Secondary Pathways Research Articles

Hybrid DFT small-cluster model of CO oxidation on CeO2/(110)

Only a few studies have examined oxidation of CO on pure CeO2. Here we describe reaction on the (110) surface of CeO2 with DFT and B3LYP calculations of small clusters, Ce5O12 and Ce6O12. We identified a weak adsorption site (0.21 eV) on top of a cerium atom and a strong site (2.31 eV) binding two oxygens to form a carbonate species. These energies are in accord with previous reports including GGA + U. Increasing the cluster size from Ce5O12 and Ce6O12 to Ce9O12 had no significant effect on the outcome. In addition a Mars-van Krevelen type reaction cycle is investigated involving the reaction of CO with a surface oxygen. A secondary pathway was discovered forming a very stable carbonate species, with the reversible reaction having a high activation barrier. This study is the first to find evidence of an activation barrier for the formation of a carbonate species as an alternative pathway to the desorption of CO2 on CeO2/(110), which would otherwise block the surface activity. We find the approach of modelling catalyst activity using a reduced cluster of atoms is accurate, flexible and advantageous.

Exploring the transcriptome signature associated with tolerance to Penicillium expansum in apple through feature selection algorithms and differential gene expression analysis

ABSTRACT Penicillium expansum is one of the most destructive post-harvest pathogens that causes fruit spoilage in apple. This study explored the molecular response of apple to this pathogen via microarray data mining based on attribute weighting algorithms (AWAs), differential expression and pathway analyses, and multivariate statistical analysis. A total of 124 probe sets were identified by at least one AWA and these yielded 29 genes with significantly differential expression. Leave-one-out cross-validation showed that the 29-gene signature could differentiate resistant (R) and susceptible (S) cultivars with 98.65% accuracy, with most of the genes showing significant expression changes in these cultivars at 1 week post-inoculation (wpi). Many genes encoding hydrolases, reductases and proteins with zinc-finger domains showed an increased expression in the R cultivars. In particular, disease resistance protein CC-NBS-LRR, resistance-related protein E3-ubiquitin and cuticle wax biosynthesis genes displayed increased expression, especially in R cultivars at 1 and 6 wpi. The secondary metabolite biosynthesis pathway, metabolic pathway and amino acid biosynthesis pathway were commonly upregulated in both R and S cultivars, but with a greater intensity in R cultivars, while the flavonoid biosynthesis pathway was downregulated in the S cultivars at 1 h post-inoculation. This study identifies candidate targets for developing resistant cultivars.

Use of Transscleral Laser in the Management of Glaucoma – Ophthalmology

Glaucoma is a pathology classed in the neuropathologies presented to the optic degree, of a chronic nature that structurally damages the connective tissue of the optic nerve head, in the presence of decreased neural tissue, where a progressive loss of nerve fibers is generated. The retina, excavation of the same and pallor of the pupil and consequently the beginning of usable deterioration, affecting the visual field, associated in most cases with alterations in intraocular pressure related to the development, progression and severity of the same. The drainage mechanism of the eye is located in the anterior part of the chamber angle, which in classic conditions is delegated from drainage of 83% to 93% through the different channels such as Schlemn’s canal, the trabecular meshwork, the intrascleral canals, and both episcleral and conjunctival veins, in addition there are secondary drainage pathways which are a mechanism named uveoscleral drainage system which are delegated to drain the rest of the humor. Cyclophotocoagulation is an appropriate treatment option for the treatment of painful and refractory absolute glaucoma, since it preserves the ocular anatomy, relieves symptoms and reports improvements in intraocular pressure and the symptoms presented in these patients in post-intervention monitoring

De nove transcriptome sequencing identifies genes involved in aconitine-type alkaloids biosynthesis in Aconitum kusnezoffii Reichb.

Ethnopharmacological relevanceAconitum kusnezoffii Reichb. is one of the plants of Aconitum genus, and it′s root, flower, bud, and leaf has been used for traditional Mongolian medicine to bactericidal, relieve pain, collapse, rheumatic fever and so on, according to the Pharmacopoeia of the People's Republic of China (2021 edition). Aim of the studyWe aimed to reveal genes involved in the biosynthesis and accumulation of the three major medicinal components (aconitine, mesaconitine and hypaconitine) of Aconitum kusnezoffii Reichb. Materials and MethodsAconitum kusnezoffii Reichb. samples of root, flower, leaf, and stem were collected for de novo transcriptome sequencing and bioinformatics analysis. Dry samples of root, flower, leaf, and stem were used for quantitative analysis of aconitine, mesaconitine and hypaconitine by HPLC analysis. Resultsthe HPLC results show the content of aconitine, mesaconitine and hypaconitine was high in the root, then in flower, and low in leaf and stem. Mesaconitine was the most abound in all the four tissues. Transcriptome sequencing analysis shows a total of 145,117 unigenes were obtained, and 38,540 of the unigenes have complete CDS. Differential analysis indicated secondary metabolite related pathways were significantly enriched in flower, including diterpenoid, alkaloid, and flavonoid biosynthesis pathway. And 55 genes related to aconitine, mesaconitine and hypaconitine biosynthesis were identified, the expression analysis showed most of the genes were low expressed root, but high expressed in flowers. Nearly 2000 genes were correlated expressed to 5 high expressed GGPS and 1 CPS genes, and 12 genes had protein-protein interaction involved in aconitine, mesaconitine and hypaconitine biosynthesis. ConclusionWe performed de novo transcriptome analysis of four different tissues of Aconitum kusnezoffii Reichb., and identified the genes involved in aconitine, mesaconitine and hypaconitine biosynthesis. The content of aconitine, mesaconitine and hypaconitine in the four tissues of Aconitum kusnezoffii Reichb. was measured. The aconitine, mesaconitine and hypaconitine biosynthesis genes expression and their content in plant tissues were inconsistent, indicated there exist a source-sink relation.

Developing Novel Therapies for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 7]: Opportunities From Restorative Neurobiology.

Study designNarrative review.ObjectivesTo provide an overview of contemporary therapies for the James Lind Alliance priority setting partnership for degenerative cervical myelopathy (DCM) question: ‘Can novel therapies, including stem-cell, gene, pharmacological and neuroprotective therapies, be identified to improve the health and wellbeing of people living with DCM and slow down disease progression?’MethodsA review of the literature was conducted to outline the pathophysiology of DCM and present contemporary therapies that may hold therapeutic value in 3 broad categories of neuroprotection, neuroregeneration, and neuromodulation.ResultsChronic spinal cord compression leads to ischaemia, neuroinflammation, demyelination, and neuronal loss. Surgical intervention may halt progression and improve symptoms, though the majority do not make a full recovery leading to lifelong disability. Neuroprotective agents disrupt deleterious secondary injury pathways, and one agent, Riluzole, has undergone Phase-III investigation in DCM. Although it did not show efficacy on the primary outcome modified Japanese Orthopaedic Association scale, it showed promising results in pain reduction. Regenerative approaches are in the early stage, with one agent, Ibudilast, currently in a phase-III investigation. Neuromodulation approaches aim to therapeutically alter the state of spinal cord excitation by electrical stimulation with a variety of approaches. Case studies using electrical neuromuscular and spinal cord stimulation have shown positive therapeutic utility.ConclusionThere is limited research into interventions in the 3 broad areas of neuroprotection, neuroregeneration, and neuromodulation for DCM. Contemporary and novel therapies for DCM are now a top 10 priority, and whilst research in these areas is limited in DCM, it is hoped that this review will encourage research into this priority.

Combined Transcriptome and Metabolome Analysis of Musa nana Laur. Peel Treated With UV-C Reveals the Involvement of Key Metabolic Pathways.

An increasing attention is being given to treat fruits with ultraviolet C (UV-C) irradiation to extend shelf-life, senescence, and protection from different diseases during storage. However, the detailed understanding of the pathways and key changes in gene expression and metabolite accumulation related to UV-C treatments are yet to be explored. This study is a first attempt to understand such changes in banana peel irradiated with UV-C. We treated Musa nana Laur. with 0.02 KJ/m2 UV-C irradiation for 0, 4, 8, 12, 15, and 18 days and studied the physiological and quality indicators. We found that UV-C treatment reduces weight loss and decay rate, while increased the accumulation of total phenols and flavonoids. Similarly, our results demonstrated that UV-C treatment increases the activity of defense and antioxidant system related enzymes. We observed that UV-C treatment for 8 days is beneficial for M. nana peels. The peels of M. nana treated with UV-C for 8 days were then subjected to combined transcriptome and metabolome analysis. In total, there were 425 and 38 differentially expressed genes and accumulated metabolites, respectively. We found that UV-C treatment increased the expression of genes in secondary metabolite biosynthesis related pathways. Concomitant changes in the metabolite accumulation were observed. Key pathways that were responsive to UV-C irradiation include flavonoid biosynthesis, phenylpropanoid bios6ynthesis, plant-pathogen interaction, MAPK signaling (plant), and plant hormone signal transduction pathway. We concluded that UV-C treatment imparts beneficial effects on banana peels by triggering defense responses against disease, inducing expression of flavonoid and alkaloid biosynthesis genes, and activating phytohormone and MAPK signaling pathways.

Chronic edible dosing of Δ9-tetrahydrocannabinol (THC) in nonhuman primates reduces systemic platelet activity and function.

Cannabis usage has steadily increased as acceptance is growing for both medical and recreational reasons. Medical cannabis is administered for treatment of chronic pain based on the premise that the endocannabinoid system signals desensitize pain sensor neurons and produce anti-inflammatory effects. The major psychoactive ingredient of cannabis is Δ9-tetrahydrocannabinol (THC) that signals mainly through cannabinoid receptor-1 (CBr), which is also present on nonneuron cells including blood platelets of the circulatory system. In vitro, CBr-mediated signaling has been shown to acutely inhibit platelet activation downstream of the platelet collagen receptor glycoprotein (GP)VI. The systemic effects of chronic THC administration on platelet activity and function remain unclear. This study investigates the effects of chronic THC administration on platelet function using a nonhuman primate (NHP) model. Our results show that female and male NHPs consuming a daily THC edible had reduced platelet adhesion, aggregation, and granule secretion in response to select platelet agonists. Furthermore, a change in bioactive lipids (oxylipins) was observed in the female cohort after THC administration. These results indicate that chronic THC edible administration desensitized platelet activity and function in response to GPVI- and G-protein coupled receptor-based activation by interfering with primary and secondary feedback signaling pathways. These observations may have important clinical implications for patients who use medical marijuana and for providers caring for these patients.

Kaempferol acts on bile acid signaling and gut microbiota to attenuate the tumor burden in ApcMin/+ mice

Emerging evidence points to a strong association between the bile acid (BA)-gut microbiota (GM) axis, and the risk of colorectal cancer (CRC). Kaempferol, a common polyphenol in the daily diet, shows various pharmacological activities. However, it remains unclear about the effect of kaempferol on the CRC development and the BA-GM homeostasis. Here, we found kaempferol effectively reduced tumor burden, restored the damaged intestinal barrier and downregulated antigen Ki67 and leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) expressions in ApcMin/+ mice. For BA metabolism, kaempferol reversed the decreasing trend in chenodesoxycholic acid (CDCA) and 12α-hydroxylated BAs by increasing the sterol 27-hydroxylase (CYP27A1) and sterol 12α-hydroxylase (CYP8B1) expressions, and upregulated FXR expression. Importantly, molecular docking analysis revealed a direct interaction between kaempferol and farnesoid X receptor (FXR), the mater regulator of BA signaling. For GM analysis, we found higher abundances of species with anticancer properties and lower abundances of species associated with inflammation, obesity, and metabolic disorders in kaempferol-treated groups. Moreover, the gut of kaempferol-treated mice was predominantly colonized by short-chain fatty acid (SCFA) and lactic acid producing bacteria. Based on the PICRUSt-predicted pathways of our GM dataset, we demonstrated that kaempferol downregulated secondary BA synthesis pathways, increased G protein-coupled receptor activity and decreased NOD-like receptor activity, affecting cell differentiation, proliferation, survival, and apoptosis. Collectively, these results reveal that kaempferol effectively attenuates the tumor burden in ApcMin/+ mice by modulating the BA signaling and GM homeostasis.

Phytomelatonin: an unexpected molecule with amazing performances in plants.

Phytomelatonin, a multifunctional molecule that has been found to be present in all plants examined to date, has an important role in plants as a modulatory agent (a biostimulator) that improves plant tolerance to both biotic and abiotic stress. We present a review of phytomelatonin that considers its roles in plant metabolism and in particular its interactions with plant hormone network. In the primary metabolism of plants, melatonin improves the rate and efficiency of photosynthesis, as well related factors such as stomatal conductance, intercellular CO2, and Rubisco activity. It has also been shown to down-regulate some senescence transcription factors. Melatonin up-regulates many enzyme transcripts related to carbohydrates (including sucrose and starch), amino acids, and lipid metabolism, optimizing N, P, and S uptake. With respect to the secondary metabolism, clear increases in polyphenol, glucosinolate, terpenoid, and alkaloid contents have been described in numerous melatonin-treated plants. Generally, the most important genes of these secondary biosynthesis pathways have been found to be up-regulated by melatonin. The great regulatory capacity of melatonin is a result of its control of the redox and plant hormone networks. Melatonin acts as a plant master regulator, up-/down-regulating different plant hormone levels and signalling, and is a key player in redox homeostasis. It has the capacity to counteract diverse critical situations such as pathogen infections and abiotic stresses, and provide plants with varying degrees of tolerance. We propose possible future applications of melatonin for crop improvement and post-harvest product preservation.

Aggression‐based social learning in the zebra finch (Taeniopygia guttata)

AbstractSelectively learning from specific types of individuals may be adaptive if demonstrator characteristics can be used to identify more beneficial sources of social information. Such “social learning biases” have been experimentally demonstrated in a number of species, but these experiments generally involve restricted laboratory conditions using a limited number of potential demonstrators and tend to consider only the characteristics of demonstrators rather than the importance of pairwise relationships on information transfer between individuals. In this study, we presented a novel foraging task to a large population of zebra finches (Taeniopygia guttata) housed in a free‐flying aviary and used multinetwork Network‐Based Diffusion Analysis (NBDA) to establish whether birds learned from individuals they shared particular relationships with. Specifically, we investigated whether task solves followed social learning pathways representing the following relationships between individuals: feeding associations, aggressive interactions, positive associations (e.g. grooming) and mating pairs. We found strong evidence that zebra finches learn from their aggressors, irrespective of the outcome of that aggressive encounter. This has been previously suggested in laboratory‐based studies on zebra finches, but never conclusively documented in a freely interacting population. We also found some weaker evidence to suggest that zebra finches learn from their mates—a social learning bias that has previously received little to no attention. However, we found that mates‐based learning occurred infrequently and was secondary to aggression‐based social learning biases. Our results therefore additionally highlight the importance of including combinations of multiple potential information pathways in social learning analyses to account for secondary learning pathways that may otherwise be missed.

Unveiling the Chemical Diversity of the Deep-Sea Sponge Characella pachastrelloides.

Sponges are at the forefront of marine natural product research. In the deep sea, extreme conditions have driven secondary metabolite pathway evolution such that we might expect deep-sea sponges to yield a broad range of unique natural products. Here, we investigate the chemodiversity of a deep-sea tetractinellid sponge, Characella pachastrelloides, collected from ~800 m depth in Irish waters. First, we analyzed the MS/MS data obtained from fractions of this sponge on the GNPS public online platform to guide our exploration of its chemodiversity. Novel glycolipopeptides named characellides were previously isolated from the sponge and herein cyanocobalamin, a manufactured form of vitamin B12, not previously found in nature, was isolated in a large amount. We also identified several poecillastrins from the molecular network, a class of polyketide known to exhibit cytotoxicity. Light sensitivity prevented the isolation and characterization of these polyketides, but their presence was confirmed by characteristic NMR and MS signals. Finally, we isolated the new betaine 6-methylhercynine, which contains a unique methylation at C-2 of the imidazole ring. This compound showed potent cytotoxicity towards against HeLa (cervical cancer) cells.

Metabolic Disturbance Induced by the Embryo Contributes to the Formation of Chalky Endosperm of a Notched-Belly Rice Mutant.

Grain chalkiness is a key quality trait of the rice grain, whereas its underlying mechanism is still not thoroughly understood because of the complex genetic and environmental interactions. We identified a notched-belly (NB) mutant that has a notched-line on the belly of grains. The line dissects the endosperm into two distinct parts, the upper translucent part, and the bottom chalky part in the vicinity of the embryo. Using this mutant, our previous studies clued the negative influence of embryo on the biochemical makeup of the endosperm, suggesting the need for the in-depth study of the embryo effect on the metabolome of developing endosperm. This study continued to use the NB mutant to evolve a novel comparison method to clarify the role of embryo in the formation of a chalky endosperm. Grain samples of the wild-type (WT) and NB were harvested at 10, 20, and 30 days after fertilization (DAF), and then divided into subsamples of the embryo, the upper endosperm, and the bottom endosperm. Using non-targeted metabolomics and whole-genome RNA sequencing (RNA-seq), a nearly complete catalog of expressed metabolites and genes was generated. Results showed that the embryo impaired the storage of sucrose, amino acid, starch, and storage proteins in the bottom endosperm of NB by enhancing the expression of sugar, amino acids, and peptide transporters, and declining the expression of starch, prolamin, and glutelin synthesis-related genes. Importantly, the competitive advantage of the developing embryo in extracting the nutrients from the endosperm, transformed the bottom endosperm into an “exhaustive source” by diverting the carbon (C) and nitrogen (N) metabolism from synthetic storage to secondary pathways, resulting in impaired filling of the bottom endosperm and subsequently the formation of chalky tissue. In summary, this study reveals that embryo-induced metabolic shift in the endosperm is associated with the occurrence of grain chalkiness, which is of relevance to the development of high-quality rice by balancing the embryo–endosperm interaction.

De novo Transcriptome Assembly of Senna occidentalis Sheds Light on the Anthraquinone Biosynthesis Pathway.

Senna occidentalis is an annual leguminous herb that is rich in anthraquinones, which have various pharmacological activities. However, little is known about the genetics of S. occidentalis, particularly its anthraquinone biosynthesis pathway. To broaden our understanding of the key genes and regulatory mechanisms involved in the anthraquinone biosynthesis pathway, we used short RNA sequencing (RNA-Seq) and long-read isoform sequencing (Iso-Seq) to perform a spatial and temporal transcriptomic analysis of S. occidentalis. This generated 121,592 RNA-Seq unigenes and 38,440 Iso-Seq unigenes. Comprehensive functional annotation and classification of these datasets using public databases identified unigene sequences related to major secondary metabolite biosynthesis pathways and critical transcription factor families (bHLH, WRKY, MYB, and bZIP). A tissue-specific differential expression analysis of S. occidentalis and measurement of the amount of anthraquinones revealed that anthraquinone accumulation was related to the gene expression levels in the different tissues. In addition, the amounts and types of anthraquinones produced differ between S. occidentalis and S. tora. In conclusion, these results provide a broader understanding of the anthraquinone metabolic pathway in S. occidentalis.

Who stole the proton? Suspect general base guanine found with a smoking gun in the pistol ribozyme.

The pistol ribozyme (Psr) is one among the most recently discovered classes of small nucleolytic ribozymes that catalyze site-specific RNA self-cleavage through 2'-O-transphosphorylation. The Psr contains a conserved guanine (G40) that in crystal structures is in a position suggesting it plays the role of the general base to abstract a proton from the nucleophile to activate the reaction. Although some functional data is consistent with this mechanistic role, a notable exception is 2-aminopurine (2AP) substitution which has no effect on the rate, unlike similar substitutions across other so-called "G + M" and "G + A" ribozyme classes. Herein we postulate that an alternate conserved guanine, G42, is the primary general base, and provide evidence from molecular simulations that the active site of Psr can undergo local refolding into a structure that is consistent with the common "L-platform/L-scaffold" architecture identified in G + M and G + A ribozyme classes with Psr currently the notable exception. We summarize the key currently available experimental data and present new classical and combined quantum mechanical/molecular mechanical simulation results that collectively suggest a new hypothesis. We hypothesize that there are two available catalytic pathways supported by different conformational states connected by a local refolding of the active site: (1) a primary pathway with an active site architecture aligned with the L-platform/L-scaffold framework where G42 acts as a general base, and (2) a secondary pathway with the crystallographic active site architecture where G40 acts as a general base. We go on to make several experimentally testable predictions, and suggest specific experiments that would ultimately bring closure to the mystery as to "who stole the proton in the pistol ribozyme?".

Extending growth inhibition during area-selective atomic layer deposition of Al2O3 on aminosilane-functionalized SiO2.

During area-selective atomic layer deposition (ALD) based on growth inhibitors, nucleation eventually occurs as the metal precursor reacts with the surface through secondary pathways. We show that ALD of Al2O3 on functionalized SiO2 can be significantly delayed by using a lower reactivity, heteroleptic precursor at well below the saturation dose.

Post-Traumatic Cerebral Edema: Pathophysiology, Key Contributors, and Contemporary Management

The development of cerebral edema following traumatic brain injury is one of the most significant predictors of outcome and is associated with high rates of morbidity and mortality. A prominent focus of neurosurgical and neurocritical care is the evaluation and aggressive management of cerebral edema and subsequent intracranial hypertension. Despite numerous advances and capabilities in neurocritical care, treatments remain primarily reactive and are instituted only after secondary pathophysiological pathways have culminated in an intracranial pressure crisis. Recent reviews have focused on several key molecular contributors to post-traumatic cerebral edema and on several potential anti-edema therapeutic targets. The present article provides a contemporary overview of post-traumatic cerebral edema by reviewing important historical concepts, fundamental pathophysiological mechanisms, various causes and key contributors specific to traumatic brain injury, and established treatments of downstream intracranial hypertension.

Ca2+ accelerates peptide fibrillogenesis via a heterogeneous secondary nucleation pathway.

A binding-induced fibrillogenesis (BIF) peptide mimics the fibrillogenesis of fibronectin, forming fibrous networks for disease theranostics. However, the mechanism of fast fibrillogenesis of the BIF peptide remains unclear. In this study, the fibrillogenesis processes of the BIF peptide in the absence and presence of receptors, i.e. Ca2+, are carefully studied. The BIF peptide, lauric acid-FFVLK-HSDVHK (LAFH) can self-assemble into nanoparticles (NPs) in solution and further transform into a fibrous structure, the fibrillogenesis of which could be accelerated by the addition of Ca2+. In detail, the fibrillogenesis of LAFH NPs without Ca2+ is achieved through a nucleation-elongation mechanism, in which homogeneous secondary nucleation is involved, followed by detachment of the newly formed fibers from pre-formed nanofibers (NFs). The fibrillogenesis of LAFH NPs in the presence of Ca2+ starts with an Ostwald ripening process, followed by a heterogeneous secondary nucleation, in which LAFH NPs bind to pre-formed LAFH NFs via Ca2+. The phenomenon of heterogeneous secondary nucleation including the attachment and shape change of LAFH NPs on pre-formed LAFH NFs is first revealed by TEM observation. These findings contribute to the understanding of the fast BIF process, supporting the mechanism study at the cellular level.

Transcription factor PagLBD21 functions as a repressor of secondary xylem development in <i>Populus</i>

During secondary growth in trees, xylem cells differentiated from cambium cells begin to synthesize secondary cell walls that are primarily composed of cellulose, hemicellulose and lignin, and are deposited between primary cell walls and plasma membranes, leading to in wood formation. Identification of regulatory genes functioning during this developmental process is valuable for increasing wood production. In this study, we functionally characterized an LBD (LATERAL ORGAN BOUNDARIES DOMAIN) transcription factor PagLBD21 as a repressor of secondary xylem development in <italic>Populus</italic>. Compared to wild type plants, transgenic plants overexpressing <italic>PagLBD21</italic> (<italic>PagLBD21OE</italic>) exhibited decreased xylem widths in cross-sections. Consistent with the functional analysis, RNA sequencing (RNA-seq) analysis revealed that genes functioning in xylem development and secondary cell wall biosynthesis pathways were significantly down-regulated in <italic>PagLBD21OE</italic> plants. We also performed DNA affinity purification followed by sequencing (DAP-seq) to identify genome-wide target genes of PagLBD21. Furthermore, we compared the RNA-seq and DAP-seq datasets of PagLBD21 and PagLBD3, and the results showed that there was a significant overlap between their target genes, suggesting these two LBD transcription factors are functionally redundant during secondary growth.

POSB392 Understanding the Secondary Care Characteristics and Pathways of Multiple Myeloma Patients Who Reach Second-Line Therapy Using the Hospital Episode Statistics (HES) Database

Despite recent advances in Multiple Myeloma (MM) treatment there is little data describing pathway and resource impact. The Objectives: of this study were to understand the demographics, clinical characteristics, and secondary care burden for MM patients up to and including second-line (2L) therapy.

Mutation of a prenyltransferase results in accumulation of subglutinols and destruxins and enhanced virulence in the insect pathogen, Metarhizium anisopliae.

The insect pathogenic fungus, Metarhizium anisopliae is a commercialized microbial agent used in biological control efforts targeting a diverse range of agricultural and other insect pests. The second step in the synthesis of a group of M. anisopliae α-pyrone diterpenoids (termed subglutinols) involves the activity of a prenyltransferase family geranylgeranyl diphosphate synthase (product of the subD/MaGGPPS5 gene). Here, we show that targeted gene disruption of MaGGPPS5 results in earlier conidial germination and faster greater vegetative growth compared to the wild type (WT) parent and complemented strains. In addition, insect bioassays revealed that the ΔMaGGPPS5 mutant strain displayed significantly increased virulence, with a ~50% decrease in the mean lethal time (LT50 , from 6 to 3 days) to kill (50% of) target insects, and an ~15-40-fold decrease in the mean lethal dose (LC50 ). Metabolite profiling indicated increased accumulation in the ΔMaGGPPS5 mutant of select subglutinols (A, B and C) and destruxins (A, A2, B and B2), the latter a set of fungal secondary metabolites that act as insect toxins, with a concomitant loss of production of subglutinol 'analogue 45'. These data suggest that the increased virulence phenotype seen for the ΔMaGGPPS5 strain can, at least in part, be attributed to a combination of faster growth and increased insect toxin production, linking the production of two different secondary metabolite pathways, and represent a novel approach for the screening of isolates with enhanced virulence via modulation of terpenoid secondary metabolite biosynthesis.