Genes
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2019
·Vol. 10
·期 6
·412
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IF 3.331
Zhangxun Wang,Hong Zhu,Yuran Cheng,Yuanyuan Jiang,Yuandong Li,Bo Huang
The polyubiquitin gene is a highly conserved open reading frame that encodes different numbers of tandem ubiquitin repeats from different species, which play important roles in different biological processes.Metarhizium robertsiiis a fungal entomopathogen that is widely applied in the biological control of pest insects. However, it is unclear whether the polyubiquitin gene is required for fungal development, stress tolerance, and virulence in the entomopathogenic fungus. In the present study, the polyubiquitin gene (MrUBI4, MAA_02160) was functionally characterized via gene deletion inM. robertsii.Compared to the control strains, theMrUBI4deletion mutant showed delayed conidial germination and significantly decreased conidial yields (39% of the wild-type 14 days post-incubation). Correspondingly, the transcript levels of several genes from the central regulatory pathways associated with conidiation, includingbrlA,abaA,andwetA, were significantly downregulated, which indicated thatMrUBI4played an important role in asexual sporulation. Deletion ofMrUBI4especially resulted in increased sensitivity to ultraviolet (UV) and heat-shock stress based on conidial germination analysis between mutant and control strains. The significant increase in sensitivity to heat-shock was accompanied with reduced transcript levels of genes related to heat-shock protein (hsp), trehalose, and mannitol accumulation (tps,tpp,nth,andmpd) in theMrUBI4deletion mutant. Deletion ofMrUBI4has no effect on fungal virulence. Altogether,MrUBI4is involved in the regulation of conidiation, conidial germination, UV stress, and heat-shock response inM. robertsii.Keywords:Metarhizium robertsii;polyubiquitin;conidiation;conidial germination;stress tolerance
研究领域:
真菌学
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分子生物学
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植物保护
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DOI
PubMed
高影响因子
Science China-Life Sciences
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2022
·Vol. 66
·期 5
·1119-1133
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IF 10.372
Luo Feifei,Tang Guirong,Hong Song,Gong Tianyu,Xin Xiu-Fang,Wang Chengshu
The ascomycete insect pathogenic fungi such as Metarhizium species have been demonstrated with the abilities to form the rhizosphere or endophytic relationships with different plants for nutrient exchanges. In this study, after the evident infeasibility of bacterial disease development in the boxed sterile soils, we established a hydroponic system for the gnotobiotic growth of Arabidopsis thaliana with the wild-type and transgenic strain of Metarhizium robertsii . The transgenic fungus could produce a high amount of pipecolic acid (PIP), a pivotal plant-immune-stimulating metabolite. Fungal inoculation experiments showed that M. robertsii could form a non-selective rhizosphere relationship with Arabidopsis . Similar to the PIP uptake by plants after exogenous application, PIP level increased in Col-0 and could be detected in the PIP-non-producing Arabidopsis mutant ( ald1 ) after fungal inoculations, indicating that plants can absorb the PIP produced by fungi. The transgenic fungal strain had a better efficacy than the wild type to defend plants against the bacterial pathogen and aphid attacks. Contrary to ald1, fmo1 plants could not be boosted to resist bacterial infection after treatments. After fungal inoculations, the phytoalexins camalexin and aliphatic glucosinolate were selectively increased in Arabidopsis via both PIP-dependent and -independent ways. This study unveils the potential mechanism of the fungus-mediated beneficial promotion of plant immunity against biological stresses. The data also highlight the added values of M. robertsii to plants beyond the direct suppression of insect pest populations.
研究领域:
植物学
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微生物学
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分子生物学
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PubMed
高影响因子
EUKARYOTIC CELL
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2015
·Vol. 14
·期 4
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IF 2.82
Yanfang Shang,Peilin Chen,Yixiong Chen,Yuzhen Lu,Chengshu Wang
Two-component signaling pathways generally include sensor histidine kinases and response regulators. We identified an ortholog of the response regulator protein Skn7 in the insect-pathogenic fungus Metarhizium robertsii, which we named MrSkn7. Gene deletion assays and functional characterizations indicated that MrSkn7 functions as a transcription factor. The MrSkn7 null mutant of M. robertsii lost the ability to sporulate and had defects in cell wall biosynthesis but was not sensitive to oxidative and osmotic stresses compared to the wild type. However, the mutant was able to produce spores under salt stress. Insect bioassays using these spores showed that the virulence of the mutant was significantly impaired compared to that of the wild type due to the failures to form the infection structure appressorium and evade host immunity. In particular, deletion of MrSkn7 triggered cell autolysis with typical features such as cell vacuolization, downregulation of repressor genes, and upregulation of autolysis-related genes such as extracellular chitinases and proteases. Promoter binding assays confirmed that MrSkn7 could directly or indirectly control different putative target genes. Taken together, the results of this study help us understand the functional divergence of Skn7 orthologs as well as the mechanisms underlying the development and control of virulence in insect-pathogenic fungi.
研究领域:
真菌学
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分子生物学
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真菌遗传学
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昆虫病理学
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微生物致病机制
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DOI
高影响因子
Cell Reports
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2026
·Vol. 45
·期 6
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IF 7.7
Xinmiao Wang,Anxin Zhang,Chaonan Yu,Xingyuan Tang,Jiahui Wang,Fenglian Chen,Kun Jiang,Wen-Bing Yin,Weiguo Fang
Many microbial symbionts form distinct partnerships with different hosts. While the mechanisms specific to each partnership are well understood, the shared strategies that a symbiont uses to interact with disparate hosts remain understudied. Here, we report that the endophytic and entomopathogenic fungus Metarhizium robertsii deploys the farnesyltransferase inhibitor barceloneic acid A (BA-A) to modulate the physiology of insects and plants to develop parasitism and mutualism, respectively. During insect infection, BA-A inhibits host Ras protein farnesylation, reducing its cell membrane localization and suppressing MAPK/ERK phosphorylation and production of the hormone 20-hydroxyecdysone. This suppresses larval pupation and decelerates larval death by upregulating antibacterial peptides to kill gut-derived opportunistic pathogens in the hemocoel, prolonging M. robertsii ’s access to nutrient-rich larval hemolymph for maximal reproduction. BA-A also inhibits the plant farnesyltransferase, downregulating the defense-related protein PR2 to facilitate mutualism development. The BA-A biosynthetic gene cluster was characterized, which is activated during interactions with insects and plants.
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
·
IF 5.7
Guang Yang,Feihu Bi,Deshui Yu,Yulong Wang,Hui Ren,Hanchen Wei,Zhangxun Wang,Bo Huang
Entomopathogenic fungi offer an ecologically sustainable and highly effective alternative to chemical pesticides for managing plant pests. However, the efficacy of mycoinsecticides in pest control suffers from environmental abiotic stresses, such as solar UV radiation and temperature fluctuations, which seriously hinder their practical application in the field. Herein, we discovered that the synthetic amphiphilic thermal-responsive polymers are able to significantly enhance the resistance of Metarhizium robertsii conidia against thermal and UV irradiation stresses. The thermosensitive polymers with extremely low cytotoxicity and good biocompatibility can be engineered onto the M. robertsii conidia surface by anchoring hydrophobic alkyl chains. Further investigations revealed that polymer supplementation remarkably augmented the capacity for penetration and the virulence of M. robertsii under heat and UV stresses. Notably, broad-spectrum entomopathogenic fungi can be protected by the polymers. The molecular mechanism was elucidated through exploring RNA sequencing and in vivo/vitro enzyme activity assays. This work provides a novel avenue for fortifying the resilience of entomopathogenic fungi, potentially advancing their practical application as biopesticides.
研究领域:
生物技术
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微生物学
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害虫管理
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环境科学
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高影响因子
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