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Yu B, Liang Y, Qin Q, Zhao Y, Yang C, Liu R, Gan Y, Zhou H, Qiu Z, Chen L, Yan S, Cao B. Transcription Cofactor CsMBF1c Enhances Heat Tolerance of Cucumber and Interacts with Heat-Related Proteins CsNFYA1 and CsDREB2. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:15586-15600. [PMID: 38949485 DOI: 10.1021/acs.jafc.4c02398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Multiprotein bridging factor 1 (MBF1) is a very important transcription factor (TF) in plants, whose members influence numerous defense responses. Our study found that MBF1c in Cucurbitaceae was highly conserved. CsMBF1c expression was induced by temperature, salt stress, and abscisic acid (ABA) in cucumber. Overexpressed CsMBF1c enhanced the heat resistance of a cucumber, and the Csmbf1c mutant showed decreased resistance to high temperatures (HTs). CsMBF1c played an important role in stabilizing the photosynthetic system of cucumber under HT, and its expression was significantly associated with heat-related TFs and genes related to protein processing in the endoplasmic reticulum (ER). Protein interaction showed that CsMBF1c interacted with dehydration-responsive element binding protein 2 (CsDREB2) and nuclear factor Y A1 (CsNFYA1). Overexpression of CsNFYA1 in Arabidopsis improved the heat resistance. Transcriptional activation of CsNFYA1 was elevated by CsMBF1c. Therefore, CsMBF1c plays an important regulatory role in cucumber's resistance to high temperatures.
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Affiliation(s)
- Bingwei Yu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
- School of Biology and Agriculture, Shaoguan University, Shaoguan 512005, China
| | - Yonggui Liang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Qiteng Qin
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Yafei Zhao
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Chenyu Yang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Renjian Liu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Yuwei Gan
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Huoyan Zhou
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Zhengkun Qiu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Letian Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Shuangshuang Yan
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Bihao Cao
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs/Guangdong Vegetable Engineering and Technology Research Center/Lingnan Guangdong Laboratory of Modern Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
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Wang G, Chen B, Zhang X, Du G, Han G, Liu J, Peng Y. The basic leucine zipper domain (bZIP) transcription factor BbYap1 promotes evasion of host humoral immunity and regulates lipid homeostasis contributing to fungal virulence in Beauveria bassiana. mSphere 2024:e0035124. [PMID: 38926907 DOI: 10.1128/msphere.00351-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
Basic leucine zipper domain transcription factors (TFs), of which yeast activator protein (Yap) is a significant class, are crucial for the development of sclerotia, the stress response, vegetative growth, and spore adhesion. Nevertheless, nothing is known about how Yap TFs contribute to the pathogenicity of entomopathogenic fungus. In this work, Beauveria bassiana was used to identify and knock out the yeast gene BbYap1, which is similar to Yap. The BbYap1 gene deletion has an impact on lipid homeostasis of B. bassiana; oleic acid, for example, dropped by 95.69%. The BbYap1 mutant exhibited much less virulence and vegetative development in comparison to the wild strain, while demonstrating a greater sensitivity to chemical stress. It is noteworthy that the physiological abnormalities brought on by BbYap1 deletion were largely repaired by the addition of exogenous oleic acid, as seen by the notable increase in insect survival in the blood cavity injection group. Following infection with the BbYap1 mutant, the host exhibits a considerable down-regulation of the expression of β-1,3-glucan recognition protein, gallerimycin, gloverin, and moricin-like protein genes. Likewise, the introduction of exogenous oleic acid markedly increased the host's expression of the aforementioned genes. In summary, BbYap1 regulates cellular enzyme lipid homeostasis and fungal virulence by eluding host humoral defense, which contributes to fungal chemical stress and vegetative development. IMPORTANCE Entomopathogenic fungi (EPF) offer an effective and eco-friendly alternative to curb insect populations in biocontrol strategy. When EPF enter the hemolymph of their host, they encounter a variety of stress reactions, such as immunological and oxidative stress. Basic leucine zipper domain transcription factors, of which yeast activator protein (Yap) is a significant class, have diverse biological functions related to metabolism, development, reproduction, conidiation, stress responses, and pathogenicity. This study demonstrates that BbYap1 of Beauveria bassiana regulates cellular enzyme lipid homeostasis and fungal virulence by eluding host humoral defense, which contributes to fungal chemical stress and vegetative development. These findings offer fresh perspectives for comprehending molecular roles of YAP in EPF.
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Affiliation(s)
- Guang Wang
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Bin Chen
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Xu Zhang
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Guangzu Du
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Guangyu Han
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Jing Liu
- Yunnan Key Laboratory of Potato Biology, School of Life Science, Yunnan Normal University, Kunming, China
| | - Yuejin Peng
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
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Pang J, Peng Y, Di T, Du G, Chen B. Virulence of Metarhizium rileyi Is Determined by Its Growth and Antioxidant Stress and the Protective and Detoxifying Enzymes of Spodoptera frugiperda. INSECTS 2023; 14:260. [PMID: 36975945 PMCID: PMC10051772 DOI: 10.3390/insects14030260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/28/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
Spodoptera frugiperda is one of the most destructive crop pests in the world. Metarhizium rileyi is an entomopathogenic fungus specific for noctuid pests and is a very promising prospect in biological control against S. frugiperda. Two M. rileyi strains (XSBN200920 and HNQLZ200714) isolated from infected S. frugiperda were used to evaluate the virulence and biocontrol potential to different stages and instars of S. frugiperda. The results showed that XSBN200920 was significantly more virulent than HNQLZ200714 to eggs, larvae, pupae, and adults of S. frugiperda. In the larvae infected with the two M. rileyi strains, the activity of three protective enzymes (including peroxidase (POD), superoxide dismutase (SOD), catalase (CAT)) and two detoxifying enzymes (including glutathione-S transferase (GST) and carboxylesterase (CarE)) increased firstly and then decreased. The expression levels of protective enzymes and detoxification enzymes in larvae treated with XSBN200920 were greater than with HNQLZ200714. Furthermore, antioxidant stress-related gene (MrSOD and MrCAT family genes) expression in the two strains was measured by RT-qPCR (real-time quantitative PCR). The expression of these genes was significantly higher in the XSBN200920 strain compared to HNQLZ200714. There were also significant differences in the sensitivity of the two strains to the growth of different carbon and nitrogen sources and oxidative stress agents. In addition, the activity expression of antioxidant enzymes on the third day of culturing in XSBN200920 was significantly higher than with HNQLZ200714. In summary, the high virulence of M. rileyi XSBN200920 was not only determined by the expression levels of protective and detoxifying enzymes of the host but also regulated by the growth of entomogenic fungi and the resistance to the oxidative stress against S. frugiperda at different stages and instars. This study provides a theoretical fundament for the systematic control of Spodoptera frugiperda using Metarhizium rileyi.
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Succinate Dehydrogenase Subunit C Contributes to Mycelial Growth and Development, Stress Response, and Virulence in the Insect Parasitic Fungus Beauveria bassiana. Microbiol Spectr 2022; 10:e0289122. [PMID: 35972281 PMCID: PMC9602434 DOI: 10.1128/spectrum.02891-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Succinate dehydrogenase (SDH), also known as respiratory chain complex II, plays a crucial role in energy production in which SdhC functions as an anchored subunit in the inner membrane of mitochondria. In this study, domain annotation analyses revealed that two SdhC domain-containing proteins were present in the filamentous insect-pathogenic fungus Beauveria bassiana, and they were named BbSdhC1 and BbSdhC2, respectively. Only BbSdhC1 localized to mitochondria; hence, this protein is considered the ortholog of SdhC in B. bassiana. Ablation of BbSdhC1 led to significantly reduced vegetative growth on various nutrients. The ΔBbsdhc1 mutant displayed the significantly reduced ATP synthesis and abnormal differentiation under aerial and submerged conditions. Notably, the BbSdhC1 loss resulted in enhanced intracellular levels of reactive oxygen species (ROS) and impaired growth of mycelia under oxidative stress. Finally, insect bioassays (via cuticle and intrahemocoel injection infection) revealed that disruption of BbSdhC1 significantly attenuated fungal virulence against the insect hosts. These findings indicate that BbSdhC1 contributes to vegetative growth, resistance to oxidative stress, differentiation, and virulence of B. bassiana due to its roles in energy generation and maintaining the homeostasis of the intracellular ROS levels. IMPORTANCE The electron transport chain (ETC) is critical for energy supply by mediating the electron flow along the mitochondrial membrane. Succinate dehydrogenase (SDH) is also known as complex II in the ETC, in which SdhC is a subunit anchored in mitochondrial membrane. However, the physiological roles of SdhC remain enigmatic in filamentous fungi. In filamentous insect-pathogenic fungus B. bassiana, SdhC is required for maintaining mitochondrial functionality, which is critical for fungal stress response, development, and pathogenicity. These findings improve our understanding of physiological mechanisms of ETC components involved in pathogenicity of the entomopathogenic fungi.
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HapX, an Indispensable bZIP Transcription Factor for Iron Acquisition, Regulates Infection Initiation by Orchestrating Conidial Oleic Acid Homeostasis and Cytomembrane Functionality in Mycopathogen Beauveria bassiana. mSystems 2020; 5:5/5/e00695-20. [PMID: 33051379 PMCID: PMC7567583 DOI: 10.1128/msystems.00695-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Conidial maturation and germination are highly coupled physiological processes in filamentous fungi that are critical for the pathogenicity of mycopathogens. Compared to the mechanisms involved in conidial germination, those of conidial reserves during maturation are less understood. The insect-pathogenic fungus Beauveria bassiana, as a representative species of filamentous fungi, is important for applied and fundamental research. In addition to its conserved roles in fungal adaptation to iron status, the bZIP transcription factor HapX acts as a master regulator involved in conidial virulence and regulates fatty acid/lipid metabolism. Further investigation revealed that the Δ9-fatty acid desaturase gene (Ole1) is a direct downstream target of HapX. This study reveals the HapX-Ole1 pathway involved in the fatty acid/lipid accumulation associated with conidial maturation and provides new insights into the startup mechanism of infection caused by spores from pathogenic fungi. In pathogenic filamentous fungi, conidial germination not only is fundamental for propagation in the environment but is also a critical step of infection. In the insect mycopathogen Beauveria bassiana, we genetically characterized the role of the basic leucine zipper (bZIP) transcription factor HapX (BbHapX) in conidial nutrient reserves and pathogen-host interaction. Ablation of BbHapX resulted in an almost complete loss of virulence in the topical inoculation and intrahemocoel injection assays. Comparative transcriptomic analysis revealed that BbHapX is required for fatty acid (FA)/lipid metabolism, and biochemical analyses indicated that BbHapX loss caused a significant reduction in conidial FA contents. Exogenous oleic acid could partially or completely restore the impaired phenotypes of the ΔBbHapX mutant, including germination rate, membrane integrity, vegetative growth, and virulence. BbHapX mediates fungal iron acquisition which is not required for desaturation of stearic acid. Additionally, inactivation of the Δ9-fatty acid desaturase gene (BbOle1) generated defects similar to those of the ΔBbHapX mutant; oleic acid also had significant restorative effects on the defective phenotypes of the ΔBbOle1 mutant. A gel retarding assay revealed that BbHapX directly regulated the expression of BbOle1. Lipidomic analyses indicated that both BbHapX and BbOle1 contributed to the homeostasis of phospholipids with nonpolar tails derived from oleic acid; therefore, exogenous phospholipids could significantly restore membrane integrity. These data reveal that the HapX-Ole1 pathway contributes to conidial fatty acid/lipid reserves and that there are important links between the lipid biology and membrane functionality involved in the early stages of infection caused by B.bassiana. IMPORTANCE Conidial maturation and germination are highly coupled physiological processes in filamentous fungi that are critical for the pathogenicity of mycopathogens. Compared to the mechanisms involved in conidial germination, those of conidial reserves during maturation are less understood. The insect-pathogenic fungus Beauveria bassiana, as a representative species of filamentous fungi, is important for applied and fundamental research. In addition to its conserved roles in fungal adaptation to iron status, the bZIP transcription factor HapX acts as a master regulator involved in conidial virulence and regulates fatty acid/lipid metabolism. Further investigation revealed that the Δ9-fatty acid desaturase gene (Ole1) is a direct downstream target of HapX. This study reveals the HapX-Ole1 pathway involved in the fatty acid/lipid accumulation associated with conidial maturation and provides new insights into the startup mechanism of infection caused by spores from pathogenic fungi.
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Zhang L, Wang Y, Zhang Q, Jiang Y, Zhang H, Li R. Overexpression of HbMBF1a, encoding multiprotein bridging factor 1 from the halophyte Hordeum brevisubulatum, confers salinity tolerance and ABA insensitivity to transgenic Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2020; 102:1-17. [PMID: 31655970 PMCID: PMC6976555 DOI: 10.1007/s11103-019-00926-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 10/13/2019] [Indexed: 05/11/2023]
Abstract
HbMBF1a was isolated and characterized in H. brevisubulatum, and overexpressed HbMBF1a could enhance the salt tolerance and ABA insensitivity in Arabidopsis thaliana. The transcript levels of stress-responsive genes were significantly increased in the transgenic lines under salt and ABA conditions. Salinity is an abiotic stress that considerably affects plant growth, yield, and distribution. Hordeum brevisubulatum is a halophyte that evolved to become highly tolerant to salinity. Multiprotein bridging factor 1 (MBF1) is a transcriptional coactivator and an important regulator of stress tolerance. In this study, we isolated and characterized HbMBF1a based on the transcriptome data of H. brevisubulatum grown under saline conditions. We overexpressed HbMBF1a in Arabidopsis thaliana and compared the phenotypes of the transgenic lines and the wild-type in response to stresses. The results indicated that HbMBF1a expression was induced by salt and ABA treatments during the middle and late stages. The overexpression of HbMBF1a in A. thaliana resulted in enhanced salt tolerance and ABA insensitivity. More specifically, the enhanced salt tolerance manifested as the increased seed germination and seedling growth and development. Similarly, under ABA treatments, the cotyledon greening rate and seedling root length were higher in the HbMBF1a-overexpressing lines, suggesting the transgenic plants were better adapted to high exogenous ABA levels. Furthermore, the transcript levels of stress-responsive genes were significantly increased in the transgenic lines under salt and ABA conditions. Thus, HbMBF1a is a positive regulator of salt and ABA responses, and the corresponding gene may be useful for producing transgenic plants that are salt tolerant and/or ABA insensitive, with few adverse effects. This study involved a comprehensive analysis of HbMBF1a. The results may provide the basis and insight for the application of MBF1 family genes for developing stress-tolerant crops.
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Affiliation(s)
- Lili Zhang
- Beijing Academy of Agriculture and Forestry Sciences, No. 9 Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Agro-Biotechnology Research Center, Beijing, 100097 China
| | - Yunxiao Wang
- Beijing Academy of Agriculture and Forestry Sciences, No. 9 Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Agro-Biotechnology Research Center, Beijing, 100097 China
| | - Qike Zhang
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024 China
| | - Ying Jiang
- Beijing Academy of Agriculture and Forestry Sciences, No. 9 Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Agro-Biotechnology Research Center, Beijing, 100097 China
| | - Haiwen Zhang
- Beijing Academy of Agriculture and Forestry Sciences, No. 9 Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Agro-Biotechnology Research Center, Beijing, 100097 China
| | - Ruifen Li
- Beijing Academy of Agriculture and Forestry Sciences, No. 9 Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Agro-Biotechnology Research Center, Beijing, 100097 China
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Huang S, Keyhani NO, Zhao X, Zhang Y. The Thm1 Zn(II)2Cys6transcription factor contributes to heat, membrane integrity and virulence in the insect pathogenic fungusBeauveria bassiana. Environ Microbiol 2019; 21:3153-3171. [DOI: 10.1111/1462-2920.14718] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 01/08/2023]
Affiliation(s)
- Shuaishuai Huang
- Biotechnology Research Center, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest UniversitySouthwest University Chongqing 400715 P. R. China
- Department of Microbiology and Cell ScienceUniversity of Florida Gainesville Florida 32611 USA
| | - Nemat O. Keyhani
- Department of Microbiology and Cell ScienceUniversity of Florida Gainesville Florida 32611 USA
| | - Xin Zhao
- Biotechnology Research Center, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest UniversitySouthwest University Chongqing 400715 P. R. China
| | - Yongjun Zhang
- Biotechnology Research Center, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest UniversitySouthwest University Chongqing 400715 P. R. China
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Lin HY, Wang JJ, Feng MG, Ying SH. Autophagy-related gene ATG7 participates in the asexual development, stress response and virulence of filamentous insect pathogenic fungus Beauveria bassiana. Curr Genet 2019; 65:1015-1024. [PMID: 30879087 DOI: 10.1007/s00294-019-00955-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/06/2019] [Accepted: 03/12/2019] [Indexed: 12/21/2022]
Abstract
Autophagy is a sophisticated mechanism for maintaining cellular homeostasis, in which E1-like enzyme (ATG7) controls the activation of ubiquitin-like conjugation system in the autophagy pathway. In the insect pathogenic fungus Beauveria bassiana, a yeast ortholog of ATG7 was identified and functionally analyzed. Ablation of BbATG7 gene blocks the autophagic process under starvation stress. The mutant ΔBbATG7 exhibited impaired growth on the media with chitin as single nitrogen source. On rich media, gene loss did not cause notable effect on vegetative growth, but resulted in a considerable reduction in conidiation (71.6%) and blastospore yield (61.1%) in the mutant. In addition, the ΔBbATG7 mutant displayed increased sensitivity to stress caused by menadione and Congo red. The virulence of ΔBbATG7 mutant was significantly attenuated as indicated in topical and intrahemocoel injection assays. Our study indicates that BbATG7 contributes to B. bassiana virulence via regulating autophagy pathway and playing non-autophagic functions in the infection cycle.
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Affiliation(s)
- Hai-Yan Lin
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jia-Jia Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
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Ding JL, Peng YJ, Chu XL, Feng MG, Ying SH. Autophagy-related gene BbATG11 is indispensable for pexophagy and mitophagy, and contributes to stress response, conidiation and virulence in the insect mycopathogen Beauveria bassiana. Environ Microbiol 2018; 20:3309-3324. [PMID: 30058280 DOI: 10.1111/1462-2920.14329] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/06/2018] [Accepted: 06/17/2018] [Indexed: 12/17/2022]
Abstract
Autophagy is a conserved degradation system in eukaryotic cells that includes non-selective and selective processes. Selective autophagy functions as a selective degradation mechanism for specific substrates in which autophagy-related protein 11 (ATG11) acts as an essential scaffold protein. In B. bassiana, there is a unique ATG11 family protein, which is designated as BbATG11. Disruption of BbATG11 resulted in significantly reduced conidial germination under starvation stress. The mutant ΔBbATG11 displayed enhanced sensitivity to oxidative stress and impaired asexual reproduction. The conidial yield was reduced by approximately 75%, and this defective phenotype could be repressed by increasing exogenous nutrients. The virulence of the ΔBbATG11 mutant strain was significantly impaired as indicated in topical and intra-hemocoel injection bioassays, with a greater reduction in topical infection. Notably, BbATG11 was involved in pexophagy and mitophagy, but these two autophagic processes appeared in different fungal physiological aspects. Both pexophagy and mitophagy were associated with nutrient shift, starvation stress and growth in the host hemocoel, but only pexophagy appeared in both oxidation-stressed cells and aerial mycelia. This study highlights that BbATG11 mediates pexophagy and mitophagy in B. bassiana and links selective autophagy to the fungal stress response, conidiation and virulence.
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Affiliation(s)
- Jin-Li Ding
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yue-Jin Peng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Xin-Ling Chu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
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Peng YJ, Ding JL, Feng MG, Ying SH. Glc8, a regulator of protein phosphatase type 1, mediates oxidation tolerance, asexual development and virulence in Beauveria bassiana, a filamentous entomopathogenic fungus. Curr Genet 2018; 65:283-291. [DOI: 10.1007/s00294-018-0876-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/29/2018] [Accepted: 08/10/2018] [Indexed: 12/29/2022]
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