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Yi Y, Luan P, Fan M, Wu X, Sun Z, Shang Z, Yang Y, Li C. Antifungal efficacy of Bacillus amyloliquefaciens ZK-9 against Fusarium graminearum and analysis of the potential mechanism of its lipopeptides. Int J Food Microbiol 2024; 422:110821. [PMID: 38970998 DOI: 10.1016/j.ijfoodmicro.2024.110821] [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: 02/20/2024] [Revised: 06/22/2024] [Accepted: 06/29/2024] [Indexed: 07/08/2024]
Abstract
Fusarium graminearum is a destructive fungal pathogen that seriously threatens wheat production and quality. In the management of fungal infections, biological control is an environmentally friendly and sustainable approach. Here, the antagonistic strain ZK-9 with a broad antifungal activity was identified as Bacillus amyloliquefaciens. ZK-9 could produce extracellular enzymes such as pectinase, protease, cellulase, and amylase, as well as plant growth-promoting substances including IAA and siderophore. Lipopeptides extracted from strain ZK-9 had the high inhibitory effects on the mycelia of F. graminearum with the minimum inhibitory concentration (MIC) of 0.8 mg/mL. Investigation on the action mechanism of lipopeptides showed they could change the morphology of mycelia, damage the cell membrane, lower the content of ergosterol and increase the relative conductivity of membrane, cause nucleic acid and proteins leaking out from the cells, and disrupt the cell membrane permeability. Furthermore, metabolomic analysis of F. graminearum revealed the significant differences in the expression of 100 metabolites between the lipopeptides treatment group and the control group, which were associated with various metabolic pathways, mainly including amino acid biosynthesis, pentose, glucuronate and glycerophospholipid metabolism. In addition, strain ZK-9 inhibited Fusarium crown rot (FCR) with a biocontrol efficacy of 82.14 % and increased the plant height and root length by 24.23 % and 93.25 %, respectively. Moreover, the field control efficacy of strain ZK-9 on Fusarium head blight (FHB) was 71.76 %, and the DON content in wheat grains was significantly reduced by 69.9 %. This study puts valuable insights into the antifungal mechanism of lipopeptides against F. graminearum, and provides a promising biocontrol agent for controlling F. graminearum.
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Affiliation(s)
- Yanjie Yi
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; Food Laboratory of Zhongyuan, Luohe 462300, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China.
| | - Pengyu Luan
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; Food Laboratory of Zhongyuan, Luohe 462300, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China
| | - Minghao Fan
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China
| | - Xingquan Wu
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China
| | - Zhongke Sun
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China
| | - Zijun Shang
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China
| | - Yuzhen Yang
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China
| | - Chengwei Li
- School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China; The Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou 450001, China.
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Liu K, Wang X, Qi Y, Li Y, Shi Y, Ren Y, Wang A, Cheng P, Wang B. Effector Protein Serine Carboxypeptidase FgSCP Is Essential for Full Virulence in Fusarium graminearum and Is Involved in Modulating Plant Immune Responses. PHYTOPATHOLOGY 2024:PHYTO02240068R. [PMID: 38831556 DOI: 10.1094/phyto-02-24-0068-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Fusarium head blight caused by Fusarium graminearum is a significant pathogen affecting wheat crops. During the infection process, effector proteins are secreted to modulate plant immunity and promote infection. The toxin deoxynivalenol is produced in infected wheat grains, posing a threat to human and animal health. Serine carboxypeptidases (SCPs) belong to the α/β hydrolase family of proteases and are widely distributed in plant and fungal vacuoles, as well as animal lysosomes. Research on SCPs mainly focuses on the isolation, purification, and production of a small number of fungi. The role of SCPs in plant secretion, growth and development, and stress resistance has also been extensively studied. However, their functions in F. graminearum, a fungal pathogen, remain relatively unknown. In this study, the biological functions of the FgSCP gene in F. graminearum were investigated. The study revealed that mutations in FgSCP affected the nutritional growth, sexual reproduction, and stress tolerance of F. graminearum. Furthermore, the deletion of FgSCP resulted in reduced pathogenicity and hindered the biosynthesis of deoxynivalenol. The upregulation of FgSCP expression 3 days after infection indicated its involvement in host invasion, possibly acting as a "smokescreen" to deceive the host and suppress the expression of host defensive genes. Subsequently, we confirmed the secretion ability of FgSCP and its ability to inhibit the cell death induced by INF1 in Nicotiana benthamiana cells, indicating its potential role as an effector protein in suppressing plant immune responses and promoting infection. In summary, we have identified FgSCP as an essential effector protein in F. graminearum, playing critical roles in growth, virulence, secondary metabolism, and host invasion.
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Affiliation(s)
- Kouhan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xintong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yuzhe Qi
- Jilin Academy of Agricultural Sciences (Northeast Agricultural Research of China), Changchun, Jilin 136100, China
| | - Ying Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yifeng Shi
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yanyan Ren
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Aolin Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Peng Cheng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Baotong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
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Srivastava N, Shiburaj S, Khare SK. Improved production of alkaline and solvent-stable proteases from a halotolerant Exiguobacterium isolate through heterologous expression. Int J Biol Macromol 2024; 260:129507. [PMID: 38244731 DOI: 10.1016/j.ijbiomac.2024.129507] [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: 06/14/2023] [Revised: 12/31/2023] [Accepted: 01/12/2024] [Indexed: 01/22/2024]
Abstract
Halophiles are excellent sources of detergent proteases that are attributed to stability in alkaline pH, salts, surfactants, and hydrophobic solvents. The lower enzymatic yields and tedious downstream processes necessitate the search for newer halophilic sources. We have previously reported a halotolerant Exiguobacterium sp. TBG-PICH-001, which secretes solvent-tolerant alkaline protease/s. The present study describes the heterologous expression of two protease genes, namely, rsep metalloprotease (WP_195864791, 1.23 Kb) and tpa serine protease (WP_195864453, 0.879 Kb) genes. These were cloned into the pET 22b + plasmid vector and expressed in Escherichia coli BL21(DE3). The recombinant proteases rsep and tpa showed respective yields of 6.3 and 6.7 IU/mg, 11 and 12-fold higher than the crude native protease/s from TBG-PICH-001. These showed soluble expression at 46 and 32 KDa, respectively. These were purified to homogeneity through Ni-NTA-affinity chromatography. The purified proteases were characterized for properties like pH & temperature optima and stability, substrate specificity, kinetic parameters, and detergent attributes. They showed affinity towards various substrates with a respective Km of 392 and 301 μM towards casein. The recombinant proteases exhibited stability in the alkaline pH (7-10), surfactants, metal ions, detergents, and hydrophobic solvents, rendering their suitability as detergent additives.
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Affiliation(s)
- Nitin Srivastava
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Sugathan Shiburaj
- Department of Botany, University of Kerala, Palayam, Thiruvananthapuram, Kerala 695034, India
| | - Sunil Kumar Khare
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
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Tendiuk N, Diakonova A, Petrova O, Mukhametzyanov T, Makshakova O, Gorshkov V. Svx Peptidases of Phytopathogenic Pectolytic Bacteria: Structural, Catalytic and Phytoimmune Properties. Int J Mol Sci 2024; 25:756. [PMID: 38255830 PMCID: PMC10815107 DOI: 10.3390/ijms25020756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/31/2023] [Accepted: 01/02/2024] [Indexed: 01/24/2024] Open
Abstract
Svx proteins are virulence factors secreted by phytopathogenic bacteria of the Pectobacterium genus into the host plant cell wall. Svx-encoding genes are present in almost all species of the soft rot Pectobacteriaceae (Pectobacterium and Dickeya genera). The Svx of P. atrosepticum (Pba) has been shown to be a gluzincin metallopeptidase that presumably targets plant extensins, proteins that contribute to plant cell wall rigidity and participate in cell signaling. However, the particular "output" of the Pba Svx action in terms of plant-pathogen interactions and plant immune responses remained unknown. The Svx proteins are largely unexplored in Dickeya species, even though some of them have genes encoding two Svx homologs. Therefore, our study aims to compare the structural and catalytic properties of the Svx proteins of Pba and D. solani (Dso) and to test the phytoimmune properties of these proteins. Two assayed Dso Svx proteins, similar to Pba Svx, were gluzincin metallopeptidases with conservative tertiary structures. The two domains of the Svx proteins form electronegative clefts where the active centers of the peptidase domains are located. All three assayed Svx proteins possessed phytoimmunosuppressory properties and induced ethylene-mediated plant susceptible responses that play a decisive role in Pba-caused disease.
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Affiliation(s)
- Natalia Tendiuk
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia; (N.T.); (A.D.); (O.P.); (O.M.)
| | - Anastasiya Diakonova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia; (N.T.); (A.D.); (O.P.); (O.M.)
| | - Olga Petrova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia; (N.T.); (A.D.); (O.P.); (O.M.)
| | - Timur Mukhametzyanov
- Department of Physical Chemistry, Kazan Federal University, 420008 Kazan, Russia;
| | - Olga Makshakova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia; (N.T.); (A.D.); (O.P.); (O.M.)
| | - Vladimir Gorshkov
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia; (N.T.); (A.D.); (O.P.); (O.M.)
- Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008 Kazan, Russia
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Liu K, Wang X, Li Y, Shi Y, Ren Y, Wang A, Zhao B, Cheng P, Wang B. Protein Disulfide Isomerase FgEps1 Is a Secreted Virulence Factor in Fusarium graminearum. J Fungi (Basel) 2023; 9:1009. [PMID: 37888265 PMCID: PMC10607971 DOI: 10.3390/jof9101009] [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: 09/19/2023] [Revised: 10/07/2023] [Accepted: 10/10/2023] [Indexed: 10/28/2023] Open
Abstract
Protein disulfide isomerase (PDI) is a member of the thioredoxin (Trx) superfamily with important functions in cellular stability, ion uptake, and cellular differentiation. While PDI has been extensively studied in humans and animals, its role in fungi remains relatively unknown. In this study, the biological functions of FgEps1, a disulfide bond isomerase in the fungal pathogen Fusarium graminearum, were investigated. It was found that FgEps1 mutation affected nutritional growth, asexual and sexual reproduction, and stress tolerance. Additionally, its deletion resulted in reduced pathogenicity and impaired DON toxin biosynthesis. The involvement of FgEps1 in host infection was also confirmed, as its expression was detected during the infection period. Further investigation using a yeast signal peptide secretion system and transient expression in Nicotiana benthamiana showed that FgEps1 suppressed the immune response of plants and promoted infection. These findings suggest that virulence factor FgEps1 plays a crucial role in growth, development, virulence, secondary metabolism, and host infection in F. graminearum.
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Affiliation(s)
| | | | | | | | | | | | | | - Peng Cheng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (K.L.); (X.W.); (Y.L.); (Y.S.); (Y.R.); (A.W.); (B.Z.)
| | - Baotong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (K.L.); (X.W.); (Y.L.); (Y.S.); (Y.R.); (A.W.); (B.Z.)
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