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Mycotoxin contamination of maize kernels by fungal pathogens Aspergillus flavus (Af) and Fusarium verticillioides (Fv) is a chronic global challenge impacting food security, health and trade. Current disease management practices are proven inadequate and strategies gearing towards hostmediated resistance can be an effective and sustainable approach to strengthen efforts to control the pathogens. Lipid modification into a diverse array of compounds, oxylipins, are recognized in response of plants to fungal pathogens. Lipoxygenase genes (LOXs) play a crucial role in the enzymatic oxidation of polyunsaturated fatty acids (PUFAs) into 9(S)- and 13(S)-hydroperoxides that are further metabolized into different oxylipins including jasmonates, oxo- and keto-fatty acids and volatiles. The involvement of maize LOXs (ZmLOXs) in this respect has been a subject of studies and their genetic manipulation resulted in the alteration of resistance or susceptibility to fungal pathogens in maize. However, the maize genome encodes six 9-LOX and seven 13-LOX isoforms and the specific role of each isoform remains elusive. The current study investigated the role of ZmLOXs in host resistance against the fungi Af and Fv using in silico and in planta approaches. The phylogenetic relationship, sequence similarity, protein domain structures, and transcript level structural variations were explored by comparing publicly available maize pan-genomes. Furthermore, the role of ZmLOXs against Af and Fv infection was investigated through their expression analysis along with further key genes involved in oxylipin biosynthesis, mycotoxin accumulation and lipid profiles in a ZmLOX4 mutant line (UFMulox4) together with W22, Mo17 and Tzi18 inbred lines at 3- and 7-days post-inoculation (dpi). ZmLOX proteins showed considerable variations in their sequences, functional domain structure and transcript structural variations among the pan-genome members. Among the studied lines, Tzi18 showed the highest resist

Mycotoxin contamination of maize kernels by fungal pathogens like Fusarium verticillioides and Aspergillus flavus is a chronic global challenge impacting food and feed security, health, and trade. Maize lipoxygenase genes (ZmLOXs) synthetize oxylipins that play defense roles and govern host-fungal interactions. The current study investigated the involvement of ZmLOXs in maize resistance against these two fungi. A considerable intraspecific genetic and transcript variability of the ZmLOX family was highlighted by in silico analysis comparing publicly available maize pan-genomes and pan-transcriptomes, respectively. Then, phenotyping and expression analysis of ZmLOX genes along with key genes involved in oxylipin biosynthesis were carried out in a maize mutant carrying a Mu transposon insertion in the ZmLOX4 gene (named UFMulox4) together with Tzi18, Mo17, and W22 inbred lines at 3- and 7-days post-inoculation with F. verticillioides and A. flavus. Tzi18 showed the highest resistance to the pathogens coupled with the lowest mycotoxin accumulation, while UFMulox4 was highly susceptible to both pathogens with the most elevated mycotoxin content. F. verticillioides inoculation determined a stronger induction of ZmLOXs and maize allene oxide synthase genes as compared to A. flavus. Additionally, oxylipin analysis revealed prevalent linoleic (18:2) peroxidation by 9-LOXs, the accumulation of 10-oxo-11-phytoenoic acid (10-OPEA), and triglyceride peroxidation only in F. verticillioides inoculated kernels of resistant genotypes.

Recent computational advancements in the simulation of biochemical processes allow investigating the mechanisms involved in protein regulation with realistic physics-based models, at an atomistic level of resolution. These techniques allowed us to design a drug discovery approach, named Pharmacological Protein Inactivation by Folding Intermediate Targeting (PPI-FIT), based on the rationale of negatively regulating protein levels by targeting folding intermediates. Here, PPI-FIT was tested for the first time on the cellular prion protein (PrP), a cell surface glycoprotein playing a key role in fatal and transmissible neurodegenerative pathologies known as prion diseases. We predicted the all-atom structure of an intermediate appearing along the folding pathway of PrP and identified four different small molecule ligands for this conformer, all capable of selectively lowering the load of the protein by promoting its degradation. Our data support the notion that the level of target proteins could be modulated by acting on their folding pathways, implying a previously unappreciated role for folding intermediates in the biological regulation of protein expression.