摘要：
The excessive use of chemical herbicides has resulted in evolution of herbicide-resistant weeds. Cytochrome P450 monooxygenases (P450s) are vital detoxification enzymes for herbicide-resistant weeds. Herein, we confirmed a resistant (R) Polypogon fugax population showing resistance to quizalofop-p-ethyl, acetolactate synthase (ALS)-inhibiting herbicide pyroxsulam, and several other ACCase (acetyl-CoA carboxylase)-inhibiting herbicides. Molecular analysis revealed no target-site gene mutations in the R population. Foliar spraying with malathion clearly reversed the quizalofop-p-ethyl phytotoxicity. Higher level of quizalofop-p-ethyl degradation was confirmed in the R population using HPLC analysis. Subsequently, RNA-Seq transcriptome analysis indicated that the overexpression of CYP89A2 gene appeared to be responsible for reducing quizalofop-p-ethyl phytotoxicity. The molecular docking results supported a metabolic effect of CYP89A2 protein on most herbicides tested. Furthermore, we found that low doses of herbicides stimulated the rhizosphere enzyme activities in P. fugax and the increase of rhizosphere dehydrogenase of R population may be related to its resistance mechanism. In summary, our research has shown that metabolic herbicide resistance mediated by CYP89A2, contributes to quizalofop-p-ethyl resistance in P. fugax.
通讯机构：
[Lu, YB ; Zhang, ZJ] Z;Zhejiang Acad Agr Sci, Inst Plant Protect & Microbiol, State Key Lab Managing Biot & Chem Threats Qual &, Hangzhou 310021, Peoples R China.
摘要：
As an economically important insect pest, the flower thrips Frankliniella intonsa (Trybom) causes great damage to host plants by directly feeding and indirectly transmitting various pathogenic viruses. The lack of a well-assembled genomic resource has hindered our understanding of the genetic basis and evolution of F. intonsa. In this study, we used Oxford Nanopore Technology (ONT) long reads and High-through chromosome conformation capture (Hi-C) linked reads to construct a high-quality reference genome assembly of F. intonsa, with a total size of 225.5 Mb and a contig N50 of 3.37 Mb. By performing the Hi-C analysis, we anchored 91.68% of the contigs into 15 pseudochromosomes. Genomic annotation uncovered 17,581 protein-coding genes and identified 20.09% of the sequences as repeat elements. BUSCO analysis estimated over 98% of genome completeness. Our study is at the first time to report the chromosome-scale genome for the species of the genus Frankliniella. It provides a valuable genomic resource for further biological research and pest management of the thrips.
摘要：
Megalurothrips usitatus (Bagnall) is a destructive pest of legumes, such as cowpea. The biology, population dynamics and control strategies of this pest have been well studied. However, the lack of a high-quality reference genome for M. usitatus has hindered the understanding of key biological questions, such as the mechanism of adaptation to feed preferentially on high-protein host plants and the resistance to proteinase inhibitors (PIs). In this study, we generated a high-resolution chromosome-level reference genome assembly (247.82 Mb, 16 chromosomes) of M. usitatus by combining Oxford Nanopore Technologies (ONT) and Hi-C sequencing. The genome assembly showed higher proportions of GC and repeat content compared to other Thripinae species. Genome annotation revealed 18,624 protein-coding genes, including 4613 paralogs that were preferentially located in TE-rich regions. GO and KEGG enrichment analyses of the paralogs revealed significant enrichment in digestion-related genes. Genome-wide identification uncovered 506 putative digestion-related enzymes; of those, proteases, especially their subgroup serine proteases (SPs), are significantly enriched in paralogs. We hypothesized that the diversity and expansion of the digestion-related genes, especially SPs, could be driven by mobile elements (TEs), which promote the adaptive evolution of M. usitatus to high-protein host plants with high serine protease inhibitors (SPIs). The current study provides a valuable genomic resource for understanding the genetic variation among different pest species adapting to different plant hosts.
通讯机构：
[Hualiang He] H;Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
摘要：
Cyproflanilide is a novel chemical that is already undergoing insecticide registration in China and has been categorized as a member of group 30 by the IRAC. Since it was first detected in 2019, the fall armyworm (FAW), Spodoptera frugiperda, has become a serious pest in China. Our laboratory and field efficacy trials indicated that cyproflanilide exhibits high larvicidal activity against FAW. However, the effect of cyproflanilide against FAW remains unknown. And it is worth exploring further before the cyproflanilide becomes commercially available. We found larvae exposed to cyproflanilide had significantly shorter body length and higher death rates compared to control larvae. Additionally, we found surviving larvae had a significantly longer developmental period compared to control larvae. The potential molecular mechanisms of cyproflanilide against FAW were investigated using comparative transcriptomic analyses on larval samples subjected to three insecticide treatments, including cyproflanilide and two other commonly used insecticides against FAW in China, chlorantraniliprole and avermectin. We found that several subunits of the γ-aminobutyric acid receptor (GABAR), a possible target protein of cyproflanilide, were significantly up-regulated at the transcriptional level during cyproflanilide-induced stress. Additionally, between the control and cyproflanilide-treated samples, we identified 131 differentially expressed genes (DEGs) associated with detoxification metabolism. Of these, we found four P450 genes that were significantly up-regulated under cyproflanilide stress but were not DEGs when exposed to chlorantraniliprole and avermectin, or 23 other pesticides from previous reports. Furthermore, we discovered an interesting gene aggregation region for insect cuticle proteins (CPs) on the 18th chromosome, which is likely related to FAW cross-resistance to cyproflanilide and avermectin. Our results contribute to a greater understanding of the mechanisms by which cyproflanilide affects FAW. Additionally, we identified the similarities and differences in transcriptomic profiling of FAW between the novel insecticide cyproflanilide and two other commonly used insecticides.
关键词：
South American tomato leafminer;invasive pest;Gelechiidae;genetic variability;dispersal avenue;population structure;cryptic forms
摘要：
Tuta absoluta (Meyrick) is a cosmopolitan invader and one of the most serious pests of tomato. This pest has expanded rapidly in China since it initially invaded Xinjiang in the northwest in 2017 and Yunnan in the south in early 2018. More complete knowledge of the migration patterns and genetic structure of this pest is important for implementing effective management strategies. To fill this knowledge gap, the COI gene of T. absoluta was sequenced based on nationwide routine monitoring. This study showed a new invasion into Gansu and Inner Mongolia, indicating ongoing expansion of this pest. Most populations of T. absoluta, both in China and worldwide, have high genetic homogeneity. Nevertheless, some degree of genetic variability was found in populations in southern China, especially in Yunnan. Two distinct haplogroups were distinguished, and clade A was predominant at the global level. The high level of sequence divergence indicated the possible existence of cryptic species. Furthermore, FST and analysis of molecular variance (AMOVA) revealed weak but significant differentiation between the Xinjiang northwestern group and southern group/subgroups and provides compelling evidence of the different dispersal avenues of T. absoluta in northwestern and southern China. T. absoluta likely established bridgehead populations in Yunnan and then spread rapidly throughout this province and neighboring territories in southern China. Knowledge regarding genetic diversity, population structure and dispersal pattern is valuable for improving management guidelines for this pest. Strict plant quarantines, local eradication and practical control measures are needed to solve the problem caused by T. absoluta.
摘要：
Eleusine indica has become a global nuisance weed and has evolved resistance to glufosinate. The involvement of target-site resistance (TSR) in glufosinate resistance in E. indica has been elucidated, while the role of nontarget-site resistance (NTSR) remains unclear. Here, we identified a glufosinate-resistant (R) population that is highly resistant to glufosinate, with a resistance index of 13.5-fold. Molecular analysis indicated that the resistance mechanism of this R population does not involve TSR. In addition, pretreatment with two known metabolic enzyme inhibitors, the cytochrome P450 (CYP450) inhibitor malathion and the glutathione S-transferase (GST) inhibitor 4-chloro-7-nitrobenzoxadiazole (NBD-Cl), increased the sensitivity of the R population to glufosinate. The results of subsequent RNA sequencing (RNA-seq) and quantitative real-time PCR (RT-qPCR) suggested that the constitutive overexpression of a GST gene (GSTU3) and three CYP450 genes (CYP94s and CYP71) may play an important role in glufosinate resistance. This study provides new insights into the resistance mechanism of E. indica.
摘要：
The ETHYLENE INSENSITIVE3-LIKE (EIL) family is one of the most important transcription factor (TF) families in plants and is involved in diverse plant physiological and biochemical processes. In this study, ten EIL transcription factors (CsEILs) in sweet orange were systematically characterized via whole-genome analysis. The CsEIL genes were unevenly distributed across the four sweet orange chromosomes. Putative cis-acting regulatory elements (CREs) associated with CsEIL were found to be involved in plant development, as well as responses to biotic and abiotic stress. Notably, quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that CsEIL genes were widely expressed in different organs of sweet orange and responded to both high and low temperature, NaCl treatment, and to ethylene-dependent induction of transcription, while eight additionally responded to Xanthomonas citri pv. Citri (Xcc) infection, which causes citrus canker. Among these, CsEIL2, CsEIL5 and CsEIL10 showed pronounced upregulation. Moreover, nine genes exhibited differential expression in response to Candidatus Liberibacter asiaticus (CLas) infection, which causes Citrus Huanglongbing (HLB). The genome-wide characterization and expression profile analysis of CsEIL genes provide insights into the potential functions of the CsEIL family in disease resistance.
摘要：
Nontarget-site resistance (NTSR) is a complex multigenic trait that is associated with the potential mechanisms of herbicide resistance which pose a serious threat to global crop protection. However, the NTSR mechanisms of Alopecurus japonicus, a malignant weed infesting wheat fields, are less characterized. In this study, we used RNA-sequencing transcriptome and enzyme activity detection to investigate the NTSR mechanisms and candidate genes involved in fenoxaprop-P-ethyl (FE) in a previously identified resistant population compared to the sensitive population of A. japonicus. Transcriptome analysis identified nine upregulated genes, which were constitutively overexpressed and upregulated by FE application in the resistant population, and the results were validated using quantitative real-time PCR. These genes including one cytochrome P450 monooxygenase (P450) gene (CYP75B4), one ATP-binding cassette (ABC) transporter gene (ABCG36), one laccase (LAC) gene (LAC15), one 9-cis-epoxycarotenoid dioxygenase (NCED) gene (NCED5), two purple acid phosphatase (PAP) genes (PAP4, PAP15), one sucrose phosphate synthase (SPS) gene (SPS3), one protein related to disease resistance gene (RGA3) and one immune protein gene (R1B-17). The activity assay of LAC, NCED, PAP and SPS revealed that the activities of these enzymes in the resistant population were significantly higher than those in the sensitive population at 0 h and after FE application at 12 h, 24 h and 72 h. Nevertheless, whether LAC, NCED, PAP and SPS genes were involved in herbicide metabolism needs to be further validated. Our results revealed that CYP, ABC transporter and LAC genes may participate in A. japonicus resistance. These genes identified in the present study provide new insights into the resistance mechanism of weeds in response to herbicide. Our study also implies the complexity of the NTSR mechanisms of weeds.
通讯机构：
[Gong Chen; Guo-Hua Huang] H;Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, Hunan, China<&wdkj&>College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, China
摘要：
Ascoviruses are insect-specific viruses thought to utilize the cellular apoptotic processes of host larvae to produce numerous virion-containing vesicles. In this study, we first determined the biochemical characteristics of ascovirus-infected, in vitro-cultured insect cells and the possible antiapoptotic capacity of ascovirus-infected insect cells. The results indicated that the ascovirus infection in the first 24h was different from the infection from 48h to the later infection stages. In the early infection stage, the Spodoptera exigua host cells had high membrane permeability and cleaved gasdermin D (GSDMD) but uncleaved Casp-6 (SeCasp-6). In contrast, the later infection stage had no such increased membrane permeability and had cleaved SeCasp-6. Four different chemicals were used to induce apoptosis at different stages of ascovirus infection: hydrogen peroxide (H(2)O(2)) and actinomycin D (ActD) had similar effects on the ascovirus-infected cells, whereas cMYC inhibitors and tumor necrosis factor alpha (TNF-α) plus SM-164 apoptosis inducers (T/S) had similar effects on infected cells. The former two inducers inhibited viral DNA replication in most situations, while the latter two inducers inhibited viral DNA replication in the early stage of infection but promoted viral DNA replication in the later infection stage. Furthermore, immunoblotting assays verified that T/S treatment could increase the expression levels of viral major capsid protein (MCP) and the host inhibitor of apoptosis protein (SeIAP). Coimmunoprecipitation assays revealed interaction between SeIAP and SeCasps, but this interaction was disturbed in ascovirus-infected cells. This study details the in vitro infection process of ascovirus, indicating the utilization of pyroptosis for antiapoptosis cytopathology. IMPORTANCE Clarifying the relationship between different types of viral infections and host regulation of cell death (RCD) can provide insights into the interaction between viruses and host cells. Ascoviruses are insect-specific viruses with apoptosis-utilizing-like infection cytopathology. However, RCD does not only include apoptosis, and while in our previous transmission electron microscopic observations, ascovirus-infected cells did not show typical apoptotic characteristics (unpublished data), in this study, they did show increased membrane permeability. These results indicate that the cytopathology of ascovirus infection is a complex process in which the virus manipulates host RCD. The RCD of insect cells is quite different from that of mammals, and studies on the former are many fewer than those on the latter, especially in the case of RCD in lepidopteran insects. Our results will lay a foundation for understanding the RCD of lepidopteran insects and its function in the process of insect virus infection.
摘要：
Brown planthopper Nilaparvata lugens, which can transmit rice ragged stunt virus, is a seri-ous and damaging pest to rice plants. Rice plants can protect themselves from the associated diseases of N.lugens by either suppressing or replacing N.lugens by releasing N.lugens infected by a special strain of Wolbachia wStri. The long-distance migration habit of N.lugens is one of the important precursors leading up to the large-scale occurrence of N.lugens. To study the effect of migration on the trans-mission of Wolbachia in N.lugens, a Wolbachia spreading dynamics model with migration of N.lugens between two patches is put forward. The existence and local stability conditions of equilibrium points of the system and its subsystems are obtained. Moreover, the effects of migration on the dynamic prop-erties and the control of N.lugens are analyzed; the results show that the system can exhibit a bistable phenomenon, and the migration can change the stability of equilibrium infected with wStri from stable to unstable. The quantitative control methods for the migration of the insect N.lugens are proposed, which provide a theoretical guidance for future field experiments. Lastly, we use the Markov chain Monte Carlo (MCMC) method to estimate the parameters of the wild N.lugens migration model based on limited observational data; the numerical simulation results show that migration can increase the quantity of N.lugens, which is consistent with the relevant experimental results.
摘要：
The Zizania latifolia is usually infected by the obligate parasitic fungus Ustilago esculenta to form an edible fleshy stem which is an aquatic vegetable called Jiaobai in China. The infection by the teliospore (T) strain of U. esculenta induces Z. latifolia forming gray fleshy stems, while the mycelia-teliospore (MT) strain of U. esculenta induces white fleshy stems which are more suitable for edibility than gray fleshy stems. The mechanism of this phenomenon is still largely unknown. One of the possible causes is the diversity of endophytic microbial communities between these two fleshy stems. Therefore, we utilized fungal ITS1 and bacterial 16S rDNA amplicon sequencing to investigate the diversity of endophytic microbial communities in the two different fleshy stems of Z. latifolia. The results revealed that the alpha diversity and richness of endophytic fungi in white Z. latifolia were significantly greater than in gray Z. latifolia. The dominant fungal genus in both fleshy stems was U. esculenta, which accounted for over 90% of the endophytic fungi. The community composition of endophytic fungi in gray and white Z. latifolia was different except for U. esculenta, and a negative correlation was observed between U. esculenta and other endophytic fungi. In addition, the dominant bacterial genus in gray Z. latifolia was Alcaligenaceae which is also negatively correlated with other bacterium communities. Additionally, the co-occurrence network of white Z. latifolia was found to have a stronger scale, connectivity, and complexity compared to that of gray Z. latifolia. And the detected beneficial bacteria and pathogens in the stems of Z. latifolia potentially compete for resources. Furthermore, the function of endophytic bacteria is more abundant than endophytic fungi in Z. latifolia. This research investigated the correlation between the development of Z. latifolia fleshy stems and endophytic microbial communities. Our findings indicate that the composition of endophytic microbial communities is closely related to the type of Z. latifolia fleshy stems. This research also suggests the potential utilization of specific microbial communities to enhance the growth and development of Z. latifolia, thereby contributing to the breeding of Z. latifolia.
