作者：
Qiu, Ze Lan*;Tan, Ying*;Zhong, Jie*;Zhang, Zhou*;Zhu, Jun Zi*
期刊：
PLANT DISEASE,2023年107(9):2848 ISSN：0191-2917
通讯作者：
Qiu, Ze Lan;Tan, Ying;Zhong, Jie;Zhang, Zhou;Zhu, Jun Zi
作者机构：
[Zhang, Zhou; Qiu, Ze Lan; Tan, Ying] Changsha, China;[Qiu, Ze Lan] 2468897832@qq.com;[Tan, Ying] 1060790535@qq.com;[Zhong, Jie] plant pathology, bHunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha City, Hunan Province, 410128, P.R. China, Changsha, China, 410128;[Zhong, Jie] 1601389330@qq.com
通讯机构：
[Zhuo Zhang; Jun Zi Zhu] H;Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan 410125, P.R. China<&wdkj&>Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, Hunan, 410128, P.R. China
摘要：
Dioscorea alata is an annual or perennial dicotyledonous plant which is a vegetatively propagated tuberous food crop (Mondo et al. 2021). In 2021, symptoms of leaf anthracnose occurred on D. alata plants at a plantation in Changsha, the Hunan Province of China (28°18' N; 113°08'E). Symptoms initially showed as small, brown water-soaked spots on the leaf surface or margins, and enlarged to irregular, dark brown or black, necrotic lesions, with a lighter center and darker edge. At latter, lesions extended to most of the leaf surface causing leaf scorch or wilting. Almost 40% of the plants surveyed were infected. Symptomatic leaf samples were collected, and small pieces were taken at their disease-healthy junction, sterilized with 70% ethanol for 10 s, 0.1% HgCl2 for 40 s, rinsed three times with sterile distilled water, and then placed on potato dextrose agar (PDA) for incubation at 26 °C for 5 days in the dark. Fungal colonies with similar morphology were observed and, in total, 10 isolates were obtained from 10 plants. On PDA, colonies were initially white with fluffy hyphae, and later became light to dark gray, showing faint concentric rings. Conidia were hyaline, aseptate, cylindrical, and rounded at both ends, measuring 11.36 to 17.67 × 3.45 to 5.9 μm (n = 50). Appressoria were dark brown, ovate, globose, measuring 6.37 to 7.55 × 10.11 to 12.3 µm. These morphological characteristics were typical of Colletotrichum gloeosporioides species complex (Weir et al. 2012). For molecular identification, the internal transcribed spacer (ITS) region of rDNA, and partial sequences of actin (ACT), chitin synthase (CHS-1), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes of a representative isolate Cs-8-5-1 were amplified and sequenced using the primer pairs ITS1/ITS4, ACT-512F/ACT-783R, CHS-79F/CHS-354R, and GDF/GDR as described previously (Weir et al. 2012). These sequences were deposited in GenBank (accession nos. OM439575 for ITS, OM459820 for ACT, OM459821 for CHS-1, and OM459822 for GAPDH). BLASTn analysis showed 99.59 to 100 % identity to the corresponding sequences of C. siamense strains. A Maximum likelihood phylogenetic tree based on the concatenated ITS, ACT, CHS-1 and GAPDH sequences was generated by MEGA 6. It revealed that the Cs-8-5-1 was clustered with the C. siamense strain CBS 132456 with 98% bootstrap support. For pathogenicity test, conidia suspension (105 spores/ml) was prepared by harvesting conidia from 7-day-old cultures growing on PDA, and 10 uL was dropped onto leaves of potted D. alata plants (8 droplets per leaf). Leaves treated with sterile water were served as controls. All the inoculated plants were placed in humid chambers (with 90% humidity) at 26°C with a photoperiod of 12 h. The pathogenicity tests were performed twice, with each had three replicated plants. Seven days after inoculation, the inoculated leaves showed symptoms of brown necrosis resembling that observed in fields, however, the control leaves remained symptomless. The fungus was specifically re-isolated and identified by morphological and molecular methods, thus fulfilling Koch's postulates. To our knowledge, this is the first report of C. siamense causing anthracnose on D. alata in China. Since this disease might seriously affect the photosynthesis of the plants, which can influence the yield, prevention and management strategies should be adopted to control this new disease. Identification of this pathogen will provide a foundation for the diagnosis and control of this disease.
通讯机构：
[Li, B.; Chen, J.] S;State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, China;State Key Laboratory of Rice Biology and Breeding, China
摘要：
Rice bacterial leaf blight (BLB) is the most destructive bacterial diseases caused by Xanthomonas oryzae pv. oryzae (Xoo). Phages have been proposed as a green and efficient strategy to kill bacterial pathogens in crops, however, the mechanism of action of phages in the control of phyllosphere bacterial diseases remain unclear. Here, the glasshouse pot experiment results showed that phage combination could reduce the disease index by up to 64.3%. High-throughput sequencing technology was used to analyze the characteristics of phyllosphere microbiome changes and the results showed that phage combinations restored the impact of pathogen invasion on phyllosphere communities to a certain extent, and increased the diversity of bacterial communities. In addition, the phage combination reduced the relative abundance of epiphytic and endophytic Xoo by 58.9% and 33.9%, respectively. In particular, Sphingomonas and Stenotrophomonas were more abundant. According to structural equation modeling, phage combination directly and indirectly affected the disease index by affecting pathogen Xoo biomass and phage resistance. In summary, phage combination could better decrease the disease index. These findings provide new insights into phage biological control of phyllosphere bacterial diseases, theoretical data support, and new ideas for agricultural green prevention and control of phyllosphere diseases.
通讯机构：
[Xin Yang] S;[Youjun Zhang] H;Hubei Engineering Technology Center for Pest Forewarning and Management, College of Agriculture, Yangtze University, Jingzhou 434025, Hubei, P. R. China<&wdkj&>State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China<&wdkj&>State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
摘要：
Bemisia tabaci has developed high resistance to many insecticides and causes substantial agricultural and economic losses annually. The insecticide resistance of whitefly has been widely reported in previous studies; however, the underlying mechanism remains little known. In this study, we cloned two P450 genes: CYP6DW3 and CYP6DW5v1; these genes were markedly overexpressed in imidacloprid-resistant whitefly populations compared with susceptible populations, and knockdown of these genes decreased the imidacloprid resistance of whitefly. Moreover, heterologous expression of whitefly P450 genes in SF9 cells and metabolic studies showed that the CYP6DW3 protein could metabolize 14.11% imidacloprid and produced imidacloprid-urea in vitro. Collectively, the expression levels of CYP6DW3 and CYP6DW5v1 are positively correlated with imidacloprid resistance in B. tabaci. Our study further reveals that cytochrome P450 enzymes affect the physiological activities related to resistance in insects, which helps scholars more deeply understand the resistance mechanism, and contributes to the development of integrated pest management framework.
摘要：
Antimicrobial peptides (AMPs) from black solider flies (Hermetia illucens, BSF) exhibiting broad-spectrum antimicrobial activity are the most promising green substitutes for preventing the infection of phytopathogenic fungi; therefore, AMPs have been a focal topic of research. Recently, many studies have focused on the antibacterial activities of BSF AMPs against animal pathogens; however, currently, their antifungal activities against phytopathogenic fungi remain unclear. In this study, 7 AMPs selected from 34 predicted AMPs based on BSF metagenomics were artificially synthesized. When conidia from the hemibiotrophic phytopathogenic fungi Magnaporthe oryzae and Colletotrichum acutatum were treated with the selected AMPs, three selected AMPs-CAD1, CAD5, and CAD7-showed high appressorium formation inhibited by lengthened germ tubes. Additionally, the MIC(50) concentrations of the inhibited appressorium formations were 40 μM, 43 μM, and 43 μM for M. oryzae, while 51 μM, 49 μM, and 44 μM were observed for C. acutatum, respectively. A tandem hybrid AMP named CAD-Con comprising CAD1, CAD5, and CAD7 significantly enhanced antifungal activities, and the MIC(50) concentrations against M. oryzae and C. acutatum were 15 μM and 22 μM, respectively. In comparison with the wild type, they were both significantly reduced in terms of virulence when infection assays were performed using the treated conidia of M. oryzae or C. acutatum by CAD1, CAD5, CAD7, or CAD-Con. Meanwhile, their expression levels of CAD1, CAD5, and CAD7 could also be activated and significantly increased after the BSF larvae were treated with the conidia of M. oryzae or C. acutatum, respectively. To our knowledge, the antifungal activities of BSF AMPs against plant pathogenic fungi, which help us to seek potential AMPs with antifungal activities, provide proof of the effectiveness of green control strategies for crop production.
摘要：
Rice blast, caused by Magnaporthe oryzae is one of the most destructive diseases of rice (Oryza sativa L.) in most rice-cultivated areas worldwide. Mowanggu (MWG) is a traditional landrace rice variety in Yunnan with broad-spectrum and durable blast resistance against rice blast fungus. However, the underlying disease-resistance mechanisms remain unknown. An integrative transcriptomic, proteomic, and phosphoproteomic analysis of MWG was performed after inoculation with M. oryzae in this study. The transcriptomic and proteomic results revealed that MWG was moderately correlated at the transcriptional and protein levels. Differentially expressed genes and proteins were up-regulated and significantly enriched in protein phosphorylation, peroxisome, plant-pathogen interactions, phenylpropanoid metabolism and phenylalanine biosynthesis pathways. The phosphoproteomic profile and phosphorylated-protein-interaction network revealed that the altered phosphoproteins were primarily associated with reactive oxygen species (ROS), glycolysis, MAPK signaling pathways, and amino acid biosynthesis. In addition, a series of physiological and biochemical parameters, including ROS, soluble sugars, soluble protein and callus accumulation and defense-related enzyme activities, were used to validate the possible blast resistance mechanisms of MWG. The integrative transcriptomic, proteomic, and phosphoproteomic analysis revealed the different expression patterns at the molecular level of the durably resistant rice cultivar MWG after inoculation with M. oryzae, which provides insight into the molecular mechanisms of rice blast resistance.
摘要：
Most emerging viruses are spilled over from mammals. Understanding the mechanism of virus cross-species transmission and identifying zoonotic viruses before their emergence are critical for the prevention and control of newly emerging viruses. This study systematically investigated the host proteins associated with the cross-species transmission of mammalian viruses based on 1,271 pairs of virus-mammal interactions including 382 viruses from 33 viral families and 73 mammal species from 11 orders. Numerous host proteins were found to contribute to the cross-species transmission of mammalian viruses. Host proteins potentially contributing to virus cross-species transmission are specific to viral families, and few overlaps of such host proteins are observed in different viral families. Based on these host proteins, the random-forest (RF) models were built to predict the cross-species transmission potential of mammalian viruses. Moderate performance was obtained when using all viruses together. However, when modeling by viral family, the performance of the RF models varied much among viral families. In 13 viral families such as Flaviviridae, Retroviridae, and Poxviridae, the AUC of the RF model was greater than 0.8. Finally, the contribution of virus receptors to cross-species transmission was evaluated, and the virus receptor was found to have a minor effect in predicting the cross-species transmission of mammalian viruses. The study deepens our understanding of the mechanism of virus cross-species transmission and provides a framework for predicting the cross-species transmission of mammalian viruses. IMPORTANCE Emerging viruses pose serious threats to humans. Understanding the mechanism of virus cross-species transmission and identifying zoonotic viruses before their emergence are critical for the prevention and control of emerging viruses. This study systematically identified host factors associated with cross-species transmission of mammalian viruses and further built machine-learning models for predicting cross-species transmission of the viruses based on host factors including virus receptors. The study not only deepens our understanding of the mechanism of virus cross-species transmission but also provides a framework for predicting the cross-species transmission of mammalian viruses based on host factors.
摘要：
The Med1 transcriptional coactivator is a crucial component of the Mediator middle complex, which regulates the expression of specific genes involved in cell development, differentiation, reproduction, and homeostasis. The Med1 LxxLL motif, a five-amino-acid peptide sequence, is essential for Med1-mediated gene expression. Our previous study revealed that the disruption of the Med1 subunit leads to a significant increase in fumonisin B1 (FB1) production in the maize pathogen Fusarium verticillioides. However, our understanding of how Med1 regulates FB1 biosynthesis in F. verticillioides, particularly through the Med1 LxxLL motifs, remains limited. To characterize the role of LxxLL motifs, we generated a series of Med1 LxxLL deletion and amino acid substitution mutants. These mutants exhibited impaired mycelial growth and conidia germination while demonstrating enhanced conidia production and virulence. Similar to the Med1 deletion mutant, Med1 LxxLL motif mutants also exhibited increased FB1 biosynthesis in F. verticillioides. Proteomic profiling revealed that the Med1 LxxLL motif regulated the biosynthesis of several key substances that affected FB1 production, including starch and carotenoid. Subsequent studies demonstrated that the production of amylopectin, which is strongly linked to FB1 biosynthesis, was significantly increased in Med1 LxxLL motif mutants. In addition, the disruption of carotenoid metabolic genes decreased carotenoid content, thus stimulating FB1 biosynthesis in F. verticillioides. Taken together, our results provide valuable insights into how the Med1 LxxLL motif regulates FB1 biosynthesis in the mycotoxigenic fungus F. verticillioides.
通讯机构：
[Huan Zhang; Won Bo Shim] A;Authors to whom correspondence should be addressed.<&wdkj&>Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
摘要：
Fumonisin contamination of corn caused by Fusarium verticillioides is a major concern worldwide. While key genes involved in fumonisin biosynthesis are known, the location within the fungal cell where this process occurs has yet to be fully characterized. In this study, three key enzymes, i.e., Fum1, Fum8, and Fum6, associated with early steps of fumonisin biosynthesis pathway, were tagged with GFP, and we examined their cellular localization. Results showed that these three proteins co-localized with the vacuole. To further understand the role of the vacuole in fumonisin B-1 (FB1) biosynthesis, we disrupted two predicted vacuole associated proteins, FvRab7 and FvVam7, resulting in a significant reduction of FB1 biosynthesis and a lack of Fum1-GFP fluorescence signal. Furthermore, we used the microtubule-targeting drug carbendazim to show that proper microtubule assembly is critical for proper Fum1 protein localization and FB1 biosynthesis. Additionally, we found that alpha 1 tubulin is a negative regulator in FB1 biosynthesis. We concluded that vacuole proteins with optimized microtubule assembly play a crucial role in proper Fum1 protein localization and fumonisin production in F. verticillioides.
通讯机构：
[Renjun Fan; Renjun Fan Renjun Fan Renjun Fan] C;[Shuping Xing; Shuping Xing Shuping Xing Shuping Xing] R;[Xuguo Zhou; Xuguo Zhou Xuguo Zhou Xuguo Zhou] D;College of Plant Protection, Shanxi Agricultural University/Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Taiyuan, China<&wdkj&>Research Institute of Applied Biology, Shanxi University, Taiyuan, China<&wdkj&>Department of Entomology, University of Kentucky, Lexington, KY, USA
