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Abstract Background Fungus infection in staple grains affects the food storage and threatens food security. The Aspergillus flavus is known to infect multiple grains and produce mycotoxin Aflatoxin B1, which is mutagenic, teratogenic and causes immunosuppression in animals. However, the molecular mechanism of maize resistance to A. flavus is largely unknown. Results Here we used corn kernels to investigate resistance genes to A. flavus using genome-wide association study (GWAS) of 313 inbred lines. We characterized the resistance levels of kernels after inoculating with A. flavus. The GWAS with 558,529 SNPs identified four associated loci involving 29 candidate genes that were linked to seed development, resistance or infection, and involved in signal pathways, seed development, germination, dormancy, epigenetic modification, and antimicrobial activity. In addition, a few candidate genes were also associated with several G-protein signaling and phytohormones that might involve in synergistic work conferring different resistance during seed development. Expression of 16 genes out of 29 during kernel development was also associated with resistance levels. Conclusions We characterized the resistance levels of 313 maize kernels after inoculating with A. flavus, and found four associated loci and 16 candidate maize genes. The expressed 16 genes involved in kernel structure and kernel composition most likely contribute to mature maize kernels’ resistance to A. flavus, and in particular, in the development of pericarp. The linked candidate genes could be experimentally transformed to validate and manipulate fungal resistance. Thus this result adds value to maize kernels in breeding programs.

Aspergillus flavus is a fungus that produces aflatoxin B1, one of the most carcinogenic secondary metabolites. Understanding the regulation mechanism of aflatoxin biosynthesis in this fungus requires precise methods for genomic integration of mutant alleles. To avoid the disadvantage of DNA integration into the genome by non-homologous or ectopic recombination, we developed a novel strategy for site-specific integration of foreign DNA by using a carboxin-resistant sdh2R allele (His 249 Leu). Our results demonstrated that the transformants were generated with a high efficiency (>96%) of correct integration into the sdh2-lcus of the genome of A. flavus NRRL 3357. The advantage of this method is that introduction of the eGFP expression cassette into the sdh2-locus had little effect on fungal growth and virulence while also being rapid and efficient. This system will be a valuable tool for genetic manipulation in A. flavus. To the best of our knowledge, this is the first report on the efficient site-specific integration at the sdh2-locus in the genome of Aspergillus.

Polyaniline−dodecylbenzene sulfonic acid (PANI‐DBSA) particles were synthesized through in situ lotion polymerization of aniline and DBSA as raw materials, followed by combining with epoxy resin (E‐44) and castor oil (CO) to prepare a PANI mixture (PANI‐DBSA/CO) which was used as a nanofiller to create a nano polyaniline/polyurethane (PANI‐PU) interpenetrating polymer network (IPN) coating. SEM, XRD and Fourier transform infrared spectroscopy were used to characterize the PANI‐DBSA and PANI‐PU IPN composite coatings that were produced. The coatings' physical and mechanical characteristics were investigated, as well as the system's corrosion behaviour in 3.5 wt% NaCl solution, utilizing electrochemical impedance spectroscopy and electrokinetic polarization. Acid, alkali and saltwater immersion investigations were used to further evaluate the coatings' medium resistance. The results show that when PANI‐DBSA is added at 1 wt%, the contact angle reaches 102.6°, the adhesion reaches S1 grade after 720 h immersion, the tensile strength is 16.22 MPa and the elongation reaches 208%. The impedance value of the composite coating grew by 569 times with the addition of 1 wt% PANI, and the resistance duration to 10 wt% H2SO4, 10 wt% NaOH and 3.5 wt% NaCl reached more than 90 days. The addition of PANI to IPN coatings can increase corrosion resistance and extend their application range. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI) particles were synthesized using aniline (AN), dodecyl benzene sulfonic acid (DBSA), and ammonium persulfate (APS). The particles were analyzed using scanning electron microscope (SEM), X‐ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). A PANI/waterborne polyurethane composite material (PANI‐WPU) was obtained by combining it with polyethylene glycol (PEG600), diphenylmethane diisocyanate (MDI), dimethylol propionic acid (DMPA), N‐methyl pyrrolidone (NMP), and dibutyltin lauric acid (DBTDL). The structure was characterized by the FTIR spectrum. The mechanical characteristics of the coating film were evaluated with respect to the PANI content, as well as its water absorption, glossiness, electrochemical corrosion resistance, and acid and alkali resistance. The PANI/waterborne polyurethane film has a maximum tensile strength of 23 ±1$$ \pm 1 $$ MPa, an elongation of 1012%, a pencil hardness of 5H, a flexibility of 2 mm, an impact resistance of 50 cm, the water absorption of 14.66%, and the glossiness of 99.9 ±0.1$$ \pm 0.1 $$ at 60°. When the PANI content is 0.7%, the mechanical characteristics, glossiness, and anti‐corrosion performance of the composite film improve. The corrosion inhibition efficiency of the aqueous polyurethane coating film with PANI can reach 99.74%, as shown by the examination of electrochemical polarization curves and impedance spectra. The tinplate is coated with a 0.7% PANI‐WPU composite material and edge sealing. This coating provides excellent protection against acid and alkali resistance, as demonstrated by its ability to withstand immersion in 10% H2SO4 and 10% NaOH solution for 90 days without any paint peeling off. [ABSTRACT FROM AUTHOR]