From ERG11 sequencing, each of these isolates displayed a Y132F and/or a Y257H/N substitution. Of the isolates, only one diverged from the two clusters formed by closely related STR genotypes, each cluster exhibiting specific ERG11 mutations. The ancestral C. tropicalis strain of these isolates subsequently spread across Brazil, having previously acquired the azole resistance-associated substitutions. The C. tropicalis STR genotyping strategy effectively highlighted unrecognized outbreaks and provided valuable insights into population genomics, including the prevalence of antifungal resistance.
The -aminoadipate (AAA) pathway, crucial for lysine production in higher fungi, stands in stark contrast to the mechanisms used by plants, bacteria, and lower fungi. Given the differences, a unique opportunity exists to develop a molecular regulatory strategy for controlling plant-parasitic nematodes, specifically utilizing nematode-trapping fungi. In the nematode-trapping fungus Arthrobotrys oligospora, this study investigated the core AAA pathway gene encoding -aminoadipate reductase (Aoaar), analyzing sequences and comparing the growth, biochemical, and global metabolic profiles of wild-type and Aoaar knockout strains. Beyond its -aminoadipic acid reductase function, essential for fungal L-lysine biosynthesis, Aoaar is also a crucial component of the non-ribosomal peptide biosynthetic gene cluster. The Aoaar strain's growth rate, conidial production, predation ring formation, and nematode feeding rate were all significantly lower than those of the WT strain, decreasing by 40-60%, 36%, 32%, and 52%, respectively. In the Aoaar strains, metabolic reprogramming encompassed amino acid metabolism, the biosynthesis of peptides and analogues, phenylpropanoid and polyketide biosynthesis, lipid and carbon metabolism. Aoaar's disruption perturbed the lysine metabolic pathway's intermediate biosynthesis, subsequently reprogramming amino acid and related secondary metabolism, and ultimately hindering A. oligospora's growth and nematocidal effectiveness. This research provides a pivotal reference for understanding the contribution of amino acid-related primary and secondary metabolic processes in nematode trapping by nematode-trapping fungi, and supports the feasibility of utilizing Aoarr as a molecular target to regulate the biocontrol efficacy of these fungi against nematodes.
Filamentous fungi metabolites are widely utilized in the food and pharmaceutical industries. The application of biotechnological methods to alter the morphology of filamentous fungal mycelia, enabled by advances in morphological engineering, has led to improvements in the yields and productivity of target metabolites during submerged fermentation. Submerged fermentation's metabolite synthesis and filamentous fungi's mycelial morphology and cell expansion are impacted by disruptions in chitin biosynthesis. This review delves into the different categories and structures of chitin synthase, details of chitin biosynthetic pathways, and the intricate link between chitin biosynthesis and fungal cell growth and metabolism in filamentous fungi. selleck In this review, we intend to elevate awareness of filamentous fungal morphological metabolic engineering, elucidating the molecular control mechanisms stemming from chitin biosynthesis, and detailing strategies to exploit morphological engineering for improved target metabolite production in submerged fungal fermentations.
Tree canker and dieback diseases are frequently attributable to Botryosphaeria species, with B. dothidea being a particularly common species. Nevertheless, the data concerning the prevalence and virulence of B. dothidea within the spectrum of Botryosphaeria species, leading to trunk cankers, remains understudied. Four Chinese hickory canker-associated Botryosphaeria pathogens, specifically B. dothidea, B. qingyuanensis, B. fabicerciana, and B. corticis, were investigated comprehensively to evaluate the competitive fitness of B. dothidea, focusing on their metabolic phenotypic diversity and genomic distinctions. Large-scale screening of physiologic traits using a phenotypic MicroArray/OmniLog system (PMs) found that B. dothidea, a Botryosphaeria species, has a broader spectrum of usable nitrogen sources, a heightened tolerance to osmotic pressure (sodium benzoate), and a stronger resistance to alkali stress. The comparative genomic analysis of B. dothidea uncovered 143 unique genes. These genes not only provide insights into the unique functions of B. dothidea, but also serve as a basis for the creation of a specific molecular identification method for B. dothidea. To accurately identify *B. dothidea* in disease diagnoses, a species-specific primer set, Bd 11F/Bd 11R, was created based on the *B. dothidea* jg11 gene sequence. Through a detailed analysis, this study provides valuable insight into the prevalence and aggressive behavior of B. dothidea among various Botryosphaeria species, assisting in developing advanced strategies for managing trunk cankers.
Crucial to the economies of several countries, the chickpea (Cicer arietinum L.) is a globally cultivated legume and a valuable source of nourishment. The disease Ascochyta blight, caused by the fungus Ascochyta rabiei, can seriously compromise yield levels. Though molecular and pathological studies have been conducted, a definitive understanding of its pathogenesis remains elusive, due to the significant variability. In the same way, many crucial details concerning plant resistance to the pathogen are yet to be unraveled. A deeper understanding of these two factors is essential for crafting effective tools and strategies to safeguard the crop. The review collates current information on the disease's pathogenesis, symptomatology, geographical distribution, environmental factors that support infection, host defense mechanisms, and the resistant qualities of chickpea genotypes. selleck Furthermore, it details current strategies for integrated pest control.
The active transport of phospholipids across cell membranes, carried out by lipid flippases of the P4-ATPase family, is crucial for vital cellular processes like vesicle budding and membrane trafficking. Furthermore, members of this transporter family have been linked to the growth of drug resistance in fungal organisms. Four P4-ATPases are present within the encapsulated fungal pathogen, Cryptococcus neoformans, with the Apt2-4p isoforms exhibiting limited understanding. In the flippase-deficient S. cerevisiae strain dnf1dnf2drs2, heterologous expression allowed for the comparison of lipid flippase activity exhibited by introduced proteins, compared to the activity of Apt1p, employing both complementation and fluorescent lipid uptake assays. For Apt2p and Apt3p to be active, the C. neoformans Cdc50 protein must be co-expressed. selleck Apt2p/Cdc50p exhibited a highly selective substrate profile, targeting exclusively phosphatidylethanolamine and phosphatidylcholine. Despite its lack of ability to transport fluorescent lipids, the Apt3p/Cdc50p complex successfully rescued the cold-sensitive phenotype of dnf1dnf2drs2, indicating a functional role played by the flippase within the secretory pathway. Apt4p, a close homolog of Saccharomyces Neo1p that functions independently of Cdc50, was unable to rescue the various phenotypic defects in flippase-deficient mutants, regardless of the presence or absence of a -subunit. These results designate C. neoformans Cdc50 as an indispensable subunit for Apt1-3p, providing a foundational understanding of the molecular mechanisms that underlie their physiological operations.
The PKA pathway within Candida albicans is implicated in its virulence mechanisms. The incorporation of glucose into the system activates this mechanism, a process that demands the involvement of at least two proteins: Cdc25 and Ras1. Both proteins play a role in specific virulence attributes. The question of Cdc25 and Ras1 independently affecting virulence remains unanswered, even when PKA's participation is considered. To ascertain their roles in virulence, Cdc25, Ras1, and Ras2 were examined under in vitro and ex vivo conditions. Our findings indicate that the ablation of CDC25 and RAS1 genes results in decreased toxicity for oral epithelial cells, but the deletion of RAS2 shows no change in toxicity. Toxicity toward cervical cells, however, is augmented in both ras2 and cdc25 mutants, yet it diminishes in ras1 mutants when compared to the wild type. Toxicity assays performed on mutants of the PKA pathway (Efg1) and MAPK pathway (Cph1) transcription factors show that the ras1 mutant’s phenotype mirrors that of the efg1 mutant; conversely, the ras2 mutant’s phenotype mirrors that of the cph1 mutant. Signal transduction pathways, as revealed by these data, are involved in niche-specific virulence regulation by different upstream components.
Monascus pigments (MPs), boasting a multitude of beneficial biological properties, have seen extensive adoption as natural food-grade colorings within the food processing industry. The mycotoxin citrinin (CIT) critically impacts the application of MPs, but the gene regulatory systems governing its biosynthesis are still under investigation. We examined the transcriptomes of high and low citrate-yielding Monascus purpureus strains via RNA-Seq, to determine the underlying transcriptional mechanisms. In parallel, qRT-PCR assays were undertaken to detect the expression of genes related to CIT biosynthesis, thereby confirming the reliability of the RNA-Seq data. The research findings showcased a significant difference in gene expression, specifically 2518 genes (1141 downregulated, 1377 upregulated), in the strain exhibiting low citrate production. Biosynthetic precursors for MPs biosynthesis were likely amplified by the upregulation of DEGs tied to energy and carbohydrate metabolism. Further investigation of the differentially expressed genes (DEGs) revealed several genes that encode transcription factors with potentially interesting functions.