The relationships between plants and bacteria are essential in agroecosystems and bioinoculant development. The leaf endophytic Pseudomonas protegens E1BL2 was previously isolated from giant Jala maize, which is a native Zea mays landrace of Nayarit, Mexico. Using different Mexican maize landraces, this work evaluated the strain’s plant growth promotion and biocontrol against eight phytopathogenic fungi in vitro and greenhouse conditions. Also, a plant field trial was conducted on irrigated fields using the hybrid maize Supremo. The grain productivity in this assay increased compared with the control treatment. The genome analysis of P. protegens E1BL2 showed putative genes involved in metabolite synthesis that facilitated its beneficial roles in plant health and environmental adaptation (bdhA, acoR, trpE, speE, potA); siderophores (ptaA, pchC); and extracellular enzymes relevant for PGPB mechanisms (cel3, chi14), protection against oxidative stress (hscA, htpG), nitrogen metabolism (nirD, nit1, hmpA), inductors of plant-induced systemic resistance (ISR) (flaA, flaG, rffA, rfaP), fungal biocontrol (phlD, prtD, prnD, hcnA-1), pest control (vgrG-1, higB-2, aprE, pslA, ppkA), and the establishment of plant-bacteria symbiosis (pgaA, pgaB, pgaC, exbD). Our findings suggest that P. protegens E1BL2 significantly promotes maize growth and offers biocontrol benefits, which highlights its potential as a bioinoculant.

Candidozyma auris is a multidrug-resistant, thermo- and osmotolerant yeast capable of persisting on biotic and abiotic surfaces, attributes likely linked to its cell wall composition. Here, seven putative genes encoding yapsins, aspartyl proteases GPI-anchored to the membrane or cell wall, were identified in the genomes of C. auris CJ97 and 20-1498, from clades III and IV, respectively. The C. auris YPS1 gene is orthologous to the SAP9 of C. albicans. The YPS7 gene is orthologous to YPS7 in C. glabrata and S. cerevisiae, so that they may share similar roles. An in silico analysis suggested an interaction between pepstatin and the catalytic domain of Yps1 and Yps7. Although this inhibitor, when combined with caffeine, had a subtle effect on the growth of C. auris, it induced alterations in the cell wall. CauYPS1 and CauYPS7 expression increased under nutrient starvation and NaCl, and at 42 °C. The transcriptome of the 20-1498 strain suggests that autophagy may play a role in thermal stress, probably degrading deleterious proteins or maintaining cell wall and vacuolar homeostasis. Therefore, CauYps1 and CauYps7 may play a role in the cell wall integrity of C. auris in stress conditions, and they could be a target of new antifungal or antivirulence agents.

Microbial ecology has entered a phase of methodological consolidation where genomic and molecular tools are being used to address ecological questions rather than being subordinate to culture-based approaches

Candidozyma auris is a multidrug resistance opportunistic pathogen, distinguished from Candida yeasts because of their thermotolerance, osmotolerance, and persistence in biotic and abiotic surfaces, attributes that seem linked to the cell wall composition. Here, seven putative genes encoding yapsins, extracellular aspartyl proteases GPI-anchored to the membrane or cell wall, were identified in the genomes of C. auris strains CJ97 and 20-1498, from clades III and IV, respectively. C. auris YPS1 gene is orthologous to the SAP9 of C. albicans. The YPS7 gene is orthologous to YPS7 of C. glabrata and S. cerevisiae, so they could coincide in roles. The CauYPS1 and CauYPS7 expression increased under nutrient starvation, 1.5 M NaCl, and at 42oC. In silico analysis suggests the interaction of pepstatin A, an aspartyl protease inhibitor, with the catalytic domain of Yps1 and Yps7. This inhibitor, in concert with caffeine, had a subtle effect on the growth of C. auris strains. However, these compounds induce alterations in the appearance of the cell wall. Thereby, yapsins CauYps1 and CauYps7 may play a role in the cell wall integrity of C. auris in stress conditions, and they could be a therapeutic target for the design of new antifungal or antivirulence agents.