通讯机构：
[Lin Qiu; Lin Qiu Lin Qiu Lin Qiu] H;Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
关键词：
Surface ion imprinting;support;heavy metal ions;adsorption
摘要：
Surface ion-imprinting technology (SIIT) is a novel and effective alternative to conventional methods of preparing ion-imprinted polymers. SIIT involves the coating of support materials with a polymeric layer that selectively binds with imprinted metal ions, particularly heavy metal ions. Given its specificity, predictability, and stability, SIIT has been quickly adopted in ion detection, separation, enrichment, and sensing. Here, building on the latest advances in this emerging new technology, we carried out a systematic review to summarize the 1) principles and basic components of surface ion-imprinted polymers (SIIPs); 2) preparations, properties, advantages, and disadvantages of three types of SIIP supporting materials, including inorganic (minerals, carbonaceous materials, metal oxides), organic, and composite (organic/organic, organic/inorganic, inorganic/inorganic) supports; 3) current applications of SIIT, and 4) future challenges and opportunities related to SIIT. Finally, perspectives and future research are discussed to address the pressing need for the development of SIIT for heavy metal ion treatment.
期刊：
Zoological Journal of the Linnean Society,2023年198(2):476-493 ISSN：0024-4082
通讯作者：
Xing Wang<&wdkj&>Guo-Hua Huang
作者机构：
[Liao, Cheng-Qing; Chen, Qi; Huang, Guo-Hua; Chen, Lu; Wang, Xing] Hunan Agr Univ, Coll Plant Protect, Changsha 410128, Hunan, Peoples R China.;[Liao, Cheng-Qing; Chen, Qi; Huang, Guo-Hua; Chen, Lu] Hunan Agr Univ, Hunan Prov Key Lab Biol & Control Plant Dis & Inse, Nongda Rd 1, Changsha 410128, Hunan, Peoples R China.;[Yagi, Sadahisa; Hirowatari, Toshiya] Kyushu Univ, Fac Agr, Entomol Lab, 744 Motooka,Nishi Ku, Fukuoka 8190395, Japan.;[Wang, Xing] Qiongtai Normal Univ, Coll Sci, Haikou 571100, Hainan, Peoples R China.;[Wang, Xing] South China Agr Univ, Dept Entomol, Guangzhou 510640, Guangdong, Peoples R China.
通讯机构：
[Xing Wang; Guo-Hua Huang] C;College of Plant Protection, Hunan Agricultural University , Changsha, Hunan 410128 , China<&wdkj&>Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University , Nongda Road 1, Furong District, Changsha, Hunan 410128 , China<&wdkj&>College of Plant Protection, Hunan Agricultural University , Changsha, Hunan 410128 , China<&wdkj&>College of Science, Qiongtai Normal University , Haikou, Hainan 571100 , China
摘要：
As one of the largest single-radiation sources of phytophagous insects, the higher level phylogeny of lepidopteran lineages has been debated for decades, especially the early divergences of nonditrysia. Here, we use 74 mitochondrial genomes representing seven nonditrysian superfamilies, including the newly sequenced mitochondrial genomes of eight families and 30 species. Four datasets were constructed and used for a phylogenetic analysis based on maximum likelihood (ML) and Bayesian inference (BI) methods. The results reveal that (1) nonditrysian lineages presented typically nested relationships with the family Micropterigidae as the sister-group to the remaining Lepidoptera, (2) monophyly of major clades in Lepidoptera, including Glossata, Heteroneura, Eulepidoptera and Ditrysia, was strongly supported, and (3) Neopseustoidea formed the sister of the remaining Glossata. Divergence-time analysis estimated that Lepidoptera originated c. 222 Mya during the Middle Triassic and that most superfamilies/families of nonditrysia originated from the Early Cretaceous to the Early Palaeogene, which largely coincided with the radiation of angiosperms. Additionally, three novel gene rearrangements in the gene cluster 'MIQ' and 'TP' were found in nonditrysian groups. Further mitochondrial genome data will help us to better understand the evolution of early nonditrysian lineages.
摘要：
Rice blast is a globally devastating fungal disease that affects the production of rice (Oryza sativa), and the screening of excellent biocontrol strains is an important direction for the biological control of the fungus that causes rice blast disease (Magnaporthe oryzae). The objectives were to obtain strains that were highly antagonistic to rice blast, analyze the genetic information of the antagonistic bacterium YN-917, and explore the resources of its antagonistic gene cluster. The antagonistic bacteria were isolated and identified by the plate confrontation method, morphological observation, physiological and biochemical identification, and molecular biology methods. In addition, the strains were subjected to whole-genome sequencing, and their sequences were analyzed. Strain YN-917 was screened from healthy rice plants of the variety Xiangzaoxian 24, which is susceptible to rice blast, and it inhibited M. oryzae by 72.63% +/- 1.30%. Additionally, the strain had different degrees of inhibitory effects on various plant pathogenic fungi and was highly resistant to stress. The morphological observation, analysis of physiological and biochemical features, 16S rRNA homology analysis, and wholegenome sequencing analysis revealed that the strain YN-917 was Bacillus cereus (GenBank No.: PRJNA687285). The total length of its whole genome was 5326162 bp, and its average G + C content was 35.37%. It was composed of one circular chromosome and one endoplasmic plasmid. There were 5483 genes encoded on average. They included 105 tRNA genes, 42 self-replicating RNA (sRNA), 178 tandem repeat sequences, three prophages, and nine genomic islands. The prediction of antagonistic gene cluster demonstrated that the genome sequence of YN-917 had six secondary metabolic gene biosynthetic clusters, including those for bacteriocins, siderophores, non-ribosomal peptide synthetases (NRPs), and terpene. This study provides a theoretical basis to further explore microbial resources and their metabolic gene clusters for agricultural biological control.
通讯机构：
[Ding, Z ] H;Hunan Agr Univ, Coll Plant Protect, Changsha 410128, Peoples R China.;Hunan Prov Engn & Technol Res Ctr Biopesticide & F, Changsha 410128, Peoples R China.
关键词：
Meloidogyne graminicola;population density;agroecosystem;soil moisture;root gall
摘要：
The rice root-knot nematode Meloidogyne graminicola is increasingly widely distributed in China and has had a severe incidence in Hunan Province. It is thus necessary to investigate its population dynamics in paddy fields. This study was conducted to ascertain the effect of direct-seeded rice agroecosystems on the population dynamics of M. graminicola and root gall development in rice. The results indicated that the population density of M. graminicola in soil was markedly influenced by the agroecosystem, rainfall and temperature. The population density of M. graminicola J2, and eggs in the soil and root galls, were significantly larger in the dry aerobic rice agroecosystem and in the rain-fed upland agroecosystem than in the lowland double-rice cropping sequence agroecosystem. As it can affect soil moisture rainfall was the key factor affecting the density of nematodes in both the rain-fed upland agroecosystem and the dry aerobic rice agroecosystem. Field flooding was still an effective way to reduce the population density of M. graminicola. In addition, we observed that M. graminicola can lay eggs outside rice roots under laboratory conditions. Therefore, we propose a hypothesis that M. graminicola lays egg masses within roots when the soil moisture is high, but lays eggs outside when the soil moisture is suitable. By clarifying the population dynamics of M. graminicola in different types of direct-seeded rice agroecosystems, this study is conducive to controlling rice root-knot nematodes.
摘要：
As an endosymbiont, Wolbachia exerts significant effects on the host, including on reproduction, immunity, and metabolism. However, the study of Wolbachia in Thysanopteran insects, such as flower thrips Frankliniella intonsa, remains limited. Here, we assembled a gap-free looped genome assembly of Wolbachia strain wFI in a length of 1,463,884 bp (GC content 33.80%), using Nanopore long reads and Illumina short reads. The annotation of wFI identified a total of 1838 protein-coding genes (including 85 pseudogenes), 3 ribosomal RNAs (rRNAs), 35 transfer RNAs (tRNAs), and 1 transfer-messenger RNA (tmRNA). Beyond this basic description, we identified mobile genetic elements, such as prophage and insertion sequences (ISs), which make up 17% of the entire wFI genome, as well as genes involved in riboflavin and biotin synthesis and metabolism. This research lays the foundation for understanding the nutritional mutualism between Wolbachia and flower thrips. It also serves as a valuable resource for future studies delving into the intricate interactions between Wolbachia and its host.
摘要：
Genetic engineering technology is an ideal method to improve insecticidal efficiency by combining the advantages of different pathogenic microorganisms. Thus, six ascovirus genes were introduced into the genomic DNA of Autographa californica nucleopolyhedrovirus (AcMNPV) to possibly transfer the intrinsically valuable insecticidal properties from ascovirus to baculovirus. The viral budded virus (BV) production and viral DNA replication ability of AcMNPV-111 and AcMNPV-165 were significantly stronger than that of AcMNPV-Egfp (used as the wild-type virus in this study), whereas AcMNPV-33 had reduced ones. AcMNPV-111 and AcMNPV-165 also exhibited excellent insecticidal efficiency in the in vivo bioassays: AcMNPV-111 showed a 24.1% decrease in the LT(50) value and AcMNPV-165 exhibited a 56.3% decrease in the LD(50) value compared with AcMNPV-Egfp against the 3rd instar of Spodoptera exigua larvae, respectively. Furthermore, the size of the occlusion bodies (OBs) of AcMNPV-33, AcMNPV-111, and AcMNPV-165 were significantly increased compared to that of AcMNPV-Egfp. AcMNPV-111 and AcMNPV-165 had stable virulence against the 2nd to 4th instars tested larvae and higher OB yield than AcMNPV-Egfp in the 3rd and 4th instar larvae. Correlation and regression analyses indicated that it is better to use 5 OBs/larva virus to infect the 2nd instar larvae to produce AcMNPV-111 and 50 OBs/larva virus to infect the 3rd instar larvae to produce AcMNPV-165. The results of this study obtained recombinant viruses with enhanced virulence and exhibited a diversity of ascovirus gene function based on the baculovirus platform, which provided a novel strategy for the improvement of baculovirus as a biological insecticide.
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
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.
摘要：
Spodoptera frugiperda (S. frugiperda) is an invasive pest that threatens global crop production and food security and poses a serious threat to maize production worldwide. Metal-organic framework (MOF) nanocarriers have great potential for agricultural pest control applications. The present study successfully prepared the chemical cross-linking of iron-based metal-organic framework nanoparticles (MIL-101(Fe)-NH(2) NPs) with sodium lignosulfonate (SL) as a pH/laccase double stimuli-responsive pesticide release system. The average particle size of the prepared chlorfenapyr (CF)-loaded nanoparticles (CF@MIL-101-SL NPs) was 161.54 nm, and the loading efficiency was 44.52%. Bioactivity assays showed that CF@MIL-101-SL NPs increased the toxicity of CF to S. frugiperda and caused the rupture of the peritrophic membrane and enlargement of the midgut. Data from 16S rRNA gene sequencing showed that CF@MIL-101-SL treatment reduced the resistance of S. frugiperda to pesticides and pathogens and affected nutrient and energy availability by remodeling the intestinal microbiota of S. frugiperda. The dysregulated microbial community interacted with the broken peritrophic membrane, which exacerbated damage to the host. Nontargeted metabolomic results showed that ABC transporters may be a potential mechanism for the enhanced toxicity of CF@MIL-101-SL to S. frugiperda. In summary, the present study provides effective strategies for toxicological studies of nanopesticides against insects.
通讯机构：
[Wei Zhou] H;Hunan Provincial Engineering & Technology Research Center for Agricultural Big Data Analysis & Decision-Making, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha 410128, China
摘要：
The fall armyworm, Spodoptera frugiperda, is an invasive agricultural pest that is a serious threat to agricultural production and global food security. Chemical control is the most effective method for preventing outbreaks of S. frugiperda. However, insecticide resistance often develops as a result of prolonged pesticide use, and the molecular mechanisms involved in insecticide resistance remain unclear. Insect cytochrome P450 monooxygenases play an important role in the detoxification of insecticides and insecticide resistance in Lepidoptera. In our study, the LC50 of a novel insecticide (cyproflanilide) and a conventional insecticide (emamectin benzoate) for S. frugiperda second-instar larvae were 7.04 and 1.61 mg/L, respectively. Furthermore, CYP321A9 expression was upregulated in larvae exposed to these insecticides. Additionally, knockdown of CYP321A9 by feeding larvae with dsRNA for 72 h significantly increased the mortality of S. frugiperda exposed to emamectin benzoate and cyproflanilide by 23.33% and 7.78%, respectively. Our results indicate that CYP321A9 may play an important role in the detoxification of emamectin benzoate and cyproflanilide in S. frugiperda. Our findings provide a basis to better understand the mechanisms of insecticide resistance and contribute to the control of S. frugiperda.
作者机构：
[Long, Qingshan; Liu, Qingshu; Tang, Ying] Hunan Inst Microbiol, Hunan Prov Engn Res Ctr Agr Microbiol Applicat, Changsha 410009, Peoples R China.;[Zhou, Wen] Chinese Acad Agr Sci, Shanghai Vet Res Inst, Key Lab Vet Chem Drugs & Pharmaceut, Minist Agr & Rural Affairs, Shanghai 200241, Peoples R China.;[Zhou, Haibo; Bian, Xiaoying] Shandong Univ, State Key Lab Microbial Technol, Helmholtz Inst Biotechnol, Helmholtz Int Lab Antiinfect, Qingdao 266237, Peoples R China.;[Chen, Wu; Chen, W] Hunan Agr Univ, Coll Plant Protect, Changsha 410128, Peoples R China.
通讯机构：
[Liu, QS ; Chen, W ] H;[Bian, XY ] S;Hunan Inst Microbiol, Hunan Prov Engn Res Ctr Agr Microbiol Applicat, Changsha 410009, Peoples R China.;Shandong Univ, State Key Lab Microbial Technol, Helmholtz Inst Biotechnol, Helmholtz Int Lab Antiinfect, Qingdao 266237, Peoples R China.;Hunan Agr Univ, Coll Plant Protect, Changsha 410128, Peoples R China.
摘要：
Covering: 2005 to August, 2023Polyamine-containing natural products (NPs) have been isolated from a wide range of terrestrial and marine organisms and most of them exhibit remarkable and diverse activities, including antimicrobial, antiprotozoal, antiangiogenic, antitumor, antiviral, iron-chelating, anti-depressive, anti-inflammatory, insecticidal, antiobesity, and antioxidant properties. Their extraordinary activities and potential applications in human health and agriculture attract increasing numbers of studies on polyamine-containing NPs. In this review, we summarized the source, structure, classification, bioactivities and biosynthesis of polyamine-containing NPs, focusing on the biosynthetic mechanism of polyamine itself and representative polyamine alkaloids, polyamine-containing siderophores with catechol/hydroxamate/hydroxycarboxylate groups, nonribosomal peptide-(polyketide)-polyamine (NRP-(PK)-PA), and NRP-PK-long chain poly-fatty amine (lcPFAN) hybrid molecules. Polyamine-containing natural products have been isolated from a wide range of terrestrial and marine organisms. Most of them exhibit remarkable and diverse activities with potential applications in human health and agriculture.
摘要：
PURPOSE: The purpose of this study was to describe genotype-phenotype associations and novel insights into genetic characteristics in a trio-based cohort of inherited eye diseases (IEDs). METHODS: To determine the etiological role of de novo mutations (DNMs) and genetic profile in IEDs, we retrospectively reviewed a large cohort of proband-parent trios of Chinese origin. The patients underwent a detailed examination and was clinically diagnosed by an ophthalmologist. Panel-based targeted exome sequencing was performed on DNA extracted from blood samples, containing coding regions of 792 IED-causative genes and their flanking exons. All participants underwent genetic testing. RESULTS: All proband-parent trios were divided into 22 subgroups, the overall diagnostic yield was 48.67% (605/1243), ranging from 4% to 94.44% for each of the subgroups. A total of 108 IED-causative genes were identified, with the top 24 genes explaining 67% of the 605 genetically solved trios. The genetic etiology of 6.76% (84/1243) of the trio was attributed to disease-causative DNMs, and the top 3 subgroups with the highest incidence of DNM were aniridia (n = 40%), Marfan syndrome/ectopia lentis (n = 38.78%), and retinoblastoma (n = 37.04%). The top 10 genes have a diagnostic yield of DNM greater than 3.5% in their subgroups, including PAX6 (40.00%), FBN1 (38.78%), RB1 (37.04%), CRX (10.34%), CHM (9.09%), WFS1 (8.00%), RP1L1 (5.88%), RS1 (5.26%), PCDH15 (4.00%), and ABCA4 (3.51%). Additionally, the incidence of DNM in offspring showed a trend of correlation with paternal age at reproduction, but not statistically significant with paternal (P = 0.154) and maternal (P = 0.959) age at reproduction. CONCLUSIONS: Trios-based genetic analysis has high accuracy and validity. Our study helps to quantify the burden of the full spectrum IED caused by each gene, offers novel potential for elucidating etiology, and plays a crucial role in genetic counseling and patient management.
摘要：
Biofertilizers have immense potential for enhancing agricultural productivity. However, there is still a need for clarification regarding the specific mechanisms through which these biofertilizers improve soil properties and stimulate plant growth. In this research, a bacterial agent was utilized to enhance plant growth and investigate the microbial modulation mechanism of soil nutrient turnover using metagenomic technology. The results demonstrated a significant increase in soil fast-acting nitrogen (by 46.7%) and fast-acting phosphorus (by 88.6%) upon application of the bacterial agent. This finding suggests that stimulated soil microbes contribute to enhanced nutrient transformation, ultimately leading to improved plant growth. Furthermore, the application of the bacterial agent had a notable impact on the accumulation of key genes involved in nitrogen cycling. Notably, it enhanced nitrification genes (amo, hao, and nar), while denitrification genes (nir and nor) showed a slight decrease. This indicates that ammonium oxidation may be the primary pathway for increasing fast-acting nitrogen in soils. Additionally, the bacterial agent influenced the composition and functional structure of the soil microbial community. Moreover, the metagenome-assembled genomes (MAGs) obtained from the soil microbial communities exhibited complementary metabolic processes, suggesting mutual nutrient exchange. These MAGs contained widely distributed and highly abundant genes encoding plant growth promotion (PGP) traits. These findings emphasize how soil microbial communities can enhance vegetation growth by increasing nutrient availability and regulating plant hormone production. This effect can be further enhanced by introducing inoculated microbial agents. In conclusion, this study provides novel insights into the mechanisms underlying the beneficial effects of biofertilizers on soil properties and plant growth. The significant increase in nutrient availability, modulation of key genes involved in nitrogen cycling, and the presence of MAGs encoding PGP traits highlight the potential of biofertilizers to improve agricultural practices. These findings have important implications for enhancing agricultural sustainability and productivity, with positive societal and environmental impacts.
作者机构：
[Bao, Jie; Liang, Shaohui; Gao, Yong] Hebei Chest Hosp, Dept Resp, Shijiazhuang 050000, Hebei, Peoples R China.;[Dai, Erhei; Gao, Huixia] Hebei Med Univ, Hosp Shijiazhuang 5, Dept Lab Med, Shijiazhuang 050021, Hebei, Peoples R China.;[He, Tongxin] Hunan Agr Univ, Coll Plant Protect, Changsha 410128, Hunan, Peoples R China.;[Li, Li] Hebei Med Univ, Hosp Shijiazhuang 5, Intens Care Unit, Shijiazhuang 050021, Hebei, Peoples R China.;[Zhang, Xin; Wang, Yuling; Wang, YL] Hebei Med Univ, Hosp Shijiazhuang 5, Dept TB, Shijiazhuang 050021, Hebei, Peoples R China.
通讯机构：
[Wang, YL ; Dai, ER ] H;Hebei Med Univ, Hosp Shijiazhuang 5, Dept Lab Med, Shijiazhuang 050021, Hebei, Peoples R China.;Hebei Med Univ, Hosp Shijiazhuang 5, Dept TB, Shijiazhuang 050021, Hebei, Peoples R China.;Hebei Med Univ, Grad Sch, Shijiazhuang 050017, Hebei, Peoples R China.
关键词：
COVID-19;Multiple sclerosis;SUMF1;rs794185
摘要：
Evidence shows that genetic factors play important roles in the severity of coronavirus disease 2019 (COVID-19). Sulfatase modifying factor 1 (SUMF1) gene is involved in alveolar damage and systemic inflammatory response. Therefore, we speculate that it may play a key role in COVID-19. We found that rs794185 was significantly associated with COVID-19 severity in Chinese population, under the additive model after adjusting for gender and age (for C allele = 0.62, 95% CI = 0.44–0.88, P = 0.0073, logistic regression). And this association was consistent with this in European population Genetics Of Mortality In Critical Care (GenOMICC: OR for C allele = 0.94, 95% CI = 0.90–0.98, P = 0.0037). Additionally, we also revealed a remarkable association between rs794185 and the prothrombin activity (PTA) in subjects (P = 0.015, Generalized Linear Model). In conclusion, our study for the first time identified that rs794185 in SUMF1 gene was associated with the severity of COVID-19.
摘要：
Sedum plumbizincicola is a perennial succulent herb that can hyperaccumulate high concentrations of cadmium and zinc (Liu et al. 2017). In October 2021, a leaf spot disease occurred on S. plumbizincicola seedlings in a nursery in Changsha (28°13' N; 112°56'E), the Hunan Province of China. Almost 30% of the nearly 1 million seedlings were infected. Symptoms initially appeared as small brown spots on the leaf surface or edges, gradually enlarged, becoming oval, and bearing chlorotic lesions with dark brown borders. Eventually, the center of the lesions became sunken and then fell off. Eight symptomatic plant samples were collected by five-point sampling method (Zheng et al. 2018). Small pieces of 5×5 mm were excised from the lesion margins, sterilized with 70% ethanol for 10 s, 0.1% HgCl2 for 40 s, rinsed with sterile distilled water three times, and then cultured on potato dextrose agar (PDA) at 26 °C for 5 days in the dark. Fungal colonies showing similar morphology were observed from all the isolated samples and, in total, eight fungal strains were obtained. On PDA, fungal colonies were initially white, and later become light gray. After cultured on V8 juice agar (V8A, each litre of medium contains 200 mL of V8 juice, 3 g of CaCO3 and 15 g of agarose) for 14 days (Hyowon et al. 2016), conidia of a representative isolate SY-1 were produced, which were oblong, muriform, with blunt ends and conical apex, pale to light brown, and constricted at the 1 to 3 major transverse septa, 38.34-46.68 μm×11.67-18.34 μm (n=50). These morphological characteristics were consistent with that of Stemphylium lycopersici (Nasehi et al. 2016). The internal transcribed spacer (ITS) region of rDNA and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene of representative isolates SY-1 to SY-3 were amplified and sequenced using the primer pairs ITS4/ITS5 and gpd1/gpd2 as described previously (Woudenberg et al. 2017). BLASTn analysis showed that ITS sequences of isolates SY-1, SY-2 and SY-3 (accession nos. OP317641, OQ852042 and OQ852043) had more than 99% identity with Stemphylium sp, while GAPDH sequences (OP331223, OQ858620 and OQ858621) had 100% identity with S. lycopersici KR911813 (Sun et al. 2016). A concatenated ITS-GAPDH phylogenetic tree grouped our isolates within the S. lycopersici clade. For the pathogenicity test, one-month-old potted S. plumbizincicola seedlings were inoculated with conidia suspension (105 conidia/ml), which was induced on V8A. Four sites of each leaf of the potted S. plumbizincicola plants were dropped with a conidia suspension of strain SY-1, with 10 μL per site. Leaves treated with sterile water were served as controls. All of the inoculated seedlings were placed in a growth chamber at 26°C with a photoperiod of 12 h. The pathogenicity tests were repeated twice, with each had three replicative plants. After 7 days, all the inoculated leaves developed brown spots resembling those observed in the nursery, whereas the control plants remained symptomless. Stemphylium lycopersici was specifically re-isolated and identified by morphological and molecular methods (accession nos. OQ852045 for ITS and OQ858622 for GAPDH, respectively), thus fulfilling Koch's postulates. To our knowledge, this is the first report of S. lycopersici causing leaf spot on S. plumbizincicola in China. Since S. plumbizincicola played an important role and widely planted for heavy metal pollution treatment (Jiang et al. 2010), and this disease might seriously influence the S. plumbizincicola seedling breeding, identification of the pathogen might provide a foundation for the diagnosis and control of the disease.
