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Cytochrome P450 enzymes are monooxygenases widely diffused in nature ranging from viruses to man. They can catalyze a very wide range of reactions, including the ketonization of C–H bonds, N/O/S-dealkylation, C–C bond cleavage, N/S-oxidation, hydroxylation, and the epoxidation of C=C bonds. Their versatility makes them valuable across various fields such as medicine, chemistry, and food processing. In this review, we aim to highlight the significant contribution of P450 enzymes to fruit quality, with a specific focus on the ripening process, particularly in grapevines. Grapevines are of particular interest due to their economic importance in the fruit industry and their significance in winemaking. Understanding the role of P450 enzymes in grapevine fruit ripening can provide insights into enhancing grape quality, flavor, and aroma, which are critical factors in determining the market value of grapes and derived products like wine. Moreover, the potential of P450 enzymes extends beyond fruit ripening. They represent promising candidates for engineering crop species that are resilient to both biotic and abiotic stresses. Their involvement in metabolic engineering offers opportunities for enhancing fruit quality attributes, such as taste, nutritional content, and shelf life. Harnessing the capabilities of P450 enzymes in crop improvement holds immense promise for sustainable agriculture and food security. [ABSTRACT FROM AUTHOR]

Simple Summary: Antibiotics are medicines used to prevent and treat infections in humans, animals, and plants. Antibiotic resistance is a naturally occurring phenomenon that has emerged as one of the most significant threats to global health and food security. Bacteria have the ability to acquire mutations that render them resistant to antibiotic molecules, contributing to the spread of resistance. The misuse and overuse of antibiotics have played a pivotal role in driving the development and proliferation of antibiotic resistance. The United Nations is estimating that by 2050, up to 10 million human deaths each year will be caused by the "superbugs", very dangerous pathogens resistant to multiple antibiotic molecules. There will be health and macroeconomic consequences for the world if antimicrobial resistance is not tackled. The availability of antibiotics without prescription contributes to their overuse and misuse. Urgent measures are required to mitigate these issues and their substantial global impact. One of these measures is the search for new antibiotics designed on the basis of new targets of resistance. In this review, we show that enzymes called flavin monooxygenases could be a new and so-far-underseen candidate. Carbapenems are a group of broad-spectrum beta-lactam antibiotics that in many cases are the last effective defense against infections caused by multidrug-resistant bacteria, such as some strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Resistance to carbapenems has emerged and is beginning to spread, becoming an ongoing public-health problem of global dimensions, causing serious outbreaks, and dramatically limiting treatment options. This paper reviews the role of flavin monooxygenases in antibiotic resistance, with a specific focus on carbapenem resistance and the recently discovered mechanism mediated by Baeyer–Villiger monooxygenases. Flavin monooxygenases are enzymes involved in the metabolism and detoxification of compounds, including antibiotics. Understanding their role in antibiotic resistance is crucial. Carbapenems are powerful antibiotics used to treat severe infections caused by multidrug-resistant bacteria. However, the rise of carbapenem-resistant strains poses a significant challenge. This paper explores the mechanisms by which flavin monooxygenases confer resistance to carbapenems, examining molecular pathways and genetic factors. Additionally, this paper highlights the discovery of Baeyer–Villiger monooxygenases' involvement in antibiotic resistance. These enzymes catalyze the insertion of oxygen atoms into specific chemical bonds. Recent studies have revealed their unexpected role in promoting carbapenem resistance. Through a comprehensive analysis of the literature, this paper contributes to the understanding of the interplay between flavin monooxygenases, carbapenem resistance, and Baeyer–Villiger monooxygenases. By exploring these mechanisms, it aims to inform the development of strategies to combat antibiotic resistance, a critical global health concern. [ABSTRACT FROM AUTHOR]

Cytochromes P450 are ancient enzymes diffused in organisms belonging to all kingdoms of life, including viruses, with the largest number of P450 genes found in plants. The functional characterization of cytochromes P450 has been extensively investigated in mammals, where these enzymes are involved in the metabolism of drugs and in the detoxification of pollutants and toxic chemicals. The aim of this work is to present an overview of the often disregarded role of the cytochrome P450 enzymes in mediating the interaction between plants and microorganisms. Quite recently, several research groups have started to investigate the role of P450 enzymes in the interactions between plants and (micro)organisms, focusing on the holobiont Vitis vinifera. Grapevines live in close association with large numbers of microorganisms and interact with each other, regulating several vine physiological functions, from biotic and abiotic stress tolerance to fruit quality at harvest. [ABSTRACT FROM AUTHOR]

Strigolactones (SLs) are carotenoid-derived phytohormones governing a wide range of physiological processes, including drought-associated stomatal closure. We have previously shown in tomato that SLs regulate the so-called after-effect of drought, whereby stomatal conductance is not completely restored for some time during recovery after a drought spell, irrespective of the water potential. To ease the elucidation of its molecular underpinnings, we investigated whether this SL effect is conserved in Arabidopsis thaliana by contrasting the physiological performances of the wild-type with SL-depleted (more axillary growth 4, max4) and insensitive (dwarf 14, d14) mutants in a drought and recovery protocol. Physiological analyses showed that SLs are important to achieve a complete after-effect in A. thaliana , while transcriptome results suggested that the SL-dependent modulation of drought responses extends to a large subset (about 4/5) of genes displaying memory transcription patterns. Among these, we show that the activation of over 30 genes related to abscisic acid metabolism and signaling strongly depends on SL signaling. Furthermore, by using promoter-enrichment tools, we identified putative cis - and trans -acting factors that may be important in the SL-dependent and SL-independent regulation of genes during drought and recovery. Finally, in order to test the accuracy of our bioinformatic prediction, we confirmed one of the most promising transcription factor candidates mediating SL signaling effects on transcriptional drought memory—BRI-EMS SUPPRESSOR1 (BES1). Our findings reveal that SLs are master regulators of Arabidopsis transcriptional memory upon drought and that this role is partially mediated by the BES1 transcription factor. [ABSTRACT FROM AUTHOR]

Symbiosis involving two (or more) prokaryotic and/or eukaryotic partners is extremely widespread in nature, and it has performed, and is still performing, a key role in the evolution of several biological systems. The interaction between symbiotic partners is based on the emission and perception of a plethora of molecules, including volatile organic compounds (VOCs), synthesized by both prokaryotic and eukaryotic (micro)organisms. VOCs acquire increasing importance since they spread above and below ground and act as infochemicals regulating a very complex network. In this work we review what is known about the VOCs synthesized by fungi prior to and during the interaction(s) with their partners (either prokaryotic or eukaryotic) and their possible role(s) in establishing and maintaining the symbiosis. Lastly, we also describe the potential applications of fungal VOCs from different biotechnological perspectives, including medicinal, pharmaceutical and agronomical. [ABSTRACT FROM AUTHOR]

This review covers our current knowledge on catalytically self-sufficient cytochromes P450. These enzymes present all the advantages of the regio- and stereo-selectivity of typical P450s combined with the fact that, due to the natural fusion with their reductases, their application in biocatalysis does not need the addition of other proteins: only NAD(P)H and substrate are needed to trigger catalysis. To this date only few catalytically self-sufficient P450s have been isolated from bacteria, fungi and plants. Their low number does not detract from their importance, as the reactions they catalyse and the turnover numbers of which they are capable (in some cases higher than 15,000 s) makes them highly relevant to the chemical and pharmaceutical industry. These enzymes will be covered in this review, together with their specific reactions relevant to the field of biocatalysis. [ABSTRACT FROM AUTHOR]

A gene coding for a class VII cytochrome P450 monooxygenase ( CYP116B5) was identified from A cinetobacter radioresistens S13 growing on media with medium ( C14, C16) and long ( C24, C36) chain alkanes as the sole energy source. Phylogenetic analysis of its N- and C-terminal domains suggests an evolutionary model involving a plasmid-mediated horizontal gene transfer from the donor R hodococcus jostii RHA1 to the receiving A . radioresistens S13. This event was followed by fusion and integration of the new gene in A . radioresistens chromosome. Heterologous expression of CYP116B5 in E scherichia coli BL21, together with the A . radioresistens Baeyer- Villiger monooxygenase, allowed the recombinant bacteria to grow on long- and medium-chain alkanes, showing that CYP116B5 is involved in the first step of terminal oxidation of medium-chain alkanes overlapping AlkB and in the first step of sub-terminal oxidation of long-chain alkanes. It was also demonstrated that CYP116B5 is a self-sufficient cytochrome P450 consisting of a heme domain (aa 1-392) involved in the oxidation step of n-alkanes degradation, and its reductase domain (aa 444-758) comprising the NADPH-, FMN- and [ 2Fe2S]-binding sites. To our knowledge, CYP116B5 is the first member of this class to have its natural substrate and function identified. [ABSTRACT FROM AUTHOR]

This work demonstrates that Acinetobacter radioresistens strain S13 during the growth on medium supplemented with long-chain alkanes as the sole energy source expresses almA gene coding for a Baeyer- Villiger monooxygenase ( BVMO) involved in alkanes subterminal oxidation. Phylogenetic analysis placed the sequence of this novel BVMO in the same clade of the prodrug activator ethionamide monooxygenase ( EtaA) and it bears only a distant relation to the other known class I BVMO proteins. In silico analysis of the 3 D model of the S13 BVMO generated by homology modelling also supports the similarities with EtaA by binding ethionamide to the active site. In vitro experiments carried out with the purified enzyme confirm that this novel BVMO is indeed capable of typical Baeyer- Villiger reactions as well as oxidation of the prodrug ethionamide. [ABSTRACT FROM AUTHOR]

Fusarium oxysporum MSA 35 [wild-type (WT) strain] is a nonpathogenic Fusarium strain, which exhibits antagonistic activity to plant pathogenic F. oxysporum isolates. The fungus lives in association with a consortium of ectosymbiotic bacteria. The WT strain, when cured of the bacterial symbionts [the cured (CU) form], is pathogenic, causing wilt symptoms similar to those of pathogenic F. oxysporum f. sp. lactucae. Both WT and CU MSA 35 strains produce microbial volatile organic compounds (MVOCs), but with a different spectrum. In vitro dual culture assays were used to assess the effects of the MVOCs produced by WT and CU strains of F. oxysporum MSA 35 on the growth and expansin gene expression of lettuce seedlings. An increase in the root length (95.6%), shoot length (75.0%) and fresh weight (85.8%) was observed only after WT strain MVOCs exposure. Leaf chlorophyll content was significantly enhanced (68%) in WT strain MVOC-treated seedlings as compared with CU strain volatiles and nontreated controls. β-Caryophyllene was found to be one of the volatiles released by WT MSA 35 responsible for the plant growth promotion effect. Semi-quantitative and quantitative reverse transcription-PCR assays indicated a significant difference in the expansin gene expression level between leaf (6.7-fold) and roots (4.4-fold) exposed to WT strain volatiles when compared with the CU strain volatiles and those that were nonexposed. [ABSTRACT FROM AUTHOR]

In this work, a protocol for zoospores production of Phytophthora cryptogea, an economically important plant pathogen was optimized. Five different concentrations of zoospores (5 × 105, 5 × 104, 5 × 103, 5 × 102, 5 × 101 zoospores/ml) from four different isolates of P. cryptogea (Maria 1, Maria 2, S3 1-A, Amazzone) were used as inoculum on pot marigold ( Calendula officinalis) and gerbera ( Gerbera jamesonii) plants. Maria 1 was the most virulent isolate both on pot marigold and gerbera plants according to disease severity. A rapid and sensitive pathogen DNA extraction protocol suitable for large quantities of plant samples was adopted. Conventional polymerase chain reaction (PCR) was able to detect the pathogen in artificially inoculated symptomless pot marigold (collected day 12) and gerbera plants (day 8) after pathogen inoculation, with the suspension of 5 × 105, 5 × 104, 5 × 103 P. cryptogea zoospores/ml. Real-time PCR showed the possibility to detect the pathogen in artificially inoculated symptomless pot marigold (collected day 8) and gerbera plants (day 4) after pathogen inoculation, with the suspension of 5 × 105, 5 × 104 P. cryptogea zoospores/ml. The first symptoms appeared on pot marigold plants 14 days after pathogen inoculation and on gerbera plants 10 days after inoculation. Real-time PCR showed the possibility to detect the pathogen 4 days before conventional PCR and 6 days before the appearance of disease symptoms both on pot marigold and gerbera plants. [ABSTRACT FROM AUTHOR]

Fusarium oxysporum MSA 35 [wild-type (WT) strain] is an antagonistic Fusarium that lives in association with a consortium of bacteria belonging to the genera Serratia, Achromobacter, Bacillus and Stenotrophomonas in an Italian soil suppressive to Fusarium wilt. Typing experiments and virulence tests provided evidence that the F. oxysporum isolate when cured of the bacterial symbionts [the cured (CU) form], is pathogenic, causing wilt symptoms identical to those caused by F. oxysporum f. sp. lactucae. Here, we demonstrate that small volatile organic compounds (VOCs) emitted from the WT strain negatively influence the mycelial growth of different formae speciales of F. oxysporum. Furthermore, these VOCs repress gene expression of two putative virulence genes in F. oxysporum lactucae strain Fuslat10, a fungus against which the WT strain MSA 35 has antagonistic activity. The VOC profile of the WT and CU fungus shows different compositions. Sesquiterpenes, mainly caryophyllene, were present in the headspace only of WT MSA 35. No sesquiterpenes were found in the volatiles of ectosymbiotic Serratia sp. strain DM1 and Achromobacter sp. strain MM1. Bacterial volatiles had no effects on the growth of the different ff. spp. of F. oxysporum examined. Hyphae grown with VOC from WT F. oxysporum f. sp. lactucae strain MSA 35 were hydrophobic whereas those grown without VOCs were not, suggesting a correlation between the presence of volatiles in the atmosphere and the phenotype of the mycelium. This is the first report of VOC production by antagonistic F. oxysporum MSA 35 and their effects on pathogenic F. oxysporum. The results obtained in this work led us to propose a new potential direct long-distance mechanism for antagonism by F. oxysporum MSA 35 mediated by VOCs . Antagonism could be the consequence of both reduction of pathogen mycelial growth and inhibition of pathogen virulence gene expression. [ABSTRACT FROM AUTHOR]

In the present article we have ascertained the presence of a consortium of ectosymbiotic bacteria belonging to Serratia, Achromobacter, Bacillus and Stenotrophomonas genera associated to the mycelium of the antagonistic Fusarium oxysporum MSA 35 [wild-type (WT) strain]. Morphological characterization carried out on the WT strain, on the F. oxysporum MSA 35 without ectosymbionts [cured (CU) strain] and on the pathogenic F. oxysporum f.sp. lactucae ( Fuslat 10) showed that the ectosymbionts, present only in the WT strain, caused a depleted production of micro conidia and aerial hyphae, and a change in shape and dimension of the latter. Virulence tests showed that the cured Fusarium was a pathogenic strain and, as shown by polymerase chain reaction and microscope analysis, pathogenicity was correlated with the capability of the cured hyphae of penetrating lettuce roots. Accordingly, the hyphae of the WT strain were impaired in entering the plant roots. Typing experiments provided evidence that both CU and WT strains belong to F. oxysporum f.sp. lactucae. This implies that the antagonistic effect of WT Fusarium is not a fungal trait, but it is due to the interaction with the ectosymbiotic bacteria. Expression analysis showed that fmk1, chsV and pl1 genes involved in F. oxysporum pathogenicity are not expressed in the WT strain whereas they are expressed in the cured fungus. These results, together with the hyphal characteristics, suggest that the inability of WT strain to penetrate the plant roots could be due to alterations in the expression profile of cell wall-degrading enzymes. In conclusion, we demonstrated a modulation of F. oxysporum gene expression in response to the interaction with the ectosymbiotic bacteria. Preliminary researches indicated that the presence of bacteria attached to the hyphae of antagonistic F. oxysporum is not an isolated phenomenon. Further investigations are necessary to better understand the rule and the diffusion of ectosymbiotic bacteria among antagonistic Fusarium. [ABSTRACT FROM AUTHOR]

In this paper we report the identification and characterization of a DNA region containing putative mcpA-like gene coding for a Methyl Accepting Chemotaxis Protein (MCP) and belonging to a Burkholderia endosymbiont of the arbuscular mycorrhizal fungus Gigaspora margarita. A genomic library of total DNA extracted from the fungal spores, representative of the bacterial genome, was used to investigate the prokaryotic genome. PCR experiments with primers designed on the Burkholderia mcpA-like gene and Southern blot analysis demonstrate that they actually belong to the genome of G. margarita endosymbiont. The expression of the mcpA-like gene in the fungal spores was demonstrated by RT-PCR experiments. The detailed comparative analysis of the bacterial MCPs available in databases allowed to draw a possible evolutionary pathway leading to the present-day mcpA genes. Accordingly, the ancestor of the mcpA-like genes was the result of a domain shuffling event involving two ancestral mini-genes encoding a PAS-PAC and a MA domains, respectively, followed by the elongation of the PAS-PAC moiety. The following evolutionary divergence involved not only point mutations, but also larger rearrangements (insertions and deletions) at the 3′ end of the gene. [ABSTRACT FROM AUTHOR]