Strain Engineering of Cd0.5Zn0.5S Nanocrystal for Efficient Photocatalytic Hydrogen Evolution from Wasted Plastic.

The challenge of synthesizing nanocrystal photocatalysts with adjustable lattice strain for effective waste-to-energy conversion is addressed in this study. Cd0.5Zn0.5S (CZS) nanocrystals are synthesized by a simple solvothermal method, regulation of the ratio between N, N-dimethylformamide, and water solvent are shown to provoke expansion and contraction, inducing an adjustable lattice strain ranging from -1.2% to 5.6%. With the hydrolyzed wasted plastic as a sacrificial agent, the 5.6% lattice-strain CZS exhibited a robust hydrogen evolution activity of 1.09 mmol m-2 h-1 (13.83 mmol g-1 h-1), 4.5 times that of pristine CZS. Characterizations and density functional theory calculation demonstrated that lattice expansion increases the spatial distance between the valence band maximum and conduction band minimum, thus reducing carrier recombination and promoting charge transfer. Additionally, lattice expansion induces surface S vacancies and adsorbed OH groups, further enhancing redox reactions. This study focuses on the synchronous regulation of crystal structure, charge separation/transport, and surface reactions through lattice strain engineering, which providing a reference for the rational design of new photocatalysts for effective waste-to-energy conversion.

Phylogeny and Fungal Community Structures of Helotiales Associated with Sclerotial Disease of Mulberry Fruits in China.

Mulberry fruit sclerotiniose is a prevalent disease caused by the fungal species Ciboria shiraiana, C. carunculoides, and Scleromitrula shiraiana of the order Helotiales, and severely affects the production of mulberry. However, these species have only been identified using morphological and rDNA-ITS sequence analyses, and their genetic variation is unclear. To address this, morphological and two-locus (ITS and RPB2) phylogenetic analyses were conducted using culture-dependent and independent methods for 49 samples from 31 orchards across four provinces in China. Illumina MiSeq sequencing was used to assess the fungal communities obtained from fruits varying in disease severity and color from an orchard in Wuhan. Conidial suspensions of C. shiraiana and C. carunculoides isolated from diseased fruits, diseased fruits affected with hypertrophy and pellet sorosis sclerotiniose, and mycelia of Sclerotinia sclerotiorum were determined to be pathogenic to the mulberry cultivar YSD10. However, fruits inoculated with S. sclerotiorum mycelia exhibited nontypical disease symptoms, and mycelia and conidia obtained from C. carunculoides and S. shiraiana strains were not pathogenic. Maximum parsimony and Bayesian analyses using the sequences of the assessed loci indicated species variability with no evidence of geographic specialization. Metagenomic analysis revealed that the diversity of fungal communities was reduced with disease progression. Furthermore, within a single fruit, the presence of two Ciboria spp. was detected. These results provide novel insights into Ciboria spp., revealing the secondary infections caused by conidia in diseased fruits, genetic variations of the pathogens, and the occurrence of coinfection. This improved understanding of fungal pathogens will aid in developing effective disease control strategies.

First Report of Neocosmospora mori Causing Root Rot and Stem Blight of Mulberry in Nanzhang, Hubei, China.

Mulberry (Morus alba L.) has been cultivated for thousands of years in many temperate regions in East Asia and is commonly used to feed silkworms. In May 2021, 5 to 8% incidence of stem blight on 4-year-old mulberry 'Nongsang 14' was observed in several orchards in Nanzhang County, Hubei Province, China. The roots and stems showed symptoms of vascular discoloration, and the tender new shoots, surrounded by white hyphae, were detached easily. Symptomatic stem tissues (5 mm × 5 mm) were excised from the border between diseased and healthy tissues, surface sterilized in a 75% ethanol solution for 30 s and 2.5% sodium hypochlorite for 1.5 min, washed three times in sterile distilled water, then placed on potato dextrose agar (PDA, 250 g potatoes, 2% dextrose, 1.6% agar), and incubated at 25°C in darkness. Two isolates (Bq2 and Bq3) were subcultured using the single-spore method. On PDA, colonies were cottony, with whitish aerial mycelium and the daily growth rate was 4.25 to 5.50 mm/day at 25°C in darkness. On carnation leaf agar, macroconidia were fusiform with slightly curved apical cells and foot-shaped basal cells, three to five septate, measuring 47.5 to 80.3 × 3.6 to 5.6 µm (average 68.7 × 4.7 µm, n = 30). On spezieller nährstoffarmer agar, microconidia were produced in false heads on monophialides, mostly 0-septate, oval, obovoid, or reniform in shape, measuring 5.1 to 10.7 × 2.7 to 5.3 µm (average 8.5 × 3.3 µm, n = 30). Chlamydospores were 4.9 to 11.0 µm in diameter (average 6.8 µm, n = 30), round shaped, thick-walled, and produced individually or in pairs or in chains. For molecular identification, the ribosomal internal transcribed spacers (ITS), translation elongation factor 1α (EF-1α), 28S large subunit nrDNA (LSU), and calmodulin (CAM) genes were amplified and sequenced with primers ITS1/ITS4 (White et al. 1990), EF1H/EF2T (O'Donnell et al. 1998), LR0R/LR5 ( Vilgalys and Hester 1990; Vilgalys and Sun 1994), and CL1/CL2A (Geiser et al. 2021; Wang et al. 2011), respectively. The sequences were deposited in GenBank (OQ711943-OQ711944 for ITS, OQ722438- Q722439 for EF-1α, OQ722441-OQ722442 for CAM, and OR116152-OR116153 for LSU). A maximum-likelihood phylogenetic analysis based on multilocus sequences was conducted using MEGA7, which showed that the two isolates grouped into a clade with Neocosmospora mori (previously Fusarium solani species complex) supported by a high bootstrap value (85%), and hence, they were identified as N. mori based on morphological and molecular analyses (Brooks et al. 2022; Crous et al. 2021; Lombard et al. 2015; Zeng and Zhuang 2023). To complete Koch's postulates, three healthy 2-month-old seedlings grown in sterile peat mix were removed from pots and the roots were washed in sterile water. Each plant was inoculated by dipping wounded and unwounded roots in a spore suspension (1 × 107 conidia/ml) for 20 min, and then 10 mL of the spore suspension was poured over the roots of each seedling after transplanting. Three plants were treated with sterilized water as a control. The tested plants were then kept in a plastic box containing sterile water and incubated at 25°C in a 12 h/12 h light/dark cycle. The pathogenicity assay was repeated three times for each isolate. Root and stem blight was observed 10 days after inoculation, while the control plants were asymptomatic. Furthermore, fungi with morphological characteristics of N. mori were only reisolated from the symptomatic stems and sequences of LSU matched those of isolates Bq2 and Bq3. This pathogen has been reported previously causing stem blight on mulberry trees in Japan and South Korea (Sandoval-Denis et al. 2019), but to our knowledge, this is the first report of N. mori causing root rot and stem blight of mulberry in China. This report will facilitate the development of effective control strategies for the disease.

A Feature Selection Approach Guided an Early Prediction of Anthocyanin Accumulation Using Massive Untargeted Metabolomics Data in Mulberry.

Identifying the early predictive biomarkers or compounds represents a pivotal task for guiding a targeted agricultural practice. Despite the various available tools, it remains challenging to define the ideal compound combination and thereby elaborate an effective predictive model fitting that. Hence, we employed a stepwise feature selection approach followed by a maximum relevance and minimum redundancy (MRMR) on the untargeted metabolism in four mulberry genotypes at different fruit developmental stages (FDSs). Thus, we revealed that 7 out of 226 differentially abundant metabolites (DAMs) explained up to 80% variance of anthocyanin based on linear regression model and stepwise feature selection approach accompanied by an MRMR across the genotypes over the FDSs. Among them, the phosphoenolpyruvate, d-mannose and shikimate show the top 3 attribution indexes to the accumulation of anthocyanin in the fruits of these genotypes across the four FDSs. The obtained results were further validated by assessing the regulatory genes expression levels and the targeted metabolism approach. Taken together, our findings provide valuable evidences on the fact that the anthocyanin biosynthesis is somehow involved in the coordination between the carbon metabolism and secondary metabolic pathway. Our report highlights as well the importance of using the feature selection approach for the predictive biomarker identification issued from the untargeted metabolomics data.

First Report of Colletotrichum aenigma Causing Anthracnose on Mulberry Leaves in China.

Mulberry (Morus alba L.) has been grown worldwide as a crop for silkworm rearing for over five thousand years (Jiao et al. 2020). In July 2021, a leaf spot disease was observed on mulberry leaves in Wuhan city (114°33'E, 30°48'N), Hubei province, China, with approximately 40% of leaves (about 300 trees) affected. Early symptoms were light brown, with small lesions subsequently expanding to larger sometimes irregular dark brown or black spots surrounded by yellow-brown margins, with easily perforated necrotic lesions. Leaf tissues (5 mm×5 mm) were excised from the border between diseased and healthy tissues, surface sterilized with 75% ethanol solution for 30 s and 2.5% sodium hypochlorite for 2 min, washed thrice in sterile distilled water, and then placed on potato dextrose agar (PDA), and incubated at 25°C in darkness. Four isolates (C1, C9, CHS2, and CHS6) were subcultured using the single-spore method. On PDA, colonies were cottony, pale white from above, and white to grayish-green on the reverse side. Conidia were aseptate, hyaline, subcylindrical with broadly rounded ends, 8.4 to 18.3×4.1 to 7.7 µm (mean = 13.9×5.5 µm, n = 30). Appressoria were typically elliptic or irregular with a few lobes, dark brown, 5.9 to 9.6×4.2 to 8.1 µm (mean = 7.9 ×5.7 µm, n = 30). The morphological characteristics of the isolates matched the descriptions of Colletotrichum gloeosporioides species complex (Weir et al. 2012). The isolates were further identified by analysis of the ribosomal internal transcribed spacers (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), calmodulin (CAL), actin (ACT), chitin synthase (CHS-1), glutamine synthetase (GS), and ß-tubulin 2 (TUB2) genes, amplified respectively with ITS1/ITS4, GDF/GDR, CL1C/CL2C, ACT-512F/ACT-783R, CHS-79F/CHS-345R, GSF1/GSR, and Bt2a/Bt2b (Glass and Donaldson 1995; Weir et al. 2012; White et al. 1990). The sequences were deposited in GenBank (ON492187-ON492214). Concatenated sequences of the seven genes in addition to Colletotrichum species sequences from GenBank were used to conduct a phylogenetic analysis using Maximum-Likelihood (ML) method in MEGA7. The four isolates were grouped into a clade with Colletotrichum aenigma supported by a high bootstrap value (89%), and hence, they were identified as C. aenigma based on the morphological and molecular analyses. To confirm Koch's postulates, wounded leaves of six healthy 2-month-old seedlings made by a sterile needle were inoculated with each isolate by spraying 10 ml of conidial suspensions (105 conidia/ml) on each plant, and the control plants were treated with sterile distilled water. All the treated plants were kept in a plastic box containing sterile water and incubated at 28°C in a 12 h/12 h light/dark cycle. The test was performed three times. After 7 days, typical anthracnose lesions appeared on all inoculated leaves, whereas control plants remained asymptotic. Furthermore, C. aenigma was only reisolated from the symptomatic leaves. Previous studies reported five Colletotrichum species (C. morifolium, C. fioriniae, C. brevisporum, C. karstii, and C. kahawae subsp. ciggaro) to cause this disease on mulberry in China (Tian, 1981; Xue et al. 2019). To our knowledge, this is the first report of C. aenigma causing anthracnose on mulberry in China. The finding will facilitate epidemiological studies and the development of effective control strategies for the disease.

Screening and Verification of Photosynthesis and Chloroplast-Related Genes in Mulberry by Comparative RNA-Seq and Virus-Induced Gene Silencing.

Photosynthesis is one of the most important factors in mulberry growth and production. To study the photosynthetic regulatory network of mulberry we sequenced the transcriptomes of two high-yielding (E1 and E2) and one low-yielding (H32) mulberry genotypes at two-time points (10:00 and 12:00). Re-annotation of the mulberry genome based on the transcriptome sequencing data identified 22,664 high-quality protein-coding genes with a BUSCO-assessed completeness of 93.4%. A total of 6587 differentially expressed genes (DEGs) were obtained in the transcriptome analysis. Functional annotation and enrichment revealed 142 out of 6587 genes involved in the photosynthetic pathway and chloroplast development. Moreover, 3 out of 142 genes were further examined using the VIGS technique; the leaves of MaCLA1- and MaTHIC-silenced plants were markedly yellowed or even white, and the leaves of MaPKP2-silenced plants showed a wrinkled appearance. The expression levels of the ensiled plants were reduced, and the levels of chlorophyll b and total chlorophyll were lower than those of the control plants. Co-expression analysis showed that MaCLA1 was co-expressed with CHUP1 and YSL3; MaTHIC was co-expressed with MaHSP70, MaFLN1, and MaEMB2794; MaPKP2 was mainly co-expressed with GH9B7, GH3.1, and EDA9. Protein interaction network prediction revealed that MaCLA1 was associated with RPE, TRA2, GPS1, and DXR proteins; MaTHIC was associated with TH1, PUR5, BIO2, and THI1; MaPKP2 was associated with ENOC, LOS2, and PGI1. This study offers a useful resource for further investigation of the molecular mechanisms involved in mulberry photosynthesis and preliminary insight into the regulatory network of photosynthesis.

The Ethylene Response Factor ERF5 Regulates Anthocyanin Biosynthesis in 'Zijin' Mulberry Fruits by Interacting with MYBA and F3H Genes.

Ethylene promotes ripening in fruits as well as the biosynthesis of anthocyanins in plants. However, the question of which ethylene response factors (ERFs) interact with the genes along the anthocyanin biosynthesis pathway is yet to be answered. Herein, we conduct an integrated analysis of transcriptomes and metabolome on fruits of two mulberry genotypes ('Zijin', ZJ, and 'Dashi', DS, with high and low anthocyanin abundance, respectively) at different post-flowering stages. In total, 1035 upregulated genes were identified in ZJ and DS, including MYBA in the MBW complex and anthocyanin related genes such as F3H. A KEGG analysis suggested that flavonoid biosynthesis and plant hormone signaling transduction pathways were significantly enriched in the upregulated gene list. In particular, among 103 ERF genes, the expression of ERF5 showed the most positive correlation with the anthocyanin change pattern across both genotypes and in the post-flowering stages, with a Pearson correlation coefficient (PCC) of 0.93. Electrophoresis mobility shift assay (EMSA) and luciferase assay suggested that ERF5 binds to the promoter regions of MYBA and F3H and transcriptionally activates their gene expression. We elucidated a potential mechanism by which ethylene enhances anthocyanin accumulation in mulberry fruits and highlighted the importance of the ERF5 gene in controlling the anthocyanin content in mulberry species. This knowledge could be used for engineering purposes in future mulberry breeding programs.

Effects of long-term straw retention on soil microorganisms under a rice-wheat cropping system.

The objective of this study was to investigate how straw-incorporating practices affect bacterial communities and carbon source utilization capacity under a rice-wheat rotational farming practice in central China. To clarify the effect of long-term straw incorporation in microbial abundance and carbon metabolism, a long-term field experiment was initiated in May 2005 (rice-planting season). Soil bacterial communities were revealed by high-throughput sequencing technology. After ten cycles of annual rice-wheat rotation (2005-2015), 2 M (straw incorporation) and 2 M + NPK (high straw incorporation + chemical fertilizer) treatments had significantly more bacterial phyla compared with CK (non-fertilization) and NPK (chemical fertilizer) treatments. Taxonomic analysis revealed that 2 M and NPK + 2 M treatments had a significantly greater abundance of microbial communities, especially the Gemmatimonadetes, Acidobacteria, Firmicutes, and Actinobacteria. In the NPK versus 2 M, 2 M treatment had a significantly greater abundance of Rozellomycota (P < 0.05). In the NPK + 2 M versus NPK, NPK + 2 M treatment also had significantly greater abundance of Ascomycota (P < 0.05). Principal component analysis (PCA) analysis showed that 2 M treatment was separate from other treatments. Using biolog-ECO method, the metabolic diversity and functional characteristics of microbial communities were used to indicate the ability of microorganisms to utilize carbon source. The carbon utilization ability of soil microorganisms in 2 M + NPK treatment was significantly higher than that of CK treatment (P < 0.05). The utilization ability of carboxylic acids, polymers, and other mixtures of carbon sources in 2 M treatment was higher than those of other treatments. These findings suggest that long-term straw incorporation affects the abundance and carbon utilization ability of soil microorganisms within 0-20 cm soil depths, among which, Gemmatimonadetes, Firmicutes, and Actinobacteria may play crucial roles in bacterial communities and carbon source utilization capacity.

Exploration of the mechanism of levofloxacin removal by N-doped-induced interfacial micro-electric field-activated persulfate.

The defects formed by N doping always coexist with pyrrole nitrogen (Po) and pyridine nitrogen (Pd), and the synergistic mechanisms of H2O2 production and PMS activation between the different Po: Pd are unknown. This paper synthesized MOF-derived carbon materials with different nitrogen-type ratios as cathode materials in an electro-Fenton system using precursors with different nitrogen-containing functional groups. Several catalysts with different Po: Pd ratios (0:4, 1:3, 2:2, 3:1, 4:0) were prepared, and the best catalyst for LEV degradation was FC-CN (Po: Pd=3:1). X-ray Photoelectron Spectroscopy (XPS) and density-functional theory (DFT) calculations show that the introduction of nitrogen creates an interfacial micro-electric field (IMEF) in the carbon layer and the metal, accelerates the electron transfer from the carbon layer to the Co atoms, and promotes cycling between the Fe3+/Co2+ redox pairs, with the electron transfer reaching a maximum at Po: Pd = 3:1. FC-CN (Po: Pd=3:1) achieved more than 95 % LEV degradation in 90 min at pH = 3-9, with a lower energy consumption of 0.11 kWh m-3 order-1. and the energy consumption of the catalyst for LEV degradation is lower than that of those catalysts reported. In addition, the degradation pathway of LEV was proposed based on UPLC-MS and Fukui function. This study offers some valuable information for the application of MOF derivatives.

Anthraquinone-based polymer modified BiVO4 photoanode with strong electron-withdrawing functional groups for boasting photoelectrochemical water oxidation.

The photoelectrochemical (PEC) performance ofBiVO4 is limited by sluggish water oxidation kinetics and severe carrier recombination. Herein, a novel high-performance BiVO4/NiFe-NOAQ photoanode is prepared by a simple one-step hydrothermal method, using BiVO4 and 1-Nitroanthraquinone (NOAQ) as raw materials. The BiVO4/NiFe-NOAQ photoanode has an excellent photocurrent density of 5.675 mA cm-2 at 1.23 VRHE, which is 3.35 times higher than that of the pure BiVO4 (1.693 mA cm-2) photoanode. The BiVO4/NiFe-NOAQ shows a significant improvement in charge separation efficiency (86.12 %) and charge injection efficiency (87.86 %). The improvement is ascribable to the NiFe-NOAQ form a type II heterojunction with BiVO4 to inhibit carrier recombination. More importantly, the kinetic isotope experiment suggests that the proton-coupled electron transfer (PCET) process can enhance the charge transfer of BiVO4/NiFe-NOAQ. The contact angle measurements show that modifying functional groups enhanced the hydrophilicity of BiVO4/NiFe-NOAQ, which can further accelerate the PCET process. The XPS and PL results as well as the tauc plot indicate that the strong electron-withdrawing ability of -NO2 which can promote the extension of π conjugation, results in more π electron delocalization and produces more efficient active sites, thus achieving efficient photoelectrochemical water oxidation.

Metabolome and Transcriptome Integrated Analysis of Mulberry Leaves for Insight into the Formation of Bitter Taste.

Mulberry leaves are excellent for health care, confirmed as a 'drug homologous food' by the Ministry of Health, China. The bitter taste of mulberry leaves is one of the main problems that hinders the development of the mulberry food industry. The bitter, unique taste of mulberry leaves is difficult to eliminate by post-processing. In this study, the bitter metabolites in mulberry leaves were identified as flavonoids, phenolic acids, alkaloids, coumarins and L-amino acids by a combined analysis of the metabolome and transcriptome of mulberry leaves. The analysis of the differential metabolites showed that the bitter metabolites were diverse and the sugar metabolites were down-regulated, indicating that the bitter taste of mulberry leaves was a comprehensive reflection of various bitter-related metabolites. Multi-omics analysis showed that the main metabolic pathway related to bitter taste in mulberry leaves was galactose metabolism, indicating that soluble sugar was one of the main factors of bitter taste difference in mulberry leaves. Bitter metabolites play a great role in the medicinal and functional food of mulberry leaves, but the saccharides in mulberry leaves have a great influence on the bitter taste of mulberry. Therefore, we propose to retain bitter metabolites with drug activity in mulberry leaves and increase the content of sugars to improve the bitter taste of mulberry leaves as strategies for mulberry leaf food processing and mulberry breeding for vegetable use.

Physiological and Transcriptome Analyses of Photosynthesis in Three Mulberry Cultivars within Two Propagation Methods (Cutting and Grafting) under Waterlogging Stress.

Mulberry is a valuable woody plant with significant economic importance. It can be propagated through two main methods: cutting and grafting. Waterlogging can have a major impact on mulberry growth and can significantly reduce production. In this study, we examined gene expression patterns and photosynthetic responses in three waterlogged mulberry cultivars propagated through cutting and grafting. Compared to the control group, waterlogging treatments reduced levels of chlorophyll, soluble protein, soluble sugars, proline, and malondialdehyde (MDA). Additionally, the treatments significantly decreased the activities of ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT) in all three cultivars, except for superoxide dismutase (SOD). Waterlogging treatments also affected the rate of photosynthesis (Pn), stomatal conductance (Gs), and transpiration rate (Tr) in all three cultivars. However, no significant difference in physiological response was observed between the cutting and grafting groups. Gene expression patterns in the mulberry changed dramatically after waterlogging stress and varied between the two propagation methods. A total of 10,394 genes showed significant changes in expression levels, with the number of differentially expressed genes (DEGs) varying between comparison groups. GO and KEGG analysis revealed important DEGs, including photosynthesis-related genes that were significantly downregulated after waterlogging treatment. Notably, these genes were upregulated at day 10 in the cutting group compared to the grafting group. In particular, genes involved in carbon fixation were significantly upregulated in the cutting group. Finally, cutting propagation methods displayed better recovery capacity from waterlogging stress than grafting. This study provides valuable information for improving mulberry genetics in breeding programs.

Isolation and Characterization of DkPK Genes Associated with Natural Deastringency in C-PCNA Persimmon.

Chinese pollination-constant non-astringent (C-PCNA) persimmon (Diospyros kaki Thunb.) is considered to be an important germplasm resource for the breeding of PCNA cultivars, though its molecular mechanisms of astringency removal remain to be elucidated. Previously, we showed that the abundance of pyruvate kinase gene transcripts increased rapidly during astringency removal in C-PCNA persimmon fruit. Here, we report the full-length coding sequences of six novel DkPK genes from C-PCNA persimmon fruit isolated based on a complementary DNA (cDNA) library and transcriptome data. The expression patterns of these six DkPK genes and correlations with the soluble proanthocyanidin (PA) content were analyzed during various fruit development stages in different types of persimmon, with DkPK1 showing an expression pattern during the last stage in C-PCNA persimmon that was positively correlated with a decrease in soluble PAs. Phylogenetic analysis revealed that DkPK1 belongs to cytosolic-1 subgroup, and subcellular localization analysis confirmed that DkPK1 is located in the cytosol. Notably, tissue expression profiling revealed ubiquitous DkPK1 expression in different persimmon organs, with the highest expression in seeds. Furthermore, transient over-expression of DkPK1 in persimmon leaves resulted in a significant decrease in the content of soluble PAs but a significant increase in the transcript levels of pyruvate decarboxylase genes (DkPDC1, -3, -4, -5), which catalyze the conversion of pyruvate to acetaldehyde. Thus, we propose that an acetaldehyde-based coagulation effect reduces the content of soluble PAs. Taken together, our results suggest that DkPK1 might be involved in the natural removal of astringency at the last developmental stage in C-PCNA persimmon. This is the first report to identify several novel full-length DkPK genes as well as their potential roles in the natural loss of astringency in C-PCNA persimmon.