The glyoxalase system is ubiquitous among all forms of life owing to its central role in relieving the cell from the accumulation of methylglyoxal, a toxic metabolic byproduct. In higher plants, this system is upregulated under diverse metabolic stress conditions, such as in the defence response to infection by pathogenic microorganisms. Despite their proven fundamental role in metabolic stresses, plant glyoxalases have been poorly studied. In this work, glyoxalase I fromZea mayshas been characterized both biochemically and structurally, thus reporting the first atomic model of a glyoxalase I available from plants. The results indicate that this enzyme comprises a single polypeptide with two structurally similar domains, giving rise to two lateral concavities, one of which harbours a functional nickel(II)-binding active site. The putative function of the remaining cryptic active site remains to be determined.

Beneficial interactions between plant-roots and Trichoderma spp. lead to a local and systemic enhancement of the plant immune system through a mechanism known as priming of defenses. In recent reports, we outlined a repertoire of genes and proteins differentially regulated in distant tissues of maize plants previously inoculated with Trichoderma atroviride. To further investigate the mechanisms involved in the systemic activation of plant responses, we continued evaluating the regulatory aspects of a selected group of genes when priming is triggered in maize plants. We conducted a time-course expression experiment from the beginning of the interaction between T. atroviride and maize roots, along plant vegetative growth and during Colletotrichum graminicola leaf infection. In addition to gene expression studies, the levels of jasmonic and salicylic acid were determined in the same samples for a comprehensive understanding of the gene expression results. Lastly, chromatin structure and modification assays were designed to evaluate the role of epigenetic marks during the long-lasting activation of the primed state of maize plants. The overall analysis of the results allowed us to shed some light on the interplay between the phytohormones and epigenetic regulatory events in the systemic and long-lasting regulation of maize plant defenses after Trichoderma inoculation

Trichoderma spp. produce diverse secondary metabolites with biological activity. This study explored the antimicrobial, antibiofilm, antioxidant, and cytotoxic properties of metabolites from two native Trichoderma strains, 10BR1 and UEPA AR12, isolated from rhizospheric soils. Organic extracts from both strains demonstrated broad-spectrum antimicrobial activity, inhibiting Gram-positive and Gram-negative bacteria, as well as various Candida species, with notable efficacy against Staphylococcus aureus (MICs: 15.6–31.25 µg/mL). The extracts also showed antibiofilm activity, with UEPA AR12 exhibiting the highest inhibition against Escherichia coli (81.8%), Enterococcus faecalis (92.8%), Candida albicans (87.9%), and Candida parapsilosis (89.3%). Antioxidant activity, assessed via DPPH assay, revealed a dose-dependent radical scavenging effect (12.88% to 39.67% at 7.8–1000 µg/mL). Cytotoxicity assays indicated that UEPA AR12 extracts were more cytotoxic (IC₅₀: 202.5–234.3 µg/mL) than 10BR1 (IC₅₀: 368.7–602.1 µg/mL) in non-tumor cells, with similar trends in tumor cells (Huh7). HPLC/MS analysis identified 21 metabolites in the extracts. Genomic analyses, supported by rpb2 gene and phylogenetic clustering, confirmed that both strains were T. afroharzianum. FUNGISMASH revealed multiple biosynthetic gene clusters, predominantly Type I polyketide synthase (T1PKS). Additionally, targeted genomic analyses did not detect mycotoxin-related genes. These findings highlight the antimicrobial, antibiofilm, and antioxidant potentials of these strains, positioning them as sources of bioactive metabolites for pharmaceutical applications.