摘要：
Strigolactones (SLs) are plant hormones that regulate diverse developmental processes and environmental responses in plants. It has been discovered that SLs play an important role in regulating plant immune resistance to pathogens but there are currently no reports on their role in the interaction between Nicotiana benthamiana and the tobacco mosaic virus (TMV). In this study, the exogenous application of SLs weakened the resistance of N. benthamiana to TMV, promoting TMV infection, whereas the exogenous application of Tis108, a SL inhibitor, resulted in the opposite effect. Virus-induced gene silencing (VIGS) inhibition of two key SL synthesis enzyme genes, NtCCD7 and NtCCD8, enhanced the resistance of N. benthamiana to TMV. Additionally, we conducted a screening of N. benthamiana related to TMV infection. TMV-infected plants treated with SLs were compared to the control by using RNA-seq. The KEGG enrichment analysis and weighted gene co-expression network analysis (WGCNA) of differentially expressed genes (DEGs) suggested that plant hormone signaling transduction may play a significant role in the SL-TMV-N. benthamiana interactions. This study reveals new functions of SLs in regulating plant immunity and provides a reference for controlling TMV diseases in production.
摘要：
The overuse of herbicide may cause pollution in water and soil environment, affecting the growth of crops. And how to reduce herbicide residues has aroused extensive attention. In this work, a novel modified biochar (Zn/SNBC) was prepared with reed straw as raw material, ZnCl2 and thiourea as modifiers to remove quinclorac (QC) residues in water and soil. Compared with primitive biochar, Zn/SN-BC, benefiting from higher specific surface area (766.5 m2 & sdot;g- 1), improved pore characteristics and abundant reactive sites (-C = O, -COOR, -C-N, -C-S, ZnS, etc), showed excellent adsorption capacity towards QC (235.9 mg & sdot;g- 1), which was much higher than others reported before. According to the characterization results, it was revealed that Zn/SN-BC adsorbed QC through pore filling, hydrogen bonding, pi-pi conjunction, electrostatic attractions and other chemical interactions. The column leaching and pot experiments demonstrated that Zn/SN-BC could reduce QC leaching and bioavailability in soil, and effectively alleviate its phytotoxicity on tobacco plants. This study gives a new insight into the application of biochar-based materials for the treatment of herbicide residues in agricultural environments.
关键词：
Lilium brownii;autotoxicity;phenolic;phytohormone;reactive oxygen species (ROS);transcriptome
摘要：
Lilium brownii F. E. Brown ex Miellez var. viridulum Baker (Longya lily) is a variety of Lilium brownii F.E. Br. ex Miellez. We used HS-SPME and GC-MS to screened the tissues of L. brownii roots, stems, bulbs, and leaves and obtained 2,4-DTBP as an autotoxic substance for subsequent analysis. 2,4-DTBP was highly autotoxic in some treatment groups. Based on changes in physiological indicators, we carried out transcriptomic analysis to investigate the mechanisms of autotoxicity of substances on L. brownii and obtained 188,505 Unigenes. GO and KEGG enrichment analyses showed that L. brownii responded differently to different concentrations and treatment times of 2,4-DTBP. We observed significant changes in genes associated with ROS, phytohormones, and MAPK signaling cascades. 2,4-DTBP affects chloroplasts, the integrity of the respiratory electron transport chain, and ribosomes, causing L. brownii autotoxicity. Our findings provide a practical genomic resource for future research on L. brownii autotoxicity and evidence for the mechanism of action of autotoxic substances.
摘要：
The fall armyworm, known as Spodoptera frugiperda, is a notorious invasive pest wreaking havoc on agricultural crops globally. In the course of this study, a novel variant of the S. litura multiple nucleopolyhedrovirus (SpltMNPV-T0) was isolated from S. litura larvae found on tobacco plants in China. This research delved into the molecular and biological characteristics of SpltMNPV-T0. Electron microscopy revealed that this variant exhibited the characteristics features of a baculovirus. The complete genome of SpltMNPV-T0 was 137,925 bp in length, with a G + C content of 42.88 %, housing a total of 130 open reading frames (ORFs). Phylogenetically, this variant was similar to the published genome of the SpltMNPV-G2 strain, aligning itself with the Alphabaculovirus group II. However, it distinguished itself from the SpltMNPV-II in terms of sequence similarity (76.45 %), shared ORFs (only 63 genes in common), and gene order (exhibiting inversion and reordering). Crucially, SpltMNPV-T0 demonstrated notable effectiveness in controlling third-instar larvae of S. frugiperda and S. litura. Furthermore, the virulence of crude SpltMNPV-T0 matched that of the commercially available virus-based pesticide (SpltMNPV-KY), as evident in terms of mortality rates and speed of kill. These findings yield valu able insights into the molecular biology and functional genomics of this newly discovered variant, characterized by its high virulence. Such knowledge holds promise for advancing bio-control technologies aimed at mitigating the destructive impact of the pest S. frugiperda.
摘要：
Although the silencing of Aminopeptidase‐N 2 resulted in a significant increase in resistance to Cry1Ac in Plutella xylostella, it also had a significant negative impact on its growth, development, and fecundity. Abstract Bacillus thuringiensis (Bt) is widely used as a biopesticide worldwide. To date, at least eight pest species have been found to be resistant to Bt in the field. As the first pest that was reported having resistance to Bt in the field, considerable research has been done on the mechanisms of Bt resistance in Plutella xylostella. However, whether the acquisition of Bt resistance by P. xylostella comes at a fitness cost is also a valuable question. In this study, Aminopeptidase‐N 2 (APN2), a Cry toxin receptor gene of P. xylostella, was knocked down by RNA interference, resulting in improved resistance to Cry1Ac. It was also found that larval mortality of APN2 knockdown P. xylostella was significantly higher than that of the control, while the pupation rate, pupal weight, eclosion rate, fecundity (egg/female), hatchability, and female adult longevity were significantly lower in APN2 knockdown P. xylostella than in the control. These results illustrate that if Cry1Ac resistance was obtained only through the reduction of APN2 expression, P. xylostella would need to incur some fitness costs for it.
摘要：
Background T-type calcium channels, characterized as low-voltage activated (LVA) calcium channels, play crucial physiological roles across a wide range of tissues, including both the neuronal and nonneuronal systems. Using in situ hybridization and RNA interference (RNAi) techniques in vitro, we previously identified the tissue distribution and physiological function of the T-type calcium channel alpha 1 subunit (DdC alpha 1G) in the plant-parasitic nematode Ditylenchus destructor. Methods and results To further characterize the functional role of DdC alpha 1G, we employed a combination of immunohistochemistry and fungus-mediated RNAi and found that DdC alpha 1G was clearly distributed in stylet-related tissue, oesophageal gland-related tissue, secretory-excretory duct-related tissue and male spicule-related tissue. Silencing DdC alpha 1G led to impairments in the locomotion, feeding, reproductive ability and protein secretion of nematodes. To confirm the defects in behavior, we used phalloidin staining to examine muscle changes in DdC alpha 1G-RNAi nematodes. Our observations demonstrated that defective behaviors are associated with related muscular atrophy. Conclusion Our findings provide a deeper understanding of the physiological functions of T-type calcium channels in plant-parasitic nematodes. The T-type calcium channel can be considered a promising target for sustainable nematode management practices.
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.
关键词：
Tobacco mosaic virus;alpha diversity;bacterial interaction;beneficial bacteria;sensitivity of bacterial community
摘要：
Background: Tobacco mosaic virus (TMV) is one famous plant virus responsible for substantial economic losses worldwide. However, the roles of bacterial communities in response to TMV in the tobacco rhizosphere remain unclear. Methods: We explored the soil physicochemical properties and bacterial community succession of the healthy (YTH) and diseased (YTD) plants with TMV infection by 16S rRNA gene sequencing and bioinformatics analysis. Results: We found that soil pH in the YTD group was significantly lower than in the YTH group, and the soil available nutrients were substantially higher. The bacterial community analysis found that the diversity and structure significantly differed post-TMV disease onset. With TMV inoculated, the alpha diversity of the bacterial community in the YTD was markedly higher than that in the YTH group at the early stage. However, the alpha diversity in the YTD group subsequently decreased to lower than in the YTH group. The early bacterial structure of healthy plants exhibited higher susceptibility to TMV infection, whereas, in the subsequent stages, there was an enrichment of beneficial bacterial (e.g., Ramlibacter, Sphingomonas, Streptomyces, and Niastella) and enhanced energy metabolism and nucleotide metabolism in bacteria. Conclusion: The initial soil bacterial community exhibited susceptibility to TMV infection, which might contribute to strengthening resistance of Tobacco to TMV.
摘要：
The pathogen Pseudomonas syringae , responsible for a variety of diseases, poses a considerable threat to global crop yields. Emerging biocontrol strategies employ antagonistic microorganisms, utilizing phyllosphere microecology and systemic resistance to combat this disease. However, the interactions between phyllosphere microbial dynamics and the activation of the plant defense system remain poorly understood. Here we show signi ficant alterations in phyllosphere microbiota structure and plant gene expression following the application of biocontrol agents. We reveal enhanced collaboration and integration of Sphingomonas and Methylobacterium within the microbial co-occurrence network. Notably, Sphingomonas inhibits P. syringae by disrupting pathogen chemotaxis and virulence. Additionally, both Sphingomonas and Methylobacterium activate plant defenses by upregulating pathogenesis-related gene expression through abscisic acid, ethylene, jasmonate acid, and salicylic acid signaling pathways. Our results highlighted that biocontrol agents promote plant health, from reconstructing bene ficial microbial consortia to enhancing plant immunity. The findings enrich our comprehension of the synergistic interplays between phyllosphere microbiota and plant immunity, offering potential enhancements in biocontrol ef ficacy for crop protection. (c) 2024 The Authors. Published by Elsevier B.V. on behalf of Chinese Society for Environmental Sciences, Harbin Institute of Technology, Chinese Research Academy of Environmental Sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
摘要：
Sogatella furcifera (Horv & aacute;th) (Hemiptera: Delphacidae), a serious rice pest, has developed significant resistance to a wide range of pesticides. Neonicotinoid insecticides are currently the primary choice for controlling S. furcifera, yet their impact on the species remains poorly understood. In this study, we investigated the binding sites of a conventional insecticide (dinotefuran) and a novel insecticide (flupyrimin), and evaluated their sublethal effects on S. furcifera. Our results revealed that the LC50 of dinotefuran and flupyrimin were 2.51 mg/L and 2.80 mg/L in third-instar S. furcifera, respectively. RNA interference (RNAi) knockdown of S. furcifera nicotinic acetylcholine receptor (nAChR) alpha2 subunit (Sf alpha 2) and S. furcifera nAChR beta1 subunit (Sf beta 1) significantly reduced the susceptibility to dinotefuran by 18.7% and 16.8%, respectively, but had no effect on flupyrimin. Reproduction of the F0 and F1 generations was significantly inhibited by the LC25 of both dinotefuran and flupyrimin. In the dinotefuran treatment at LC25, the intrinsic growth rate (r) and finite growth rate (lambda) were reduced to 0.15 and 0.16 days, respectively; the mean generation time (T) increased to 27.77 days, and the relative fitness was only 0.76 compared to the control. Additionally, the relative fitness (Rf) of the flupyrimin-treated group was reduced to 0.93 and 0.86 times that of the control group. The population dynamics of S. furcifera are significantly affected by both dinotefuran and flupyrimin, making these insecticides valuable tools for integrated pest management and the rational use of insecticides. Graphical Abstract
摘要：
P0 proteins encoded by the pepper vein yellow virus (PeVYV) are pathogenic factors that cause hypersensitive response (HR). However, the host gene expression related to PeVYV P0-induced HR has not been thoroughly studied. Transcriptomic technology was used to investigate the host pathways mediated by the PeVYV P0 protein to explore the molecular mechanisms underlying its function. We found 12,638 differentially expressed genes (DEGs); 6784 and 5854 genes were significantly upregulated and downregulated, respectively. Transcriptomic and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) analyses revealed that salicylic acid (SA) and jasmonic acid (JA) synthesis-related gene expression was upregulated, and ethylene synthesis-related gene expression was downregulated. Ultrahigh performance liquid chromatography-tandem mass spectrometry was used to quantify SA and JA concentrations in Nicotiana benthamiana, and the P0 protein induced SA and JA biosynthesis. We then hypothesized that the pathogenic activity of the P0 protein might be owing to proteins related to host hormones in the SA and JA pathways, modulating host resistance at different times. Viral gene silencing suppression technology was used in N. benthamiana to characterize candidate proteins, and downregulating NbHERC3 (Homologous to E6-AP carboxy-terminus domain and regulator of choromosome condensation-1 dmain protein 3) accelerated cell necrosis in the host. The downregulation of NbCRR reduced cell death, while that of NbBax induced necrosis and curled heart leaves. Our findings indicate that NbHERC3, NbBax, and NbCRR are involved in P0 protein-driven cell necrosis.
摘要：
Plant viral diseases compromise the growth and yield of the crop globally, and they tend to be more serious under extreme temperatures and drought climate changes. Currently, regulatory dynamics during plant development and in response to virus infection at the plant cell level remain largely unknown. In this study, single-cell RNA sequencing on 23 226 individual cells from healthy and tomato chlorosis virus-infected leaves was established. The specific expression and epigenetic landscape of each cell type during the viral infection stage were depicted. Notably, the mesophyll cells showed a rapid function transition in virus-infected leaves, which is consistent with the pathological changes such as thinner leaves and decreased chloroplast lamella in virus-infected samples. Interestingly, the F-box protein SKIP2 was identified to play a pivotal role in chlorophyll maintenance during virus infection in tomato plants. Knockout of the SlSKIP2 showed a greener leaf state before and after virus infection. Moreover, we further demonstrated that SlSKIP2 was located in the cytomembrane and nucleus and directly regulated by ERF4. In conclusion, with detailed insights into the plant responses to viral infections at the cellular level, our study provides a genetic framework and gene reference in plant-virus interaction and breeding in the future research. The responses of different cell types in tomato leaves to tomato chlorosis virus (ToCV) infection were analyzed at the cellular level. We further determined that ERF4 regulates SlSKIP2, and the latter plays a crucial role in chlorophyll maintenance during ToCV infection in tomato leaves.
