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Kiwifruit brown spot caused by Corynespora cassiicola is the most significant fungal disease in Sichuan, resulting in premature defoliation, which had a significant impact on yield and fruit quality. The objective of the study was to determine the occurrence regularity and suitability of kiwifruit brown spot in Sichuan. The occurrence of the disease in the main producing region was continuously monitored, the maximum entropy (MaxEnt) model was used to predict its potential distribution, and the key environmental variables were identified using the jackknife method. The results indicated that kiwifruit brown spot was widely distributed across the entire producing region in Sichuan, predominantly affecting the variety "Hongyang". The incidence (p < 0.01) and disease index (p < 0.05) showed a significant positive correlation with the cultivar, and decreased with the altitude increasing. The average area under the ROC curve (AUC) of 10 replicates was 0.933 ± 0.012, with an accuracy of 84.44% in a field test, confirming the reliability of the predicted results. The highly suitable distribution areas of kiwifruit brown spot were mainly located in the Chengdu and Ya'an regions. The entire Panzhihua region was an unsuitable distribution area, and the entire Pujiang County and Mingshan District were highly suitable distribution areas. The key environmental variables affecting the potential distribution of kiwifruit brown spot included isothermality (24.3–33.7%), minimum temperature in August (16.3–23.6 °C), maximum temperature in July (25.5–31.2 °C), minimum temperature in June (15.6–20.9 °C), precipitation in August (158–430 mm), and average temperature in October (15.6–18.8 °C). This study provides a theoretical basis for the reasonable layout of the cultivar and the precise prevention and control of the disease. [ABSTRACT FROM AUTHOR]

Barley yellow dwarf virus (BYDV) has caused considerable losses in the global production of grain crops such as wheat, barley and maize. We investigated the phylodynamics of the virus by analysing 379 and 485 nucleotide sequences of the genes encoding the coat protein and movement protein, respectively. The maximum clade credibility tree indicated that BYDV-GAV and BYDV-MAV, BYDV-PAV and BYDV-PAS share the same evolutionary lineage, respectively. The diversification of BYDV arises from its adaptability to vector insects and geography. Bayesian phylogenetic analyses showed that the mean substitution rates of the coat and movement proteins of BYDV ranged from 8.327 × 10− 4 (4.700 × 10− 4–1.228 × 10− 3) and 8.671 × 10− 4 (6.143 × 10− 4–1.130 × 10− 3) substitutions/site/year, respectively. The time since the most recent common BYDV ancestor was 1434 (1040–1766) CE (Common Era). The Bayesian skyline plot (BSP) showed that the BYDV population experienced dramatic expansions approximately 8 years into the 21st century, followed by a dramatic decline in less than 15 years. Our phylogeographic analysis showed that the BYDV population originating in the United States was subsequently introduced to Europe, South America, Australia and Asia. The migration pathways of BYDV suggest that the global spread of BYDV is associated with human activities. [ABSTRACT FROM AUTHOR]

Blumeria graminis f. sp. tritici, which causes wheat powdery mildew, is an obligate biotrophic pathogen that can easily genetically adapt to its host plant. Understanding the virulence structure of and genetic variations in this pathogen is essential for disease control and for breeding resistance to wheat powdery mildew. This study investigated 17 pathogenic populations in Sichuan, China and classified 109 isolates into two distinct groups based on pathogenicity analysis: high virulence (HV, 92 isolates) and low virulence (LV, 17 isolates). Populations from Yibin (Southern region), Xichang (Western region), and Meishan (Middle region) showed lower virulence frequencies than populations from other regions. Many of the previously known resistance genes did not confer resistance in this study. The resistance gene Pm21 displayed an immune response to pathogenic challenge with all populations in Sichuan, and Pm13, Pm5b, Pm2+6, and PmXBD maintained resistance. AMOVA revealed significantly higher levels of variation within populations and lower levels of variation among populations within regions. High levels of gene flow were detected among populations in the four regions. Closely related populations within each region were distinguished by cluster analyses using ISSR and SRAP alleles. Both ISSR and SRAP allele profiling analyses revealed high levels of genetic diversity among pathogenic populations in Sichuan. Although ISSR and SRAP profiling analysis showed similar resolutions, the SRAP alleles appeared to be more informative. We did not detect any significant association between these alleles and the virulence or pathogenicity of the pathogen. Our results suggest that ISSR and SRAP alleles are more efficient for the characterization of small or closely related populations versus distantly related populations. [ABSTRACT FROM AUTHOR]

To elucidate the symptoms and pathogens diversity of corn Fusarium sheath rot (CFSR), diseased samples were collected from 21 county-level regions in 12 prefecture-level districts of Sichuan Province from 2015 to 2018 in the present study. In the field, two symptom types appeared including small black spots with a linear distribution and wet blotches with a tawny or brown color. One hundred thirty-seven Fusarium isolates were identified based on morphological characteristics and phylogenetic analysis (EF1-α), and Koch's postulates were also assessed. The results identified the isolates as 8 species in the Fusarium genus, including F. verticillioides, F. proliferatum, F. fujikuroi, F. asiaticum, F. equiseti, F. meridionale, F. graminearum and F. oxysporum, with isolation frequencies of 30.00, 22.67, 15.33, 7.33, 6.00, 5.33, 3.33 and 1.33%, respectively. Fusariumverticillioides and F. proliferatum were the dominant and subdominant species, respectively. Two or more Fusarium species such as F. verticillioides and F. proliferatum were simultaneously identified at a mixed infection rate of 14.67% in the present study. The pathogenicity test results showed that F. proliferatum and F. fujikuroi exhibited the highest virulence, with average disease indices of 30.28 ± 2.87 and 28.06 ± 1.96, followed by F. equiseti and F. verticillioides, with disease indices of 21.48 ± 2.14 and 16.21 ± 1.84, respectively. Fusarium asiaticum, F. graminearum and F. meridonale showed lower virulence, with disease indices of 13.80 ± 2.07, 11.57 ± 2.40 and 13.89 ± 2.49, respectively. Finally, F. orysporum presented the lowest virulence in CFSR, with a disease index of 10.14 ± 1.20. To the best of our knowledge, this is the first report of F. fujikuroi, F. meridionale and F. asiaticum as CFSR pathogens in China. [ABSTRACT FROM AUTHOR]

Soil washing with green eluent is an efficient technique to remediate heavy metal contaminated farmland. In addition to eluent, less is known about the roles of accompanying ions on heavy metal removal. We investigated the effects of accompanying ions including Fe3+, Mn2+, Ca2+, Mg2+, Al3+, Si4+ and PO 4 3− on the desorption of Pb2+ and Cd2+ in paddy and arid soils using ethylenediaminetetraacetic acid and polyepoxysuccinic acid as eluents. The release rates of target and accompanying ions showed significant fast and slow reaction stages based on corresponding analysis and kinetic models. In fast reaction stage, Pb2+ and Cd2+ performed geochemical analogy with Ca2+, Mg2+ and PO 4 3−. The release curves of these ions were fitted well with Elovich model, indicating that they released from oxysalt surface into solution via ion exchange, and dissolution of Fe/Mn/Al/Si (hydr)oxides through H+- and ligand-promoted dissolution. In slow reaction stage, Pb2+ and Cd2+ were related to Fe3+, Mn2+, Al3+ and Si4+, which were controlled by intraparticle diffusion process. H+ slowly diffused into interlayer of phyllosilicates to displace target and accompanying ions by ion exchange. Therefore, this research filled the gap of accompanying ions driving the release behavior of heavy metal ions during leaching. [Display omitted] • Fast-slow reaction stages of ions were indicated by correspondence analysis. • Pb2+ and Cd2+ have geochemical analogy with Ca2+, Mg2+, PO 4 3− in fast reaction stage. • Pb2+ and Cd2+ fast released from soil oxysalt surface and dissolution of (hydr)oxide. • H+ entered phyllosilicate interlayer to displace target ions and Fe3+/Mn2+/Al3+/Si4+. [ABSTRACT FROM AUTHOR]

Abstract Soil nitrogen (N) is controlled by climate, topography, parent material and vegetation in less-disturbed ecosystems. However, a comprehensive understanding of the interactions among these soil-forming factors on soil N fractions (SNFs) is still unclear. We measured SNFs at 89 sites across a 3300-m gradient elevation in the southeastern Tibetan Plateau, which spans a large range of climates, parent materials and plant communities. The results showed that different SNFs were correlated with different predictors. Inorganic N was related to elevation and plant species diversity; labile organic N was mainly controlled by parent material; and moderate and recalcitrant organic N were governed by mean annual temperature, parent material and plant species diversity. We concluded that the combined effects of the soil-forming factors controlled SNFs; plant species diversity and parent material were the first and second crucial factors for predicting SNFs. Aspect, elevation and mean annual temperature not only directly affected some fractions, but also indirectly influenced them via plant species diversity. Our results stress the importance of incorporating abiotic and biotic factors when predicting soil N–environment feedback across a large scale. Graphical abstract Unlabelled Image Highlights • Mean annual temperature predominantly governed recalcitrant organic nitrogen. • Parent material acted as primary for soil nitrogen fractions. • Plant community played as intermediary between impact factors and soil nitrogen. [ABSTRACT FROM AUTHOR]

The complete genome sequence of a wild tomato mosaic virus (WTMV) isolate (named WTMV-Sn) was determined and identified in Solanum nigrum in China. The complete genome of WTMV-Sn is 9,659 nucleotides in length, excluding the poly(A) tail and encodes a polyprotein of 3,074 amino acids. This is the first report of WTMV infecting S. nigrum. Despite the high degree of sequence similarity between the WTMV-Sn and WTMV-XC-1 isolates, the 349 nucleotides at the 5′ terminus of WTMV-Sn appear to have originated by recombination with another isolate. The recombination parent remains unknown, but the recombination region shares 74.57% sequence identity with isolate WTMV-Laichau, which is below the species demarcation threshold for the genus Potyvirus. A pathogenicity test showed that WTMV-Sn can infect tobacco. This suggests that variation in the P1 cistron of WTMV-Sn may contribute to its ability to infect S. nigrum. [ABSTRACT FROM AUTHOR]

Virtual screening is an efficient way to obtain new drugs, which has become an important method in the field of pesticide research. Protein neural wiskott-Aldrich syndrome isoform X1 (PcnWAS) is a target protein that exists in the haemocytes of Pomacea canaliculata , and in this study, isothermal titration calorimetry (ITC) was used to evaluate the binding ability of protein PcnWAS and pedunsaponin A in vitro. Furthermore, it was set as a receptor, and the design of molluscicidal compounds based on protein PcnWAS was carried out. Results showed that, pedunsaponin A had high binding capacity with protein PcnWAS, and the binding constant (Ka) was 2.98 ± 1.74 × 10−4. A new potential molluscicidal compound thionicotinamide-adenine-dinucleotide (thionicotinamide-DPN) was obtained by virtual screening. In-vivo bioassay indicated that, the LC 50 value was 57.7102 mg/L (72 h), and the oxygen consumption rate, ammonia excretion rate, oxygen nitrogen ratio and hemocyanin content of P. canaliculata declined after 60 mg/L thionicotinamide-DPN treated. Furthermore, the treatment of thionicotinamide-DPN also decreased gene expression level of protein PcnWAS. The results of ITC test showed that thionicotinamide-DPN can bind with protein PcnWAS efficiently, which means that it has the same target with pedunsaponin A when interacted with P. canaliculata. All the above results lay a foundation for the development of new molluscicides. [Display omitted] • Protein PcnWAS was expressed in vitro for the first time • Isothermal calorimetric titration was carried out to verify that PcnWAS is the target protein of Pomacea canaliculata • A new molluscicidal compound thionicotinamide-DPN was obtained through virtual screening • Thionicotinamide-DPN has strong toxicity to P. canaliculata , which could significantly affect physiological state of it [ABSTRACT FROM AUTHOR]

Blumeria graminis f. sp. tritici (Bgt) is an obligate biotrophic fungus that causes wheat powdery mildew, which is a devastating disease in wheat. However, little is known about the pathogenesis of this fungus, and differences in the pathogenesis of the same pathogen at various resistance levels in hosts have not been determined. In the present study, leaf tissues of both Pm40-expressing hexaploid wheat line L658 and its Pm40-deficient sister line L958 were harvested at 0 (without inoculation), 6, 12, 24, 48 and 72 hours post-inoculation (hpi) with Bgt race 15 and then subjected to RNA sequencing (RNA-seq). In addition, we also observed changes in fungal growth morphology at the aforementioned time points. There was a high correlation between percentage of reads mapped to the Bgt reference genome and biomass of the fungus within the leaf tissue during the growth process. The percentage of mapped reads of Bgt in compatible interactions was significantly higher (at the p<0.05 level) than that of reads in incompatible interactions from 24 to 72 hpi. Further functional annotations indicated that expression levels of genes encoding H+-transporting ATPase, putative secreted effector proteins (PSEPs) and heat shock proteins (HSPs) were significantly up-regulated in compatible interactions compared with these levels in incompatible interactions, particularly at 72 hpi. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis suggested that genes involved in the endocytosis pathway were also enriched in compatible interactions. Overall, genes encoding H+-transporting ATPase, PSEPs and HSPs possibly played crucial roles in successfully establishing the pathogenesis of compatible interactions during late stages of inoculation. The study results also indicated that endocytosis is likely to play a potential role in Bgt in establishing compatible interactions. [ABSTRACT FROM AUTHOR]

Pedunsaponin A, a novel molluscicidal compound isolated from Pueraria peduncularis , exhibits strong toxicity against Pomacea canaliculata . To determine the mechanisms of Pedunsaponin A toxicity, its effects on the organs and hemocytes of P. canaliculata were examined in this study. The results showed that Pedunsaponin A had significant toxic effects on different organs of the snail, including the lungs, gills, mantle, siphon tube, ventricle, pericardial cavity, hepatopancreas, kidneys, and the major symptom of this toxicity was the loss of cilia in the lungs and gills. Additionally, in further studies on the effects of Pedunsaponin A treatment, we found that the hemocyte count was changed and hemocyte morphology was damaged, which was primarily reflected by cytoplasm leakage, nuclei deformation, and significant reductions in the number of ribosomes and granulocyte mitochondria. Based on these results and considering that blood vessels are distributed in the lungs and gills, we hypothesized that Pedunsaponin A would first destroy the cilia, which disrupt physiological activities such as respiration, excretion and feeding, and then enter the hemolymph through blood vessels, disrupt the normal function of the hemocytes and destroy the snail immune system, eventually resulting in the death of the snail. [ABSTRACT FROM AUTHOR]

Pomacea canaliculata is an invasive snail that can adversely affect biodiversity, agricultural crop yields and human health. Schima superba, which belongs to the Theaceae family, exhibits insecticidal and antibacterial activity, but few studies have focused on its potential molluscicidal activity. In this study, we systematically evaluated the molluscicidal activity of S. superba extract against P. canaliculata in a variety of conditions, including multiple exposure intervals (24, 48 and 72 h), temperatures (15, 20 and 25 °C) and shell diameters (1.5 ± 0.2, 2.5 ± 0.2 and 3.5 ± 0.2 cm). The molluscicidal activities of a 10% microemulsion of S. superba extract were tested on rice in plastic pots filled with mud at different exposure intervals (1, 3, 5 and 7 days). In addition, we isolated and purified the active components from S. superba extract and described them. S. superba was highly toxic to P. canaliculata; the LC values for the crude extract at 72 h were 12.25 mg L (15 °C), 11.31 mg L (20 °C), 8.33 mg L (25 °C) with 2.5 ± 0.2 cm shell diameter and 9.43 mg L (1.5 ± 0.2 cm shell diameter), 9.48 mg L (2.5 ± 0.2 cm shell diameter), 10.06 mg L (3.5 ± 0.2 cm shell diameter) at 25 °C. There was a positive correlation between the molluscicidal activity of the extract and treatment temperature after 24 h of treatment, but there was no clear correlation beyond 24 h. In addition, there was no statistically significant correlation between the molluscicidal activity of the extract and shell diameters. Pot trials showed that the crude extract effectively controlled P. canaliculata at 8 and 10 mg L. We isolated and characterized two pentacyclic triterpenoid saponins from S. superba, maetenoside B and sasanquasaponin III, which had high molluscicidal activity. This study provides an important foundation for future research on the potential value of S. superba as a molluscicide. [ABSTRACT FROM AUTHOR]

Huge amounts of Pb smelting residues were generally stored in landfills or unprocessed worldwide, and thus demand novel strategies to implement clean production. In this paper, we proposed a clean, efficient and economical hydrometallurgical route to recycle the toxic heavy metals including Zn, Pb and Cd from the Pb residue by the biodegradable low-molecular-weight organic acids (LMWOAs) and the cation exchange resin (CER, 001 × 7). The multi-objective leaching process of the three metals was optimized by combining saturated D-optimal design with desirability function simultaneously. The recovery rates of Zn, Pb and Cd were 88.72–96.36, 65.40–85.31 and 92.63–97.10% at the optimal conditions of 0.73–1.00 mol L−1 agent concentrations, 2.0–3.3 solution pH values and 71–120 min durations, respectively. Adsorption with CER from the resulting leachates recycled over 91.48% of the metal ions. The treated residues were almost completely decontaminated. Therefore, this research filled the gap of clean production route of hydrometallurgical recycling for metal resources from the low-grade slag. [Display omitted] • Citric, malic and acetic acids are promising extractants for metal leaching in Pb residue. • Saturated D-optimal design coupled with desirability function was first employed for multi-objective optimization. • Cation exchange resin (001 × 7) was an efficient adsorbent for the toxic metal ions. • Environmental risk of heavy metals significantly reduced by three organic acids leaching. [ABSTRACT FROM AUTHOR]

Previous studies have found that temperature influences molluscicidal the activity of pedunsaponin A (PA), which may be related to the expression of Hsp70 , a cold-tolerance gene in Pomacea canaliculata. We determined the temperature effect of PA and the relationship between Hsp70 and temperature sensitivity of P. canaliculata poisoned by PA. Toxicity tests resulted in LC 50 values of 17.7239 mg⋅L−1 at 10 °C, which decreased to 2.5774 mg⋅L−1 at 30 °C, implying a positive correlation between toxicity of PA and temperature. After Hsp70 being interfered, the mortality rate of P. canaliculata treated with PA for 72 h was 70%, which was significantly higher than that of snails treated with PA for 72 h without interfering (56.7%). Meanwhile, immune enzyme activities such as SOD, ACP and AKP were significantly increased in the interfered group and expression level of PcAdv in the gill was also significantly increased. These results suggest that deletion of Hsp70 promotes the activation of some immune enzymes of P. canaliculata and elevates the content of target proteins to cope with the dual stresses of low temperatures and molluscicides. These findings indicate that the Hsp70 plays an important role in influencing the temperature sensitivity of P. canaliculata when treated with PA. [Display omitted] • There is positive correlation between toxicity of PA and temperature. • Hsp70 is related to the temperature sensitivity of snails poisoned by PA. • Interference with Hsp70 can affect immune enzyme activity. • Interference with Hsp70 can affect the mRNA content of Pc AdV. [ABSTRACT FROM AUTHOR]

Soil labile organic carbon fractions (LOCF) are valuable indicators of changes in soil quality and soil total organic carbon (TOC), and they are easily influenced by changes in soil management practice. To explore the sensitivity of LOCF and their enzymatic conversion under straw mulch for scientific management of crop straw use on the Chengdu plain, a straw mulch field experiment was conducted to observe the LOCF changes and explore their relationships with C-cycle enzymes during wheat growth. The treatments included no fertilizer or straw (Control), only mineral fertilizer (MF), 10% rice straw nitrogen (N) plus 90% fertilizer N (RS1), 20% rice straw N plus 80% fertilizer N (RS2), 30% rice straw N plus 70% fertilizer N (RS3), 100% rice straw (RS). The water-soluble organic carbon (WSOC) and microbial biomass carbon (MBC) under straw treatments in the 0–20 cm soil layer were significantly higher than those of Control and MF treatments from the seedling stage, and showed significant differences among straw treatments from the tillering stage. Correspondingly, the dissolved organic carbon (DOC) and permanganate oxidized carbon (POXC) showed no obvious differences among straw treatments in most growth stages. Therefore, WSOC and MBC were the most sensitive indicators for assessing soil organic carbon (SOC) change under straw mulch. Moreover, stepwise multiple linear regression revealed that cellulase and β-glucosidase were significantly positive impact factors for LOCF in the two soil layers, while polyphenol oxidase had both positive and negative impacts on WSOC at different soil layers, and peroxidase was a negative factor for LOCF. [ABSTRACT FROM AUTHOR]

Bipolaris zeicola is a fungal pathogen that causes Northern corn leaf spot (NCLS), which is a serious foliar disease in maize and one of the most significant pathogens affecting global food security. Here, we report a genome-wide transcriptional profile analysis using next-generation sequencing (NGS) of maize leaf development after inoculation with B. zeicola. We performed High-Throughput Digital Gene Expression analysis to identify differentially expressed genes (DEGs) in resistant inbred Mo17 lines after infection with B. zeicola at four successive disease development stages—CP (contact period), PP (penetration period), IP (incubation period), and DP (disease period); the expression of the genes was compared with those in a CK (mock-treatment) control. In addition, a sensitive maize line (Zheng58) was used for the comparisons with the Mo17. Among all tested genes, 466 differentially expressed genes were identified in all libraries, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of these genes suggested that they are involved in many biological processes related to systemic symptom development, such as plant hormone signal transduction, starch and sucrose metabolism, phenylpropanoid biosynthesis and photosynthesis. Our systematic analysis provides comprehensive transcriptomic information regarding systemic symptom development in fungal-infected plants. This information will help in furthering our understanding of the detailed mechanisms of plant responses to fungal infection. [ABSTRACT FROM AUTHOR]

The Pb removal efficiencies from contaminated soils by low molecular weight organic acid (LMWOA) and nanoscale zero-valent iron (nZVI) were investigated through batch soil washing experiments. Results showed that significant promotion on Pb-removal with the mixed solutions of LMWOA and nZVI ( p < 0.05). The Pb removal efficiencies reached 64% and 83% for mine and farmland soil by addition of 0.2 M citric acid and 2.0 g L −1 nZVI, respectively. They decreased with increasing pH from 3 to 9. The mixed solutions of LMWOA and nZVI induced Pb(II) releases processes including a rapid desorption within 4 h and a slow desorption in the following hours. The second-order model was the most appropriate for describing the kinetic processes of Pb(II) desorption. The main fractions of Pb removal were exchangeable and reducible. Compared with LMWOA, the loss rates of nitrogen, phosphorus and potassium decreased after washing with the mixed solutions. Our study suggests that combining of LMWOA and nZVI would be a promising alternative approach for remediation Pb-contaminated soils. [ABSTRACT FROM AUTHOR]

Guanglin 9 ( Eucalyptus grandis × Eucalyptus urophlla ) and Eucalyptus grandis 5 are two eucalyptus species which have been found to grow normally in soils contaminated with lanthanum and cerium, but the tolerance mechanisms are not clear yet. In this study, a pot experiment was conducted to investigate the tolerance mechanisms of the eucalyptus to lanthanum and cerium. Cell walls stored 45.40–63.44% of the metals under lanthanum or cerium stress. Peroxidase and catalase activities enhanced with increasing soil La or Ce concentrations up to 200 mg kg −1 , while there were no obvious changes in glutathione and ascorbate concentrations. Non-protein thiols concentrations increased with increasing treatment levels up to 200 mg kg −1 , and then decreased. Phytochelatins concentrations continued to increase under La or Ce stress. Therefore, the two eucalyptus species are La and Ce tolerant plants, and the tolerance mechanisms include cell wall deposition, antioxidant system response, and thiol compound synthesis. [ABSTRACT FROM AUTHOR]

Glabridin is a natural plant-derived compound that has been widely used in medicine and cosmetic applications. However, the fungicidal mechanism of glabridin against phytopathogens remains unclear. In this study, we determined the biological activity and physiological effects of glabridin against F. graminearum. Then the differentially expressed proteins of F. graminearum were screened. The EC 50 values of glabridin in inhibiting the mycelial growth and conidial germination of F. graminearum were 110.70 mg/L and 40.47 mg/L respectively. Glabridin-induced cell membrane damage was indicated by morphological observations, DiBAC 4 (3) and PI staining, and measurements of relative conductivity, ergosterol content and respiratory rates. These assays revealed that the integrity of the membrane was destroyed, the content of ergosterol decreased, and the respiratory rate was inhibited. A proteomics analysis showed that 186 proteins were up-regulated and 195 proteins were down-regulated. Mechanically sensitive ion channel proteins related to transmembrane transport and ergosterol biosynthesis ERG4/ERG24 , related to ergosterol synthesis were blocked. It is speculated that glabridin acts on ergosterol synthesis-related proteins to destroy the integrity of the cell membrane, resulting in abnormal transmembrane transport and an increased membrane potential. Finally, the morphology of mycelia was seriously deformed, growth and development were inhibited. As a result death was even induced. [Display omitted] • Glabridin has significant fungicidal activity against F. graminearum. • The integrity of the membrane destroyed and mycelia morphological changed. • Electrical conductivity and depolarization of cell membrane increased. • Glabridin regulates ergosterol biosynthesis ERG4 to disrupt ergosterol biosynthesis. • Glabridin regulates mechanosensitive ion channel protein to increase permeability. [ABSTRACT FROM AUTHOR]

Abstract: Chelant assisted phytoextraction has been proposed to enhance the efficiency of remediation. This study evaluated the effects of biodegradable ethylene diamine tetraacetate (EDDS), nitrilotriacetic (NTA) and anionic polyacrylamide (APAM) on the tolerance and uptake of Siegesbeckia orientalis L. at 10 and 100mgkg−1 Cd-contaminated soils. On the 80th and 90th days of transplanting, pots were treated with EDDS and NTA at 0 (control), 1 and 2mmolkg−1 soils, and APAM at 0 (control), 0.07 and 0.14gkg−1. Generally, the root and shoot biomass of S. orientalis in all treatments reduced not significantly compared with the control, and the activities of peroxidase and catalase in leaves generally increased by the application of chelants (P <0.05). The concentrations of Cd in the shoots were increased significantly by addition of all chelants. As a result, the Cd accumulation of S. orientalis under treatments with higher dosages of the three chelants on the 80th day were 1.40–2.10-fold and 1.12–1.25-fold compared to control at 10 and 100mgkg−1 Cd, respectively. Under the addition of 2mmolkg−1 NTA on the 80th day, the highest metal extraction ratio reached 1.2% and 0.4% at 10 and 100mgkg−1 Cd soils, respectively. Therefore, the applications of EDDS, NTA and APAM may provide more efficient choices in chemical-enhanced phytoextraction. [Copyright &y& Elsevier]

Abstract: Identification of new higher yield cadmium (Cd)-hyperaccumulating cultivars from native species is key to the phytoremediation of Cd contaminated soils. A pot experiment with different soil Cd concentrations and a plot experiment at 28.44mgCdkg−1 were conducted to investigate Cd tolerance and accumulation by Siegesbeckia orientalis following a field survey. In the pot experiment, at Cd concentration of 150mgkg−1, S. orientalis grew normally and shoot biomass was not reduced significantly compared with the no Cd control. The activities of superoxide dismutase and catalase in roots and leaves, and peroxidase in leaves significantly increased with increasing soil Cd (P <0.05). The highest shoot Cd concentrations were 117.48, 192.92 and 77.10mgkg−1, in the field survey, pot and plot experiments, respectively and their corresponding accumulations were 6.762mgplant−1, 4.134mgpot−1 and 18.45mgm−2. All Cd bioconcentration factors and translocation factors were more than 1.0. Therefore, S. orientalis is a Cd-accumulator with hyperaccumulating ability. [Copyright &y& Elsevier]

Abstract: Restored engineering leads to the sequestration of soil organic carbon (SOC), including labile and refractory fractions in the soils of the degraded lands. This study was conducted to estimate the changes in SOC fractions in the topsoil of croplands, horticultural plots and afforestation areas from degraded lands in the Liusha River Valley, Sichuan. The cover and shoot biomass of plants, soil thickness and bulk density in the restored lands differed significantly from those of the degraded lands (P <0.05). When compared with the degraded lands, the concentrations of SOC fractions in restored lands were substantially enhanced (P <0.05). Among the three restoration classes, the concentrations of total organic carbon (TOC), dichromate oxidizable carbon, permanganate oxidizable carbon (POXC) and water-soluble carbon (WSOC) were higher in the croplands and afforestation areas than in the horticultural plots (P <0.05), while the humic carbon and humic acid carbon (HAC) were higher in the afforestation areas than in the horticultural plots (P <0.05). The SOC fraction concentrations displayed significant relationships with the cover and shoot biomass of plants, elevation, soil thickness and bulk density (P <0.05), except that WSOC showed no relationship with elevation (P >0.05). Additionally, POXC, WSOC and HAC represented 14.62–16.17, 0.91–1.15 and 7.73–8.66% of the TOC of the restored soils, respectively, and improved significantly during the restoration process. Therefore, these fractions can be considered indicators of changes in restoration-induced soil quality and sensitivity to environmental factors and restoration practices. [Copyright &y& Elsevier]

Abstract: Because of its toxicity to animals and humans, cadmium (Cd) is an environmentally important heavy metal. Consequently, researchers are interested in using hyperaccumulator and accumulator plants to decontaminate Cd polluted soils. To investigate Cd tolerance, uptake and accumulation by Amaranthus hybridus L., Cd concentration gradients were applied to a soil (at rates of 0, 30, 60, 90, 120, 150 and 180mgkg−1) and hydroponics solutions (at rates of 0, 5, 10, 15, 20, 30, and 40mgL−1) following a field survey. A. hybridus grew normally at added Cd concentrations≤90mgkg−1 and≤20mgL−1 in the soil culture and in the hydroponics solutions, respectively. In the hydroponics solutions, peroxidase activity showed a quadratic relationship and catalase activity changed irregularly with increasing Cd concentrations. The highest Cd concentration and accumulation in shoots were 241.56mgkg−1 and 1006.95μgpot−1 in the soil culture, and 354.56mgkg−1 and 668.42μgpot−1 in the hydroponics experiment. Bioconcentration factors in soil culture and hydroponics solutions were 0.58–1.22 and 5.18–17.55, and translocation factors were 0.64–1.50 and 0.33–0.92, respectively. A. hybridus has potential phytoremediation capability in Cd polluted soils. [Copyright &y& Elsevier]

Photosynthesis is not only a primary generator of reactive oxygen species (ROS) but also a component of plant defence. To determine the relationships among photosynthesis, ROS, and defence responses to powdery mildew in wheat, we compared the responses of the Pm40-expressing wheat line L658 and its susceptible sister line L958 at 0, 6, 12, 24, 48, and 72 h post-inoculation (hpi) with powdery mildew via analyses of transcriptomes, cytology, antioxidant activities, photosynthesis, and chlorophyll fluorescence parameters. The results showed that H2O2 accumulation in L658 was significantly greater than that in L958 at 6 and 48 hpi, and the enzymes activity and transcripts expression of peroxidase and catalase were suppressed in L658 compared with L958. In addition, the inhibition of photosynthesis in L658 paralleled the global downregulation of photosynthesis-related genes. Furthermore, the expression of the salicylic acid-related genes non-expressor of pathogenesis related genes 1 (NPR1), pathogenesis-related 1 (PR1), and pathogenesis-related 5 (PR5) was upregulated, while the expression of jasmonic acid- and ethylene-related genes was inhibited in L658 compared with L958. In conclusion, the downregulation of photosynthesis-related genes likely led to a decline in photosynthesis, which may be combined with the inhibition of peroxidase (POD) and catalase (CAT) to generate two stages of H2O2 accumulation. The high level of H2O2, salicylic acid and PR1 and PR5 in L658 possible initiated the hypersensitive response. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in soils poses a serious threat to microorganisms, which play important roles in soil biogeochemical process. However, the key fractions of heavy metals affecting soil microorganisms are still unclear. In this study, DNA sequencing, redundancy and variance partition analysis were performed to investigate the combined effects of heavy metal fractions and soil chemical properties on microbial communities in Pb, Cd, and Zn co-contaminated soils. The results showed that long-term exposure of microorganisms to these metals changed the richness, diversity, and structure of their communities. The bacterial and fungal Chao richness indexes decreased, but only the bacterial Shannon index improved with increasing metal concentrations. Moreover, soil available potassium and acid-extractable Pb made the greatest contributions to variations in the bacterial community structure, while soil pH, water-extractable Pb and Zn were the dominant factors influencing the fungal community structure. In addition, Marmoricola , Nocardioides , and Gibberella were sensitive to these metals. Overall, the effects of different heavy metal fractions on microorganisms varied significantly, and these metal fractions together with soil chemical properties determined the soil microbial communities. Unlabelled Image • Acid-extractable Pb was the main fraction affecting bacterial community structure. • Water-extractable Pb and Zn were dominant factors shaping fungal community. • Heavy metals together with soil chemical properties determined microbial communities. • Marmoricola , Nocardioides and Gibberella could be considered as bioindicators. [ABSTRACT FROM AUTHOR]

Wheat powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) is considered a major wheat leaf disease in the main wheat producing regions of the world. Although many resistant wheat cultivars to this disease have been developed, little is known about their resistance mechanisms. Pm40 is a broad, effective resistance gene against powdery mildew in wheat line L699. The aim of this study was to investigate the resistance proteins after Bgt inoculation in wheat lines L699, Neimai836, and Chuannong26. Neimai836 with Pm21 was used as the resistant control, and Chuannong26 without any effective Pm genes was the susceptible control. Proteins were extracted from wheat leaves sampled 2, 4, 8, 12, and 24 h after Bgt inoculation, separated by two-dimensional electrophoresis, and stained with Coomassie brilliant blue G-250. The results showed that different proteins were upregulated and downregulated in three wheat cultivars at different time points. For the wheat cultivar L699, a total of 62 proteins were upregulated and 71 proteins were downregulated after Bgt inoculation. Among these, 46 upregulated proteins were identified by mass spectrometry analysis using the NCBI nr database of Triticum. The identified proteins were predicted to be associated with the defense response, photosynthesis, signal transduction, carbohydrate metabolism, energy pathway, protein turnover, and cell structure functions. It is inferred that the proteins are not only involved in defense response, but also other physiological and cellular processes to confer wheat resistance against Bgt. Therefore, the resistance products potentially mediate the immune response and coordinate other physiological and cellular processes during the resistance response to Bgt. The lipoxygenase, glucan exohydrolase, glucose adenylyltransferasesmall, phosphoribulokinase, and phosphoglucomutase are first reported to be involved in the interactions of wheat-Bgt at early stage. The further study of these proteins will deepen our understanding of their detailed functions and potentially develop more efficient disease control strategies. [ABSTRACT FROM AUTHOR]