZHE-226 in response to P. brassicae. This response consists of a fast initiation of receptor kinases by P. brassicae; the possible activation of host intercellular G proteins which might, together with an enhanced Ca²⁺ signaling, promote the production of reactive oxygen species; and programmed cell death in the host. Meanwhile, a strong ability to maintain homeostasis of auxin and cytokinin in ZHE-226 might effectively limit the formation of clubs on host roots. Our study provides initial insights into resistance mechanism in rapeseed to P. brassicae.

Peach brown rot, attributed to Monilinia fructicola , presents a significant threat to postharvest peach cultivation, causing losses of up to 80%. With an increasing number of countries, spearheaded by the European Union, imposing bans on chemical agents in fruit production, there is a growing interest in mining highly active antibacterial compounds from biological control strains for postharvest disease management. In this study, we highlight the unique ability of Streptomyces lincolnensis strain JCP1‐7 to inhibit M. fructicola sporulation, despite its limited antimicrobial efficacy. Through GC–MS analysis, eucalyptol was identified as the key compound. Fumigation of diseased fruits with eucalyptol at a concentration of 0.0335 μg cm ⁻³ demonstrated an in vivo inhibition rate against M. fructicola of 93.13%, completely suppressing spore formation. Transcriptome analysis revealed the impact of eucalyptol on multiple pathogenesis‐related pathways, particularly through the inhibition of catalase 2 (Cat2) expression. Experiments with a MfCat2 knockout strain (ΔMfCat2) showed reduced pathogenicity and sensitivity to JCP1‐7 and eucalyptol, suggesting MfCat2 as a potential target of JCP1‐7 and eucalyptol against M. fructicola . Our findings elucidate that eucalyptol produced by S. lincolnensis JCP1‐7 inhibits M. fructicola sporulation by regulating MfCat2 , thereby effectively reducing postharvest peach brown rot occurrence. The use of fumigation of eucalyptol offers insights into peach brown rot management on a large scale, thus making a significant contribution to agricultural research.