Synthesis of Chiral Sulfoxides by A Cyclic Oxidation-Reduction Multi-Enzymatic Cascade Biocatalysis.

Optically pure sulfoxides are valuable organosulfur compounds extensively employed in medicinal and organic synthesis. In this study, we present a biocatalytic oxidation-reduction cascade system designed for the preparation of enantiopure sulfoxides. The system involves the cooperation of a low-enantioselective chimeric oxidase SMO (styrene monooxygenase) with a high-enantioselective reductase MsrA (methionine sulfoxide reductase A), facilitating "non-selective oxidation and selective reduction" cycles for prochiral sulfide oxidation. The regeneration of requisite cofactors for MsrA and SMO was achieved via a cascade catalysis process involving three auxiliary enzymes, sustained by cost-effective D-glucose. Under the optimal reaction conditions, a series of heteroaryl alkyl, aryl alkyl and dialkyl sulfoxides in R configuration were synthesized through this "one-pot, one step" cascade reaction. The obtained compounds exhibited high yields of >90 % and demonstrated enantiomeric excess (ee) values exceeding 90 %. This study represents an unconventional and efficient biocatalytic way in utilizing the low-enantioselective oxidase for the synthesis of enantiopure sulfoxides.

Rab7/Retromer-based endolysosomal trafficking is essential for proper host invasion in rice blast.

Secretion is a fundamental process that plant pathogens utilize to deliver effectors into the host to downregulate immunity and promote infection. Here, we uncover a fascinating membrane trafficking and delivery route that originates from vacuolar membranes in Magnaporthe oryzae and conduits to the host interface and plasma membrane. To perform such secretory/trafficking function, MoRab7 first recruits the retromer complex to the vacuolar membrane, enabling recognition of a family of SNARE proteins, including MoSnc1. Live-cell imaging confirmed a highly dynamic vesicular trafficking of the retromer complex component(s) and MoSnc1 toward and across the host interface or plasma membrane, and subsequent fusion with target membranes. Interestingly, disruption of the MoRab7/Retromer/MoSnc1-based endolysosomal cascade affects effector secretion and fungal pathogenicity. Taken together, we discovered an unconventional protein and membrane trafficking route starting from the fungal endolysosomes to the M. oryzae-rice interaction interface and dissect the role of MoRab7/Retromer/MoSnc1 sorting machinery in effector secretion during biotrophy and invasive growth in rice blast fungus.

Kinetic resolution of sulfoxides with high enantioselectivity using a new homologue of methionine sulfoxide reductase B.

Optically pure sulfoxides are noteworthy compounds that find wide applications in various industrial fields. Here, we report a methionine sulfoxide reductase B (MsrB) homologue that exhibits high enantioselectivity and broad substrate scope for the kinetic resolution of racemic (rac) sulfoxides. This MsrB homologue, named liMsrB, was identified from Limnohabitans sp. 103DPR2 and showed good activity together with enantioselectivity towards a series of aromatic, heteroaromatic, alkyl and thioalkyl sulfoxides. Chiral sulfoxides in the S configuration were prepared in approximately 50% yield and 92-99% enantiomeric excess through kinetic resolution at an initial substrate concentration of up to 90 mM (11.2 g L-1). This study presents an efficient route for the enzymatic preparation of (S)-sulfoxides through kinetic resolution.

[MinerVa: A high performance bioinformatic algorithm for the detection of minimal residual disease in solid tumors].

How to improve the performance of circulating tumor DNA (ctDNA) signal acquisition and the accuracy to authenticate ultra low-frequency mutation are major challenges of minimal residual disease (MRD) detection in solid tumors. In this study, we developed a new MRD bioinformatics algorithm, namely multi-variant joint confidence analysis (MinerVa), and tested this algorithm both in contrived ctDNA standards and plasma DNA samples of patients with early non-small cell lung cancer (NSCLC). Our results showed that the specificity of multi-variant tracking of MinerVa algorithm ranged from 99.62% to 99.70%, and when tracking 30 variants, variant signals could be detected as low as 6.3 × 10 -5 variant abundance. Furthermore, in a cohort of 27 NSCLC patients, the specificity of ctDNA-MRD for recurrence monitoring was 100%, and the sensitivity was 78.6%. These findings indicate that the MinerVa algorithm can efficiently capture ctDNA signals in blood samples and exhibit high accuracy in MRD detection.

Involvement of Arabidopsis Acyl Carrier Protein 1 in PAMP-Triggered Immunity.

Plant fatty acids (FAs) and lipids are essential in storing energy and act as structural components for cell membranes and signaling molecules for plant growth and stress responses. Acyl carrier proteins (ACPs) are small acidic proteins that covalently bind the fatty acyl intermediates during the elongation of FAs. The Arabidopsis thaliana ACP family has eight members. Through reverse genetic, molecular, and biochemical approaches, we have discovered that ACP1 localizes to the chloroplast and limits the magnitude of pattern-triggered immunity (PTI) against the bacterial pathogen Pseudomonas syringae pv. tomato. Mutant acp1 plants have reduced levels of linolenic acid (18:3), which is the primary precursor for biosynthesis of the phytohormone jasmonic acid (JA), and a corresponding decrease in the abundance of JA. Consistent with the known antagonistic relationship between JA and salicylic acid (SA), acp1 mutant plants also accumulate a higher level of SA and display corresponding shifts in JA- and SA-regulated transcriptional outputs. Moreover, methyl JA and linolenic acid treatments cause an apparently enhanced decrease of resistance against P. syringae pv. tomato in acp1 mutants than that in WT plants. The ability of ACP1 to prevent this hormone imbalance likely underlies its negative impact on PTI in plant defense. Thus, ACP1 links FA metabolism to stress hormone homeostasis to be negatively involved in PTI in Arabidopsis plant defense. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

First Report of Trichoderma crassum Causing Leaf Spot on Tomato (Solanum lycopersicum cv. M82) in Ohio.

Trichoderma is a genus of wood-decaying fungi generally found in soil (Druzhinina and Kubicek 2005). Trichoderma crassum was confirmed to be a sister species to T. virens according to the molecular sequencing results (Chaverri et al. 2003). A foliar disease with ~70% incidence on Solanum lycopersicum was observed in a greenhouse at The Ohio State University (40°0'8'' north latitude, 83°1'36'' west longitude), Columbus, United States, in December 2021. On average up to 60% of the leaves per two-month-old tomato plant were infected. Initially, the dark-grey color and irregular spots appeared at the leaf tips. As the disease progressed, the yellow necrotic lesions were observed surrounding the preformed disease spots. Finally, the infected leaves appeared curled and wilted as a whole. The leaf fragments from three tomato plants 40 inches apart were cut from the diseased lesions and surface sterilized with 75% ethanol (30 seconds) and 1% NaOCl (60 seconds), subsequently rinsed with sterilized deionized water three times. Nine pieces of the sterilized leaf tissues were then placed on the PDA plates at 28℃ in the dark and incubated in one incubator for 4 days. The pure cultures of five isolates were acquired and examined with a light microscope. The fungus from all the isolates changed from white to dark green with the radial pattern and profuse sporulation on the PDA. The produced round conidia were observed under a light microscope (Fig S1). The DNA was extracted from two representative isolates which showed the same morphology. The internal transcribed spacer (ITS) region and a conserved fungal rRNA region were amplified using the primers ITS1/ITS4 (5'-TCCGTAGGTGAACCTGCGG-3' and 5'-TCCTCCGCTTATTGATATGC-3') (White et al. 1990) and SR6f/SR7r (5'-TGTTACGACTTTTACTT-3' and 5'-AGTTAAAAAGCTCGTAGTTG-3') (Hirose et al. 2012), respectively. The PCR products were further sequenced by Sanger sequencing (Table S1). Based on the BLAST results through NCBI website, the ITS sequences of the two isolates were 99% (566/572) and 98% (558/572) identical to Trichoderma crassum DAOM 164916 (EU280067). Their SR sequences both showed 99% (290/293; 289/293) identity to the same strain. The phylogenetic tree was also created with the sequences of ITS region by MEGA software (version 11) (Fig S2). Therefore, the fungus was identified as Trichoderma crassum based on its morphological characteristics (green conidia), Sanger sequencing results, and phylogenetic tree. To complete Koch's postulates, the 5-mm-diameter fungal agar discs of 7-day-old pure cultures were used for the inoculation on 18 healthy leaves of six tomato cv. M82 plants with two-month-old. The sterile pure PDA discs of the equal size were used for the mock inoculation as a comparison. Fungal plug method was chosen in this study because it had been widely applied to characterization of the fungal pathogens causing leaf spot disease (Pornsuriya et al. 2020; Yang et al. 2021). Five days later, the same symptom as those that occurred on the previously naturally infected tomato plants were observed on all the inoculated leaves (Fig S3A). However, there were no symptoms on the leaves with the mock inoculation. The fungus re-isolated from the symptomatic leaves showed the consistent morphology (dark-green color with radial sporulation) with the original isolates (Fig S3B). Thus, Trichoderma crassum was verified as the causal agent of the foliar disease on Solanum lycopersicum cv. M82 in our greenhouse. To our knowledge, it is the first report of Trichoderma crassum leading to the leaf spot and wilt on tomato in Ohio. The identification of the causal agent lays the groundwork for the development of necessary disease management techniques. We acknowledge the funding support from CFAES Internal Grants Program 2021009.

Arabidopsis Plasma Membrane ATPase AHA5 Is Negatively Involved in PAMP-Triggered Immunity.

Plants evolve a prompt and robust immune system to defend themselves against pathogen infections. Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is the first battle layer activated upon the PAMP's perception, which leads to multiple defense responses. The plasma membrane (PM) H+-ATPases are the primary ion pumps to create and maintain the cellular membrane potential that is critical for various essential biological processes, including plant growth, development, and defense. This study discovered that the PM H+-ATPase AHA5 is negatively involved in Arabidopsis PTI against the virulent pathogen Pseudomonas syringae pvr. tomato (Pto) DC3000 infection. The aha5 mutant plants caused the reduced stomata opening upon the Pto infection, which was associated with the salicylic acid (SA) pathway. In addition, the aha5 mutant plants caused the increased levels of callose deposition, defense-related gene expression, and SA accumulation. Our results also indicate that the PM H+-ATPase activity of AHA5 probably mediates the coupling of H2O2 generation and the apoplast alkalization in PTI responses. Moreover, AHA5 was found to interact with a vital defense regulator, RPM1-interacting protein 4 (RIN4), in vitro and in vivo, which might also be critical for its function in PTI. In summary, our studies show that AHA5 functions as a novel and critical component that is negatively involved in PTI by coordinating different defense responses during the Arabidopsis-Pto DC3000 interaction.

Genome Sequence Resource of Bacillus sp. RRD69, a Beneficial Bacterial Endophyte Isolated from Switchgrass Plants.

We report here the genome sequence of Bacillus sp. RRD69, a plant-growth-promoting bacterial endophyte isolated from switchgrass plants grown on a reclaimed coal-mining site in Kentucky. RRD69 is predicted to contain 3,758 protein-coding genes, with a genome size of 3.715 Mbp and a 41.41% GC content.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Characterization and fine mapping of a new dwarf mutant in Brassica napus.

BACKGROUND: Plant height is an important plant characteristic closely related to yield performance of many crops. Reasonable reduction of plant height of crops is beneficial for improving yield and enhancing lodging resistance. RESULTS: In the present study, we described the Brassica napus dwarf mutant bnd2 that was isolated using ethyl methanesulfonate (EMS) mutagenesis. Compared to wild type (WT), bnd2 exhibited reduced height and shorter hypocotyl and petiole leaves. By crossing the bnd2 mutant with the WT strain, we found that the ratio of the mutant to the WT in the F2 population was close to 1:3, indicating that bnd2 is a recessive mutation of a single locus. Following bulked segregant analysis (BSA) by resequencing, BND2 was found to be located in the 13.77-18.08 Mb interval of chromosome A08, with a length of 4.31 Mb. After fine mapping with single nucleotide polymorphism (SNP) and insertion/deletion (InDel) markers, the gene was narrowed to a 140-Kb interval ranging from 15.62 Mb to 15.76 Mb. According to reference genome annotation, there were 27 genes in the interval, of which BnaA08g20960D had an SNP type variation in the intron between the mutant and its parent, which may be the candidate gene corresponding to BND2. The hybrid line derived from a cross between the mutant bnd2 and the commercial cultivar L329 had similar plant height but higher grain yield compared to the commercial cultivar, suggesting that the allele bnd2 is beneficial for hybrid breeding of lodging resistant and high yield rapeseed. CONCLUSION: In this study, we identified a novel dwarf mutant of rapeseed with a new locus, which may be useful for functional analyses of genetic mechanisms of plant architecture and grain yield in rapeseed.

Deciphering the Novel Role of AtMIN7 in Cuticle Formation and Defense against the Bacterial Pathogen Infection.

The cuticle is the outermost layer of plant aerial tissue that interacts with the environment and protects plants against water loss and various biotic and abiotic stresses. ADP ribosylation factor guanine nucleotide exchange factor proteins (ARF-GEFs) are key components of the vesicle trafficking system. Our study discovers that AtMIN7, an Arabidopsis ARF-GEF, is critical for cuticle formation and related leaf surface defense against the bacterial pathogen Pseudomonas syringae pathovar tomato (Pto). Our transmission electron microscopy and scanning electron microscopy studies indicate that the atmin7 mutant leaves have a thinner cuticular layer, defective stomata structure, and impaired cuticle ledge of stomata compared to the leaves of wild type plants. GC-MS analysis further revealed that the amount of cutin monomers was significantly reduced in atmin7 mutant plants. Furthermore, the exogenous application of either of three plant hormones-salicylic acid, jasmonic acid, or abscisic acid-enhanced the cuticle formation in atmin7 mutant leaves and the related defense responses to the bacterial Pto infection. Thus, transport of cutin-related components by AtMIN7 may contribute to its impact on cuticle formation and related defense function.

FKF1 F-box protein promotes flowering in part by negatively regulating DELLA protein stability under long-day photoperiod in Arabidopsis.

FLAVIN-BINDING KELCH REPEAT F-BOX 1 (FKF1) encodes an F-box protein that regulates photoperiod flowering in Arabidopsis under long-day conditions (LDs). Gibberellin (GA) is also important for regulating flowering under LDs. However, how FKF1 and the GA pathway work in concert in regulating flowering is not fully understood. Here, we showed that the mutation of FKF1 could cause accumulation of DELLA proteins, which are crucial repressors in GA signaling pathway, thereby reducing plant sensitivity to GA in flowering. Both in vitro and in vivo biochemical analyses demonstrated that FKF1 directly interacted with DELLA proteins. Furthermore, we showed that FKF1 promoted ubiquitination and degradation of DELLA proteins. Analysis of genetic data revealed that FKF1 acted partially through DELLAs to regulate flowering under LDs. In addition, DELLAs exerted a negative feedback on FKF1 expression. Collectively, these findings demonstrate that FKF1 promotes flowering partially by negatively regulating DELLA protein stability under LDs, and suggesting a potential mechanism linking the FKF1 to the GA signaling DELLA proteins.

Analysis of factors influencing hospital-acquired infection in postoperative patients with intracranial aneurysm.

BACKGROUND: Hospital-acquired infection (HAI) is a serious complication of neurosurgery. In recent years, the medical body has paid increasing attention to this issue. AIM: We investigated the status of HAIs in patients who had undergone surgery for intracranial aneurysms and analysed their risk factors. METHODS: A retrospective analysis was carried out on the medical records of 542 patients with intracranial aneurysms after they were admitted for neurosurgery at Xuanwu Hospital of Capital Medical University between January and December 2016. Cases studied were divided into an infection group and a control group. Logistic regression analysis of the data was carried out. FINDINGS: Of the 542 patients with intracranial aneurysms who underwent surgery, 77 HAIs occurred in 64 patients, with an infection prevalence of 11.8% and prevalence of infection cases of 14.2%. Logistic regression showed that an admission Glasgow Coma Scale (GCS) score of less than 8 points (odds ratio = 4.261, 95% confidence interval 1.102-16.476), hyperglycaemia (2.759, 1.159-6.564), hypothermia treatment (6.557, 2.244-19.159), and central venous catheterisation (CVC) (8.853, 2.860-27.398) were independent risk factors for HAIs in patients with intracranial aneurysm who underwent surgery. CONCLUSION: Being comatose upon hospital admission, having hyperglycaemia or hypothermia, and indwelling CVC are major risk factors for HAIs in patients undergoing surgery for intracranial aneurysms.

Introduction of heterologous transcription factors and their target genes into Penicillium oxalicum leads to increased lignocellulolytic enzyme production.

Genetic engineering of transcription factors is an efficient strategy to improve lignocellulolytic enzyme production in fungi. In this study, the xylanase transcriptional regulators of Trichoderma reesei (Xyr1) and Neurospora crassa (XLR-1), as well as their constitutively active mutants (Xyr1A824V and XLR-1A828V), were heterologously expressed in Penicillium oxalicum. The two heterologous regulators were identified to be able to activate lignocellulolytic enzyme gene expression in P. oxalicum. Particularly, expression of T. reesei Xyr1 resulted in a higher cellulase production level compared with the expression of native xylanase transcriptional regulator XlnR using the same promoter. Xyr1A824V and XLR-1A828V were found to be able to confer P. oxalicum more enhanced lignocellulolytic abilities than wild-type regulators Xyr1 and XLR-1. Furthermore, introduction of regulatory modules containing Xyr1A824V/XLR-1A828V and their target cellulase genes resulted in greater increases in cellulase production than alone expression of transcriptional regulators. Through the cumulative introduction of three regulatory modules containing regulator mutants and their corresponding target cellulase genes from P. oxalicum, T. reesei, and N. crassa, a 2.8-fold increase in cellulase production was achieved in P. oxalicum.

The 5-oxoprolinase is required for conidiation, sexual reproduction, virulence and deoxynivalenol production of Fusarium graminearum.

In eukaryotic organisms, the 5-oxoprolinase is one of the six key enzymes in the γ-glutamyl cycle that is involved in the biosynthetic pathway of glutathione (GSH, an antioxidative tripeptide counteracting the oxidative stress). To date, little is known about the biological functions of the 5-oxoprolinase in filamentous phytopathogenic fungi. In this study, we investigated the 5-oxoprolinase in Fusarium graminearum for the first time. In F. graminearum, two paralogous genes (FgOXP1 and FgOXP2) were identified to encode the 5-oxoprolinase while only one homologous gene encoding the 5-oxoprolinase could be found in other filamentous phytopathogenic fungi or Saccharomyces cerevisiae. Deletion of FgOXP1 or FgOXP2 in F. graminearum led to significant defects in its virulence on wheat. This is likely caused by an observed decreased deoxynivalenol (DON, a mycotoxin) production in the gene deletion mutant strains as DON is one of the best characterized virulence factors of F. graminearum. The FgOXP2 deletion mutant strains were also defective in conidiation and sexual reproduction while the FgOXP1 deletion mutant strains were normal for those phenotypes. Double deletion of FgOXP1 and FgOXP2 led to more severe defects in conidiation, DON production and virulence on plants, suggesting that both FgOXP1 and FgOXP2 play a role in fungal development and plant colonization. Although transformation of MoOXP1into ΔFgoxp1 was able to complement ΔFgoxp1, transformation of MoOXP1 into ΔFgoxp2 failed to restore its defects in sexual development, DON production and pathogenicity. Taken together, these results suggest that FgOXP1 and FgOXP2 are likely to have been functionally diversified and play significant roles in fungal development and full virulence in F. graminearum.

Synergistic and Dose-Controlled Regulation of Cellulase Gene Expression in Penicillium oxalicum.

Filamentous fungus Penicillium oxalicum produces diverse lignocellulolytic enzymes, which are regulated by the combinations of many transcription factors. Here, a single-gene disruptant library for 470 transcription factors was constructed and systematically screened for cellulase production. Twenty transcription factors (including ClrB, CreA, XlnR, Ace1, AmyR, and 15 unknown proteins) were identified to play putative roles in the activation or repression of cellulase synthesis. Most of these regulators have not been characterized in any fungi before. We identified the ClrB, CreA, XlnR, and AmyR transcription factors as critical dose-dependent regulators of cellulase expression, the core regulons of which were identified by analyzing several transcriptomes and/or secretomes. Synergistic and additive modes of combinatorial control of each cellulase gene by these regulatory factors were achieved, and cellulase expression was fine-tuned in a proper and controlled manner. With one of these targets, the expression of the major intracellular ß-glucosidase Bgl2 was found to be dependent on ClrB. The Bgl2-deficient background resulted in a substantial gene activation by ClrB and proved to be closely correlated with the relief of repression mediated by CreA and AmyR during cellulase induction. Our results also signify that probing the synergistic and dose-controlled regulation mechanisms of cellulolytic regulators and using it for reconstruction of expression regulation network (RERN) may be a promising strategy for cellulolytic fungi to develop enzyme hyper-producers. Based on our data, ClrB was identified as focal point for the synergistic activation regulation of cellulase expression by integrating cellulolytic regulators and their target genes, which refined our understanding of transcriptional-regulatory network as a "seesaw model" in which the coordinated regulation of cellulolytic genes is established by counteracting activators and repressors.

Thoracic sarcopenia was a poor prognostic predictor in patients receiving immunotherapy retain-->for advanced non-small-cell retain-->lung cancer.

RATIONALE AND OBJECTIVES: Sarcopenia, as measured at the level of the third lumbar (L3) has been shown to predict the survival of cancer patients. However, many patients with advanced non-small cell lung cancer (NSCLC) do not undergo routine abdominal imaging. The objective of this study was to investigate the association of thoracic sarcopenia with survival outcomes among patients who underwent immunotherapy for NSCLC. MATERIALS AND METHODS: In this retrospective study, patients who initiated immunotherapy for advanced NSCLC from 2019 to 2022 were enrolled. and detailed patient data were collected. Cross sectional skeletal muscle area was calculated at the fifth thoracic vertebra (T5) on pretreatment chest computed tomography (CT) scan. Gender-specific lowest quartile values was used to define sarcopenia. The risk factors were analyzed using Cox analyses. The log-rank test and the random survival forest (RSF) were used to compare progression free survival (PFS). The model's performance was assessed using calibration curve and the receiver operating characteristic curve (ROC). RESULTS: A total of 242 patients was included (discovery cohort n = 194, validation cohort n = 48). In the discovery cohort, patients with sarcopenia exhibited significantly poorer PFS (p < 0.001) than patients without sarcopenia. Univariate cox regression revealed that sarcopenia, lung cancer stage, body mass index, smoking status, and neutrophil-to-lymphocyte ratio were predictors of poor PFS. A RSF model was constructed based on the aforementioned parameters, to evaluate the model's efficacy, the ROC curve was utilized. with an area under the curve for predicting 6-month PFS of 0.68 and for 12-month PFS of 0.69. The prediction models for survival outcomes built by the discovery cohort showed similar performance in the validation cohort. CONCLUSION: Sarcopenia at T5 is independent prognostic factors in patients who received immunotherapy for advanced NSCLC.

Unveiling therapeutic potential: Adipose tissue-derived mesenchymal stem cells and their exosomes in the management of diabetes mellitus, wound healing, and chronic ulcers.

Diabetes mellitus (DM) is a pervasive global health issue with substantial morbidity and mortality, often resulting in secondary complications, including diabetic wounds (DWs). These wounds, arising from hyperglycemia, diabetic neuropathy, anemia, and ischemia, afflict approximately 15% of diabetic patients, with a considerable 25% at risk of lower limb amputations. The conventional approaches for chronic and diabetic wounds management involves utilizing various therapeutic substances and techniques, encompassing growth factors, skin substitutes and wound dressings. In parallel, emerging cell therapy approaches, notably involving adipose tissue-derived mesenchymal stem cells (ADMSCs), have demonstrated significant promise in addressing diabetes mellitus and its complications. ADMSCs play a pivotal role in wound repair, and their derived exosomes have garnered attention for their therapeutic potential. This review aimed to unravel the potential mechanisms and provide an updated overview of the role of ADMSCs and their exosomes in diabetes mellitus and its associated complications, with a specific focus on wound healing.

Engineering of methionine sulfoxide reductase A with simultaneously improved stability and activity for kinetic resolution of chiral sulfoxides.

Methionine sulfoxide reductase A (MsrA) has emerged as promising biocatalysts in the enantioselective kinetic resolution of racemic (rac) sulfoxides. In this study, we engineered robust MsrA variants through directed evolution, demonstrating substantial improvements of thermostability. Mechanism analysis reveals that the enhanced thermostability results from the strengthening of intracellular interactions and increase in molecular compactness. Moreover, these variants demonstrated concurrent improvements in catalytic activities, and notably, these enhancements in stability and activity collectively contributed to a significant improvement in enzyme substrate tolerance. We achieved kinetic resolution on a series of rac-sulfoxides with high enantioselectivity under initial substrate concentrations reaching up to 93.0 g/L, representing a great improvement in the aspect of the substrate concentration for biocatalytic preparation of chiral sulfoxide. Hence, the simultaneously improved thermostability, activity and substrate tolerance of MsrA represent an excellent biocatalyst for the green synthesis of optically pure sulfoxides.

Plant Growth Promotion and Plant Disease Suppression Induced by Bacillus amyloliquefaciens Strain GD4a.

Botrytis cinerea, the causative agent of gray mold disease (GMD), invades plants to obtain nutrients and disseminates through airborne conidia in nature. Bacillus amyloliquefaciens strain GD4a, a beneficial bacterium isolated from switchgrass, shows great potential in managing GMD in plants. However, the precise mechanism by which GD4a confers benefits to plants remains elusive. In this study, an A. thaliana-B. cinerea-B. amyloliquefaciens multiple-scale interaction model was used to explore how beneficial bacteria play essential roles in plant growth promotion, plant pathogen suppression, and plant immunity boosting. Arabidopsis Col-0 wild-type plants served as the testing ground to assess GD4a's efficacy. Additionally, bacterial enzyme activity and targeted metabolite tests were conducted to validate GD4a's potential for enhancing plant growth and suppressing plant pathogens and diseases. GD4a was subjected to co-incubation with various bacterial, fungal, and oomycete pathogens to evaluate its antagonistic effectiveness in vitro. In vivo pathogen inoculation assays were also carried out to investigate GD4a's role in regulating host plant immunity. Bacterial extracellular exudate (BEE) was extracted, purified, and subjected to untargeted metabolomics analysis. Benzocaine (BEN) from the untargeted metabolomics analysis was selected for further study of its function and related mechanisms in enhancing plant immunity through plant mutant analysis and qRT-PCR analysis. Finally, a comprehensive model was formulated to summarize the potential benefits of applying GD4a in agricultural systems. Our study demonstrates the efficacy of GD4a, isolated from switchgrass, in enhancing plant growth, suppressing plant pathogens and diseases, and bolstering host plant immunity. Importantly, GD4a produces a functional bacterial extracellular exudate (BEE) that significantly disrupts the pathogenicity of B. cinerea by inhibiting fungal conidium germination and hypha formation. Additionally, our study identifies benzocaine (BEN) as a novel small molecule that triggers basal defense, ISR, and SAR responses in Arabidopsis plants. Bacillus amyloliquefaciens strain GD4a can effectively promote plant growth, suppress plant disease, and boost plant immunity through functional BEE production and diverse gene expression.

Detection, Diagnosis, and Preventive Management of the Bacterial Plant Pathogen Pseudomonas syringae.

Plant diseases caused by the pathogen Pseudomonas syringae are serious problems for various plant species worldwide. Accurate detection and diagnosis of P. syringae infections are critical for the effective management of these plant diseases. In this review, we summarize the current methods for the detection and diagnosis of P. syringae, including traditional techniques such as culture isolation and microscopy, and relatively newer techniques such as PCR and ELISA. It should be noted that each method has its advantages and disadvantages, and the choice of each method depends on the specific requirements, resources of each laboratory, and field settings. We also discuss the future trends in this field, such as the need for more sensitive and specific methods to detect the pathogens at low concentrations and the methods that can be used to diagnose P. syringae infections that are co-existing with other pathogens. Modern technologies such as genomics and proteomics could lead to the development of new methods of highly accurate detection and diagnosis based on the analysis of genetic and protein markers of the pathogens. Furthermore, using machine learning algorithms to analyze large data sets could yield new insights into the biology of P. syringae and novel diagnostic strategies. This review could enhance our understanding of P. syringae and help foster the development of more effective management techniques of the diseases caused by related pathogens.