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Zhao X, Fan Y, Zhang L, Zhang W, Xiang M, Kang S, Wang S, Liu X. Multiple Roles of the Low-Affinity Calcium Uptake System in Drechslerella dactyloides, a Nematode-Trapping Fungus That Forms Constricting Rings. J Fungi (Basel) 2023; 9:975. [PMID: 37888231 PMCID: PMC10607529 DOI: 10.3390/jof9100975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/28/2023] Open
Abstract
(1) Background: the low-affinity calcium uptake system (LACS) has been shown to play a crucial role in the conidiation and formation of adhesive nets and knobs by nematode-trapping fungi (NTF), but its involvement in the formation of constricting rings (CRs), mechanical traps to capture free-living nematodes, remains unexplored. (2) Methods: we investigated the function of two LACS genes (DdaFIG_1 and DdaFIG_2) in Drechslerella dactyloides, an NTF that forms CRs. We generated single (DdaFIG_1Ri and DdaFIG_2Ri) and double (DdaFIG_1,2Ri) knockdown mutants via the use of RNA interference (RNAi). (3) Results: suppression of these genes significantly affected conidiation, trap formation, vegetative growth, and response to diverse abiotic stresses. The number of CRs formed by DdaFIG_1Ri, DdaFIG_2Ri, and DdaFIG_1,2Ri decreased to 58.5%, 59.1%, and 38.9% of the wild-type (WT) level, respectively. The ring cell inflation rate also decreased to 73.6%, 60.6%, and 48.8% of the WT level, respectively. (4) Conclusions: the LACS plays multiple critical roles in diverse NTF.
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Affiliation(s)
- Xiaozhou Zhao
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Yani Fan
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liao Zhang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Weiwei Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meichun Xiang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Seogchan Kang
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Shunxian Wang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Xingzhong Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
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Abstract
Nematode-trapping fungi (NTF) are the majority of carnivorous microbes to capture nematodes through diverse and sophisticated trapping organs derived from hyphae. They can adopt carnivorous lifestyles in addition to saprophytism to obtain extra-nutrition from nematodes. As a special group of fungi, the NTF are not only excellent model organism for studying lifestyle transition of fungi but also natural resources of exploring biological control of nematodes. However, the carnivorous mechanism of NTF remains poorly understood. Nowadays, the omics studies of NTF have provided numerous genes and pathways that are associated with the phenotypes of carnivorous traits, which need molecular tools to verify. Here, we review the development and progress of gene manipulation tools in NTF, including methodology and strategy of transformation, random gene mutagenesis methods and target gene mutagenesis methods. The principle and practical approach for each method was summarized and discussed, and the basic operational flow for each tool was described. This paper offers a clear reference and instruction for researchers who work on NTF as well as other group of fungi.
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Affiliation(s)
- Shunxian Wang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin, China
| | - Xingzhong Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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Chen Y, Liu J, Fan Y, Xiang M, Kang S, Wei D, Liu X. SNARE Protein DdVam7 of the Nematode-Trapping Fungus Drechslerella dactyloides Regulates Vegetative Growth, Conidiation, and the Predatory Process via Vacuole Assembly. Microbiol Spectr 2022; 10:e0187222. [PMID: 36287065 PMCID: PMC9769606 DOI: 10.1128/spectrum.01872-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/30/2022] [Indexed: 01/07/2023] Open
Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins play conserved roles in membrane fusion events in eukaryotes and have been documented to be involved in fungal growth and pathogenesis. However, little is known about the roles of SNAREs in trap morphogenesis in nematode-trapping fungi (NTF). Drechslerella dactyloides, one of the constricting ring-forming NTF, captures free-living nematodes via rapid ring cell inflation. Here, we characterized DdVam7 of D. dactyloides, a homolog of the yeast SNARE protein Vam7p. Deletion of DdVam7 significantly suppressed vegetative growth and conidiation. The mutation significantly impaired trap formation and ring cell inflation, resulting in a markedly decreased nematode-trapping ability. A large vacuole could develop in ring cells within ~2.5 s after instant inflation in D. dactyloides. In the ΔDdVam7 mutant, the vacuoles were small and fragmented in hyphae and uninflated ring cells, and the large vacuole failed to form in inflated ring cells. The localization of DdVam7 in vacuoles suggests its involvement in vacuole fusion. In summary, our results suggest that DdVam7 regulates vegetative growth, conidiation, and the predatory process by mediating vacuole assembly in D. dactyloides, and this provides a basis for studying mechanisms of SNAREs in NTF and ring cell rapid inflation. IMPORTANCE D. dactyloides is a nematode-trapping fungus that can capture nematodes through a constricting ring, the most sophisticated trapping device. It is amazing that constricting ring cells can inflate to triple their size within seconds to capture a nematode. A large centrally located vacuole is a unique signature associated with inflated ring cells. However, the mechanism underpinning trap morphogenesis, especially vacuole dynamics during ring cell inflation, remains unclear. Here, we documented the dynamics of vacuole assembly during ring cell inflation via time-lapse imaging for the first time. We characterized a SNARE protein in D. dactyloides (DdVam7) that was involved in vacuole assembly in hyphae and ring cells and played important roles in vegetative growth, conidiation, trap morphogenesis, and ring cell inflation. Overall, this study expands our understanding of biological functions of the SNARE proteins and vacuole assembly in NTF trap morphogenesis and provides a foundation for further study of ring cell rapid inflation mechanisms.
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Affiliation(s)
- Yue Chen
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin, China
| | - Jia Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin, China
| | - Yani Fan
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Meichun Xiang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Seogchan Kang
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, State College, Pennsylvania, USA
| | - Dongsheng Wei
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin, China
| | - Xingzhong Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin, China
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Zhu MC, Li XM, Zhao N, Yang L, Zhang KQ, Yang JK. Regulatory Mechanism of Trap Formation in the Nematode-Trapping Fungi. J Fungi (Basel) 2022; 8:jof8040406. [PMID: 35448637 PMCID: PMC9031305 DOI: 10.3390/jof8040406] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 01/21/2023] Open
Abstract
Nematode-trapping (NT) fungi play a significant role in the biological control of plant- parasitic nematodes. NT fungi, as a predator, can differentiate into specialized structures called “traps” to capture, kill, and consume nematodes at a nutrient-deprived condition. Therefore, trap formation is also an important indicator that NT fungi transition from a saprophytic to a predacious lifestyle. With the development of gene knockout and multiple omics such as genomics, transcriptomics, and metabolomics, increasing studies have tried to investigate the regulation mechanism of trap formation in NT fungi. This review summarizes the potential regulatory mechanism of trap formation in NT fungi based on the latest findings in this field. Signaling pathways have been confirmed to play an especially vital role in trap formation based on phenotypes of various mutants and multi-omics analysis, and the involvement of small molecule compounds, woronin body, peroxisome, autophagy, and pH-sensing receptors in the formation of traps are also discussed. In addition, we also highlight the research focus for elucidating the mechanism underlying trap formation of NT fungi in the future.
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Bai YC, Li BX, Xu CY, Raza M, Wang Q, Wang QZ, Fu YN, Hu JY, Imoulan A, Hussain M, Xu YJ. Intercropping Walnut and Tea: Effects on Soil Nutrients, Enzyme Activity, and Microbial Communities. Front Microbiol 2022; 13:852342. [PMID: 35369467 PMCID: PMC8971985 DOI: 10.3389/fmicb.2022.852342] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 11/21/2022] Open
Abstract
The practice of intercropping, which involves growing more than one crop simultaneously during the same growing season, is becoming more important for increasing soil quality, land-use efficiency, and subsequently crop productivity. The present study examined changes in soil physicochemical properties, enzymatic activity, and microbial community composition when walnut (Juglans spp.) was intercropped with tea (Camellia sinensis L.) plants in a forest and compared with a walnut and tea monocropping system. The results showed that walnut-tea intercropping improved the soil nutrient profile and enzymatic activity. The soil available nitrogen (AN), available phosphorus (AP), available potassium (AK), organic matter (OM) content, and sucrase activity were significantly boosted in intercropped walnut and tea than in monocropping forests. The interaction between crops further increased bacterial and fungal diversity when compared to monoculture tea forests. Proteobacteria, Bacteroidetes, Firmicutes, Chlamydiae, Rozellomycota, and Zoopagomycota were found in greater abundance in an intercropping pattern than in monoculture walnut and tea forest plantations. The walnut-tea intercropping system also markedly impacted the abundance of several bacterial and fungal operational taxonomic units (OTUs), which were previously shown to support nutrient cycling, prevent diseases, and ameliorate abiotic stress. The results of this study suggest that intercropping walnut with tea increased host fitness and growth by positively influencing soil microbial populations.
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Affiliation(s)
- Yong-Chao Bai
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Bao-Xin Li
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | | | - Mubashar Raza
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Qi Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Qi-Zhu Wang
- Center for Walnut Technology of Baokang County, Xiangyang, China
| | - Ya-Nan Fu
- Center for Walnut Technology of Baokang County, Xiangyang, China
| | - Jian-Yang Hu
- State Key Laboratory of the Discovery and Development of Novel Pesticides, Shenyang Sinochem Agrochemicals R&D Co., Ltd., Shenyang, China
| | - Abdessamad Imoulan
- Department of Biology, Faculty of Science and Technics of Errachidia, Mouly Ismail University, Meknes, Morocco
| | - Muzammil Hussain
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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Zhou D, Zhu Y, Bai N, Xie M, Zhang KQ, Yang J. Aolatg1 and Aolatg13 Regulate Autophagy and Play Different Roles in Conidiation, Trap Formation, and Pathogenicity in the Nematode-Trapping Fungus Arthrobotrys oligospora. Front Cell Infect Microbiol 2022; 11:824407. [PMID: 35145926 PMCID: PMC8821819 DOI: 10.3389/fcimb.2021.824407] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/29/2021] [Indexed: 11/13/2022] Open
Abstract
Autophagy is a conserved cellular recycling and trafficking pathway in eukaryotes that plays an important role in cell growth, development, and pathogenicity. Atg1 and Atg13 form the Atg1–Atg13 complex, which is essential for autophagy in yeast. Here, we characterized the roles of the Aolatg1 and Aolatg13 genes encoding these autophagy-related proteins in the nematode-trapping fungus Arthrobotrys oligospora. Investigation of the autophagy process by using the AoAtg8-GFP fusion protein showed that autophagosomes accumulated inside vacuoles in the wild-type (WT) A. oligospora strain, whereas in the two mutant strains with deletions of Aolatg1 or Aolatg13, GFP signals were observed outside vacuoles. Similar results were observed by using transmission electron microscopy. Furthermore, deletion of Aolatg1 caused severe defects in mycelial growth, conidiation, conidial germination, trap formation, and nematode predation. In addition, transcripts of several sporulation-related genes were significantly downregulated in the ΔAolatg1 mutant. In contrast, except for the altered resistance to several chemical stressors, no obvious differences were observed in phenotypic traits between the WT and ΔAolatg13 mutant strains. The gene ontology analysis of the transcription profiles of the WT and ΔAolatg1 mutant strains showed that the set of differentially expressed genes was highly enriched in genes relevant to membrane and cellular components. The Kyoto Encyclopedia of Genes and Genomes analysis indicated that differentially expressed genes were highly enriched in those related to metabolic pathways, autophagy and autophagy-related processes, including ubiquitin-mediated proteolysis and SNARE interaction in vesicular transport, which were enriched during trap formation. These results indicate that Aolatg1 and Aolatg13 play crucial roles in the autophagy process in A. oligospora. Aolatg1 is also involved in the regulation of asexual growth, trap formation, and pathogenicity. Our results highlight the importance of Aolatg1 in the growth and development of A. oligospora, and provide a basis for elucidating the role of autophagy in the trap formation and pathogenicity of nematode-trapping fungi.
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Affiliation(s)
- Duanxu Zhou
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Yingmei Zhu
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Na Bai
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Meihua Xie
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Jinkui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- School of Life Sciences, Yunnan University, Kunming, China
- *Correspondence: Jinkui Yang,
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