摘要：
Synergistic effect of dimethomorph (DIM) and pyrimethanil (PYM) was evaluated using the Wadley method and the molecular mechanism of the antifungal effects of the combined treatment was systematically investigated. DIM+PYM had a synergistic effect on Phytophthora capsici, with the synergistic effect being observed at 5:1, at which the synergy coefficient was 1.8536. The mycelia of the pathogen treated with DIM+PYM were branched, uneven in thickness, and swollen. Moreover, scanning electron microscopy (SEM) revealed that DIM+PYM caused mycelium breaks, swelling, and apex enlargement, while transmission electron microscopy (TEM) revealed structural damage, cavities, and cell membrane morphological abnormalities. DIM+PYM inhibited the growth of mycelia, destroyed the cell membrane, interfered with energy metabolism, reduced protein and sugar content. Additionally, the transcriptome and metabolome of fungi treated with DIM+PYM changed significantly; specifically, there were 1571 differentially expressed genes and 802 differential metabolites. DIM+PYM may mainly damage the cell membrane, energy, protein, soluble sugar pathways.
摘要：
Phenazine-1-carboxylic acid (PCA) is a new type of agrochemical used to prevent plant diseases, but its effects on aquatic organisms are unclear. To comprehensively assess the impacts of PCA for aquatic organisms and its associated environmental risks, this study investigated, taking zebrafish as the research object, the toxicological mechanism of PCA by means of optical microscopy, hematoxylin and eosin (HE) staining, ultrastructural observation, physiological and biochemical testing, transcriptome sequencing, metabolome analysis, fluorescence quantitative PCR and molecular simulation. The results indicated that PCA was detrimental to zebrafish embryos, larvae and adults, with LC50 values at 96 h of 3.9093 mg/L, 8.5075 mg/L, and 13.6388 mg/L, respectively. PCA caused abnormal spontaneous movement, slowed the heart rate, delayed hatching, shortened the body length, slowed growth, and caused malformations. PCA mainly affected the brain, liver, heart, and ovaries. PCA distorted cell morphology, damaged mitochondrial membranes, disintegrated mitochondrial ridges, and dissociated nuclear membranes. PCA inhibited the enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX), decreased the malondialdehyde (MDA) content and disrupted antioxidant effects. The results of omics studies confirmed that PCA interfered with the transcriptional and metabolic network of zebrafish, downregulating most genes and metabolites. PCA mainly affected functions related to mitochondrial steroids, lipids, sterols, oxidoreductase activity and pathways involving cofactors, steroids, porphyrin, cytochromes, which specifically bound to targets such as panx3, agmat, and ace2. PCA was moderately toxic to zebrafish, and its usage should be strictly controlled to reduce toxic effects on aquatic organisms. The results of this study provide a new insights for ecotoxicology research.
期刊：
JOURNAL OF ECONOMIC ENTOMOLOGY,2023年116(2):574-583 ISSN：0022-0493
通讯作者：
Xuguo Zhou<&wdkj&>Xianhong Zhang
作者机构：
[Lu, Junjiao; Ren, Meifeng; Dong, Jinming; Li, Daqi; Yang, Jing; Zhang, Xianhong] Shanxi Agr Univ, Coll Plant Protect, Taiyuan, Peoples R China.;[Zhou, Xuguo] Hunan Agr Univ, Coll Plant Protect, Changsha, Peoples R China.;[Niu, Yanbing] Shanxi Agr Univ, Coll Life Sci, Taigu, Peoples R China.;[Zhang, Yuying] Univ Kentucky, Dept Entomol, Lexington, KY USA.
通讯机构：
[Xuguo Zhou] D;[Xianhong Zhang] C;Department of Entomology, University of Kentucky, Lexington, KY, USA <&wdkj&>College of Plant Protection, Shanxi Agricultural University, Taiyuan, China
关键词：
chitin;chitin synthase;insecticide;animal;biological pest control;larva;Lepidoptera;moth;procedures;Animals;Chitin;Chitin Synthase;Insecticides;Larva;Lepidoptera;Moths;Pest Control, Biological
摘要：
The black cutworm, Agrotis ipsilon (Hufnagel), a seasonal migrant and a prolific generalist, can feed on nearly all vegetables and grain crops, causing considerable economic impacts on a global scale. Given its cryptic nature, A. ipsilon management has been extremely challenging. Chitin synthase (CHS), a key enzyme involved in chitin biosynthetic pathway and crucially important for the growth and development of insects, is the molecular target of chitin synthesis inhibitors, a group of broad-spectrum insecticides that is compatible with Integrated Pest Management practices. In this study, we investigated the potential of targeting chitin synthases to control A. ipsilon. As a result, two chitin synthases, AiCHS1 and AiCHS2, were identified and cloned from A. ipsilon. The temporal-spatial distribution study showed that AiCHS1 was predominantly expressed at the pupal stage and most abundant among tissues of head capsule and integument, while AiCHS2 was mainly expressed at the sixth instar larval stage and tissues of foregut and midgut. RNAi-based functional study confirmed gene silencing caused significant reduction in the expression levels of the corresponding mRNA, as well as resulted in abnormal pupation and mortality, respectively. Furthermore, under the treatment of lufenuron, a chitin synthesis inhibitor, A. ipsilon responded with an elevated expression in AiCHS1 and AiCHS2, while larvae showed difficulty in shedding old cuticle, and a cumulative mortality of 69.24% at 48 h. In summary, chitin synthases are crucial for chitin biosynthesis in A. ipsilon and can be targeted for the control (e.g., RNAi-based biopesticides) of this devastating insect pest.
通讯机构：
[Zhihuai Liang] H;Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Hunan Agricultural Biotechnology Research Institute, Changsha, People’s Republic of China
通讯机构：
[Xiaogang Li] C;College of Plant Protection, Hunan Agricultural University, Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Changsha 410128, China
关键词：
Community structure;Methane;Network;Thifluzamide
摘要：
Thifluzamide is an effective agent for controlling rice sheath blight and has a long half-life in soil. However, the effects of thifluzamide on the abundance of microbes harboring methane-cycle genes and soil microbial community assembly patterns are not well known. Thus, we conducted a three-month indoor mesocosm experiment to ascertain the effects of thifluzamide (0.05, 0.5, and 5 mg kg(-1) soil; 0.05 mg kg(-1) soil being recommended) on bacterial and archaeal community structure and on the abundance of methanogen genes using two typical paddy soils: sandy soil from Hangzhou (HZ) and loam sandy soil from Jiansanjiang (JSJ). The effects of thifluzamide on soil microorganisms were related to soil type. In JSJ loam sandy soil, thifluzamide significantly increased bacterial α diversity after 7-30 d and archaeal α diversity at 30 and 60 d. In HZ sandy soil, however, α diversity did not change significantly. Network analysis showed that thifluzamide-treated soils possessed more complex networks with more total nodes and links, a higher average degree of connectivity, and more keystone species. Thifluzamide application increased the number of keystone species associated with methane production in both types of paddy soil. A relatively greater number of modules were significantly negatively correlated with mcrA abundance in the HZ T10 network, but more modules were positively correlated with mcrA abundance in the JSJ T100 network. The half-life of thifluzamide varied for the different doses, i.e., from 152.0 to 419.6 d. The results reveal that methane-cycle genes, soil microbiome assembly, and interactions among microbial species all change in response to thifluzamide stress.
通讯机构：
[Huang Huang; Can Chen] A;Authors to whom correspondence should be addressed.<&wdkj&>Hunan Rice Field Ecological Planting and Breeding Engineering Technology Research Center, Changsha 410128, China<&wdkj&>College of Agriculture, Hunan Agricultural University, Changsha 410128, China
关键词：
direct straw return;straw biochar returning;rice-duck co-culture;culm morphology;anatomy and lodging resistance
摘要：
<jats:p>Lodging has a negative effect on rice production and leads to a great loss in yield and quality. It is necessary to clarify the effects of straw return measures coupled with rice-duck co-culture on lodging and to explore a measure that can improve lodging resistance. A randomized block experiment with six treatments (rice monoculture (RNN), rice-duck co-culture (RND), direct straw return and rice monoculture (RSN), direct straw return coupled with rice-duck co-culture (RSD), straw carbon and rice monoculture (RBN), and straw carbon coupled with rice-duck co-culture (RBD)) was conducted to investigate the mechanism of the change in lodging resistance. RNN’s rice yield was 6258.02 kg ha−1. The yield of RND, RSN, RSD, and RBN increased by 15.51, 3.06, 10.23, and 1.59%, respectively, while RBD decreased by 5.01% relative to RNN. Direct straw return and straw biochar return coupled with rice-duck co-culture has both negative and positive effects on lodging resistance because of its properties. The stem’s mechanical properties were mainly decided by weight, length, plumpness, and culm anatomy. The increased bending moment at breaking, lodging strength, and bending strength with the RND, RSN, RSD, RBN, and RBD treatments increased, indicated an increase in lodging resistance. Our results clearly demonstrate that direct straw return and straw biochar return coupled with rice-duck co-culture could increase the lodging resistance. In total, rice-duck co-culture could increase the lodging resistance with a higher yield. Compared to straw biochar application, straw return can stabilize the yield and improve the lodging resistance of rice. Thus, direct straw return coupled with rice-duck co-culture should be explored for improving lodging resistance under the condition of ensuring yield.</jats:p>
期刊：
Archives of Microbiology,2022年204(8):455 ISSN：0302-8933
通讯作者：
Liang, Z.;Liu, E.
作者机构：
[Liu, Erming; Xiao, Jiling] Hunan Agr Univ, Coll Plant Protect, Changsha 410125, Peoples R China.;[Xiao, Jiling; Yang, Ke; Liang, Zhihuai] Hunan Agr Biotechnol Res Inst, Changsha 410125, Peoples R China.;[Wei, Lin; Tang, Yanying] Hunan Plant Protect Inst, Changsha 410125, Peoples R China.;[Zhang, Yi] Hunan Rice Res Inst, Changsha 410125, Peoples R China.
通讯机构：
[Erming Liu] C;[Zhihuai Liang] H;College of Plant Protection, Hunan Agricultural University, Changsha, China<&wdkj&>Hunan Agricultural Biotechnology Research Institute, Changsha, China
关键词：
Fusarium oxysporum;MAPKs;Protein kinase;Ime2
摘要：
Fusarium oxysporum f.sp. niveum is one of the most serious diseases impairing watermelon yield and quality. Inducer of meiosis 2 (Ime2) is the founding member of a family of serine/threonine protein kinases and plays important roles in yeasts and other filamentous fungi. In this study, we analyzed the functions of FoIme2, the ortholog of Saccharomyces cerevisiae Ime2 in F. oxysporum f.sp. niveum. The FoIme2-deleted mutants exhibited obvious morphological abnormalities, including slower vegetative growth, more branches in the edge hyphae and a reduction in conidia production. Compared to the wild type, the mutants were hypersensitive to the osmotic stressor NaCl but were more insensitive to the membrane stressor SDS. The deletion of FoIme2 also caused a reduction in pathogenicity. Transcriptional analysis revealed that FoIme2 acts downstream of FoOpy2 which is an upstream sensor of the MAPK kinase cascade. These results indicate that FoIme2 is important in the development and pathogenicity of F. oxysporum, and provide new insight for the analysis of the pathogenic mechanism of F. oxysporum.
摘要：
<jats:title>Abstract</jats:title><jats:p>The xenobiotic transcription factor cap ‘n’ collar isoform C (CncC) is considered the central regulator of antioxidant and detoxification genes. Previous research indicated that CncC regulates three‐phase enzymes responsible for insecticide resistance. In this study, the <jats:italic>SlituCncC</jats:italic> gene from <jats:italic>Spodoptera litura</jats:italic> was obtained and characterized. Quantitative polymerase chain reaction (qPCR) analysis showed that <jats:italic>SlituCncC</jats:italic> was expressed in all developmental stages and tissues, but was highly expressed in 3rd‐ and 4th‐instar larvae, and in the Malpighian tubule, fat body, and midgut. In addition, <jats:italic>SlituCncC</jats:italic> was up‐regulated and more highly induced with indoxacarb treatment in the indoxacarb‐resistant strains compared with the susceptible strain. RNA interference‐mediated gene silencing of <jats:italic>SlituCncC</jats:italic> significantly increased mortality of <jats:italic>S.litura</jats:italic> when exposed to indoxacarb. Furthermore, comparative transcriptome analysis showed that 842 genes were down‐regulated and 127 genes were up‐regulated in <jats:italic>SlituCncC</jats:italic> knockdown <jats:italic>S. litura</jats:italic>. Further analysis indicated that 18 three‐phase enzymes were identified in the down‐regulated genes, of which seven were associated with indoxacarb resistance in <jats:italic>S. litura</jats:italic>. qPCR analysis confirmed that expression of six of these seven genes was consistent with RNA sequencing data. All six detoxification genes were induced by indoxacarb, and the expression patterns were similar to that of <jats:italic>SlituCncC</jats:italic>. Finally, the CncC–Maf binding site was predicted in all six gene promoters. This study indicates that the transcription factor <jats:italic>SlituCncC</jats:italic> may regulate multiple detoxification genes that mediate indoxacarb resistance in <jats:italic>S. litura</jats:italic>.</jats:p>
作者机构：
[Sun, Dan; Cheng, Jiaxu; Yang, Yuting; Xia, Jixing; Xie, Wen; Xu, Baoyun; Wu, Qingjun; Wang, Shaoli; Guo, Zhaojiang] Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China;College of Plant Protection, Hunan Agricultural University, Changsha 410128, China;[Han, Haolin; Zhang, Youjun] College of Plant Protection, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
通讯机构：
[Zhaojiang Guo] D;[Youjun Zhang] C;Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China <&wdkj&>College of Plant Protection, Hunan Agricultural University, Changsha 410128, China <&wdkj&>Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
通讯机构：
[Xiaogang Li] C;College of Plant Protection, Hunan Agricultural University, Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Changsha, China
关键词：
Carbon black;Liquid chromatography;Mass spectrometry;Dissipation rates;Field conditions;Graphitized carbon black;Kinetic modeling;Limit of quantitations;Provide guidances;Sensitive method;Ultra-high performance liquid chromatographies;Matrix algebra;black carbon;concentration (composition);crop residue;detection method;liquid chromatography;rice;straw;herbicide;pesticide residue;chemistry;high performance liquid chromatography;Oryza;procedures;tandem mass spectrometry;Chromatography, High Pressure Liquid;Herbicides;Oryza;Pesticide Residues;Tandem Mass Spectrometry
