Development of natural perfume as potential fungicide candidates: construction and biological evaluation of vanillin analogs bearing the 1,3,4-oxadiazole/1,3-thiazolidin-4-one fragments.

Two series of vanillin derivatives containing 1,3,4-oxadiazole and 1,3-thiazolidin-4-one scaffolds were prepared and evaluated for their antifungal activity. The results revealed that compounds 6j (29.73 µg/ml) and 7a (38.15 µg/ml) displayed excellent inhibitory activity against the spore of Fusarium solani. The inhibitory activity of compound 7d (10.53 µg/ml) against the spore of Alternaria solani was more than 42-fold that of vanillin. Compound 7a (37.54 µg/ml) showed better antifungal activity against the spore of B. cinerea than positive controls. The cytotoxicity assay confirmed that compounds 6k, 7a, and 7d showed good selectivity and less toxicity to normal mammalian cells.

Ice crystal guided folding of graphene oxides in a confined space: a facile approach to 1D functional graphene structures.

The controlled conformational changes of planar graphene nanosheets are of great importance to the realization of their practical applications. Despite substantial effort in the area, the controlled folding of two-dimensional (2D) graphene sheets into one-dimensional (1D) structures still remains a significant challenge. Here, for the first time, we report an ice crystal guided folding strategy to fabricate 1D folded graphene nanobelts (FGBs), where the formation and growth of ice crystals in a confined space function to guide the folding of 2D graphene oxide (GO) nanosheets into 1D nanobelts (i.e. folded graphene oxide belts, FGOBs), which were subsequently converted to FGBs after annealing. Thin aqueous GO containing films were obtained by blowing air through a GO dispersion in the presence of a surfactant, polyoxypropylenediamine (D400), resulting in a foam containing uniform air bubbles. Subsequent shock cooling of the foam using liquid nitrogen resulted in the facile fabrication of FGOBs. This technique provides a general approach to encapsulate catalytic nanomaterials such as Fe3O4 nanorods, TiO2 and Co3O4 nanoparticles into the folded graphene structure for practical applications such as Li-ion batteries.

The effects of virtual nature exposure on pro-environmental behaviour.

Exposure to (virtual) natural environments may encourage people to care about environmental protection and to engage in pro-environmental behaviour. Previous research on this effect produced inconsistent results, suggesting that it may depend on the type of nature and behaviour under study. In the present study (N = 266), we investigated nature exposure effects on effortful pro-environmental behaviour in an online experiment. After watching pictures of either intact or destroyed natural environments, participants could exert voluntary extra efforts to generate real donations to an environmental organisation. In comparison to the intact nature condition, participants exerted significantly more effort for environmental protection after being exposed to pictures of destroyed nature. No clear differences were observed between the nature exposure conditions and a no-picture control condition. These findings illustrate the complexity of nature exposure effects and suggest that different types of nature exposure may differentially affect people's pro-environmental behaviour.

Natural Sesquiterpene Lactone as Source of Discovery of Novel Fungicidal Candidates: Structural Modification and Antifungal Activity Evaluation of Xanthatin Derived from Xanthium strumarium L.

As part of our ongoing efforts to discover novel agricultural fungicidal candidates from natural sesquiterpene lactones, in the present work, sixty-three xanthatin-based derivatives containing a arylpyrazole, arylimine, thio-acylamino, oxime, oxime ether, or oxime ester moiety were synthesized. Their structures were well characterized by 1H and 13C nuclear magnetic resonance and high-resolution mass spectrometry, while the absolute configurations of compounds 5' and 6a were further determined by single-crystal X-ray diffraction. Meanwhile, the antifungal activities of the prepared compounds against several phytopathogenic fungi were investigated using the spore germination method and the mycelium growth rate method in vitro. The bioassay results illustrated that compounds 5, 5', and 15 exhibited excellent inhibitory activity against the tested fungal spores and displayed remarkable inhibitory effects on fungal mycelia. Compounds 5 and 5' exhibited more potent inhibitory activity (IC50 = 1.1 and 24.8 µg/mL, respectively) against the spore of Botrytis cinerea than their precursor xanthatin (IC50 = 37.6 µg/mL), wherein the antifungal activity of compound 5 was 34-fold higher than that of xanthatin and 71-fold higher than that of the positive control, difenoconazole (IC50 = 78.5 µg/mL). Notably, compound 6'a also demonstrated broad-spectrum inhibitory activity against the four tested fungal spores. Meanwhile, compounds 2, 5, 8, and 15 showed prominent inhibitory activity against the mycelia of Cytospora mandshurica with the EC50 values of 2.3, 11.7, 11.1, and 3.0 µg/mL, respectively, whereas the EC50 value of xanthatin was 14.8 µg/mL. Additionally, compounds 5' and 15 exhibited good in vivo therapeutic and protective effects against B. cinerea with values of 55.4 and 62.8%, respectively. The preliminary structure-activity relationship analysis revealed that the introduction of oxime, oxime ether, or oxime ester structural fragment at the C-4 position of xanthatin or the introduction of a chlorine atom at the C-3 position of xanthatin might be significantly beneficial to antifungal activity. In conclusion, the comprehensive investigation indicated that partial xanthatin-based derivatives from this study could be considered for further exploration as potential lead structures toward developing novel fungicidal candidates for crop protection.

Discovery of Natural Sesquiterpene Lactone 1-O-Acetylbritannilactone Analogues Bearing Oxadiazole, Triazole, or Imidazole Scaffolds for the Development of New Fungicidal Candidates.

In recent decades, natural products have been considered important resources for developing of new agrochemicals because of their novel architectures and multibioactivities. Consequently, herein, 1-O-acetylbritannilactone (ABL), a natural sesquiterpene lactone from Inula britannica L., was used as a lead for further modification to discover fungicidal candidates. Six series of ABL-based derivatives containing an oxadiazole, triazole, or imidazole moiety were designed and synthesized, and their antifungal activities were also evaluated in vitro and in vivo. Bioassay results revealed that compounds 8d, 8h, and 8j (EC50 = 61.4, 30.9, and 12.4 µg/mL, respectively) exhibited more pronounced inhibitory activity against Fusarium oxysporum than their precursor ABL (EC50 > 500 µg/mL) and positive control hymexazol (EC50 = 77.2 µg/mL). Derivatives 8d and 11j (EC50 = 19.6 and 41.5 µg/mL, respectively) exhibited more potent antifungal activity toward Cytospora mandshurica than ABL (EC50 = 68.3 µg/mL). Compound 10 exhibited excellent and broad-spectrum antifungal activity against seven phytopathogenic fungal mycelia. Particularly, the inhibitory activity of compound 10 against the mycelium of Botrytis cinerea was more than 10.8- and 2.3-fold those of ABL and hymexazol, respectively. Meanwhile, derivative 10 (IC50 = 47.7 µg/mL) displayed more pronounced inhibitory activity against the spore of B. cinerea than ABL (IC50 > 500 µg/mL) and difenoconazole (IC50 = 80.8 µg/mL). Additionally, the in vivo control efficacy of compound 10 against B. cinerea was further studied using infected tomatoes (protective effect = 58.4%; therapeutic effect = 48.7%). The preliminary structure-activity relationship analysis suggested that the introduction of the 1,3,4-oxadiazole moiety (especially the 1,3,4-oxadiazole heterocycle containing the 4-chlorophenyl, 2-furyl, or 2-pyridinyl group) on the skeleton of ABL was more likely to produce potential antifungal compounds. These findings pave the way for further design and development of ABL-based derivatives as potential antifungal agents.

The Verticillium dahliae Small Cysteine-Rich Protein VdSCP23 Manipulates Host Immunity.

Verticillium wilt caused by Verticillium dahliae is a notorious soil-borne fungal disease and seriously threatens the yield of economic crops worldwide. During host infection, V. dahliae secretes many effectors that manipulate host immunity, among which small cysteine-rich proteins (SCPs) play an important role. However, the exact roles of many SCPs from V. dahliae are unknown and varied. In this study, we show that the small cysteine-rich protein VdSCP23 inhibits cell necrosis in Nicotiana benthamiana leaves, as well as the reactive oxygen species (ROS) burst, electrolyte leakage and the expression of defense-related genes. VdSCP23 is mainly localized in the plant cell plasma membrane and nucleus, but its inhibition of immune responses was independent of its nuclear localization. Site-directed mutagenesis and peptide truncation showed that the inhibition function of VdSCP23 was independent of cysteine residues but was dependent on the N-glycosylation sites and the integrity of VdSCP23 protein structure. Deletion of VdSCP23 did not affect the growth and development of mycelia or conidial production in V. dahliae. Unexpectedly, VdSCP23 deletion strains still maintained their virulence for N. benthamiana, Gossypium hirsutum and Arabidopsis thaliana seedlings. This study demonstrates an important role for VdSCP23 in the inhibition of plant immune responses; however, it is not required for normal growth or virulence in V. dahliae.

Variational Bayesian inference for association over phylogenetic trees for microorganisms.

With the advance of next generation sequencing technologies, researchers now routinely obtain a collection of microbial sequences with complex phylogenetic relationships. It is often of interest to analyze the association between certain environmental factors and characteristics of the microbial collection. Though methods have been developed to test for association between the microbial composition with environmental factors as well as between coevolving traits, a flexible model that can provide a comprehensive picture of the relationship between microbial community characteristics and environmental variables will be tremendously beneficial. We developed a Bayesian approach for association analysis while incorporating the phylogenetic structure to account for the dependence between observations. To overcome the computational difficulty related to the phylogenetic tree, a variational algorithm was developed to evaluate the posterior distribution. As the posterior distribution can be readily obtained for parameters of interest and any derived variables, the association relationship can be examined comprehensively. With two application examples, we demonstrated that the Bayesian approach can uncover nuanced details of the microbial assemblage with regard to the environmental factor. The proposed Bayesian approach and variational algorithm can be extended for other problems involving dependence over tree-like structures.

Temperature-Responsive Aldehyde Hydrogels with Injectable, Self-Healing, and Tunable Mechanical Properties.

Injectable and self-healing hydrogels with exemplary biocompatibility and tunable mechanical properties are urgently needed due to their significant advantages for tissue engineering applications. Here, we report a new temperature-responsive aldehyde hydrogel with dual physical-cross-linked networks and injectable and self-healing properties prepared from an ABA-type triblock copolymer, poly{[FPMA(4-formylphenyl methacrylate)-co-DEGMA[di(ethylene glycol) methyl ether methacrylate]-b-MPC(2-methacryloyloxyethyl phosphorylcholine)-b-(FPMA-co-DEGMA)}. The thermoresponsive poly(DEGMA) segments drive the dehydration and hydrophobic interaction, enabling polymer chain winding as the first cross-linking network, when the temperature is raised above the critical gelation temperature. Meanwhile, the benzaldehyde groups offer physical interactions, including hydrogen bonding and hydrophobic and π-π stacking interactions as the second cross-linking network. When increasing the benzaldehyde content in the triblock copolymers from 0 to 8.2 mol %, the critical gelation temperature of the resulted hydrogels dropped from 35.5 to 19.9 °C and the mechanical modulus increased from 21 to 1411 Pa. Owing to the physical-cross-linked networks, the hydrogel demonstrated excellent injectability and self-healing properties. The cell viabilities tested from MTT assays toward both normal lung fibroblast cells (MRC-5) and cancerous cervical (HeLa) cells were found to be 100 and 101%, respectively, for varying polymer concentrations up to 1 mg/mL. The 3D cell encapsulation of the hydrogels was evaluated by a cytotoxicity Live/Dead assay, showing 92% cell viability. With these attractive physiochemical and biological properties, this temperature-responsive aldehyde hydrogel can be a promising candidate as a cell scaffold for tissue engineering.

Glycopolymer-Cell-Penetrating Peptide (CPP) Conjugates for Efficient Epidermal Growth Factor Receptor (EGFR) Silencing.

Overexpression of epidermal growth factor receptor (EGFR) is observed in multiple cancers such as colorectal, lung, and cervical solid tumors. Regulating the EGFR expression is an efficient strategy to manage these malignancies, and it can be achieved by using short interfering RNA (siRNA). Cell-penetrating peptides (CPPs) demonstrated an excellent capability to enhance the cellular uptake of siRNA, but high knockdown efficiencies have not been achieved due to endosomal entrapment. In this work, Schiff's base reaction was used to modify a block {P[LAEMA(2-lactobionamidoethyl methacrylamide)37]-b-P[FPMA(4-formyl phenyl methacrylate)2-st-DMA(N,N-dimethylacrylamide)2], P2} and two statistical [P(LAEMA23-st-FPMA3) (P3) and P(LAEMA25-st-FPMA2-st-DMA2) (P4)] aldehyde-based and galactose-based polymers, prepared via reversible addition-fragmentation chain-transfer (RAFT) polymerization. An arginine-rich peptide (ARP, KRRKRRRRRK) was used as a cell-penetrating peptide (CPP) and conjugated to the polymers via a Schiff base reaction. The resulting glycopolymer-peptide conjugates were utilized to condense the siRNA to prepare polyplexes with multivalent CPPs (MCPPs, a nanoparticle with multiple copies of the CPP) to enhance the endosomal escape. The polyplexes have different surface properties as determined by the architecture of polymers and the insertion of dimethyl amide moieties. The enhancement of cellular internalization of ARP was observed by labeling the polyplexes with fluorescein isothiocyanate (FITC)-siRNA showing a localization of polyplexes in the cytoplasm of a HeLa (cervical cancer) cell line. In the in vitro EFGR silencing study, the statistical glycopolymer-peptide (P3-P) polyplexes had superior EGFR silencing efficiency in comparison with the other polymers that were studied. Furthermore, P3-P polyplexes led to less off-targeting silencing than lipofectamine 3000. These encouraging results confirmed the potency of decorating galactose-based polymers with CPP, like ARP for their application in siRNA delivery and management of cervical carcinomas.

Zwitterionic Block Copolymer Prodrug Micelles for pH Responsive Drug Delivery and Hypoxia-Specific Chemotherapy.

Tirapazamine (TPZ) and its derivatives (TPZD) have shown their great potential for efficiently killing hypoxic cancer cells. However, unsatisfactory clinical outcomes resulting from the low bioavailability of the low-molecular TPZ and TPZD limited their further applications. Precise delivery and release of these prodrugs via functional nanocarriers can significantly improve the therapeutic effects due to the targeted drug delivery and enhanced permeability and retention (EPR) effect. Herein, zwitterionic block copolymer (BCP) micelles with aldehyde functional groups are prepared from the self-assembly of poly(2-methacryloyloxyethyl phosphorylcholine-b-poly(di(ethylene glycol) methyl ether methacrylate-co-4-formylphenyl methacrylate) [PMPC-b-P(DEGMA-co-FPMA)]. TPZD is then grafted onto PMPC-b-P(DEGMA-co-FPMA) to obtain a polymer-drug conjugate, PMPC-b-P(DEGMA-co-FPMA-g-TPZD) (BCP-TPZ), through the formation of a pH-responsive imine bond, exhibiting a pH-dependent drug release profile owing to the cleavage of the imine bond under acidic conditions. Outstandingly, BCP-TPZ shows around 13.7-fold higher cytotoxicity to hypoxic cancer cells in comparison to normoxic cancer cells evaluated through an in vitro cytotoxicity assay. The pH-responsiveness and hypoxia-specific cytotoxicity confer BCP-TPZ micelles a great potential to achieve precise delivery of TPZD and thus enhance the therapeutic effect toward tumor-hypoxia.

Synthesis and in vitro antifungal activity of new Michael-type amino derivatives of xanthatin, a natural sesquiterpene lactone from Xanthium strumarium L.

Structural optimization using plant secondary metabolites as templates is one of the important approach to discover pesticide molecules with novel skeletons. Xanthatin, a natural sesquiterpene lactone isolated from the Xanthium plants (Family: Compositae), exhibits important biological properties. In this work, a series of Michael-type amino derivatives were prepared from xanthatin and their structures were characterized by 1H NMR, 13C NMR and HR-MS, and their antifungal activities against several phytopathogenic fungi were evaluated according to the spore germination method and mycelium growth rate method in vitro. The results illustrated that compounds 2g (IC50 = 78.91 µg/mL) and 2o (IC50 = 64.51 µg/mL) exhibited more promising inhibition activity against spores of F. solani than precursor xanthatin, compounds 2g, 2l, and 2r exhibited remarkable antifungal effect on C. mandshurica with the average inhibition rates (AIRs) >90%, whereas the AIR of xanthatin was only 59.34%. Meanwhile, the preliminary structure-activity relationships suggested that the amino containing 2-methoxyethyl or 4-chlorophenylmethyl group appended in the C-13 position of xanthatin could yield potential compounds against fungal spores, and the exocyclic double bond of xanthatin is essential to maintain its mycelial growth inhibitory activity. Therefore, the aforementioned findings indicate that partial xanthatin amino-derivatives could be considered for further exploration as the potential lead structures toward development of the new environmentally friendly fungicidal candidates for sustainable crop protection.

Prevalence and Strain Composition of Potato virus Y Circulating in Potato Fields in China's North-Central Province of Shanxi.

Potato is an important crop in Shanxi province, located in north-central China. In 2019 to 2020, 319 potato leaf samples were collected from eight locations distributed in three major potato production areas in Shanxi. BioChip testing revealed the presence of several potato viruses, of which Potato virus Y (PVY) was the most common, reaching an incidence of 87.8% of all symptomatic samples. Immunocaptured multiplex reverse transcription (RT) PCR was used to identify strains for all 280 PVY-positive samples, unveiling 242 samples infected with a single strain of PVY (86.4%) and 38 (13.6%) with a mixed infection. Of samples with a single-strain infection, PVY-SYR-II accounted for 102 (42.1%), followed by PVYN-Wi (33, 13.6%), PVY-SYR-I (28, 11.6%), 261-4 (22, 9.1%), PVYNTNa (20, 8.3%), PVYNTNb (19, 7.9%), and PVY-SYR-III (18, 7.4%). Seven isolates representing different recombinants were selected for whole genome sequencing. Phylogenetic and recombination analyses confirmed the RT-PCR-based strain typing for all seven strains of PVY found in Shanxi. SXKL-12 is the first SYR-III strain from potato reported from China. However, unlike that in other known SYR-III isolates, the region positioned from 1,764 to 1,902 nt in SXKL-12 shared the highest sequence identity of 82.2% with an uncharacterized PVY isolate, JL-23, from China. Interestingly, PVYN-Wi isolate SXZY-40 also possessed a more divergent sequence for the region positioned from 6,156 to 6,276 nt than other N-Wi isolates known to date, sharing the highest identity of 86.6% with an uncharacterized Chinese PVY isolate, JL-11. Pathogenicity analysis of dominant strains PVY-SYR-II and PVYN-Wi in six local popular potato cultivars revealed that 'Kexin 13', 'Helan 15', and 'Jizhangshu 12' were susceptible to these two strains, with mild mottling or mosaic symptom expression, and three cultivars, 'Jinshu 16', 'Qingshu 9', and 'Xisen 6', were fully resistant.

Synergistic Effects of Clonostachys rosea Isolates and Succinate Dehydrogenase Inhibitors Fungicides against Gray Mold on Tomato.

Gray mold caused by Botrytis cinerea is a devastating disease in tomatoes. Site-specific fungicide application is still key to disease management; however, chemical control has many drawbacks. Here, the combined application of a biological agent, Clonostachys rosea, with newly developed succinate dehydrogenase inhibitors (SDHI) fungicides showed stronger synergistic effects than the application of SDHI fungicides alone on tomato gray mold control. C. rosea 67-1 has been reported as an efficient biological control agent (BCA) for B. cinerea. Little information is currently available about the combination of C. rosea and fungicides in the control of gray mold. By testing the sensitivity to fungicides with different action mechanisms, C. rosea isolates showed high tolerance to SDHI fungicides (1000 µg mL-1) on PDA, and the conidial germination rate was almost not affected under 120 µg mL-1 of fluxapyroxad and fluopyram. In greenhouse experiments, the control effect of the combination of C. rosea and fluxapyroxad or fluopyram against tomato gray mold was significantly increased than the application of BCA or SDHI fungicides alone, and the combination allows a two-fold reduction of both the fungicide and BCA dose. Further, the biomass of B. cinerea and C. rosea on tomato plants was determined by qPCR. For B. cinerea, the trend of detection level for different treatments was consistent with that of the pot experiments, and the lowest biomass of B. cinerea was found when treated with C. rosea combined with fluxapyroxad and fluopyram, respectively. For C. rosea, qPCR assay confirmed its colonization on tomato plants when mixed with fluopyram and fluxapyroxad. These results indicated that combining C. rosea 67-1 with the SDHI fungicides could synergistically increase control efficacy against tomato gray mold.

Electrolyte/Structure-Dependent Cocktail Mediation Enabling High-Rate/Low-Plateau Metal Sulfide Anodes for Sodium Storage.

As promising anodes for sodium-ion batteries, metal sulfides ubiquitously suffer from low-rate and high-plateau issues, greatly hindering their application in full-cells. Herein, exemplifying carbon nanotubes (CNTs)-stringed metal sulfides superstructure (CSC) assembled by nano-dispersed SnS2 and CoS2 phases, cocktail mediation effect similar to that of high-entropy materials is initially studied in ether-based electrolyte to solve the challenges. The high nano-dispersity of metal sulfides in CSC anode underlies the cocktail-like mediation effect, enabling the circumvention of intrinsic drawbacks of different metal sulfides. By utilizing ether-based electrolyte, the reversibility of metal sulfides is greatly improved, sustaining a long-life effectivity of cocktail-like mediation. As such, CSC effectively overcomes low-rate flaw of SnS2 and high-plateau demerit of CoS2, simultaneously realizes a high rate and a low plateau. In half-cells, CSC delivers an ultrahigh-rate capability of 327.6 mAh g-1anode at 20 A g-1, far outperforming those of monometallic sulfides (SnS2, CoS2) and their mixtures. Compared with CoS2 phase and SnS2/CoS2 mixture, CSC shows remarkably lowered average charge voltage up to ca. 0.62 V. As-assembled CSC//Na1.5VPO4.8F0.7 full-cell shows a good rate capability (0.05 ~ 1.0 A g-1, 120.3 mAh g-1electrode at 0.05 A g-1) and a high average discharge voltage up to 2.57 V, comparable to full-cells with alloy-type anodes. Kinetics analysis verifies that the cocktail-like mediation effect largely boosts the charge transfer and ionic diffusion in CSC, compared with single phase and mixed phases. Further mechanism study reveals that alternative and complementary electrochemical processes between nano-dispersed SnS2 and CoS2 phases are responsible for the lowered charge voltage of CSC. This electrolyte/structure-dependent cocktail-like mediation effect effectively enhances the practicability of metal sulfide anodes, which will boost the development of high-rate/-voltage sodium-ion full batteries.

Comparison of mitochondrial genomes provides insights into intron dynamics and evolution in Botryosphaeria dothidea and B. kuwatsukai.

Botryosphaeria dothidea is one of the most common fungal pathogens on a large number of hosts worldwide. Botryosphaeria dothidea and B. kuwatsukai are also the main causal agents of apple ring rot. In this study, we sequenced, assembled and annotated the circular mitogenomes of 12 diverse B. dothidea isolates (105.7-114.8 kb) infecting various plants including apple, and five diverse B. kuwatsukai isolates (118.0-124.6 kb) from apple. B. dothidea mitogenomes harboured a set of 29-31 introns and 48-52 ORFs. In contrast, B. kuwatsukai mitogenomes harboured more introns (32-34) and ORFs (51-54). The variation in mitogenome sizes was associated mainly with different numbers of introns and insertions of mobile genetic elements. Interestingly, B. dothidea and B. kuwatsukai displayed distinct intron distribution patterns, with three intron loci showing presence/absence dynamics in each species. Large numbers of introns (57% in B. dothidea and 49% in B. kuwatsukai) were most likely obtained through horizontal transfer from non-Dothideomycetes. The mitochondrial gene phylogeny supported the differentiation of the two species. Overall, this study sheds light into the mitochondrial evolution of the plant pathogens B. dothidea and B. kuwatsukai, and intron distribution patterns could be useful markers for studies on population diversity.

Molecular Dissection of Perithecial Mating Line Development in Colletotrichum fructicola, a Species with a Nontypical Mating System Featuring Plus-to-Minus Switch and Plus-Minus-Mediated Sexual Enhancement.

The genetic regulation of Colletotrichum (Glomerella) sexual reproduction does not strictly adhere to the Ascomycota paradigm and remains poorly understood. Morphologically different but sexually compatible strain types, termed plus and minus, have been recognized, but the biological and molecular distinctions between these strain types remain elusive. In this study, we characterized the sexual behaviors of a pair of plus and minus strains of C. fructicola with the aid of live-cell nucleus-localized fluorescent protein labeling, gene expression, and gene mutation analyses. We confirmed a genetically stable plus-to-minus switching phenomenon and demonstrated the presence of both cross-fertilized and self-fertilized perithecia within the mating line (perithecia cluster at the line of colony contact) between plus and minus strains. We demonstrated that pheromone signaling genes (a-factor-like and α-factor-like pheromones and their corresponding GPCR receptors) were differently expressed between vegetative hyphae of the two strains. Moreover, deletion of pmk1 (a FUS/KSS1 mitogen-activate protein kinase) in the minus strain severely limited mating line formation, whereas deletion of a GPCR (FGSG_05239 homolog) and two histone modification factors (hos2, snt2) in the minus strain did not affect mating line development but altered the ratio between cross-fertilization and self-fertilization within the mating line. We propose a model in which mating line formation in C. fructicola involves enhanced protoperithecium differentiation and enhanced perithecium maturation of the minus strain mediated by both cross-fertilization and diffusive effectors. This study provides insights into mechanisms underlying the mysterious phenomenon of plus-minus-mediated sexual enhancement being unique to Colletotrichum fungi. IMPORTANCE Plus-minus regulation of Colletotrichum sexual differentiation was reported in the early 1900s. Both plus and minus strains produce fertile perithecia in a homothallic but inefficient manner. However, when the two strain types encounter each other, efficient differentiation of fertile perithecia is triggered. The plus strain, by itself, can also generate minus ascospore progeny at high frequency. This nontypical mating system facilitates sexual reproduction and is Colletotrichum specific; the underlying molecular mechanisms, however, remain elusive. The current study revisits this longstanding mystery using C. fructicola as an experimental system. The presence of both cross-fertilized and self-fertilized perithecia within the mating line was directly evidenced by live-cell imaging with fluorescent markers. Based on further gene expression and gene mutation analysis, a model explaining mating line development (plus-minus-mediated sexual enhancement) is proposed. Data reported here have the potential to allow us to better understand Colletotrichum mating and filamentous ascomycete sexual regulation.

Dual-Cross-Linked Network Hydrogels with Multiresponsive, Self-Healing, and Shear Strengthening Properties.

Dual-cross-linked network (DCN) hydrogels with multiresponsive and self-healing properties are attracting intensive interests due to their enhanced mechanical strength for a wide range of applications. Herein, we developed a DCN hydrogel that combines a dynamic imine and a benzoxaboronic ester with a neutral pKa value (∼7.2) as dual linkages and contains biocompatible zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) [poly(MPC)] as the backbone. Oscillatory rheology result indicated shear strengthening mechanical properties compared to the single-cross-linked network (SCN) hydrogels, which use either imine bond or benzoxaboronic ester as the linkage alone. Due to the coexistence of stimuli-responsive imine and benzoxaboronic ester, the DCN hydrogels show sensitive multiple responsiveness to pH, sugar, and hydrogen peroxide. The dynamic nature of the dual linkages endows the DCN hydrogels with excellent self-healing ability after fracture. More importantly, the excellent biocompatibility and performance in three-dimensional (3D) cell encapsulation were established by a cytotoxicity Live/Dead assay, indicating DCN hydrogel's great potential as a cell culture scaffold. The biocompatible poly(MPC)-based backbone and the rapid formation of the cross-linking network make the DCN hydrogels promising candidates for future biomedical applications.

Two-photon photodynamic ablation of tumour cells using an RGD peptide-conjugated ruthenium(ii) photosensitiser.

An RGD-peptide conjugated ruthenium(ii) complex has been developed, which functions as a two-photon absorption (TPA) photodynamic therapy (PDT) agent for ablating tumours by selectively targeting the mitochondria of integrin αvß3-rich tumour cells. This approach offers a new and effective design and application for tumour-targeting metallo-anticancer drugs via two-photon PDT.

Combination of Ruthenium Complex and Doxorubicin Synergistically Inhibits Cancer Cell Growth by Down-Regulating PI3K/AKT Signaling Pathway.

Combinational use of drugs has been a common strategy in cancer treatment because of synergistic advantages in reducing dose and toxicity, minimizing or delaying drug resistance. To improve the efficacy of chemotherapy, various potential combinations have been investigated. Ruthenium complex is considered a potential alternative of the platinum-based drugs due to its significant efficacy and safety. Previously, we reported that ruthenium(II) complex (Δ-Ru1) has great anticancer potential and minor toxicity toward normal tissues. However, the therapeutic efficacy and mechanism of action of ruthenium(II) complex combined with other anticancer drugs is still unknown. Here, we investigated the combinational effect of Δ-Ru1 and doxorubicin in different cancer cells. The data assessed by Chou-Talalay method showed significant synergism in MCF-7 cells. Furthermore, the results in antiproliferation efficacy indicated that the combination showed strong cytotoxicity and increasing apoptosis of MCF-7 cells in 2D and 3D multicellular tumor spheroids (MCTSs). Significant inhibition of MCF-7 cells accompanied with increased ROS generation was observed. Furthermore, the expression of PI3K/AKT was significantly down-regulated, while the expression of PTEN was strongly up-regulated in cells treated with combination of Δ-Ru1 and doxorubicin. The expression of NF-κB and XIAP decreased while the expression of P53 increased and associated with apoptosis. These findings suggest that the combination of ruthenium complex and doxorubicin has a significant synergistic effect by down-regulating the PI3K/AKT signaling pathway in MCF-7 cells. This study may trigger more research in ruthenium complex and combination therapy that will be able to provide opportunities for developing better therapeutics for cancer treatment.