Ca2+-triggered Atg11-Bmh1/2-Snf1 complex assembly initiates autophagy upon glucose starvation.

Autophagy is essential for maintaining glucose homeostasis. However, the mechanism by which cells sense and respond to glucose starvation to induce autophagy remains incomplete. Here, we show that calcium serves as a fundamental triggering signal that connects environmental sensing to the formation of the autophagy initiation complex during glucose starvation. Mechanistically, glucose starvation instigates the release of vacuolar calcium into the cytoplasm, thus triggering the activation of Rck2 kinase. In turn, Rck2-mediated Atg11 phosphorylation enhances Atg11 interactions with Bmh1/2 bound to the Snf1-Sip1-Snf4 complex, leading to recruitment of vacuolar membrane-localized Snf1 to the PAS and subsequent Atg1 activation, thereby initiating autophagy. We also identified Glc7, a protein phosphatase-1, as a critical regulator of the association between Bmh1/2 and the Snf1 complex. We thus propose that calcium-triggered Atg11-Bmh1/2-Snf1 complex assembly initiates autophagy by controlling Snf1-mediated Atg1 activation in response to glucose starvation.

A selective colorimetric and efficient removal strategy for mercury(II) in aquatic systems using mesoporous Fe3O4-loaded silver probes.

Mesoporous Fe3O4-loaded silver nanocomposites (Fe3O4@Ag) were simply fabricated as bi-functional nanozymes for the catalysis-based detection and removal of Hg2+ ions. It was found that the as-prepared magnetic Fe3O4@Ag could display peroxidase-like catalysis activity that could be rationally enhanced in the presence of Hg2+ ions. To our surprise, the shell of the Ag element may decrease the catalysis of the Fe3O4 to some degree. However, the Ag particles could serve as the probes for specifically recognizing Hg2+ ions and trigger increased catalysis through the formation of Ag-Hg alloys, with a decreased signal background. A high-throughput colorimetric analytical method was thereby developed based on the Fe3O4@Ag catalysis for probing Hg2+ ions in the muscles of fish by using 96-well plates, at linear Hg2+ concentrations ranging from 0.010 to 2.5 mg kg-1. Moreover, the developed colorimetric analytical method was applied to evaluate Hg2+ levels in muscle samples of different kinds of fish. Unexpectedly, an obvious difference of Hg2+ levels in muscles of four kinds of fish was discovered, with the order of snakehead (Ophicephalus argus) > largemouth bass (Micropterus salmoides) > crucian carp (Carassius auratus) > silver carp (Hypophthalmichthys molitrix), where the carnivorous fish showed higher Hg2+ levels than the omnivorous or plant-based ones. Moreover, the as-fabricated Fe3O4@Ag adsorbents with their large specific surface area and high environmental robustness could exhibit efficient Hg2+ adsorption with capacities of up to 397.60 mg g-1. A removal efficiency of 99.40% can also be expected for Hg2+ ions from wastewater, with the magnet-aided recycling of Fe3O4@Ag adsorbents. Such an Fe3O4@Ag-based colorimetric analysis and removal strategy for Hg2+ ions should find wide applications in the fields of aquatic food safety, environmental monitoring, and clinical diagnostics of Hg-poisoning diseases.

Construction of the flagellin F mutant of Vibrio parahaemolyticus and its toxic effects on silver pomfret (Pampus argenteus) cells.

Vibrio parahaemolyticus causes diseases in aquatic organisms, leading to substantial financial losses to the aquaculture industry; its flagellin F (flaF) protein triggers severe inflammation in host cells. To enhance the understanding of the function of flaF in V. parahaemolyticus infection, in this study, a flaF-deficient mutant was constructed by employing two-step homologous recombination. The flaF-deficient mutant induced a significantly lower toll-like receptor 5 (TLR5) expression and apoptosis in fish intestinal epithelial cells than the wild-type V. parahaemolyticus. Furthermore, fluorescence labelling and microscopy analysis of TLR5 showed that V. parahaemolyticus and its mutant strain significantly enhanced TLR5 expression. Additionally, the findings suggest that flaF deletion did not significantly affect the expression of myeloid differentiation factor 88 (MyD88) and interleukin-8 (IL-8) induced by V.parahaemolyticus. In summary, V. parahaemolyticus induced a TLR5-dependent inflammatory response and apoptosis through MyD88, which was observed to be influenced by flaF deletion. In this study, we obtained stable mutants of V. parahaemolyticus via target gene deletion-which is a rapid and effective approach-and compared the induction of inflammatory response and apoptosis by V. parahaemolyticus and its mutant strain, providing novel perspectives for functional gene research in V. parahaemolyticus.

TOR-mediated Ypt1 phosphorylation regulates autophagy initiation complex assembly.

The regulation of autophagy initiation is a key step in autophagosome biogenesis. However, our understanding of the molecular mechanisms underlying the stepwise assembly of ATG proteins during this process remains incomplete. The Rab GTPase Ypt1/Rab1 is recognized as an essential autophagy regulator. Here, we identify Atg23 and Atg17 as binding partners of Ypt1, with their direct interaction proving crucial for the stepwise assembly of autophagy initiation complexes. Disruption of Ypt1-Atg23 binding results in significantly reduced Atg9 interactions with Atg11, Atg13, and Atg17, thus preventing the recruitment of Atg9 vesicles to the phagophore assembly site (PAS). Likewise, Ypt1-Atg17 binding contributes to the PAS recruitment of Ypt1 and Atg1. Importantly, we found that Ypt1 is phosphorylated by TOR at the Ser174 residue. Converting this residue to alanine blocks Ypt1 phosphorylation by TOR and enhances autophagy. Conversely, the Ypt1S174D phosphorylation mimic impairs both PAS recruitment and activation of Atg1, thus inhibiting subsequent autophagy. Thus, we propose TOR-mediated Ypt1 as a multifunctional assembly factor that controls autophagy initiation via its regulation of the stepwise assembly of ATG proteins.

The role of flagellin F in Vibrio Parahaemolyticus-induced intestinal immunity and functional domain identification.

The marine pathogen Vibrio parahaemolyticus has caused huge economic losses to aquaculture. Flagellin is a key bacterial virulence factor that induces an inflammatory response via activation of Toll-like receptor 5 (TLR5) signaling. Herein, to explore the inflammatory activity of V. parahaemolyticus flagellins (flaA, flaB, flaC, flaD, flaE, and flaF), we investigated their ability to induce apoptosis in a fish cell line. All six flagellins induced severe apoptosis. Moreover, treatment with V. parahaemolyticus flagellins increased TLR5 and myeloid differentiation factor 88 (MyD88) expression and the production of TNF-α and IL-8 significantly. This indicated that flagellins might induce a TLR5-meditated immune response via an MyD88-dependent pathway. FlaF exhibited the strongest immunostimulatory effect; therefore, the interaction between TLR5 and flaF was screened using the yeast two-hybrid system. A significant interaction between the two proteins was observed, indicating that flaF binds directly to TLR5. Finally, the amino acids that participate in the TLR5-flaF interaction were identified using molecular simulation, which indicated three binding sites. These results deepen our understanding of the immunogenic properties of flagellins from V. parahaemolyticus, which could be used for vaccine development in the future.

A microdots array-based fluoremetric assay with superwettability profile for simultaneous and separate analysis of iron and copper in red wine.

A microdots array-based fluoremetric method with superwettability profile has been developed for the simultaneous and separate detection of Fe3+ and Cu2+ ions in red wine samples. A wettable micropores array was initially designed with high density by using polyacrylic acid (PAA) and hexadecyltrimethoxysilane (HDS), followed by the NaOH etching route. Zinc metal organic frameworks (Zn-MOFs) were fabricated as the fluorescent probes to be immobilized into the micropores array to obtain the fluoremetric microdots array platform. It was found that the fluorescence of Zn-MOFs probes could decrease significantly in the presence of Fe3+ and/or Cu2+ ions towards their simultaneous analysis. Yet, the specific responses to Fe3+ ions could be expected if using histidine to chelate Cu2+ ions. Moreover, the developed Zn-MOFs-based microdots array with superwettability profile can enable the accumulation of targeting ions from the complicated samples without any tedious pre-processing. Also, the cross-contamination of different samples droplets can be largely avoided so as to facilitate the analysis of multiple samples. Subsequently, the feasibility of simultaneous and separate detection of Fe3+ and Cu2+ ions in red wine samples was demonstrated. Such a design of microdots array-based detection platform may promise the wide applications in analyzing Fe3+ and/or Cu2+ ions in the fields of food safety, environmental monitoring, and medical diseases diagnostics.

Global-scale no-tillage impacts on soil aggregates and associated carbon and nitrogen concentrations in croplands: A meta-analysis.

No-tillage treatment, including no-tillage with straw retention (NTS) and without (NT), has been widely used as an efficient and sustainable alternative to conventional tillage with straw retention (CTS) and without (CT) and greatly affects soil physical quality and organic matter dynamics in cropland ecosystems. Although some studies have reported the effects of NTS on soil aggregate stability and soil organic carbon (SOC) concentration, the underlying mechanisms of how soil aggregates, aggregate-associated SOC and total nitrogen (TN) respond to no-tillage remain unclear. Through a global meta-analysis of 91 studies in cropland ecosystems, we evaluated the effects of no-tillage on soil aggregates and their associated SOC and TN concentrations. On average, no-tillage treatment significantly decreased the proportions of microaggregates (MA) by 21.4 % (95 % CI, -25.5 to -17.3 %) and silt+clay size particles (SIC) by 24.1 (95 % CI, -30.9 to -17.0 %), and increased the proportions of large macroaggregate (LA) by 49.5 % (95 % CI, 36.7-63.0 %) and small macroaggregate (SA) by 6.1 % (95 % CI, 2.0-10.9 %) compared to those in conventional tillage. The SOC concentrations for all three aggregate sizes increased significantly with no tillage: for LA by 28.2 % (95 % CI, 18.8-39.5 %), SA by 18.0 % (95 % CI, 12.8-23.3 %), and MA by 9.1 % (95 % CI, 2.6-16.8 %). TN also increased significantly for all sizes with no tillage, with LA by 13.6 % (95 % CI, 8.6-17.6 %), SA by 11.0 % (95 % CI, 5.0-17.0 %), MA by 11.7 % (95 % CI, 7.0-16.4 %), and SIC by 7.6 % (95 % CI, 2.4-13.8 %). The magnitude of the no-tillage treatment effect on soil aggregation, aggregate-associated SOC and TN varied with the environmental and experimental conditions. The positive effect on the proportions of LA occurred with initial soil organic matter (SOM) content >10 g kg-1, whereas SOM <10 g kg-1 did not change significantly. Additionally, the effect size of NTS compared with CTS was lower than that of NT compared with CT. These findings suggest that NTS may promote physically protective SOC accumulation through the formation of macroaggregates by reducing disturbance destruction and increasing plant-derived binding agents. The findings highlight that no-tillage may enhance the formation of soil aggregates and the associated SOC and TN concentrations in global cropland ecosystems.

Integrated comparative transcriptome and weighted gene co-expression network analysis provide valuable insights into the response mechanisms of crayfish (Procambarus clarkii) to copper stress.

One of the significant limitations of aquaculture worldwide is the prevalence of divalent copper (Cu). Crayfish (Procambarus clarkii) are economically important freshwater species adapted to a variety of environmental stimuli, including heavy metal stresses; however, large-scale transcriptomic data of the hepatopancreas of crayfish in response to Cu stress are still scarce. Here, integrated comparative transcriptome and weighted gene co-expression network analyses were initially applied to investigate gene expression profiles of the hepatopancreas of crayfish subjected to Cu stress for different periods. As a result, 4662 significant differentially expressed genes (DEGs) were identified following Cu stress. Bioinformatics analyses revealed that the "focal adhesion" pathway was one of the most significantly upregulated response pathways following Cu stress, and seven DEGs mapped to this pathway were identified as hub genes. Furthermore, the seven hub genes were examined by quantitative PCR, and each was found to have a substantial increase in transcript abundance, suggesting a critical role of the "focal adhesion" pathway in the response of crayfish to Cu stress. Our transcriptomic data can be a good resource for the functional transcriptomics of crayfish, and these results may provide valuable insights into the molecular response mechanisms underlying crayfish to Cu stress.

First worldwide report of Exserohilum rostratum causing leaf spot on strawberry (Fragaria × ananassa Duch.).

During April 2022, leaf spot was observed on strawberry (Fragaria × ananassa Duch.) with a disease incidence of approximately 45% among 100 plants. Strawberry was cultivated in a nursery at Huzhou University (30.87゜N, 120.13゜E), Zhejiang Province, China. In the strawberry greenhouse, the average temperature was 15-18 degrees, 40%-60% humidity. Early symptoms appeared as dark brown or black spotted necrotic lesions, which expanded from 2 to 6 mm in diameter. Dark brown spots with yellow halos occupied half of the leaf area and eventually developed leaf blight with large yellow halos. To isolate the causal agent, 0.5 cm x 0.5 cm fragments were cut from three symptomatic leaves, and were surface sterilized with 75% ethanol for 30 s and then rinsed three times with sterilized water. The airdried leaf fragments were placed on PDA with 50 µg/ml ampicillin and incubated in the dark at 25℃ for two days. Isolates were obtained by transferring hyphal plugs of 1 mm in diameter onto PDA. The colony morphology was circular and dark brown on the upperside and black on the underside, with cottony mycelium and an large amount of gray aerial mycelium. Conidia were large, light olive-brown to dark olive-brown and light olive-black and septate. The typical conidia were oval or rod-shaped, rarely curved, and dark septa defined the basal and apical cells. In the two typical forms of conidia, the average size of oval conidia was approximately 18.77 × 54.92 µm (11.99 to 26.97 × 35.13 to 74.59 µm, n = 20), and the average size of the rod-shaped conidia was approximately 14.80 × 103.24 µm (11.24 to 24.64 × 73.11 to 131.51 µm, n = 20). The morphological characteristics matched well with previous descriptions of Exserohilum rostratum (Sharma et al. 2014; Liu et al. 2021). The identity of C1-L and C1-S from symptomatic tissues was confirmed by means of multi-locus gene sequencing. Genomic DNA was extracted from the mycelium using the CTAB (cetyltrimethylammonium bromide) method (Griffith & Shaw 1998). Molecular identification was conducted by sequencing the internal transcribed spacer (ITS) rDNA region, partial glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, partial actin (ACT) gene, and partial beta-tubulin 2 (TUB2), using the primers ITS1/ITS4 (White et al. 1990), GDF/GDR (Templeton et al. 1992), ACT512F/ACT783R (Carbone and Kohn 1999), T1 (O'Donnell and Cigelnik 1997) and Bt2b (Glass and Donaldson, 1995). The obtained sequences of C1-L and C1-S were the same. Moreover, the sequences have been deposited in GenBank under accession numbers ON982516 (ITS), ON996915 (GAPDH), ON996916 (ACT), and ON996917 (TUB2). The results of Basic Local Alignment Search Tool (BLAST) analysis revealed that the ITS, GAPDH, and ACT had 100% identity with the sequences of E. rostratum (GenBank Accession No. LT837834, LT883550, and LT837672, respectively), the TUB2 had 99.61% similarity with BLAST sequences of E. rostratum (LT899391). These morphological characteristics and molecular analyses allowed the identification of the pathogen as E. rostratum. Koch's postulates were performed with five healthy detached strawberry leaves with three inoculations per leaf of the 'Akihime' strawberry variety. Surface-sterilized leaves were wounded with an aseptic needle, and inoculated with 2 mm diameter mycelial plugs from 5-day-old cultures of E. rostratum. Control leaves were also wounded with the aseptic needle, and inoculated with a sterile PDA agar plug. The leaves were incubated at 25℃ in Petri plates with petioles wrapped in moist sterile cotton. The diseased symptoms included black spots on the epidermis of the wounded leaves within 5, 10, and 20 days after inoculation. Mock-inoculated controls remained asymptomatic, and three biological repetitions were conducted. The fungus reisolated from the diseased leaves was confirmed as E. rostratum by sequencing. Abundant reports have shown that E. rostratum can infect many economically important crops such as maize, rice, and pineapple (Sun et al. 2021; Kabore et al. 2022; Luo et al. 2012). To the best of our knowledge, this is the first report of E. rostratum on strawberry in China and worldwide.

Mec1 regulates PAS recruitment of Atg13 via direct binding with Atg13 during glucose starvation-induced autophagy.

Mec1 is a DNA damage sensor, which performs an essential role in the DNA damage response pathway and glucose starvation-induced autophagy. However, the functions of Mec1 in autophagy remain unclear. In response to glucose starvation, Mec1 forms puncta, which are recruited to mitochondria through the adaptor protein Ggc1. Here, we show that Mec1 puncta also contact the phagophore assembly site (PAS) via direct binding with Atg13. Functional analysis of the Atg13-Mec1 interaction revealed two previously unrecognized protein regions, the Mec1-Binding Region (MBR) on Atg13 and the Atg13-Binding Region (ABR) on Mec1, which mediate their mutual association under glucose starvation conditions. Disruption of the MBR or ABR impairs the recruitment of Mec1 puncta and Atg13 to the PAS, consequently blocking glucose starvation-induced autophagy. Additionally, the MBR and ABR regions are also crucial for DNA damage-induced autophagy. We thus propose that Mec1 regulates glucose starvation-induced autophagy by controlling Atg13 recruitment to the PAS.

Covalent organic framework-loaded silver nanoparticles as robust mimetic oxidase for highly sensitive and selective colorimetric detection of mercury in blood.

Covalent organic frameworks (COFs) were fabricated with a hierarchical flower-like hollow structure, possessing a large specific surface area, high porosity, and excellent environmental stability. In situ growth of noble silver nanoparticles (AgNPs) onto COFs was conducted yielding COF-Ag nanozymes. The structural advantages of COFs can ensure the uniform dispersion and effective size control of AgNPs. More interestingly, the oxidase-like catalytic activity of the obtained COF-Ag nanozymes could be enhanced in the presence of Hg2+ ions, which could specifically interact with AgNPs to form Ag-Hg alloys. A COF-Ag catalysis-based colorimetric platform was thereby constructed for highly selective and sensitive analysis of Hg2+ ions, showing a linear concentration range from 0.050 to 10.0 µM, with a limit of detection of about 3.7 nM. Besides, the developed colorimetric strategy was successfully applied for detecting Hg2+ ions in human blood with favorable detection recoveries, indicating its potential for applications in the biomedical analysis, environmental monitoring, and food safety fields.

Regulatory roles of Bxy-laf-1 in reproductive behaviour of Bursaphelenchus xylophilus.

Bursaphelenchus xylophilu is a worldwide quarantine nematode, causing huge economic losses and ecological disasters in many countries. The sex ratio of B. xylophilus plays an important role in the nematode infestation. The laf-1-related genes are highly conserved in animals, playing crucial roles in sex determination. Therefore, we investigated the expression pattern and biological function of its orthologue, Bxy-laf-1 in B. xylophilus. Bxy-laf-1 has two typical conserved DNA-binding domains, DEAD and Helicase C. The real-time quantitative PCR data revealed that Bxy-laf-1 expression was required throughout the entire life of B. xylophilus, with the maximum expression in the J2 stage and the lowest expression in the adult stage. mRNA in situ hybridization showed that Bxy-laf-1 is mainly located in the cephalopharynx and reproductive organs of B. xylophilus. RNA interference (RNAi) indicated that the head swing frequency was dramatically decreased. The RNA interference results displayed that a significant reduction in motility was observed in the hatched larvae. The female to male sex ratio was also decreased in the F0 and F1 generations, but recovered in the F2 generation. The tail of female adults with eggs in the belly appeared deformities. This phenomenon appeared in the F0 and F1 generations, but recovered in the F2 generation. Bxy-laf-1 is a typical sex-determination gene with distinct expression patterns in males and females. As demonstrated in other species, the sex ratio was altered after knocking down Bxy-laf-1 expression. The results of this study contribute to our understanding of the molecular processes of Bxy-laf-1 in B. xylophilus, which may provide clues about how to control pine wilt disease by inhibiting ontogenic growth and reducing nematode fertility.

Integrated next-generation sequencing and comparative transcriptomic analysis of leaves provides novel insights into the ethylene pathway of Chrysanthemum morifolium in response to a Chinese isolate of chrysanthemum virus B.

BACKGROUND: Chrysanthemum virus B (CVB), a key member of the genus Carlavirus, family Betaflexiviridae, causes severe viral diseases in chrysanthemum (Chrysanthemum morifolium) plants worldwide. However, information on the mechanisms underlying the response of chrysanthemum plants to CVB is scant. METHODS: Here, an integrated next-generation sequencing and comparative transcriptomic analysis of chrysanthemum leaves was conducted to explore the molecular response mechanisms of plants to a Chinese isolate of CVB (CVB-CN) at the molecular level. RESULTS: In total, 4934 significant differentially expressed genes (SDEGs) were identified to respond to CVB-CN, of which 4097 were upregulated and 837 were downregulated. Gene ontology and functional classification showed that the majority of upregulated SDEGs were categorized into gene cohorts involved in plant hormone signal transduction, phenylpropanoid and flavonoid biosynthesis, and ribosome metabolism. Enrichment analysis demonstrated that ethylene pathway-related genes were significantly upregulated following CVB-CN infection, indicating a strong promotion of ethylene biosynthesis and signaling. Furthermore, disruption of the ethylene pathway in Nicotiana benthamiana, a model plant, using virus-induced gene silencing technology rendered them more susceptible to cysteine-rich protein of CVB-CN induced hypersensitive response, suggesting a crucial role of this pathway in response to CVB-CN infection. CONCLUSION: This study provides evidence that ethylene pathway has an essential role of plant in response to CVB and offers valuable insights into the defense mechanisms of chrysanthemum against Carlavirus.

Two new threonine-containing metabolites from fungus Curvularia inaequalis strain HS-FG-257.

Two new threonine-containing metabolites, N-[4-hydroxy-3-prenyl-benzoyl]-L-threonine (1) and N-[2,2-dimethyl-2H-chromene-6-carbonyl]-L-threonine (2), were isolated from the fermentation broth of the soil fungus Curvularia inaequalis strain HS-FG-257. Their structures were elucidated through the interpretation of HR-ESIMS and extensive NMR spectroscopic data. Both compounds exhibited no cytotoxic activity against the test cell lines A549 and HCT-116.

First report of Colletotrichum fructicola causing anthracnose on cherry (Prunus avium) in China.

Cherry (Prunus avium) has become an important economical fruit in China. In October 2020, a leaf spot disease was found on cherry in the orchard of Taizhou Academy of Agriculture Sciences, Zhejiang, China. The symptoms appeared as small, water-soaked spots on the leaves, which later became larger, dark brown, and necrotic lesions of 1 cm to 3 cm in width, 4 cm to 8 cm in length. Disease incidences of approximately 60% of the leaves were observed by sampling five locations. To isolate the causing agent, small fragments from five target symptomatic leaves were surface-sterilized with 1.0% sodium hypochlorite solution for 1 min and then rinsed three times with sterilized water. Afterwards the leaf fragments were air-dried, plated onto potato dextrose agar (PDA) medium, and incubated at 25 ℃ in the dark for 2 days. The pure cultures were obtained by transferring hyphal plug of 2 mm in diameter onto PDA, which followed single spore isolation. The colony morphology showed light to dark gray, cottony mycelium, with the underside of the culture became brownish after 7 days. Conidia (n = 28) were hyaline, smooth-walled, cylindrical, aseptate, broadly rounded ends, and average size around 3.84 × 12.82 µm (2.99 to 4.87 × 10.27 to 15.68 µm). Appressoria (n = 27) were mostly brown, ovoid and slightly irregular in shape, and average size around 8.04 × 9.68 µm (6.29 to 9.67 × 9.32 to 12.06 µm). Perithecia average size is 106.25 µm, textura angularis, thick-walled. Asci 26.35-49.18 × 5.00-12.03 µm (average size 37.44 × 7.80 µm, n = 17), unitunicate, thin-walled, clavate or cymbiform. Ascospores 13.69-20.93 × 3.86-6.69 µm (average size 16.00 × 5.42 µm, n = 30), one-celled, hyaline, one or two large guttulate at the centre, slightly rounded ends. The morphological characteristics matched well with previous descriptions of Colletotrichum species of C. gloeosporioides species complex, including C. fructicola (Prihastuti et al. 2009; Fu et al. 2019). The identity of two representative isolates (cf2-3 and cf4-4) from different leaves was confirmed by means of multi-locus gene sequencing. To this end, genomic DNA was extracted by the Plant Direct PCR kit (Vazyme Biotech Co., Ltd, China). Molecular identification was conducted by sequencing the internal transcribed spacer (ITS) rDNA region, partial glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, partial actin (ACT) gene, partial beta-tubulin 2 gene (TUB2), and partial chitin synthase gene (CHS). The obtained sequences have been deposited in GenBank under accession numbers MW581851 and MW581852 (ITS), MW590586 and MW590587 (GAPDH), MW616561 and MW616562 (ACT), MW729380 and MW729381 (TUB2), MW729378 and MW729379 (CHS). The results of Basic Local Alignment Search Tool (BLAST) analysis revealed that the ITS, GAPDH, ACT, TUB2 and CHS sequences of both isolates matched with 100% identity to Colletotrichum fructicola culture collection sequences in GenBank database (JX010165, JX009998, JX009491, JX010405, and JX009866 respectively). These morphological characteristics and molecular analyses allowed the identification of the pathogen as C. fructicola. Koch's postulates were performed with healthy detached cherry leaves of cultivar namely 'HongMi' from Taizhou Academy of Agriculture Sciences. Surface-sterilized leaves were inoculated with five-day-old cultures of C. fructicola mycelial discs of 2 mm in diameter after being wounded with a needle or non-wounded. Control leaves were inoculated with discs of same size PDA agar. Treated leaves were incubated at 25 ℃ in the dark at high relative humidity. Anthracnose symptoms appeared within 3 days both on non-wounded and wounded inoculation approaches. Mock-inoculated controls remained asymptomatic. Biological repetitions were carried out three times. The fungus was reisolated from infected leaves and confirmed as C. fructicola following the methods described above. Until recently, it has been found that C. fructicola can infect tea, apple, pear, Pouteria campechiana in China (Fu et al. 2014; Li et al. 2013; Shi et al. 2018; Yang et al. 2020). To the best of our knowledge, this is the first report of C. fructicola on cherry in China.

Exposure of Helicoverpa armigera Larvae to Plant Volatile Organic Compounds Induces Cytochrome P450 Monooxygenases and Enhances Larval Tolerance to the Insecticide Methomyl.

Plants release an array of volatile chemicals into the air to communicate with other organisms in the environment. Insect attack triggers emission of herbivore-induced plant volatiles (HIPVs). How insect herbivores use these odors to plan their detoxification systems is vital for insect adaptation to environmental xenobiotics. Here we show that the larvae of Helicoverpa armigera (Hübner), a broadly polyphagous lepidopteran herbivore, have the capacity to use plant volatiles as cues to upregulate multiple detoxification systems, including cytochrome P450 monooxygenases (P450s), for detoxification of insecticides. Olfactory exposure of the fifth instars to two terpene volatiles limonene and nerolidol, and two green-leaf volatiles 2-heptanone and cis-3-hexenyl acetate significantly reduced larval susceptibility to the insecticide methomyl. However, larval pretreatment with piperonyl butoxide (PBO), a known P450 inhibitor, neutralized the effects of volatile exposure. Furthermore, larval exposure to the four plant volatiles enhanced activities of P450 enzymes in midguts and fatbodies, and upregulated expression of CYP6B2, CYP6B6 and CYP6B7, P450s involved in detoxification of the insecticide. Larval exposure to 2-heptanone and limonene volatiles also enhanced activities of glutathione-s-transferase and carboxylesterase. Our findings suggest that olfactory exposure to HIPVs enhances larval insecticide tolerance via induction of detoxification P450s.

Gut Microbiota Influence Lipid Metabolism of Skeletal Muscle in Pigs.

Gut microbiota is recognized as a strong determinant of host physiology including fat metabolism and can transfer obesity-associated phenotypes from donors to recipients. However, the relationship between gut microbiota and intramuscular fat (IMF) is still largely unknown. Obese Jinhua pigs (JP) have better meat quality that is associated with higher IMF content than lean Landrace pigs (LP). The present study was conducted to test the contribution of gut microbiota to IMF properties by transplanting fecal microbiota of adult JP and LP to antibiotics-treated mice. Similar to JP donors, the mice receiving JP's microbiota (JM) had elevated lipid and triglyceride levels and the lipoprotein lipase activity, as well as reduced mRNA level of angiopoietin-like 4 (ANGPTL4) in the gastrocnemius muscles, compared to those in mice receiving LP's microbiota (LM). High-throughput 16S rRNA sequencing confirmed that transplantation of JP and LP feces differently reconstructed the gut microbiota in both jejunum and colon of mouse recipients. In colonic samples, we observed an elevated ratio of Firmicutes to Bacteroidetes and increased abundance of genus Romboutsia in JM, which were positively correlated with obesity. Furthermore, the abundance of Akkermansia decreased in JM, which is positively correlated with lean. Colonic concentrations of acetate (P = 0.047) and butyrate (P = 0.014) were significantly lower in JM than in LM, and consistently, the terminal genes for butyrate synthesis, butyryl CoA: acetate CoA transferase were less abundant in colonic microbiota of JM. Taken together, these gut microbiota of obese JP intrinsically promotes IMF accumulation and can transfer the properties to mouse recipients. Manipulation of intestinal microbiota will, therefore, have the potential to improve the meat quality and flavor of pigs and even to ameliorate the metabolic syndrome in human.

The Change Mechanism of Structural Characterization and Thermodynamic Properties of Tannase from Aspergillus niger NL112 Under High Temperature.

Tannase from Aspergillus niger NL112 was purified 5.1-fold with a yield of 50.44% via ultrafiltration, DEAE-Sepharose Fast Flow column chromatography, and Sephadex G-100 column chromatography. The molecular weight of the purified tannase was estimated as 45 kDa. The optimum temperature and pH for its activity were 45 °C and 5.0, respectively. The results of circular dichroism, FT-IR (Fourier transform infrared) spectroscopy, and fluorescence spectra indicated that high temperature could lead to the change of tannase secondary and tertiary structures. Tannase had a greater affinity for tannic acid at 40 °C with a Km value of 2.12 mM and the greatest efficiency hydrolysis (Kcat/Km) at 45 °C. The rate of inactivation (k) increased with the increase of temperature and the half-life (t1/2) gradually decreased. It was found to be 1.0 of the temperature quotient (Q10) value for tannic acid hydrolysis by tannase. The thermodynamic parameters of the interaction system were calculated at various temperatures. The positive enthalpy (ΔH) values and decreasing ΔH values with the increase of temperature indicated that the hydrolysis of tannase was an endothermic process. Our results indicated that elevated temperature could change the tertiary structure of tannase and reduce its thermostability, which caused a gradual decrease of tannase activity with an increase in temperature.

Agromyces kandeliae sp. nov., isolated from rhizosphere soil of Kandelia candel in a mangrove.

A novel, Gram-stain-positive, aerobic, non-spore-forming, non-motile and irregular rod-shaped bacterium designated Q22T was isolated from the rhizosphere soil of mangrove plant, Kandelia candel collected in Zhangzhou, Fujian province, China. Strain Q22T was able to grow at 10-40 °C (optimum 30 °C), pH 5.5-9.0 (optimum 7.0-8.0) and with 0-5.0% (w/v) NaCl (optimum 1.0 %). The genomic DNA G+C content was 71.9%. The average nucleotide identity, and in silico DNA-DNA hybridization values between strain Q22T and the reference strains were 79.7-88.9% and 22.6-37.4%, respectively. The predominant isoprenoid quinone was MK-12 and the major fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. The major polar lipids of strain Q22T were diphosphatidylglycerol, phosphatidylglycerol, one glycolipid and three unidentified lipids. The strain Q22T contained 2,4-diaminobutyric acid, alanine acid, glutamic acid and glycine in the peptidoglycans. The phylogenetic analysis and genotypic features, along with the phenotypic and chemotaxonomic characteristics, indicate that strain Q22T represents a novel species of the genus Agromyces, for which the name Agromyces kandeliae sp. nov. is proposed. The type strain is Q22T (=MCCC 1K03340T= KCTC 39961T).