Pesticide Biochemistry and Physiology最新文献

{"title":"The down-regulation of salivary protein gene expression by etofenprox partially contributed to reducing the risk of increased fecundity in the brown planthopper","authors":"Haoli Gao ,&nbsp;Xiaowei Yuan ,&nbsp;Tianshun He ,&nbsp;Zhen Zhang ,&nbsp;Jingting Wang ,&nbsp;Huihui Zhang ,&nbsp;Xumin Lin ,&nbsp;Zewen Liu","doi":"10.1016/j.pestbp.2024.106118","DOIUrl":"10.1016/j.pestbp.2024.106118","url":null,"abstract":"<div><p>Etofenprox is a pyrethroid insecticide that acts on the nervous system of insects. Due to its low toxicity to aquatic animals, it is permitted for use in controlling insect pests in rice fields. The brown planthopper (BPH), <em>Nilaparvata lugens,</em> a significant piercing-sucking pest feeding on rice exclusively, secretes various salivary components when feeding. Salivary proteins are essential for BPH feeding, but their response to etofenprox is not well understood. The application of etofenprox down-regulated the expression of 21 salivary protein genes, among which 9 genes (<em>NlShpa</em>, <em>Salivap 3</em>, <em>CA</em>, <em>NlSEF1</em>, <em>Nl12</em>, <em>NlHSC70–3</em>, <em>NlSP1</em>, <em>NlG14</em>, and <em>NlDNAJB9</em>) showed significant differences. Most differentially expressed genes are found important for BPH physiological processes, except <em>Nl12</em>. Here we found that silencing <em>Nl12</em> impeded ovary development, thereby inhibiting oocyte formation. The potential explanation was that <em>Nl12</em> was highly expressed in both salivary gland and ovary, and the ovary development abnormality may be due to the direct effect from expression reduction in ovary and/or indirect influence from expression reduction in salivary gland. Altogether, our findings provide a new insight into the mechanism of action of etofenprox on insect pests and explain part of the reason why etofenprox does not stimulate reproduction in BPH.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"205 ","pages":"Article 106118"},"PeriodicalIF":4.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Juvenile hormone inhibits lipogenesis of Spodoptera exigua to response to Bacillus thuringiensis GS57 infection","authors":"Bo Gao ,&nbsp;Yujie Ji ,&nbsp;Dan Zhao ,&nbsp;Yitong Yan ,&nbsp;Lu Zhang ,&nbsp;Han Wu ,&nbsp;Yifan Xie ,&nbsp;Qiuyu Shi ,&nbsp;Yao Wang ,&nbsp;Wei Guo","doi":"10.1016/j.pestbp.2024.106110","DOIUrl":"10.1016/j.pestbp.2024.106110","url":null,"abstract":"<div><p>The application of <em>Bacillus thuringiensis</em> (Bt) has brought environmental benefits and delayed resistance development of pests. Most studies focus on the Bt insecticidal activity against pests, however, the molecular mechanism of Bt on impairing the growth and development of <em>Spodoptera exigua</em> remains unknown. Here, we show that juvenile hormone (JH) inhibits the lipogenesis mediated by <em>fatty acid synthases</em> (<em>Fas</em>) of <em>S. exigua</em> in response to Bt infection. The weight and lipid accumulation of <em>S. exigua</em> larvae post Bt infection were less than those of larvae without Bt infection. We further demonstrated that Bt infection causes the JH titer with a significant increase, which downregulates the expression of lipogenesis-related genes, <em>SeFas3</em>, <em>SeFas4</em>, and <em>SeFas5</em>, resulting in the delayed development of <em>S. exigua</em> larvae<em>.</em> In addition, the expression levels of <em>SeFas</em> genes were regulated by <em>SeACC</em>, indicating that <em>SeFas</em> genes were modulated by multiple pathways. Our findings reveal that novel insights into the molecular mechanisms underlying the impaired development caused by Bt infection which can inform the development of strategies for the sustainable pest control in the future.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"205 ","pages":"Article 106110"},"PeriodicalIF":4.2,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myosuppressin signaling deficiency affects ovarian development via repression of 20-hydroxyecdysone biosynthesis in Grapholita molesta","authors":"Jie Cheng ,&nbsp;Jing-Kai Liu ,&nbsp;Tian-Li Wang ,&nbsp;Wei Wei ,&nbsp;Hui-Ming Xiang ,&nbsp;Xian-Wei Li ,&nbsp;Rui-Yan Ma ,&nbsp;Zhi-Guo Zhao","doi":"10.1016/j.pestbp.2024.106116","DOIUrl":"10.1016/j.pestbp.2024.106116","url":null,"abstract":"<div><p>The steroid 20-hydroxyecdysone (20E) is crucial in regulating ovarian development. However, the neuropeptidergic mechanisms underlying ovarian development via 20E are underexplored. In this study, we investigated myosuppressin (MS) signaling in the dominant fruit pest <em>Grapholita molesta</em> and revealed that MS signaling is necessary for 20E biosynthesis during ovarian maturation. Pharmacological and molecular docking analyses confirmed that the GmMS mature peptide could activate its receptor GmMSR. Additionally, transcript expression analyses of <em>GmMS</em> and <em>GmMSR</em> showed different distribution patterns in adults. Notably, <em>GmMSR</em> was also detected in the ovaries of sexually mature females. RNAi-mediated dysfunction of <em>GmMS</em> or <em>GmMSR</em> specifically decreased fertility in females. Furthermore, <em>GmMS</em> or <em>GmMSR</em> knockdown decreased vitellogenin synthesis and uptake, thereby delaying ovarian development. RNA-seq, gene expression validation, and hormone quantification further revealed that GmMS signaling depletion blocked 20E biosynthesis in the ovary. Finally, exogenous MS rescued most dsGmMS<em>-</em> or dsGmMSR-induced ovarian defects and 20E titers. These results suggest that MS/MSR-to-20E signaling regulates ovarian development through vitellogenesis, providing a new perspective on the development of neuroendocrine targets that suppress pest field populations.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"205 ","pages":"Article 106116"},"PeriodicalIF":4.2,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trichoderma harzianum TIND02 upregulates the expression of pathogenesis-related genes and enzymes and enhances gray blight resistance in tea","authors":"Abhay K. Pandey ,&nbsp;Shivanand Yadav ,&nbsp;Mahesh K. Samota ,&nbsp;Harshit K. Sharma ,&nbsp;Somnath Roy","doi":"10.1016/j.pestbp.2024.106115","DOIUrl":"10.1016/j.pestbp.2024.106115","url":null,"abstract":"<div><p>The gray blight incited by <em>Pestalotiopsis</em> and allied genera is a prevalent disease affecting tea cultivation, and managing it with <em>Trichoderma</em> spp. is an alternative to synthetic fungicides. Plants modify their arsenal system against pathogens when they are exposed to <em>Trichoderma</em> spp., which produces proteins and enzymes associated with pathogenesis. Understanding the expression pattern of defense-related markers will help in developing gray blight resistance tea cultivars. Thus, this study intended to induce resistance against gray blight in tea by <em>Trichoderma harzianum</em> TIND02. For this, a total of eight <em>Trichoderma</em> isolates originated from organic tea rhizospheres were characterized and evaluated for their efficacy. Dual culture test revealed isolate TIND02 as the most potential candidate with 74.6% inhibitory activity against gray blight pathogen <em>Pseudopestalotiopsis theae</em>. Molecular characterization based on ITS and <em>tef-1 alpha</em> genes confirmed isolate TIND02 as <em>T. harzianum</em>. Scanning electron microscopic study showed the mycoparasitic nature of <em>T. harzianum</em> TIND02 (TH-TIND02) to <em>Ps. theae</em>. The ethyl acetate extract of TH-TIND02 at 100 and 200 μg mL⁻¹ showed potential inhibitory activity (&gt;69.9%) against <em>Ps. theae</em> which confirmed the presence of higher volatile metabolites. Gas chromatography–Mass spectrometry study revealed that ethyl acetate extract of TH-TIND02 was composed of 21 major and minor volatile organic compounds with acetamide, 2, 2, 2-trifluoro-N, N-bis trimethyIsilyl–C (94.74%) as a major component. The isolate also produced chitinase, cellulase, β-1, 3 glucanase, and protease hydrolytic enzymes. Nursery experiments revealed that 2% and 5% doses (2 × 10⁶ CFU mL⁻¹) of TH-TIND02 significantly reduced respective 65.0% and 70.0% disease severity over control with improved plant growth. Besides, expressions of defense-related enzymes (chitinase, pHenolics, peroxidase, phenylalanine ammonia lyase, <em>β</em>-1, 3-glucanase, and polyphenol oxidase) and pathogenesis-related genes (<em>chitinase</em> and <em>β-1, 3-glucanase</em>) due to TH-TIND02 were determined. The secretion of defense-related enzymes was highly upregulated in plants applied with TH-TIND02 followed by <em>Ps. theae</em> inoculation compared to controls. The RT-qPCR analysis showed that the expression of both genes in co-inoculated plants was two-fold higher than in control after 21-day post incubation. These results suggest that TH-TIND02 application reduced gray blight severity by elevated enzyme activity and overexpressed pathogenesis-related genes in tea plants which offer for its eco-friendly and sustainable use as a bio-fungicide in tea gardens.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"205 ","pages":"Article 106115"},"PeriodicalIF":4.2,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142161541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design, synthesis, and evaluation of novel isoxazoline derivatives containing 2-phenyloxazoline moieties as potential insecticides","authors":"Xiangmin Song ,&nbsp;Haojing Wang ,&nbsp;Yongchao Gao ,&nbsp;Kaijie Xu ,&nbsp;Zheng Sun ,&nbsp;Chen Zhao ,&nbsp;Guangkai Yao ,&nbsp;Hanhong Xu","doi":"10.1016/j.pestbp.2024.106109","DOIUrl":"10.1016/j.pestbp.2024.106109","url":null,"abstract":"<div><p>Isoxazoline insecticides have shown broad-spectrum insecticidal activity against a variety of insect pests. However, the high toxicity of isoxazoline compounds towards honeybees restricts their application in crop protection. To mitigate this issue, a series of isoxazoline derivatives containing 2-phenyloxazoline were designed and synthesized. Bioassays revealed that several compounds exhibited promising insecticidal activities against <em>Plutella xylostella</em>, with <strong>G28</strong> showing particularly excellent insecticidal activity, reflected by an LC₅₀ value of 0.675 mg/L, which is comparable to that of fluxametamide (LC₅₀ = 0.593 mg/L). Furthermore, <strong>G28</strong> also exhibited effective insecticidal activity against <em>Solenopsis invicta</em>. Importantly, bee toxicity experiments indicated that <strong>G28</strong> had significantly lower acute oral toxicity (LD₅₀ = 2.866 μg/adult) compared to fluxametamide (LD₅₀ = 1.083 μg/adult) and fluralaner (LD₅₀ = 0.022 μg/adult), positioning it as a promising candidate with reduced toxicity to bees. Theoretical simulation further elucidated the reasons for the selective differences in the ability of isoxazoline to achieve higher insecticidal activity while maintaining lower bee toxicity. This research suggests that isoxazoline compounds containing 2-phenyloxazoline group hold potential as new insecticide candidates and offers insights into the development of novel isoxazoline insecticides with both high efficacy and environmental safety.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"204 ","pages":"Article 106109"},"PeriodicalIF":4.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The development of silk glands and transcriptome aberration induced by cyantraniliprole in Bombyx mori","authors":"Xiaohan Liu ,&nbsp;Ruinan Qi ,&nbsp;Fanchi Li ,&nbsp;Minjin Han ,&nbsp;Bing Li ,&nbsp;Haina Sun","doi":"10.1016/j.pestbp.2024.106111","DOIUrl":"10.1016/j.pestbp.2024.106111","url":null,"abstract":"<div><p><em>Bombyx mori</em> is an insect species of great economic importance, and its silk gland is a vital organ for the synthesis and secretion of silk protein. However, long-term artificial domestication of <em>B. mori</em> has resulted in high sensitivity to chemical toxins, especially insecticides. Cyantraniliprole (Cya), a second-generation ryanodine receptor modulator insecticide, is widely utilized in agriculture for pest control. In this study, the impact of Cya toxicity on the development of silk glands in the 5th instar larvae of <em>B. mori</em> was assessed using Cya LC₅, LC₁₀ and LC₂₀, as well as a starvation treatment group for comparison. Short-term exposure (24 h) to different concentrations of Cya resulted in delayed development of silk glands in <em>B. mori</em>. Meanwhile, the body weight, silk gland weight, silk gland index and cocoon quality were significantly reduced in a concentration-dependent manner, except for the Cya LC₅ treatment. Histopathological and ultrastructural analysis revealed that Cya LC₁₀ induced disruption of the nuclear membrane and endoplasmic reticulum in the posterior silk gland (PSG) cells, leading to the formation of intracellular vacuoles. Transcriptome sequencing of PSGs identified 2152 genes that were differentially expressed after exposure to Cya LC₁₀, with 1153 down-regulated genes and 999 up-regulated genes. All differentially expressed genes were subjected to functional annotation using gene ontology and Kyoto encyclopedia of genes and genomes database, and it was found that protein synthesis-related pathways were significantly enriched, with the majority of genes being down-regulated. Furthermore, the transcription levels of genes involved in “protein processing in endoplasmic reticulum”, “protein export”, “proteasome” and “DNA replication” were quantified using qRT-PCR. Our findings suggested that short-term exposure to Cya LC₁₀ resulted in disruption of DNA replication, as well as protein transport, processing and hydrolysis in the PSG cells of <em>B. mori</em>. The results of this study provide a theoretical foundation for the safe utilization of Cya in sericulture production.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"204 ","pages":"Article 106111"},"PeriodicalIF":4.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design the fusion double-strand RNAs to control two global sap-sucking pests","authors":"Qin-Qin Xu ,&nbsp;Feng Shang ,&nbsp;Si-Ying Feng ,&nbsp;Qian-Ping Xie ,&nbsp;Wei Zhang ,&nbsp;Zi-Guo Wang ,&nbsp;Jin-Jun Wang","doi":"10.1016/j.pestbp.2024.106114","DOIUrl":"10.1016/j.pestbp.2024.106114","url":null,"abstract":"<div><p>RNA interference (RNAi) is an effective pest management strategy through silencing the crucial genes in target organisms. However, the effectiveness of targeting a single gene is often limited by the silencing efficiency due to tissue or developmental stage-specific gene expression. Moreover, multiple pests often infest the same crop simultaneously under current ecological conditions. Therefore, a combined strategy of “targeting multiple genes” and “controlling multiple pests” is expected to yield better management results. In this study, homologous genes from two globally sap-sucking pests, the peach aphid (<em>Myzus persicae</em>) and the whitefly (<em>Bemisia tabaci</em>), were screened on a genome-wide scale. Subsequently, RNAi bioassays showed silencing the genes (<em>MpAbd-A</em>, <em>MpH3</em>, <em>MpRpL27a</em>, and <em>MpScr</em>) exhibited high mortalities in both species, which were further selected for designing fusion dsRNAs. These fusion dsRNAs resulted in higher mortalities in both pests than single gene silencing and posed a minimal off-target risk to the predator ladybeetle (<em>Propylaea japonica</em>) based on the sequence analysis. Finally, the tobacco plants expressing the fusion dsRNAs through virus-induced gene silencing (VIGS) technology enhanced the resistance to both pests. In conclusion, this study proposes a novel RNAi-based approach for managing two sap-sucking pests simultaneously.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"205 ","pages":"Article 106114"},"PeriodicalIF":4.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zeta class glutathione S-transferase is involved in phoxim tolerance and is potentially regulated by the transcription factor CncC in Agrotis ipsilon (Lepidoptera: Noctuidae)","authors":"Su Liu ,&nbsp;Hao-Lan Yang ,&nbsp;Yu Gao ,&nbsp;Xin-Yi Liu ,&nbsp;Wen Shi ,&nbsp;Dong-Yang Liu ,&nbsp;Jia-Min Yu ,&nbsp;Mao-Ye Li","doi":"10.1016/j.pestbp.2024.106106","DOIUrl":"10.1016/j.pestbp.2024.106106","url":null,"abstract":"<div><p>The black cutworm, <em>Agrotis ipsilon</em> (Lepidoptera: Noctuidae), is an important agricultural pest. Phoxim is an organophosphate insecticide that has been widely used to control <em>A. ipsilon</em>. The extensive application of phoxim has resulted in a reduction in phoxim susceptibility in <em>A. ipsilon</em>. However, the molecular mechanisms underlying phoxim tolerance in <em>A. ipsilon</em> remain unclear. In this work, we report the involvement of AiGSTz1, a zeta class glutathione <em>S</em>-transferase, in phoxim tolerance in <em>A. ipsilon</em>. Exposure to a sublethal concentration (LC₅₀) of phoxim dramatically upregulated the transcription level of the <em>AiGSTz1</em> gene in <em>A. ipsilon</em> larvae, and this upregulation might be caused by phoxim-induced oxidative stress. The recombinant AiGSTz1 protein expressed in <em>Escherichia coli</em> was able to metabolize phoxim. Furthermore, AiGSTz1 displayed antioxidant activity to protect against oxidative stress. Knockdown of <em>AiGSTz1</em> by RNA interference significantly increased the mortality rate of <em>A. ipsilon</em> larvae in response to phoxim. In addition, the transcription factor AiCncC can bind to the cap ‘n’ collar isoform C: muscle aponeurosis fibromatosis (CncC:Maf) binding site in the putative promoter of the <em>AiGSTz1</em> gene. Silencing of <em>AiCncC</em> resulted in a dramatic downregulation of <em>AiGSTz1</em>. These results indicated that AiGSTz1 is involved in phoxim tolerance and is potentially regulated by AiCncC. These findings provide valuable insights into the defense mechanisms used by <em>A. ipsilon</em> against phoxim.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"204 ","pages":"Article 106106"},"PeriodicalIF":4.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The biological activity of bacterial rhamnolipids on Arabidopsis thaliana and the cyst nematode Heterodera schachtii is linked to their molecular structure","authors":"Sandra Bredenbruch ,&nbsp;Conrad Müller ,&nbsp;Henry A. Nvenankeng ,&nbsp;Lukas Schröder ,&nbsp;Antonia C. Zeisel ,&nbsp;Rainier C. Medina ,&nbsp;Till Tiso ,&nbsp;Lars M. Blank ,&nbsp;Florian M.W. Grundler ,&nbsp;A. Sylvia S. Schleker","doi":"10.1016/j.pestbp.2024.106103","DOIUrl":"10.1016/j.pestbp.2024.106103","url":null,"abstract":"<div><p>Rhamnolipids (RLs) are amphiphilic compounds of bacterial origin that offer a broad range of potential applications as biosurfactants in industry and agriculture. They are reported to be active against different plant pests and pathogens and thus are considered promising candidates for nature-derived plant protection agents. However, as these glycolipids are structurally diverse, little is known about their exact mode of action and, in particular, the relation between molecular structure and biological activity against plant pests and pathogens.</p><p>Engineering the synthesis pathway in recombinant <em>Pseudomonas putida</em> strains in combination with advanced HPLC techniques allowed us to separately analyze the activities of mixtures of pure mono-RLs (mRLs) and of pure di-RL (dRLs), as well as the activity of single congeners. In a model system with the plant <em>Arabidopsis thaliana</em> and the plant-parasitic nematode (PPN) <em>Heterodera schachtii</em> we demonstrate that RLs can significantly reduce infection, whereas their impact on the host plant varied depending on their molecular structure. While mRLs reduced plant growth even at a low concentration, dRLs showed a neutral to beneficial impact on plant development. Treating plants with dRLs triggered an increased reactive oxygen species (ROS) production, indicating the activation of stress-response signaling and possibly plant defense. Pretreatment of plants with mRLs or dRLs prior to application of flagellin (flg22), a known ROS inducer, further increased the ROS response to flg22. While dRLs stimulated an elevated flg22-induced ROS peak, a pretreatment with mRLs resulted in a prolonged synthesis of ROS indicating a generally elevated stress level. Neither mRLs nor dRLs induced the expression of plant defense marker genes of salicylic acid, jasmonic acid, and ethylene pathways.</p><p>Detailed studies on dRLs revealed that even high concentrations up to 755 ppm of these molecules have no lethal impact on <em>H. schachtii</em> infective juveniles. Infection assays with individual dRL congeners showed that the C10-C8 acyl chained dRL was the only congener without effect, while dRLs with C10-C12 and C10-C12:1 acyl chains were most efficient in reducing nematode infection even at concentrations below 2 ppm. As determined by phenotyping and ROS measurements, <em>A. thaliana</em> reacted more sensitive to long-chained dRLs in a concentration-dependent manner.</p><p>Our experiments show a clear structure-activity relation for the effect of RLs on plants. In conclusion, functional assessment and analysis of the mode of action of RLs in plants and other organisms require careful consideration of their molecular structure and composition.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"204 ","pages":"Article 106103"},"PeriodicalIF":4.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0048357524003365/pdfft?md5=dc9ea41e9f56e9389b70aab6c7abdcc6&pid=1-s2.0-S0048357524003365-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142135807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic resistance mechanism to glufosinate in Eleusine indica","authors":"Tianhong Lei ,&nbsp;Tangqi Feng ,&nbsp;Lei Wang ,&nbsp;Xiangrui Yuan ,&nbsp;Lan Wu ,&nbsp;Biao Wu ,&nbsp;Jie Du ,&nbsp;Jianhong Li ,&nbsp;Hongju Ma","doi":"10.1016/j.pestbp.2024.106083","DOIUrl":"10.1016/j.pestbp.2024.106083","url":null,"abstract":"<div><p><em>Eleusine indica</em> is one of the most troublesome weeds in farmland worldwide, especially in Citrus Orchard of China. Glufosinate, as an efficient non-selective broad-spectrum herbicide, has been widely utilized for the control of <em>E. indica</em> in Citrus Orchard. The <em>E. indica</em> resistant population (R) was collected from a Citrus Orchard in Yichang City in Hubei province, China. Bioassay experiments showed that the R plants exhibited 3-fold resistance to glufosinate compared with the <em>E. indica</em> susceptible population (S). No known glutamine synthetase (<em>GS</em>) gene mutation associated with glufosinate resistance was found in R plants. And there was also no significant difference in GS activity between R and S plants. Those results indicated that the resistance to glufosinate in R did not involve target-site resistance. However, glutathione <em>S</em>-transferase (GST) inhibitor 4-chloro-7-nitrobenzoxadiazole (NBD-Cl) plus glufosinate gave a better control of R plants compared with glufosinate treatment alone. Moreover, both before and after glufosinate treatment, the GST activity in R plants was significantly higher than that in S plants. By RNA-seq, the expression of <em>GSTU6</em> and <em>GST4</em> up-regulated in R plants relative to S plants with or without glufosinate treatment. They were also significantly up-regulated expression in <em>E. indica</em> field resistant populations compared with S population. In summary, the study elucidated that R plants developed metabolic resistance to glufosinate involving GST. And <em>GSTU6</em> and <em>GST4</em> genes may play an important role in this glufosinate metabolic resistance. The research results provide a theoretical basis for a deeper understanding of resistance mechanism to glufosinate in <em>E. indica</em>.</p></div>","PeriodicalId":19828,"journal":{"name":"Pesticide Biochemistry and Physiology","volume":"204 ","pages":"Article 106083"},"PeriodicalIF":4.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142095710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}