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.
关键词：
Apoptosis;Colletotrichum fructicola;Hypovirulence;Mycovirus;β subunit of voltage-gated potassium channel
摘要：
Colletotrichum fructicola is a globally significant phytopathogenic fungus. Mycovirus-induced hypovirulence has great potential for biological control and study of fungal pathogenic mechanisms. We previously reported that the mycovirus Colletotrichum alienum partitivirus 1 (CaPV1) is associated with the hypovirulence of C. fructicola, and the present study aimed to further investigate a host factor and its roles in mycovirus-induced hypovirulence. A gene named CfKOB1, which encodes putative protein homologous to the β-subunit of voltage-gated potassium channels and aldo-keto reductase, is downregulated upon CaPV1 infection and significantly upregulated during the early infection phase of Nicotiana benthamiana by C. fructicola. Deleting the CfKOB1 gene resulted in diminished vegetative growth, decreased production of asexual spores, hindered appressorium formation, reduced virulence, and altered tolerance to abiotic stresses. Transcriptome analysis revealed that CfKOB1 regulates many metabolic pathways as well as the cell cycle and apoptosis. Furthermore, enhanced apoptosis was observed in the ΔCfKOB1 mutants. Viral RNA accumulation was significantly increased in the CfKOB1 deletion mutant. Additionally, our findings demonstrated that CaPV1 infection in the WT strain also induced cell apoptosis. Collectively, these results highlight the diverse biological roles of the CfKOB1 gene in the fungus C. fructicola, while it also participates in mycovirus-induced hypovirulence by regulating apoptosis.
摘要：
This study presents the development of thermoresponsive pyraclostrobin (PYR) microcapsules (PYR@PNIPAm-MCs) designed for controlled temperature-regulated pesticide release. These microcapsules, characterized by a regular spherical shape, smooth surface, and average size of 7.08 mu m, achieved a 14.99% drug loading capacity. Wide-angle X-ray diffraction (WAXD) analysis confirmed the efficient encapsulation of PYR. The release kinetics of PYR from the PYR@PNIPAm-MCs demonstrated a sustained, temperature-sensitive release pattern influenced by drug diffusion and matrix erosion. The efficacy of the PYR@PNIPAm-MCs against Magnaporthe oryzae paralleled that of 97% PYR technical concentrate at elevated temperatures. Acute toxicity assays revealed a significantly reduced toxicity of PYR@PNIPAm-MCs to aquatic life (LC50 = 7.71 mg/L), and the formulation showed no adverse effects on rice seedling growth. The results underscore the potential of this formulation to enhance the application of PYR in rice disease management, offering targeted release and improved safety profiles.
摘要：
Anthracnose caused by Colletotrichum scovillei is a significant disease of pepper, including in postharvest stage. Bacillus species represent a potential microbial resource for controlling postharvest plant diseases. Here, a strain HG-8-2 was obtained and identified as Bacillus velezensis through morphological, biochemical, physiological, and molecular analyses. The culture filtrate showed highly antifungal activity against C. scovillei both in vitro and on pepper fruit. Crude lipopeptide extracts, which had excellent stability, could effectively inhibit mycelial growth of C. scovillei with an EC50 value of 28.48 ± 1.45 μg mL−1 and inhibited conidial germination. Pretreatment with the extracts reduced the incidence and lesion size of postharvest anthracnose on pepper fruit. Analysis using propidium iodide staining, malondialdehyde content detection and scanning electron microscope observation suggested that the crude lipopeptide extracts harbored antifungal activity by damaging cell membranes and mycelial structures. The RNA-seq analysis conducted on C. scovillei samples treated with the extracts, as compared to untreated samples, revealed significant alterations in the expression of multiple genes involved in protein biosynthesis. Overall, these results demonstrated that B. velezensis HG-8-2 and its crude lipopeptide extracts exhibit highly antagonistic ability against C. scovillei, thereby offering an effective biological agent for the control of anthracnose in pepper fruit.
Anthracnose caused by Colletotrichum scovillei is a significant disease of pepper, including in postharvest stage. Bacillus species represent a potential microbial resource for controlling postharvest plant diseases. Here, a strain HG-8-2 was obtained and identified as Bacillus velezensis through morphological, biochemical, physiological, and molecular analyses. The culture filtrate showed highly antifungal activity against C. scovillei both in vitro and on pepper fruit. Crude lipopeptide extracts, which had excellent stability, could effectively inhibit mycelial growth of C. scovillei with an EC50 value of 28.48 ± 1.45 μg mL−1 and inhibited conidial germination. Pretreatment with the extracts reduced the incidence and lesion size of postharvest anthracnose on pepper fruit. Analysis using propidium iodide staining, malondialdehyde content detection and scanning electron microscope observation suggested that the crude lipopeptide extracts harbored antifungal activity by damaging cell membranes and mycelial structures. The RNA-seq analysis conducted on C. scovillei samples treated with the extracts, as compared to untreated samples, revealed significant alterations in the expression of multiple genes involved in protein biosynthesis. Overall, these results demonstrated that B. velezensis HG-8-2 and its crude lipopeptide extracts exhibit highly antagonistic ability against C. scovillei, thereby offering an effective biological agent for the control of anthracnose in pepper fruit.
摘要：
Colletotrichum spp. are economically important phytopathogenic fungi that cause anthracnose in a variety of plant species worldwide. Hypovirulence-associated mycoviruses provide new options for the biological control of plant fungal diseases. Here, we found a novel partitivirus from Colletotrichum alienum and named it Colletotrichum alienum partitivirus 1 (CaPV1). CaPV1 contained two dsRNA segments encoding an RNA-dependent RNA polymerase and a capsid protein and was classified under the genus Gammapartitivirus of the family Partitiviridae. CaPV1 significantly decreased host virulence, mycelial growth, appressorial development, and appressorium turgor but increased conidial production with abnormal morphology. In addition, CaPV1 could be successfully transfected into other Colletotrichum species, including C. fructicola, C. spaethianum, and C. gloeosporioides, and caused hypovirulence, indicating the broad application potential of this virus. CaPV1 caused significant transcriptional rewiring of the host fungus C. alienum. Notably, some genes related to vesicle transport in the CaPV1-infected strain were downregulated, consistent with the impaired endocytosis pathway in this fungus. When the Rab gene CaRab7, which is associated with endocytosis in vesicle transport, was knocked out, the virulence of the mutants was reduced. Overall, our findings demonstrated that CaPV1 has the potential to control anthracnose caused by Colletotrichum, and the mechanism by which Colletotrichum induces hypovirulence is caused by affecting vesicle transport.IMPORTANCEColletotrichum is a kind of economically important phytopathogenic fungi that cause anthracnose disease in a variety of plant species worldwide. We found a novel mycovirus of the Gammapartitivirus genus and Partitiviridae family from the phytopathogenic fungus Colletotrichum alienum and named it CaPV1. This study revealed that CaPV1 infection significantly decreased host virulence and fitness by affecting mycelial growth, appressorial development, and appressorium turgor. In addition, CaPV1 could also infect other Colletotrichum species, including C. fructicola, C. spaethianum, and C. gloeosporioides, by viral particle transfection and resulting in hypovirulence of these Colletotrichum species. Transcriptomic analysis showed that CaPV1 caused significant transcriptional rewiring of the host fungus C. alienum, especially the genes involved in vesicle transport. Moreover, endocytosis and gene knockout assays demonstrated that the mechanism underlying CaPV1-induced hypovirulence is, at least in part, caused by affecting the vesicle transport of the host fungus. This study provided insights into the mechanisms underlying the pathogenesis of Colletotrichum species and mycovirus-fungus interactions, linking the role of mycovirus and fungus vesicle transport systems in shaping fungal pathogenicity.
作者：
Ya Wang;Jing Tian;Zihao Wang;Chaonan Li;Xiaogang Li*
期刊：
ACS Agricultural Science and Technology,2022年2(3):534-545 ISSN：2692-1952
通讯作者：
Xiaogang Li
作者机构：
[Ya Wang; Jing Tian; Zihao Wang; Chaonan Li] College of Plant Protection, Hunan Agricultural University, Changsha 410128, China;Hunan Provincial Engineering & Technology Research Center for Bio Pesticide and Formulating Processing, Changsha 410128, China;[Xiaogang Li] College of Plant Protection, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Hunan Provincial Engineering & Technology Research Center for Bio Pesticide and Formulating Processing, Changsha 410128, China
通讯机构：
[Xiaogang Li] C;College of Plant Protection, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Hunan Provincial Engineering & Technology Research Center for Bio Pesticide and Formulating Processing, Changsha 410128, China
作者机构：
[Wang, Zihao; Li, Xiaogang; Li, Chaonan; Wang, Ya] Hunan Agr Univ, Coll Plant Protect, Engn & Technol Res Ctr Bio Pesticide & Formulating, Changsha 410128, Peoples R China.
通讯机构：
[Xiaogang Li] E;Engineering & Technology Research Center for Bio Pesticide and Formulating Processing, College of Plant Protection, Hunan Agricultural University, Changsha410128, China
作者机构：
[Li, Xiao-Gang; Zhong, Jie; Li, Ping; Zhu, Jun-Zi] Hunan Agr Univ, Hunan Prov Key Lab Biol & Control Plant Dis & Ins, Nongda Rd 1, Changsha 410128, Peoples R China.;[Li, Xiao-Gang; Zhu, Jun-Zi] Hunan Agr Univ, Hunan Engn Res Ctr Agr Pest Early Warning & Contr, Nongda Rd 1, Changsha 410128, Peoples R China.
通讯机构：
[Jie Zhong; Xiao-Gang Li] A;Authors to whom correspondence should be addressed.<&wdkj&>Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Hunan Engineering Research Center of Agricultural Pest Early Warning and Control, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China
作者：
Zhu, Jun Zi*;Ma, Ya-ming;Wang, Xiao Li*;Zhong, Jie*;Zhang, Zhuo*;...
期刊：
PLANT DISEASE,2022年106(9):2531 ISSN：0191-2917
通讯作者：
Zhu, Jun Zi;Ma, Ya-Ming;Wang, Xiao Li;Zhong, Jie;Zhang, Zhuo;Li, Xiao Gang
作者机构：
[Zhong, Jie; Zhu, Jun Zi; Li, Xiao Gang] Hunan Agr Univ, Hunan Prov Key Lab Biol & Control Plant Dis & Ins, Changsha 410128, Hunan, Peoples R China.;[Ma, Ya-ming] Jinyun Plant Protect Stn, Lishui City 321400, Zhejiang, Peoples R China.;[Wang, Xiao Li] Technol Ctr Changsha Customs Dist, Changsha 410004, Hunan, Peoples R China.;[Zhang, Zhuo] Hunan Acad Agr Sci, Hunan Plant Protect Inst, Changsha 410125, Hunan, Peoples R China.
通讯机构：
[Jie Zhong; Zhuo Zhang; Xiao Gang Li] H;Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Furong District, Changsha City, Hunan Province, 410128, P.R. China<&wdkj&>Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan 410125, China
摘要：
Aloe vera (L.) Burm f., which belongs to the family Aloaceae, is a perennial succulent plant and cultivated for its medicinal, cosmetic, vegetable and ornamental uses. In summer of 2021, about 15% (60 infected among 400 surveyed plants) of A. vera (A. barbadensis) plants in two gardens in Lishui, Zhejiang Province of China showed symptoms of southern blight disease. Symptomatic plants primarily exhibited slightly sunken water-soaked, dark brown lesions on taproot and basal part of the stems. As the disease progressed, leaves in the basal part of stems and subsequently the whole plant rotted and withered, with white mycelial mats occurring on infected stems and leaves. Numerous brown, spherical sclerotia were observed on the colonized tissues and soil surfaces around the infected plants. Mycelial fragments and sclerotia from symptomatic leaves were plated directly to potato dextrose agar (PDA) amended with 100 μg/ml streptomycin and incubated at 26°C in the dark. By hyphal-tip method, a total of five pure isolates were obtained from five diseased leaf samples. When cultured on PDA at 26°C for three days, colonies showed white and thick aerial mycelium, with a radial growth rate of 23.7 mm/day. Typical clamp connection structures were observed microscopically after three days and numerous globoid, rapeseed shape sclerotia, measuring 1 to 2 mm in diameter (n=50) formed after six days. These sclerotia were initially white and gradually turned dark brown with age. On the basis of morphological characteristics, the fungal isolates were identified as Athelia rolfsii (Curzi) C.C. Tu & Kimbr (anamorph Sclerotium rolfsii Sacc) (Mordue 1974). The internal transcribed spacer (ITS) and translation elongation factor 1-α gene (TEF1) regions of a representative isolate LHBJ2-4 were amplified and sequenced using the primers ITS4/ITS5 (White et al. 1990) and EF1/EF2, respectively (accession no. MZ956758 and OL365370). BLASTn search showed that the amplified ITS and TEF1 sequences had 99.71% (680/682 bp) and 99.80% (498/499 bp) identity with the A. rolfsii isolates CBS 115.22 (MH854711.1) and Sr_286 (JF267815), respectively. Neighbor-joining phylogenetic tree based on the ITS sequences revealed that LHBJ2-4 clustered with A. rolfsii isolates. For pathogenicity test, three potted A. vera plants (~30 cm tall) were inoculated by placing a 0.5 cm mycelial plug of isolate LHBJ2-4 (three-day old) at the base of each A. vera plant. Three A. vera plants inoculated with sterile PDA plugs served as controls. All the inoculated plants were placed in a growth chamber at 27°C under a 12/12 h light/dark cycle. The inoculation assays were carried out twice. After 5 to 7 days, stem bases of the inoculated plants showed brown lesions that were similar to those observed in the field. However, control plants remained symptomless. Athelia rolfsii was re-isolated from all the inoculated plants and identified using morphological and molecular method described above, thus confirming Koch's postulates. Although A. rolfsii has been reported to cause disease on A. vera in India (Dubey and Pandey 2009), to the best of our knowledge, this is the first report of A. rolfsii causing southern blight on A. vera in China. Because A. rolfsii has a wide host range and is difficult to control (Punja 1985), occurrence of southern blight in China might be a serious threat for A. vera production and appropriate management strategies should be developed to control this disease.
作者机构：
[Liu, Kailin; Li, Xiaogang; Zheng, Qianqi; Li, Shaomei; Liu, Lejun; Zhao, Jingyu] Hunan Agr Univ, Coll Plant Protect, Changsha 410128, Peoples R China.;[Liu, Kailin; Bai, Lianyang] Hunan Acad Agr Sci, Hunan Agr Biotechnol Res Inst, Key Lab Biol & Control Weeds, Coll Plant Protect, Changsha 410125, Peoples R China.;[Song, Rong] Hunan Acad Agr Sci, Inst Agr Environm & Ecol, Changsha 410125, Peoples R China.;[Li, Hui] North Carolina State Univ, Dept Crop & Soil Sci, Raleigh, NC 27695 USA.
通讯机构：
[Rong Song] I;[Kailin Liu] C;College of Plant Protection, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Key Laboratory for Biology and Control of Weeds, Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China<&wdkj&>Institute of Agricultural Environment and Ecology, Hunan academy of Agricultural Sciences, Changsha 410125, China
摘要：
Pest control effectiveness and residues of pesticides are contradictory concerns in agriculture and environmental conservation. On the premise of not affecting the insecticidal effect, the pesticide residues in the later stage should be degraded as fast as possible. In the present study, composite nanoparticles in a double-layer structure, consisting of imidacloprid (IMI) in the outer layer and plant hormone 24-epibrassinolide (24-EBL) in the inner layer, were prepared by the W/O/W solvent evaporation method using Eudragit RL/RS and polyhydroxyalkanoate as wall materials. The release of IMI in the outer layer was faster and reached the maximum within 24 h, while the release of 24-EBL in the inner layer was slower and reached the maximum within 96 h. The contact angle of the composite nanoparticles was half that of the 5% IMI emulsifiable concentrate (EC), and the deposition of composite nanoparticles on rice was twice that of 5% IMI EC, which increased the pesticide utilization efficiency. Compared with the common pesticide, 5% IMI EC, the insecticidal effect of the composite nanoparticles was stronger than that of planthoppers, with a much lower final residue amount on rice after 21 days. The composite nanoparticles prepared in this study to achieve sustained release of pesticides and, meanwhile, accelerate the degradation of pesticide residues have a strong application potential in agriculture for controlling pests and promoting crop growth.
作者：
Zhong, Jie;Li, Ping;Gao, Bi Da;Zhong, Shuang Yu;Li, Xiao Gang;...
期刊：
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY,2022年12:980970 ISSN：2235-2988
通讯作者：
Li, X.G.;Hu, Z.;Zhu, J.Z.
作者机构：
[Zhong, Jie; Li, Xiao Gang; Zhu, Jun Zi] Hunan Agr Univ, Hunan Engn Res Ctr Agr Pest Early Warning & Contro, Changsha, Peoples R China.;[Gao, Bi Da; Zhong, Jie; Li, Ping; Zhong, Shuang Yu; Hu, Zhao; Zhu, Jun Zi] Hunan Agr Univ, Hunan Prov Key Lab Biol & Control Plant Dis & Inse, Changsha, Peoples R China.
通讯机构：
[Li, X.G.; Zhu, J.Z.; Hu, Z.] H;Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, China;Hunan Engineering Research Center of Agricultural Pest Early Warning and Control, China
摘要：
Alternaria dianthicola is a pathogenic fungus that causes serious leaf or flower blight on some medicinal plants worldwide. In this study, multiple dsRNA bands in the range of 1.2-10 kbp were found in a Alternaria dianthus strain HNSZ-1, and eleven full-length cDNA sequences of these dsRNA were obtained by high-throughput sequencing, RT-PCR detection and conventional Sanger sequencing. Homology search and phylogenetic analyses indicated that the strain HNSZ-1 was infected by at least nine mycoviruses. Among the nine, five viruses were confirmed to represent novel viruses in the families Hypoviridae, Totiviridae, Mymonaviridae and a provisional family Ambiguiviridae. Virus elimination and horizontal transmission indicated that the (-) ssRNA virus, AdNSRV1, might be associated with the slow growth and irregular colony phenotype of the host fungus. As far as we know, this is the first report for virome characterization of A. dianthus, which might provide important insights for screening of mycovirus for biological control and for studying of the interactions between viruses or viruses and their host.
作者：
Zhu, Jun Zi;Guo, Jun;Hu, Zhao;Zhang, Xu Tong;Li, Xiao Gang;...
期刊：
Frontiers in Microbiology,2021年12:653809 ISSN：1664-302X
通讯作者：
Zhong, J.;Li, X.G.
作者机构：
[Zhu, Jun Zi; Li, Xiao Gang] Hunan Agr Univ, Hunan Engn Res Ctr Agr Pest Early Warning & Contr, Changsha, Peoples R China.;[Zhang, Xu Tong; Zhong, Jie; Guo, Jun; Hu, Zhao; Zhu, Jun Zi; Li, Xiao Gang] Hunan Agr Univ, Prov Key Lab Biol & Control Plant Dis & Insect Pe, Changsha, Peoples R China.
通讯机构：
[Li, X.G.; Zhong, J.] H;Hunan Engineering Research Center of Agricultural Pest Early Warning and Control, China;Hunan Provincial Key Laboratory for Biology, China
摘要：
Here, we report a novel double-stranded RNA virus designated Colletotrichum liriopes partitivirus 1 (ClPV1) from the plant pathogenic fungus C. liriopes. ClPV1 genome has two double stranded RNAs (dsRNAs), named as dsRNA 1 and dsRNA 2, which in the lengths of 1,807 and 1,706 bp, respectively. The dsRNA 1 and dsRNA 2 encoded proteins showing significant amino acid (aa) sequence identity to the RNA-dependent RNA polymerase (RdRp) and coat protein (CP) of partitiviruses, respectively. Phylogenetic analysis using the aa sequences of RdRp and CP indicated that ClPV1 was grouped to members of the putative Epsilonpartitivirus genus in the Partitiviridae family. Spherical viral particles in approximately 35 nm in diameter and packaging the ClPV1 genome were isolated. Virus elimination and virus transfection with purified viral particles, and biological comparison revealed that ClPV1 could reduce the virulence and conidia production of C. liriopes. To the best of our knowledge, this is the first report of mycovirus in C. liriopes fungus.
