The aim of this study was to evaluate the performance of volatile organic compounds (VOCs) for evolution monitoring and early detection of Aspergillus flavus (A. flavus) contamination in walnuts. We successfully applied headspace–gas chromatography–ion mobility spectrometry (HS‐GC‐IMS) to evaluate walnut VOC changes caused by A. flavus contamination. A total of 48 VOCs were identified in walnuts contaminated with A. flavus. After identification of VOCs, a heat map and principal component analysis (PCA) highlighted ethyl acetate‐D, 3‐methyl‐2‐butanol, and cyclohexanone as potential biomarkers specific to A. flavus contamination in walnuts. These results provided valid targets for the development of sensors to evaluate the early mold contamination in stored walnuts.

The COBRA-like (COBL) genes play key roles in cell anisotropic expansion and the orientation of microfibrils. Mutations in these genes cause the brittle stem and induce pathogen responsive phenotypes in Arabidopsis and several crop plants. In this study, an in silico genome-wide analysis was performed to identify the COBL family members in Brassica. We identified 44, 20 and 23 COBL genes in B. napus and its diploid progenitor species B. rapa and B. oleracea, respectively. All the predicted COBL genes were phylogenetically clustered into two groups: the AtCOB group and the AtCOBL7 group. The conserved chromosome locations of COBLs in Arabidopsis and Brassica, together with clustering, indicated that the expansion of the COBL gene family in B. napus was primarily attributable to whole-genome triplication. Among the BnaCOBLs, 22 contained all the conserved motifs and derived from 9 of 12 subgroups. RNA-seq analysis was used to determine the tissue preferential expression patterns of various subgroups. BnaCOBL9, BnaCOBL35 and BnaCOBL41 were highly expressed in stem with high-breaking resistance, which implies these AtCOB subgroup members may be involved in stem development and stem breaking resistance of rapeseed. Our results of this study may help to elucidate the molecular properties of the COBRA gene family and provide informative clues for high stem-breaking resistance studies.

Autophagy, a conserved cellular recycling process, plays a crucial role in maintaining homeostasis under stress conditions. It also regulates the development and virulence of numerous filamentous fungi. In this study, we investigated the specific function of ATG8, a reliable autophagic marker, in the opportunistic pathogen Aspergillus flavus. To investigate the role of atg8 in A. flavus, the deletion and complemented mutants of atg8 were generated according to the homologous recombination principle. Deletion of atg8 showed a significant decrease in conidiation, spore germination, and sclerotia formation compared to the WT and atg8^C strains. Additionally, aflatoxin production was found severely impaired in the ∆atg8 mutant. The stress assays demonstrated that ATG8 was important for A. flavus response to oxidative stress. The fluorescence microscopy showed increased levels of reactive oxygen species in the ∆atg8 mutant cells, and the transcriptional result also indicated that genes related to the antioxidant system were significantly reduced in the ∆atg8 mutant. We further found that ATG8 participated in regulating the pathogenicity of A. flavus on crop seeds. These results revealed the biological role of ATG8 in A. flavus, which might provide a potential target for the control of A. flavus and AFB1 biosynthesis.

With the rapid development of industry, heavy metal pollution has emerged as a significant threat to food safety and human health. Among these pollutions, cadmium (Cd) pollution has become a global environmental concern. Caenorhabditis elegans, with its short life cycle and evolutionary conservation with humans, serves as an ideal model organism for studying toxicity mechanisms. In this study, we investigated the mechanisms of toxicity induced by Cd in C. elegans and the intervention of ascorbic acid (V_C) and fruit juices on toxicity induced by Cd. Using fluorescent probes, we observed that Cd exposure (5 mg/mL and 8 mg/mL of CdCl₂) significantly decreased the vitality of C. elegans in a dose-dependent manner within 6 h. Reactive oxygen species (ROS) and nitric oxide (NO) accumulated concurrently. Further exploration revealed that ROS played a crucial role in Cd-induced acute toxicity. The inhibition of ROS by Imidazole (IMZ) and Pyridine (PY) not only reduced NO levels but also restored the vitality of C. elegans. Conversely, the removal of NO by cPTIO [2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide] or L-NMMA (N^G-Monomethyl-L-arginine) improved the vitality; however, it still did not affect ROS levels, indicating that ROS accumulation is a primary event in Cd-induced toxicity. We also examined the protective effects of V_C and fruit juices. Both V_C (0.5 mg/mL, 1 mg/mL) and fruit juices (50% (v/v) of the total volume of the medium) significantly enhanced the vitality of C. elegans under CdCl₂ stress and reduced the accumulation of ROS and NO. This suggests that V_C-rich materials effectively scavenge ROS and NO, thereby alleviating Cd-induced oxidative stress and toxicity. In summary, our results elucidate that CdCl₂ exposure leads to ROS accumulation in C. elegans, which in turn triggers NO production and ultimately reduces nematode activity. V_C and V_C-rich materials can effectively mitigate CdCl₂ toxicity by scavenging ROS and NO, providing a potential strategy for alleviating Cd poisoning.