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Zhou J, Wang S, Xia Y, Peng G. MaAzaR, a Zn 2Cys 6/Fungus-Specific Transcriptional Factor, Is Involved in Stress Tolerance and Conidiation Pattern Shift in Metarhizium acridum. J Fungi (Basel) 2024; 10:468. [PMID: 39057353 PMCID: PMC11278141 DOI: 10.3390/jof10070468] [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: 06/11/2024] [Revised: 06/28/2024] [Accepted: 06/29/2024] [Indexed: 07/28/2024] Open
Abstract
Entomopathogenic fungi are valuable sources of biological pesticides, with conidial yield and quality being pivotal factors determining their broad applications. AzaR, a fungus-specific zinc-cluster transcription factor, is known to regulate the biosynthesis of polyketone secondary metabolites in Aspergillus niger; however, its role in pathogenic fungi remains unclear. This study investigated the role of MaAzaR in the growth, development, and environmental tolerance of Metarhizium acridum. MaAzaR deletion slowed down conidial germination rate, caused reduction in conidial yield, lowered fungal tolerance to UV radiation, did not affect fungal heat-shock tolerance, and increased fungal sensitivity to the cell-wall-destructive agent calcofluor white. Furthermore, MaAzaR deletion transformed microcycle conidiation to normal conidiation on the microcycle conidiation medium. Transcription profile analysis demonstrated that MaAzaR could regulate transformation of the conidiation pattern by controlling the expression of genes related to cell division, mycelium growth and development, and cell wall integrity. Thus, this study identified a new gene related to fungal conidiation and environmental tolerance, enriching our understanding of the molecular mechanism of microcycle conidiation and providing theoretical support and genetic resources for the development of high-yielding strains.
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Affiliation(s)
- Jinyuan Zhou
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
| | - Siqin Wang
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
| | - Guoxiong Peng
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
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Luo XC, Yu L, Xu SY, Ying SH, Feng MG. Photoreactivation Activities of Rad5, Rad16A and Rad16B Help Beauveria bassiana to Recover from Solar Ultraviolet Damage. J Fungi (Basel) 2024; 10:420. [PMID: 38921406 PMCID: PMC11205155 DOI: 10.3390/jof10060420] [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: 04/07/2024] [Revised: 06/02/2024] [Accepted: 06/12/2024] [Indexed: 06/27/2024] Open
Abstract
In budding yeast, Rad5 and Rad7-Rad16 play respective roles in the error-free post-replication repair and nucleotide excision repair of ultraviolet-induced DNA damage; however, their homologs have not yet been studied in non-yeast fungi. In the fungus Beauveria bassiana, a deficiency in the Rad7 homolog, Rad5 ortholog and two Rad16 paralogs (Rad16A/B) instituted an ability to help the insect-pathogenic fungus to recover from solar UVB damage through photoreactivation. The fungal lifecycle-related phenotypes were not altered in the absence of rad5, rad16A or rad16B, while severe defects in growth and conidiation were caused by the double deletion of rad16A and rad16B. Compared with the wild-type and complemented strains, the mutants showed differentially reduced activities regarding the resilience of UVB-impaired conidia at 25 °C through a 12-h incubation in a regime of visible light plus dark (L/D 3:9 h or 5:7 h for photoreactivation) or of full darkness (dark reactivation) mimicking a natural nighttime. The estimates of the median lethal UVB dose LD50 from the dark and L/D treatments revealed greater activities of Rad5 and Rad16B than of Rad16A and additive activities of Rad16A and Rad16B in either NER-dependent dark reactivation or photorepair-dependent photoreactivation. However, their dark reactivation activities were limited to recovering low UVB dose-impaired conidia but were unable to recover conidia impaired by sublethal and lethal UVB doses as did their photoreactivation activities at L/D 3:9 or 5:7, unless the night/dark time was doubled or further prolonged. Therefore, the anti-UV effects of Rad5, Rad16A and Rad16B in B. bassiana depend primarily on photoreactivation and are mechanistically distinct from those for their yeast homologs.
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Affiliation(s)
| | | | | | | | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China; (X.-C.L.); (L.Y.); (S.-Y.X.); (S.-H.Y.)
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Luo XC, Yu L, Xu SY, Ying SH, Feng MG. Rad6, a ubiquitin conjugator required for insect-pathogenic lifestyle, UV damage repair, and genomic expression of Beauveria bassiana. Microbiol Res 2024; 281:127622. [PMID: 38246123 DOI: 10.1016/j.micres.2024.127622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/09/2023] [Accepted: 01/13/2024] [Indexed: 01/23/2024]
Abstract
The E2 ubiquitin conjugator Rad6 is required for DNA damage bypass in budding yeast but remain functionally unknown in filamentous fungi. Here, we report pleiotropic effect of Rad6 ortholog in Beauveria bassiana, a wide-spectrum fungal insecticide. Global ubiquitination signal was greatly attenuated in the absence of rad6. The blocked ubiquitination led to severe growth defect, blocked asexual development, and abolished infectivity/insect pathogenicity, which correlated with compromised conidial quality (including viability, hydrophobicity, adherence to insect cuticle, and thermotolerance) and blocked secretion of cuticle-degrading enzymes including Pr1 family proteases. Importantly, Rad6 played much greater role in photoreactivation of UVB-impaired conidia by a 3- or 5-h light plus 9- or 7-h dark incubation than in dark reactivation of those impaired conidia by a 12-h dark incubation. The high activity of Rad6 in photoreactivation in vivo was derived from its link to a protein complex cored by the photolyase regulators WC1 and WC2 via the strong interactions of Rad6 with the E3 partner Rad18 and Rad18 with WC2 revealed in yeast two-hybrid assays. Transcriptomic analysis resulted in identification of 2700 differentially regulated genes involved in various function categories and metabolism pathways, indicating a regulatory role of Rad6-mediated ubiquitination in gene expression networks and genomic stability. Conclusively, Rad6 is required for asexual and insect-pathogenic lifecycles, solar UV damage repair, and genomic expression of B. bassiana. The primary dependence of its strong anti-UV role on photoreactivation in vivo unveils a scenario distinct from the core role of its yeast ortholog in DNA damage bypass.
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Affiliation(s)
- Xin-Cheng Luo
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Lei Yu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Si-Yuan Xu
- 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
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Peng H, Zhang YL, Ying SH, Feng MG. Rad2, Rad14 and Rad26 recover Metarhizium robertsii from solar UV damage through photoreactivation in vivo. Microbiol Res 2024; 280:127589. [PMID: 38154444 DOI: 10.1016/j.micres.2023.127589] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 12/30/2023]
Abstract
Rad2, Rad14 and Rad26 recover ultraviolet (UV) damage by nucleotide excision repair (NER) in budding yeast but their functions in filamentous fungi have not been elucidated. Here, we report mechanistically different anti-UV effects of nucleus-specific Rad2, Rad14 and Rad26 orthologs in Metarhizium robertsii, an insect-pathogenic fungus. The null mutants of rad2, rad14 and rad26 showed a decrease of ∼90% in conidial resistance to UVB irradiation. When conidia were impaired at a UVB dose of 0.15 J/cm2, they were photoreactivated (germinated) by only 6-13% through a 5-h light plus 19-h dark incubation, whereas 100%, 80% and 70% of the wild-type conidia were photoreactivated at 0.15, 0.3 and 0.4 J/cm2, respectively. The dose-dependent photoreactivation rates were far greater than the corresponding 24-h dark reactivation rates and were largely enhanced by the overexpression (OE) of rad2, rad14 or rad26 in the wild-type strain. The OE strains exhibited markedly greater activities in photoreactivation of conidia inactivated at 0.5-0.7 J/cm2 than did the wild-type strain. Confirmed interactions of Rad2, Rad14 and Rad26 with photolyase regulators and/or Rad1 or Rad10 suggest that each of these proteins could have evolved into a component of the photolyase regulator-cored protein complex to mediate photoreactivation. The interactions inhibited in the null mutants resulted in transcriptional abolishment or repression of those factors involved in the complex. In conclusion, the anti-UV effects of Rad2, Rad14 and Rad26 depend primarily on DNA photorepair-dependent photoreactivation in M. robertsii and mechanistically differ from those of yeast orthologs depending on NER.
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Affiliation(s)
- Han Peng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China; Clinical Research Institute, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| | - Yi-Lu Zhang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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Yu L, Xu SY, Luo XC, Ying SH, Feng MG. High photoreactivation activities of Rad2 and Rad14 in recovering insecticidal Beauveria bassiana from solar UV damage. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 251:112849. [PMID: 38277960 DOI: 10.1016/j.jphotobiol.2024.112849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/28/2023] [Accepted: 01/21/2024] [Indexed: 01/28/2024]
Abstract
Anti-ultraviolet (UV) roles of Rad2 and Rad14 depend on nucleotide excision repair (NER) of UV-induced DNA lesions in budding yeast but remain unexplored yet in filamentous fungi. Here, nucleus-specific Rad2 and Rad14 orthologs are shown to recover Beauveria bassiana, a main source of wide-spectrum mycoinsecticides, from solar UV damage through photorepair-depending photoreactivation. As a photorepair index, photoreactivation (germination) rates of lethal UVB dose-irradiated conidia via a 3- or 5-h light plus 9- or 7-h dark incubation at 25 °C were drastically reduced in the Δrad2 and Δrad14 mutants versus a wild-type strain. As an NER index, nighttime-mimicking 12-h dark reactivation rates of low UVB dose-impaired conidia decreased sharply compared to the corresponding photoreactivation rates in the presence or absence of either ortholog, indicating that its extant NER activity was limited to recovering light UVB damage in the field. The high photoreactivation activity of either Rad2 or Rad14 was derived from its tight link to a large protein complex formed by photolyase regulators and other anti-UV proteins through multiple protein-protein interactions revealed by yeast two-hybrid assays. Therefore, Rad2 and Rad14 recover B. bassiana from solar UV damage through photoreactiovation in vivo that depends primarily on photorepair, although they contribute little to the fungal lifecycle-related phenotypes. These findings unveil a novel scenario distinguished from the NER-depending anti-UV roles of Rad2 and Rad14 in the model yeast and broaden a biological basis crucial for rational application of fungal insecticides to improve pest control efficacy via feasible recovery of solar UV damage.
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Affiliation(s)
- Lei Yu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Si-Yuan Xu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xin-Cheng Luo
- 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
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Zhang YL, Peng H, Zhang K, Ying SH, Feng MG. Divergent roles of Rad4 and Rad23 homologs in Metarhizium robertsii's resistance to solar ultraviolet damage. Appl Environ Microbiol 2023; 89:e0099423. [PMID: 37655890 PMCID: PMC10537586 DOI: 10.1128/aem.00994-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 07/13/2023] [Indexed: 09/02/2023] Open
Abstract
The anti-ultraviolet (UV) role of a Rad4-Rad23-Rad33 complex in budding yeast relies on nucleotide excision repair (NER), which is mechanistically distinct from photorepair of DNA lesions generated under solar UV irradiation but remains poorly known in filamentous fungi. Here, two nucleus-specific Rad4 paralogs (Rad4A and Rad4B) and nucleocytoplasmic shuttling Rad23 ortholog are functionally characterized by multiple analyses of their null mutants in Metarhizium robertsii, an entomopathogenic fungus lacking Rad33. Rad4A was proven to interact with Rad23 and contribute significantly more to conidial UVB resistance (90%) than Rad23 (65%). Despite no other biological function, Rad4A exhibited a very high activity in photoreactivation of UVB-impaired/inactivated conidia by 5-h light exposure due to its interaction with Rad10, an anti-UV protein clarified previously to have acquired a similar photoreactivation activity through its interaction with a photolyase in M. robertsii. The NER activity of Rad4A or Rad23 was revealed by lower reactivation rates of moderately impaired conidia after 24-h dark incubation but hardly observable at the end of 12-h dark incubation, suggesting an infeasibility of its NER activity in the field where nighttime is too short. Aside from a remarkable contribution to conidial UVB resistance, Rad23 had pleiotropic effect in radial growth, aerial conidiation, antioxidant response, and cell wall integrity but no photoreactivation activity. However, Rad4B proved redundant in function. The high photoreactivation activity of Rad4A unveils its essentiality for M. robertsii's fitness to solar UV irradiation and is distinct from the yeast homolog's anti-UV role depending on NER. IMPORTANCE Resilience of solar ultraviolet (UV)-impaired cells is crucial for the application of fungal insecticides based on formulated conidia. Anti-UV roles of Rad4, Rad23, and Rad33 rely upon nucleotide excision repair (NER) of DNA lesions in budding yeast. Among two Rad4 paralogs and Rad23 ortholog characterized in Metarhizium robertsii lacking Rad33, Rad4A contributes to conidial UVB resistance more than Rad23, which interacts with Rad4A rather than functionally redundant Rad4B. Rad4A acquires a high activity in photoreactivation of conidia severely impaired or inactivated by UVB irradiation through its interaction with Rad10, another anti-UV protein previously proven to interact with a photorepair-required photolyase. The NER activity of either Rad4A or Rad23 is seemingly extant but unfeasible under field conditions. Rad23 has pleiotropic effect in the asexual cycle in vitro but no photoreactivation activity. Therefore, the strong anti-UV role of Rad4A depends on photoreactivation, unveiling a scenario distinct from the yeast homolog's NER-reliant anti-UV role.
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Affiliation(s)
- Yi-Lu Zhang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Han Peng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ke Zhang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
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Xu SY, Yu L, Luo XC, Ying SH, Feng MG. Co-Regulatory Roles of WC1 and WC2 in Asexual Development and Photoreactivation of Beauveria bassiana. J Fungi (Basel) 2023; 9:jof9030290. [PMID: 36983459 PMCID: PMC10056576 DOI: 10.3390/jof9030290] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/30/2023] Open
Abstract
The white collar proteins WC1 and WC2 interact with each other to form a white collar complex acting as a well-known transcription regulator required for the operation of the circadian clock in Neurospora, but their roles in insect-pathogenic fungal lifecycles remain poorly understood. Here, we report that WC1 and WC2 orthologs co-regulate the conidiation capacity and conidial resistance to solar ultraviolet-B (UVB) irradiation in Beauveria bassiana, after their high activities in the photorepair of UVB-induced DNA damages were elucidated previously in the insect mycopathogen, which features non-rhythmic conidiation and high conidiation capacity. The conidial yield, UVB resistance, and photoreactivation rate of UVB-impaired conidia were greatly reduced in the null mutants of wc1 and wc2 compared to their control strains. However, many other lifecycle-related phenotypes, except the antioxidant response, were rarely affected in the two mutants. Transcriptomic analysis revealed largely overlapping roles for WC1 and WC2 in regulating the fungal gene networks. Most of the differentially expressed genes identified from the null mutants of wc1 (1380) and wc2 (1001) were co-downregulated (536) or co-upregulated (256) at similar levels, including several co-downregulated genes required for aerial conidiation and DNA photorepair. These findings expand a molecular basis underlying the fungal adaptation to solar UV irradiation and offer a novel insight into the genome-wide co-regulatory roles of WC1 and WC2 in B. bassiana's asexual development and in vivo photoreactivation against solar UV damage.
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Affiliation(s)
- Si-Yuan Xu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Lei Yu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xin-Cheng Luo
- 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
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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