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Zhao Y, Yang K, Wang Y, Li X, Xia C, Huang Y, Li Z, Zhu C, Cui Z, Ye X. A novel xylanase from a myxobacterium triggers a plant immune response in Nicotiana benthamiana. MOLECULAR PLANT PATHOLOGY 2024; 25:e13488. [PMID: 38924248 PMCID: PMC11196902 DOI: 10.1111/mpp.13488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024]
Abstract
Xylanases derived from fungi, including phytopathogenic and nonpathogenic fungi, are commonly known to trigger plant immune responses. However, there is limited research on the ability of bacterial-derived xylanases to trigger plant immunity. Here, a novel xylanase named CcXyn was identified from the myxobacterium Cystobacter sp. 0969, which displays broad-spectrum activity against both phytopathogenic fungi and bacteria. CcXyn belongs to the glycoside hydrolases (GH) 11 family and shares a sequence identity of approximately 32.0%-45.0% with fungal xylanases known to trigger plant immune responses. Treatment of Nicotiana benthamiana with purified CcXyn resulted in the induction of hypersensitive response (HR) and defence responses, such as the production of reactive oxygen species (ROS) and upregulation of defence gene expression, ultimately enhancing the resistance of N. benthamiana to Phytophthora nicotianae. These findings indicated that CcXyn functions as a microbe-associated molecular pattern (MAMP) elicitor for plant immune responses, independent of its enzymatic activity. Similar to fungal xylanases, CcXyn was recognized by the NbRXEGL1 receptor on the cell membrane of N. benthamiana. Downstream signalling was shown to be independent of the BAK1 and SOBIR1 co-receptors, indicating the involvement of other co-receptors in signal transduction following CcXyn recognition in N. benthamiana. Moreover, xylanases from other myxobacteria also demonstrated the capacity to trigger plant immune responses in N. benthamiana, indicating that xylanases in myxobacteria are ubiquitous in triggering plant immune functions. This study expands the understanding of xylanases with plant immune response-inducing properties and provides a theoretical basis for potential applications of myxobacteria in biocontrol strategies against phytopathogens.
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Affiliation(s)
- Yuqiang Zhao
- Institute of BotanyJiangsu Province and Chinese Academy of SciencesNanjingChina
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
| | - Kun Yang
- Crop Research InstituteGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Yanxin Wang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
- College of Life SciencesLiaocheng UniversityLiaochengChina
| | - Xu Li
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
| | - Chengyao Xia
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
| | - Yan Huang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
| | - Zhoukun Li
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
| | - Cancan Zhu
- Institute of BotanyJiangsu Province and Chinese Academy of SciencesNanjingChina
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
| | - Xianfeng Ye
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life SciencesNanjing Agricultural UniversityNanjingChina
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Umer MJ, Zheng J, Yang M, Batool R, Abro AA, Hou Y, Xu Y, Gebremeskel H, Wang Y, Zhou Z, Cai X, Liu F, Zhang B. Insights to Gossypium defense response against Verticillium dahliae: the Cotton Cancer. Funct Integr Genomics 2023; 23:142. [PMID: 37121989 DOI: 10.1007/s10142-023-01065-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 05/02/2023]
Abstract
The soil-borne pathogen Verticillium dahliae, also referred as "The Cotton Cancer," is responsible for causing Verticillium wilt in cotton crops, a destructive disease with a global impact. To infect cotton plants, the pathogen employs multiple virulence mechanisms such as releasing enzymes that degrade cell walls, activating genes that contribute to virulence, and using protein effectors. Conversely, cotton plants have developed numerous defense mechanisms to combat the impact of V. dahliae. These include strengthening the cell wall by producing lignin and depositing callose, discharging reactive oxygen species, and amassing hormones related to defense. Despite the efforts to develop resistant cultivars, there is still no permanent solution to Verticillium wilt due to a limited understanding of the underlying molecular mechanisms that drive both resistance and pathogenesis is currently prevalent. To address this challenge, cutting-edge technologies such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), host-induced gene silencing (HIGS), and gene delivery via nano-carriers could be employed as effective alternatives to control the disease. This article intends to present an overview of V. dahliae virulence mechanisms and discuss the different cotton defense mechanisms against Verticillium wilt, including morphophysiological and biochemical responses and signaling pathways including jasmonic acid (JA), salicylic acid (SA), ethylene (ET), and strigolactones (SLs). Additionally, the article highlights the significance of microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs) in gene expression regulation, as well as the different methods employed to identify and functionally validate genes to achieve resistance against this disease. Gaining a more profound understanding of these mechanisms could potentially result in the creation of more efficient strategies for combating Verticillium wilt in cotton crops.
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Affiliation(s)
- Muhammad Jawad Umer
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Jie Zheng
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
- Hainan Yazhou Bay Seed Laboratory, China/National Nanfan, Research Institute of Chinese Academy of Agricultural Sciences, Sanya, 572025, China
| | - Mengying Yang
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Raufa Batool
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Aamir Ali Abro
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Yuqing Hou
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Yanchao Xu
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Haileslassie Gebremeskel
- Mehoni Agricultural Research Center, Ethiopian Institute of Agricultural Research, Addis Ababa, Ethiopia
| | - Yuhong Wang
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - ZhongLi Zhou
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Xiaoyan Cai
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
- Hainan Yazhou Bay Seed Laboratory, China/National Nanfan, Research Institute of Chinese Academy of Agricultural Sciences, Sanya, 572025, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University/Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang, China
| | - Fang Liu
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China.
- Hainan Yazhou Bay Seed Laboratory, China/National Nanfan, Research Institute of Chinese Academy of Agricultural Sciences, Sanya, 572025, China.
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University/Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang, China.
| | - Baohong Zhang
- State Key Laboratory of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China.
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA.
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Sattrapai N, Chaiprom U, Lindow SE, Chatnaparat T. A Phosphate Uptake System Is Required for Xanthomonas citri pv. glycines Virulence in Soybean. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:261-272. [PMID: 36574016 DOI: 10.1094/mpmi-11-22-0241-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The genes encoding the phosphate uptake system in Xanthomonas citri pv. glycines 12-2 were previously found to be upregulated when in soybean leaves. This study thus explored the role of the phosphate uptake system on its virulence to soybean. While phoB and pstSCAB mutants were greatly impaired in both inciting disease symptoms and growth in soybean, the virulence and growth in soybean of a phoU mutant was not reduced when compared with the wild-type strain. The expression of phoB and pstSCAB was highly induced in phosphate-deficient media. In addition, the expression of phoB, assessed with a fusion to a promoterless ice nucleation reporter gene, was greatly increased in soybean leaves, confirming that the soybean apoplast is a phosphorus-limited habitat for X. citri pv. glycines. Global gene expression profiles of phoB and phoU mutants of X. citri pv. glycines conducted under phosphate-limitation conditions in vitro, using RNA-seq, revealed that PhoB positively regulated genes involved in signal transduction, the xcs cluster type II secretion system, cell motility, and chemotaxis, while negatively regulating cell wall and membrane biogenesis, DNA replication and recombination and repair, and several genes with unknown function. PhoU also positively regulated the same genes involved in cell motility and chemotaxis. The severity of bacterial pustule disease was decreased in soybean plants grown under high phosphate fertilization conditions, demonstrating that high phosphate availability in soybean plants can affect infection by X. citri pv. glycines by modulation of the expression of phosphate uptake systems. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Nutthakan Sattrapai
- Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies for Agriculture and Food (CASAF), Kasetsart University, Bangkok, Thailand
| | - Usawadee Chaiprom
- National Biobank of Thailand (NBT), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
| | - Steven E Lindow
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, U.S.A
| | - Tiyakhon Chatnaparat
- Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies for Agriculture and Food (CASAF), Kasetsart University, Bangkok, Thailand
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Piombo E, Guaschino M, Jensen DF, Karlsson M, Dubey M. Insights into the ecological generalist lifestyle of Clonostachys fungi through analysis of their predicted secretomes. Front Microbiol 2023; 14:1112673. [PMID: 36876087 PMCID: PMC9978495 DOI: 10.3389/fmicb.2023.1112673] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/30/2023] [Indexed: 02/18/2023] Open
Abstract
Introduction The fungal secretome comprise diverse proteins that are involved in various aspects of fungal lifestyles, including adaptation to ecological niches and environmental interactions. The aim of this study was to investigate the composition and activity of fungal secretomes in mycoparasitic and beneficial fungal-plant interactions. Methods We used six Clonostachys spp. that exhibit saprotrophic, mycotrophic and plant endophytic lifestyles. Genome-wide analyses was performed to investigate the composition, diversity, evolution and gene expression of Clonostachys secretomes in relation to their potential role in mycoparasitic and endophytic lifestyles. Results and discussion Our analyses showed that the predicted secretomes of the analyzed species comprised between 7 and 8% of the respective proteomes. Mining of transcriptome data collected during previous studies showed that 18% of the genes encoding predicted secreted proteins were upregulated during the interactions with the mycohosts Fusarium graminearum and Helminthosporium solani. Functional annotation of the predicted secretomes revealed that the most represented protease family was subclass S8A (11-14% of the total), which include members that are shown to be involved in the response to nematodes and mycohosts. Conversely, the most numerous lipases and carbohydrate-active enzyme (CAZyme) groups appeared to be potentially involved in eliciting defense responses in the plants. For example, analysis of gene family evolution identified nine CAZyme orthogroups evolving for gene gains (p ≤ 0.05), predicted to be involved in hemicellulose degradation, potentially producing plant defense-inducing oligomers. Moreover, 8-10% of the secretomes was composed of cysteine-enriched proteins, including hydrophobins, important for root colonization. Effectors were more numerous, comprising 35-37% of the secretomes, where certain members belonged to seven orthogroups evolving for gene gains and were induced during the C. rosea response to F. graminearum or H. solani. Furthermore, the considered Clonostachys spp. possessed high numbers of proteins containing Common in Fungal Extracellular Membranes (CFEM) modules, known for their role in fungal virulence. Overall, this study improves our understanding of Clonostachys spp. adaptation to diverse ecological niches and establishes a basis for future investigation aiming at sustainable biocontrol of plant diseases.
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Affiliation(s)
- Edoardo Piombo
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Micol Guaschino
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Grugliasco, Italy
| | - Dan Funck Jensen
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Magnus Karlsson
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Mukesh Dubey
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Shabbir A, Batool W, Yu D, Lin L, An Q, Xiaomin C, Guo H, Yuan S, Malota S, Wang Z, Norvienyeku J. Magnaporthe oryzae Chloroplast Targeting Endo-β-1,4-Xylanase I MoXYL1A Regulates Conidiation, Appressorium Maturation and Virulence of the Rice Blast Fungus. RICE (NEW YORK, N.Y.) 2022; 15:44. [PMID: 35960402 PMCID: PMC9374862 DOI: 10.1186/s12284-022-00584-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Endo-β-1,4-Xylanases are a group of extracellular enzymes that catalyze the hydrolysis of xylan, a principal constituent of the plant primary cell wall. The contribution of Endo-β-1,4-Xylanase I to both physiology and pathogenesis of the rice blast fungus M. oryzae is unknown. Here, we characterized the biological function of two endoxylanase I (MoXYL1A and MoXYL1B) genes in the development of M. oryzae using targeted gene deletion, biochemical analysis, and fluorescence microscopy. Phenotypic analysis of ∆Moxyl1A strains showed that MoXYL1A is required for the full virulence of M. oryzae but is dispensable for the vegetative growth of the rice blast fungus. MoXYL1B, in contrast, did not have a clear role in the infectious cycle but has a critical function in asexual reproduction of the fungus. The double deletion mutant was severely impaired in pathogenicity and virulence as well as asexual development. We found that MoXYL1A deletion compromised appressorium morphogenesis and function, leading to failure to penetrate host cells. Fluorescently tagged MoXYL1A and MoXYL1B displayed cytoplasmic localization in M. oryzae, while analysis of MoXYL1A-GFP and MoXYL1B-GFP in-planta revealed translocation and accumulation of these effector proteins into host cells. Meanwhile, sequence feature analysis showed that MoXYL1A possesses a transient chloroplast targeting signal peptide, and results from an Agrobacterium infiltration assay confirmed co-localization of MoXYL1A-GFP with ChCPN10C-RFP in the chloroplasts of host cells. MoXYL1B, accumulated to the cytoplasm of the host. Taken together, we conclude that MoXYL1A is a secreted effector protein that likely promotes the virulence of M. oryzae by interfering in the proper functioning of the host chloroplast, while the related xylanase MoXYL1B does not have a major role in virulence of M. oryzae.
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Affiliation(s)
- Ammarah Shabbir
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Wajjiha Batool
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- Institute of Oceanography, Minjiang University, Fuzhou, 350108 China
| | - Dan Yu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
| | - Lili Lin
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Qiuli An
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Chen Xiaomin
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Hengyuan Guo
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
| | - Shuangshuang Yuan
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Sekete Malota
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Zonghua Wang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Shenyang Agriculture University, Shenyang, China
| | - Justice Norvienyeku
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
- Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China
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Huang W, Zhang Y, Zhou J, Wei F, Feng Z, Zhao L, Shi Y, Feng H, Zhu H. The Respiratory Burst Oxidase Homolog Protein D ( GhRbohD) Positively Regulates the Cotton Resistance to Verticillium dahliae. Int J Mol Sci 2021; 22:ijms222313041. [PMID: 34884844 PMCID: PMC8657740 DOI: 10.3390/ijms222313041] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 11/30/2021] [Accepted: 11/30/2021] [Indexed: 01/02/2023] Open
Abstract
Verticillium wilt, mainly caused by a soil-inhabiting fungus Verticillium dahliae, can seriously reduce the yield and quality of cotton. The complex mechanism underlying cotton resistance to Verticillium wilt remains largely unknown. In plants, reactive oxygen species (ROS) mediated by Rbohs is one of the earliest responses of plants to biotic and abiotic stresses. In our previous study, we performed a time-course phospho-proteomic analysis of roots of resistant and susceptible cotton varieties in response to V. dahliae, and found early differentially expressed protein burst oxidase homolog protein D (GhRbohD). However, the role of GhRbohD-mediated ROS in cotton defense against V. dahliae needs further investigation. In this study, we analyzed the function of GhRbohD-mediated resistance of cotton against V. dahliae in vitro and in vivo. Bioinformatics analysis showed that GhRbohD possessed the conservative structural attributes of Rbohs family, 12 members of RbohD out of 57 Rbohs in cotton. The expression of GhRbohD was significantly upregulated after V. dahliae inoculation, peaking at 6 hpi, and the phosphorylation level was also increased. A VIGS test demonstrated that ROS production, NO, H2O2 and Ca2+ contents of GhRbohD-silenced cotton plants were significantly reduced, and lignin synthesis and callose accumulation were damaged, important reasons for the impairment of GhRbohD-silenced cotton’s defense against V. dahliae. The expression levels of resistance-related genes were downregulated in GhRbohD-silenced cotton by qRT-PCR, mainly involving the lignin metabolism pathway and the jasmonic acid signaling pathway. However, overexpression of GhRbohD enhanced resistance of transgenic Arabidopsis to V. dahliae challenge. Furthermore, Y2H assays were applied to find that GhPBL9 and GhRPL12C may interact with GhRbohD. These results strongly support that GhRbohD activates ROS production to positively regulate the resistance of plants against V. dahliae.
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Affiliation(s)
- Wanting Huang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Life Science, Zhengzhou University, Zhengzhou 450001, China
| | - Yalin Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
| | - Jinglong Zhou
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
| | - Feng Wei
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Zili Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
| | - Lihong Zhao
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
| | - Yongqiang Shi
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
| | - Hongjie Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (H.F.); (H.Z.); Tel.: +86-0372-2562280 (H.Z.)
| | - Heqin Zhu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (W.H.); (Y.Z.); (J.Z.); (F.W.); (Z.F.); (L.Z.); (Y.S.)
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (H.F.); (H.Z.); Tel.: +86-0372-2562280 (H.Z.)
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Wang D, Chen JY, Song J, Li JJ, Klosterman SJ, Li R, Kong ZQ, Subbarao KV, Dai XF, Zhang DD. Cytotoxic function of xylanase VdXyn4 in the plant vascular wilt pathogen Verticillium dahliae. PLANT PHYSIOLOGY 2021; 187:409-429. [PMID: 34618145 PMCID: PMC8418393 DOI: 10.1093/plphys/kiab274] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 05/22/2021] [Indexed: 05/24/2023]
Abstract
Phytopathogen xylanases play critical roles in pathogenesis, likely due to their ability to degrade plant structural barriers and manipulate host immunity. As an invader of plant xylem vessels, the fungus Verticillium dahliae is thought to deploy complex cell wall degrading enzymes. Comparative genomics analyses revealed that the V. dahliae genome encodes a family of six xylanases, each possessing a glycosyl hydrolase 11 domain, but the functions of these enzymes are undetermined. Characterizing gene deletion mutants revealed that only V. dahliae xylanase 4 (VdXyn4) degraded the plant cell wall and contributed to the virulence of V. dahliae. VdXyn4 displayed cytotoxic activity and induced a necrosis phenotype during the late stages of infection, leading to vein and petiole collapse that depended on the enzyme simultaneously localizing to nuclei and chloroplasts. The internalization of VdXyn4 was in conjunction with that of the plasma membrane complexLeucine-rich repeat (LRR)-receptor-like kinase suppressor of BIR1-1 (SOBIR1)/LRR-RLK BRI1-associated kinase-1 (BAK1), but we could not rule out the possibility that VdXyn4 may also act as an apoplastic effector. Immune signaling (in the SA-JA pathways) induced by VdXyn4 relative to that induced by known immunity effectors was substantially delayed. While cytotoxic activity could be partially suppressed by known effectors, they failed to impede necrosis in Nicotiana benthamiana. Thus, unlike typical effectors, cytotoxicity of VdXyn4 plays a crucial intracellular role at the late stages of V. dahliae infection and colonization, especially following pathogen entry into the xylem; this cytotoxic activity is likely conserved in the corresponding enzyme families in plant vascular pathogens.
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Affiliation(s)
- Dan Wang
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jie-Yin Chen
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jian Song
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jun-Jiao Li
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Steven J. Klosterman
- Department of Agriculture, Agricultural Research Service, Crop Improvement and Protection Research Unit, Salinas, California, USA
| | - Ran Li
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhi-Qiang Kong
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Krishna V. Subbarao
- Department of Plant Pathology, University of California, Davis, c/o U.S. Agricultural Research Station, Salinas, California, USA
| | - Xiao-Feng Dai
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Dan-Dan Zhang
- Team of Crop Verticillium wilt, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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Tanui CK, Shyntum DY, Sedibane PK, Bellieny-Rabelo D, Moleleki LN. Pectobacterium brasiliense 1692 Chemotactic Responses and the Role of Methyl-Accepting Chemotactic Proteins in Ecological Fitness. FRONTIERS IN PLANT SCIENCE 2021; 12:650894. [PMID: 33968106 PMCID: PMC8100591 DOI: 10.3389/fpls.2021.650894] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
To adapt to changing environmental niches, bacteria require taxis, a movement toward or away from a stimulus (ligand). Chemotaxis has been studied in some members of the Soft Rot Pectobacteriaceae (SRP), particularly members of the genus Dickeya. On the contrary, there are fewer studies on this topic for the other genus in the SRP group, namely Pectobacterium. This study evaluated chemotactic responses in Pectobacterium brasiliense (Pb 1692) to various ligands. A total of 34 methyl-accepting chemotactic proteins (MCPs) were identified in the Pb 1692 genome and the domain architectures of these MCPs were determined. Four Pb 1692 MCPs previously shown to be differentially expressed during potato tuber infection were selected for further functional characterization. Toward this end, Pb 1692 mutant strains each lacking either AED-0001492, AED-0003671, AED-0000304, or AED-0000744 were generated. Two of these mutants (AED-0001492 and AED-0003671), were attenuated in their ability to grow and respond to citrate and are thus referred to as MCP cit2 and MCP cit1 , respectively, while the other two, AED-0000304 (MCP xyl ) and AED-0000744 (MCP asp ), were affected in their ability to respond to xylose and aspartate, respectively. Trans-complementation of the mutant strains restored swimming motility in the presence of respective ligands. The four MCP mutants were not affected in virulence but were significantly attenuated in their ability to attach to potato leaves suggesting that ecological fitness is an important contribution of these MCPs toward Pb 1692 biology.
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Affiliation(s)
| | - Divine Yutefar Shyntum
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa
| | - Precious K. Sedibane
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Daniel Bellieny-Rabelo
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa
| | - Lucy N. Moleleki
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
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9
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Guo R, Ji S, Wang Z, Zhang H, Wang Y, Liu Z. Trichoderma asperellum xylanases promote growth and induce resistance in poplar. Microbiol Res 2021; 248:126767. [PMID: 33873138 DOI: 10.1016/j.micres.2021.126767] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/29/2021] [Accepted: 04/03/2021] [Indexed: 12/18/2022]
Abstract
Xylanase secreted by Trichoderma asperellum ACCC30536 can stimulate the systemic resistance of host plants against pathogenic fungi. Following T. asperellum conidia co-culture with Populus davidiana × P. alba var. pyramidalis Louche (PdPap) seedlings, the expression of xylanases TasXyn29.4 and TasXyn24.2 in T. asperellum were upregulated, peaking at 12 h, by 106 (26.74) and 10.1 (23.34)-fold compared with the control, respectively. However, the expression of TasXyn24.4 and TasXyn24.0 was not detected. When recombinant xylanases rTasXyn29.4 and rTasXyn24.2 were heterologously expressed in Pichia pastoris GS115, their activities reached 18.9 IU/mL and 20.4 IU/mL, respectively. In PdPap seedlings induced by rTasXyn29.4 and rTasXyn24.2, the auxin and jasmonic acid signaling pathways were activated to promote growth and enhance resistance against pathogens. PdPap seedlings treated with both xylanases showed increased methyl jasmonate contents at 12 hpi, reaching 122 % (127 μg/g) compared with the control. However, neither of the xylanases could induce the salicylic acid signaling pathway in PdPap seedlings. Meanwhile, both xylanases could enhance the antioxidant ability of PdPap seedlings by improving their catalase activity. Both xylanases significantly induced systemic resistance of PdPap seedlings against Alternaria alternata, Rhizoctonia solani, and Fusarium oxysporum. However, the xylanases could only be sensed by the roots of the PdPap seedlings, not the leaves. In summary, rTasXyn29.4 and rTasXyn24.2 from T. asperellum ACCC30536 promoted growth and induced systemic resistance of PdPap seedlings, which endowed the PdPap seedlings broad-spectrum resistance to phytopathogens.
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Affiliation(s)
- Ruiting Guo
- School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Shida Ji
- College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China.
| | - Zhiying Wang
- School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Huifang Zhang
- College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China
| | - Yucheng Wang
- College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China; School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China
| | - Zhihua Liu
- College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China; School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.
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10
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Backes A, Guerriero G, Ait Barka E, Jacquard C. Pyrenophora teres: Taxonomy, Morphology, Interaction With Barley, and Mode of Control. FRONTIERS IN PLANT SCIENCE 2021; 12:614951. [PMID: 33889162 PMCID: PMC8055952 DOI: 10.3389/fpls.2021.614951] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 03/08/2021] [Indexed: 05/27/2023]
Abstract
Net blotch, induced by the ascomycete Pyrenophora teres, has become among the most important disease of barley (Hordeum vulgare L.). Easily recognizable by brown reticulated stripes on the sensitive barley leaves, net blotch reduces the yield by up to 40% and decreases seed quality. The life cycle, the mode of dispersion and the development of the pathogen, allow a quick contamination of the host. Crop residues, seeds, and wild grass species are the inoculum sources to spread the disease. The interaction between the barley plant and the fungus is complex and involves physiological changes with the emergence of symptoms on barley and genetic changes including the modulation of different genes involved in the defense pathways. The genes of net blotch resistance have been identified and their localizations are distributed on seven barley chromosomes. Considering the importance of this disease, several management approaches have been performed to control net blotch. One of them is the use of beneficial bacteria colonizing the rhizosphere, collectively referred to as Plant Growth Promoting Rhizobacteria. Several studies have reported the protective role of these bacteria and their metabolites against potential pathogens. Based on the available data, we expose a comprehensive review of Pyrenophora teres including its morphology, interaction with the host plant and means of control.
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Affiliation(s)
- Aurélie Backes
- Unité de Recherche Résistance Induite et Bioprotection des Plantes, Université de Reims Champagne-Ardenne, Reims, France
| | - Gea Guerriero
- Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Hautcharage, Luxembourg
| | - Essaid Ait Barka
- Unité de Recherche Résistance Induite et Bioprotection des Plantes, Université de Reims Champagne-Ardenne, Reims, France
| | - Cédric Jacquard
- Unité de Recherche Résistance Induite et Bioprotection des Plantes, Université de Reims Champagne-Ardenne, Reims, France
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11
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Zhu D, Liu X, Xie X, Yang S, Lin H, Chen H. Characteristics of a
XIP
‐resistant xylanase from
Neocallimastix
sp.
GMLF
1 and its advantage in barley malt saccharification. Int J Food Sci Technol 2020. [DOI: 10.1111/ijfs.14341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dongdong Zhu
- College of Life Sciences Henan Agricultural University 95 Wenhua Road Zhengzhou 450002 China
| | - Xinyu Liu
- College of Life Sciences Henan Agricultural University 95 Wenhua Road Zhengzhou 450002 China
| | - Xia Xie
- College of Life Sciences Henan Agricultural University 95 Wenhua Road Zhengzhou 450002 China
| | - Sen Yang
- College of Life Sciences Henan Agricultural University 95 Wenhua Road Zhengzhou 450002 China
| | - Hui Lin
- College of Life Sciences Henan Agricultural University 95 Wenhua Road Zhengzhou 450002 China
| | - Hongge Chen
- College of Life Sciences Henan Agricultural University 95 Wenhua Road Zhengzhou 450002 China
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12
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Global Characterization of GH10 Family Xylanase Genes in Rhizoctonia cerealis and Functional Analysis of Xylanase RcXYN1 During Fungus Infection in Wheat. Int J Mol Sci 2020; 21:ijms21051812. [PMID: 32155734 PMCID: PMC7084588 DOI: 10.3390/ijms21051812] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 02/08/2023] Open
Abstract
Wheat (Triticum aestivum L.) is an important staple crop. Rhizoctonia cerealis is the causal agent of diseases that are devastating to cereal crops, including wheat. Xylanases play an important role in pathogenic infection, but little is known about xylanases in R. cerealis. Herein, we identified nine xylanase-encoding genes from the R. cerealis genome, named RcXYN1–RcXYN9, examined their expression patterns, and investigated the pathogenicity role of RcXYN1. RcXYN1–RcXYN9 proteins contain two conserved glutamate residues within the active motif in the glycoside hydrolase 10 (GH10) domain. Of them, RcXYN1–RcXYN4 are predicted to be secreted proteins. RcXYN1–RcXYN9 displayed different expression patterns during the infection process of wheat, and RcXYN1, RcXYN2, RcXYN5, and RcXYN9 were expressed highly across all the tested inoculation points. Functional dissection indicated that the RcXYN1 protein was able to induce necrosis/cell-death and H2O2 generation when infiltrated into wheat and Nicotiana benthamiana leaves. Furthermore, application of RcXYN1 protein followed by R. cerealis led to significantly higher levels of the disease in wheat leaves than application of the fungus alone. These results demonstrate that RcXYN1 acts as a pathogenicity factor during R. cerealis infection in wheat. This is the first investigation of xylanase genes in R. cerealis, providing novel insights into the pathogenesis mechanisms of R. cerealis.
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13
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Song R, Li J, Xie C, Jian W, Yang X. An Overview of the Molecular Genetics of Plant Resistance to the Verticillium Wilt Pathogen Verticillium dahliae. Int J Mol Sci 2020; 21:ijms21031120. [PMID: 32046212 PMCID: PMC7037454 DOI: 10.3390/ijms21031120] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/09/2020] [Accepted: 01/28/2020] [Indexed: 01/01/2023] Open
Abstract
Verticillium dahliae is a soil-borne hemibiotrophic fungus that can lead to plant vascular disease and significant economic loss worldwide. Its hosts include over 400 dicotyledon plant species, such as annual herbs, perennials, and woody plants. The average yield loss of cotton crop caused by Verticillium wilt is approximately 10–35%. As the control of this disease is an urgent task for many countries, further understanding of the interaction between plants and V. dahliae is essential. Fungi can promote or inhibit plant growth, which is important; however, the most important relationship between plants and fungi is the host–pathogen relationship. Plants can become resistant to V. dahliae through diverse mechanisms such as cell wall modifications, extracellular enzymes, pattern recognition receptors, transcription factors, and salicylic acid (SA)/jasmonic acid (JA)/ethylene (ET)-related signal transduction pathways. Over the last decade, several studies on the physiological and molecular mechanisms of plant resistance to V. dahliae have been undertaken. In this review, many resistance-related genes are summarised to provide a theoretical basis for better understanding of the molecular genetic mechanisms of plant resistance to V. dahliae. Moreover, it is intended to serve as a resource for research focused on the development of genetic resistance mechanisms to combat Verticillium wilt.
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Affiliation(s)
| | | | - Chenjian Xie
- Correspondence: (C.X.); (X.Y.); Tel.: +86-23-6591-0315 (C.X. & X.Y.)
| | | | - Xingyong Yang
- Correspondence: (C.X.); (X.Y.); Tel.: +86-23-6591-0315 (C.X. & X.Y.)
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14
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Matilla MA, Krell T. The effect of bacterial chemotaxis on host infection and pathogenicity. FEMS Microbiol Rev 2018; 42:4563582. [PMID: 29069367 DOI: 10.1093/femsre/fux052] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/19/2017] [Indexed: 12/26/2022] Open
Abstract
Chemotaxis enables microorganisms to move according to chemical gradients. Although this process requires substantial cellular energy, it also affords key physiological benefits, including enhanced access to growth substrates. Another important implication of chemotaxis is that it also plays an important role in infection and disease, as chemotaxis signalling pathways are broadly distributed across a variety of pathogenic bacteria. Furthermore, current research indicates that chemotaxis is essential for the initial stages of infection in different human, animal and plant pathogens. This review focuses on recent findings that have identified specific bacterial chemoreceptors and corresponding chemoeffectors associated with pathogenicity. Pathogenicity-related chemoeffectors are either host and niche-specific signals or intermediates of the host general metabolism. Plant pathogens were found to contain an elevated number of chemotaxis signalling genes and functional studies demonstrate that these genes are critical for their ability to enter the host. The expanding body of knowledge of the mechanisms underlying chemotaxis in pathogens provides a foundation for the development of new therapeutic strategies capable of blocking infection and preventing disease by interfering with chemotactic signalling pathways.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
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15
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Matei A, Ernst C, Günl M, Thiele B, Altmüller J, Walbot V, Usadel B, Doehlemann G. How to make a tumour: cell type specific dissection of Ustilago maydis-induced tumour development in maize leaves. THE NEW PHYTOLOGIST 2018; 217:1681-1695. [PMID: 29314018 DOI: 10.1111/nph.14960] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 11/09/2017] [Indexed: 05/09/2023]
Abstract
The biotrophic fungus Ustilago maydis causes smut disease on maize (Zea mays), which is characterized by immense plant tumours. To establish disease and reprogram organ primordia to tumours, U. maydis deploys effector proteins in an organ-specific manner. However, the cellular contribution to leaf tumours remains unknown. We investigated leaf tumour formation at the tissue- and cell type-specific levels. Cytology and metabolite analysis were deployed to understand the cellular basis for tumourigenesis. Laser-capture microdissection was performed to gain a cell type-specific transcriptome of U. maydis during tumour formation. In vivo visualization of plant DNA synthesis identified bundle sheath cells as the origin of hyperplasic tumour cells, while mesophyll cells become hypertrophic tumour cells. Cell type-specific transcriptome profiling of U. maydis revealed tailored expression of fungal effector genes. Moreover, U. maydis See1 was identified as the first cell type-specific fungal effector, being required for induction of cell cycle reactivation in bundle sheath cells. Identification of distinct cellular mechanisms in two different leaf cell types and of See1 as an effector for induction of proliferation of bundle sheath cells are major steps in understanding U. maydis-induced tumour formation. Moreover, the cell type-specific U. maydis transcriptome data are a valuable resource to the scientific community.
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Affiliation(s)
- Alexandra Matei
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), BioCenter, University of Cologne, Zuelpicher Str. 47a, Cologne, 50674, Germany
| | - Corinna Ernst
- Center for Familial Breast and Ovarian Cancer, Medical Faculty, University Hospital Cologne, University of Cologne, Cologne, NRW, 50931, Germany
| | - Markus Günl
- Plant Sciences, IBG-2, Forschungszentrum Jülich, Wilhelm-Johnen Str, Jülich, 52428, Germany
| | - Björn Thiele
- Plant Sciences, IBG-2, Forschungszentrum Jülich, Wilhelm-Johnen Str, Jülich, 52428, Germany
| | - Janine Altmüller
- Cologne Center for Genomics and Center for Molecular Medicine Cologne, University of Cologne, Cologne, D-50674, Germany
| | - Virginia Walbot
- Department of Biology MC5020, Stanford University, 385 Serra Mall, Stanford, CA, 94305, USA
| | - Björn Usadel
- BioSC, IBG-2, Institute for Botany, RWTH Aachen, Worringer Weg 3, Aachen, 52078, Germany
| | - Gunther Doehlemann
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), BioCenter, University of Cologne, Zuelpicher Str. 47a, Cologne, 50674, Germany
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16
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Lai MW, Liou RF. Two genes encoding GH10 xylanases are essential for the virulence of the oomycete plant pathogen Phytophthora parasitica. Curr Genet 2018; 64:931-943. [PMID: 29470644 DOI: 10.1007/s00294-018-0814-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/14/2018] [Accepted: 02/16/2018] [Indexed: 12/29/2022]
Abstract
Plant cell walls are pivotal battlegrounds between microbial pathogens and their hosts. To penetrate the cell wall and thereby to facilitate infection, microbial pathogens are equipped with a wide array of cell wall-degrading enzymes to depolymerize the polysaccharides in the cell wall. However, many of these enzymes and their role in the pathogenesis of microbial pathogens are not characterized, especially those from Oomycetes. In this study, we analyzed the function of four putative endo-beta-1,4-xylanase-encoding genes (ppxyn1-ppxyn4) from Phytophthora parasitica, an oomycete plant pathogen known to cause severe disease in a wide variety of plant species. All four genes belong to the glycoside hydrolase family 10 (GH10). Recombinant proteins of ppxyn1, ppxyn2, and ppxyn4 obtained from the yeast Pichia pastoris showed degrading activities toward birch wood xylan, but they behaved differently in terms of the conditions for optimal activity, thermostability, and durability. Quantitative RT-PCR revealed upregulated expression of all four genes, especially ppxyn1 and ppxyn2, during plant infection. In contrast, ppxyn3 was highly expressed in cysts and its close homolog, ppxyn4, in germinating cysts. To uncover the role of ppxyn1 and ppxyn2 in the pathogenesis of P. parasitica, we generated silencing transformants for these two genes by double-stranded RNA-mediated gene silencing. Silencing ppxyn1 and ppxyn2 reduced the virulence of P. parasitica toward tobacco (Nicotiana benthamiana) and tomato plants. These results demonstrate the crucial role of xylanase-encoding ppxyn1 and ppxyn2 in the infection process of P. parasitica.
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Affiliation(s)
- Ming-Wei Lai
- Department of Plant Pathology and Microbiology, National Taiwan University, #1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan
| | - Ruey-Fen Liou
- Department of Plant Pathology and Microbiology, National Taiwan University, #1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan.
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17
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Jaroszuk-Ściseł J, Kurek E, Słomka A, Janczarek M, Rodzik B. Activities of cell wall degrading enzymes in autolyzing cultures of three Fusarium culmorum isolates: growth-promoting, deleterious and pathogenic to rye (Secale cereale). Mycologia 2017; 103:929-45. [DOI: 10.3852/10-300] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Anna Słomka
- Department of Environmental Microbiology, Institute of Microbiology and Biotechnology, University of Maria Curie-Skłodowska, Akademicka 19, 20-033, Lublin, Poland
| | - Monika Janczarek
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, University of Maria Curie-Skłodowska, Akademicka 19, 20-033, Lublin, Poland
| | - Beata Rodzik
- Department of Mathematical Statistics, Institute of Mathematics, University of Maria Curie-Skłodowska, Curie-Skłodowska Sq. 1, 20-031, Lublin, Poland
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18
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Ramos AM, Gally M, Szapiro G, Itzcovich T, Carabajal M, Levin L. In vitro growth and cell wall degrading enzyme production by Argentinean isolates of Macrophomina phaseolina, the causative agent of charcoal rot in corn. Rev Argent Microbiol 2016; 48:267-273. [PMID: 27825736 DOI: 10.1016/j.ram.2016.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 06/07/2016] [Accepted: 06/20/2016] [Indexed: 11/29/2022] Open
Abstract
Macrophomina phaseolina is a polyphagous phytopathogen, causing stalk rot on many commercially important species. Damages caused by this pathogen in soybean and maize crops in Argentina during drought and hot weather have increased due its ability to survive as sclerotia in soil and crop debris under non-till practices. In this work, we explored the in vitro production of plant cell wall-degrading enzymes [pectinases (polygalacturonase and polymethylgalacturonase); cellulases (endoglucanase); hemicellulases (endoxylanase) and the ligninolytic enzyme laccase] by several Argentinean isolates of M. phaseolina, and assessed the pathogenicity of these isolates as a preliminary step to establish the role of these enzymes in M. phaseolina-maize interaction. The isolates were grown in liquid synthetic medium supplemented with glucose, pectin, carboxymethylcellulose or xylan as carbon sources and/or enzyme inducers and glutamic acid as nitrogen source. Pectinases were the first cell wall-degrading enzymes detected and the activities obtained (polygalacturonase activity was between 0.4 and 1.3U/ml and polymethylgalacturonase between 0.15 and 1.3U/ml) were higher than those of cellulases and xylanases, which appeared later and in a lesser magnitude. This sequence would promote initial tissue maceration followed by cell wall degradation. Laccase was detected in all the isolates evaluated (activity was between 36U/l and 63U/l). The aggressiveness of the isolates was tested in maize, sunflower and watermelon seeds, being high on all the plants assayed. This study reports for the first time the potential of different isolates of M. phaseolina to produce plant cell wall-degrading enzymes in submerged fermentation.
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Affiliation(s)
- Araceli M Ramos
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, INMIBO-CONICET, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Marcela Gally
- Cátedra de Fitopatología, Facultad de Agronomía, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Gala Szapiro
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, INMIBO-CONICET, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Tatiana Itzcovich
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, INMIBO-CONICET, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Maira Carabajal
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, INMIBO-CONICET, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Laura Levin
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, INMIBO-CONICET, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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19
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Chang HX, Yendrek CR, Caetano-Anolles G, Hartman GL. Genomic characterization of plant cell wall degrading enzymes and in silico analysis of xylanases and polygalacturonases of Fusarium virguliforme. BMC Microbiol 2016; 16:147. [PMID: 27405320 PMCID: PMC4941037 DOI: 10.1186/s12866-016-0761-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 07/02/2016] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Plant cell wall degrading enzymes (PCWDEs) are a subset of carbohydrate-active enzymes (CAZy) produced by plant pathogens to degrade plant cell walls. To counteract PCWDEs, plants release PCWDEs inhibitor proteins (PIPs) to reduce their impact. Several transgenic plants expressing exogenous PIPs that interact with fungal glycoside hydrolase (GH)11-type xylanases or GH28-type polygalacturonase (PG) have been shown to enhance disease resistance. However, many plant pathogenic Fusarium species were reported to escape PIPs inhibition. Fusarium virguliforme is a soilborne pathogen that causes soybean sudden death syndrome (SDS). Although the genome of F. virguliforme was sequenced, there were limited studies focused on the PCWDEs of F. virguliforme. Our goal was to understand the genomic CAZy structure of F. viguliforme, and determine if exogenous PIPs could be theoretically used in soybean to enhance resistance against F. virguliforme. RESULTS F. virguliforme produces diverse CAZy to degrade cellulose and pectin, similar to other necrotorphic and hemibiotrophic plant pathogenic fungi. However, some common CAZy of plant pathogenic fungi that catalyze hemicellulose, such as GH29, GH30, GH44, GH54, GH62, and GH67, were deficient in F. virguliforme. While the absence of these CAZy families might be complemented by other hemicellulases, F. virguliforme contained unique families including GH131, polysaccharide lyase (PL) 9, PL20, and PL22 that were not reported in other plant pathogenic fungi or oomycetes. Sequence analysis revealed two GH11 xylanases of F. virguliforme, FvXyn11A and FvXyn11B, have conserved residues that allow xylanase inhibitor protein I (XIP-I) binding. Structural modeling suggested that FvXyn11A and FvXyn11B could be blocked by XIP-I that serves as good candidate for developing transgenic soybeans. In contrast, one GH28 PG, FvPG2, contains an amino acid substitution that is potentially incompatible with the bean polygalacturonase-inhibitor protein II (PvPGIP2). CONCLUSIONS Identification and annotation of CAZy provided advanced understanding of genomic composition of PCWDEs in F. virguliforme. Sequence and structural analyses of FvXyn11A and FvXyn11B suggested both xylanases were conserved in residues that allow XIP-I inhibition, and expression of both xylanases were detected during soybean roots infection. We postulate that a transgenic soybean expressing wheat XIP-I may be useful for developing root rot resistance to F. virguliforme.
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Affiliation(s)
- Hao-Xun Chang
- />Department of Crop Sciences, University of Illinois, Urbana, IL 61801 USA
| | | | | | - Glen L. Hartman
- />Department of Crop Sciences, University of Illinois, Urbana, IL 61801 USA
- />USDA–Agricultural Research Services, Urbana, IL 61801 USA
- />National Soybean Research Center, University of Illinois, 1101 W. Peabody Dr., Urbana, IL 61801 USA
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Nováková M, Kim PD, Šašek V, Burketová L, Jindřichová B, Šantrůček J, Valentová O. Separation and identification of candidate protein elicitors from the cultivation medium of Leptosphaeria maculans inducing resistance in Brassica napus. Biotechnol Prog 2016; 32:918-28. [PMID: 27009514 DOI: 10.1002/btpr.2266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/21/2016] [Indexed: 12/18/2022]
Abstract
The Dothideomycete Leptosphaeria maculans, a worldwide fungal pathogen of oilseed rape (Brassica napus), secretes a broad spectrum of molecules into the cultivation medium during growth in vitro. Here, candidate elicitor molecules, which induce resistance in B. napus to L. maculans, were identified in the cultivation medium. The elicitation activity was indicated by increased transcription of pathogenesis-related gene 1 (PR1) and enhanced resistance of B. napus plants to the invasion of L. maculans. The elicitation activity was significantly lowered when the cultivation medium was heated to 80°C. Active components were further characterized by specific cleavage with the proteolytic enzymes trypsin and proteinase K and with glycosidases α-amylase and β-glucanase. The elicitor activity was eliminated by proteolytic digestion while glycosidases had no effect. The filtered medium was fractionated by either ion-exchange chromatography or isoelectric focusing. Mass spectrometry analysis of the most active fractions obtained by both separation procedures revealed predominantly enzymes that can be involved in the degradation of plant cell wall polysaccharides. This is the first study searching for L. maculans-specific secreted elicitors with a potential to be used as defense-activating agents in the protection of B. napus against L. maculans in agriculture. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:918-928, 2016.
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Affiliation(s)
- Miroslava Nováková
- Dept. of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic.,Laboratory of Pathological Plant Physiology, Inst. of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02 Prague 6, Czech Republic
| | - Phuong Dinh Kim
- Dept. of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic
| | - Vladimír Šašek
- Laboratory of Pathological Plant Physiology, Inst. of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02 Prague 6, Czech Republic
| | - Lenka Burketová
- Laboratory of Pathological Plant Physiology, Inst. of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02 Prague 6, Czech Republic
| | - Barbora Jindřichová
- Dept. of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic.,Laboratory of Pathological Plant Physiology, Inst. of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02 Prague 6, Czech Republic
| | - Jiří Šantrůček
- Dept. of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic
| | - Olga Valentová
- Dept. of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic
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Chatnaparat T, Prathuangwong S, Lindow SE. Global Pattern of Gene Expression of Xanthomonas axonopodis pv. glycines Within Soybean Leaves. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:508-22. [PMID: 27003800 DOI: 10.1094/mpmi-01-16-0007-r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
To better understand the behavior of Xanthomonas axonopodis pv. glycines, the causal agent of bacterial pustule of soybean within its host, its global transcriptome within soybean leaves was compared with that in a minimal medium in vitro, using deep sequencing of mRNA. Of 5,062 genes predicted from a draft genome of X. axonopodis pv. glycines, 534 were up-regulated in the plant, while 289 were down-regulated. Genes encoding YapH, a cell-surface adhesin, as well as several others encoding cell-surface proteins, were down-regulated in soybean. Many genes encoding the type III secretion system and effector proteins, cell wall-degrading enzymes and phosphate transporter proteins were strongly expressed at early stages of infection. Several genes encoding RND multidrug efflux pumps were induced in planta and by isoflavonoids in vitro and were required for full virulence of X. axonopodis pv. glycines, as well as resistance to soybean phytoalexins. Genes encoding consumption of malonate, a compound abundant in soybean, were induced in planta and by malonate in vitro. Disruption of the malonate decarboxylase operon blocked growth in minimal media with malonate as the sole carbon source but did not significantly alter growth in soybean, apparently because genes for sucrose and fructose uptake were also induced in planta. Many genes involved in phosphate metabolism and uptake were induced in planta. While disruption of genes encoding high-affinity phosphate transport did not alter growth in media varying in phosphate concentration, the mutants were severely attenuated for growth in soybean. This global transcriptional profiling has provided insight into both the intercellular environment of this soybean pathogen and traits used by X. axonopodis pv. glycines to promote disease.
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Affiliation(s)
- Tiyakhon Chatnaparat
- 1 Department of Plant Pathology, Kasetsart University, Thailand
- 2 Center for Advanced Studies in Tropical Natural Resources, Kasetsart University, Bangkok, Thailand; and
| | - Sutruedee Prathuangwong
- 1 Department of Plant Pathology, Kasetsart University, Thailand
- 2 Center for Advanced Studies in Tropical Natural Resources, Kasetsart University, Bangkok, Thailand; and
| | - Steven E Lindow
- 3 Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, U.S.A
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Sperschneider J, Gardiner DM, Dodds PN, Tini F, Covarelli L, Singh KB, Manners JM, Taylor JM. EffectorP: predicting fungal effector proteins from secretomes using machine learning. THE NEW PHYTOLOGIST 2016; 210:743-61. [PMID: 26680733 DOI: 10.1111/nph.13794] [Citation(s) in RCA: 251] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/05/2015] [Indexed: 05/02/2023]
Abstract
Eukaryotic filamentous plant pathogens secrete effector proteins that modulate the host cell to facilitate infection. Computational effector candidate identification and subsequent functional characterization delivers valuable insights into plant-pathogen interactions. However, effector prediction in fungi has been challenging due to a lack of unifying sequence features such as conserved N-terminal sequence motifs. Fungal effectors are commonly predicted from secretomes based on criteria such as small size and cysteine-rich, which suffers from poor accuracy. We present EffectorP which pioneers the application of machine learning to fungal effector prediction. EffectorP improves fungal effector prediction from secretomes based on a robust signal of sequence-derived properties, achieving sensitivity and specificity of over 80%. Features that discriminate fungal effectors from secreted noneffectors are predominantly sequence length, molecular weight and protein net charge, as well as cysteine, serine and tryptophan content. We demonstrate that EffectorP is powerful when combined with in planta expression data for predicting high-priority effector candidates. EffectorP is the first prediction program for fungal effectors based on machine learning. Our findings will facilitate functional fungal effector studies and improve our understanding of effectors in plant-pathogen interactions. EffectorP is available at http://effectorp.csiro.au.
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Affiliation(s)
- Jana Sperschneider
- Centre for Environment and Life Sciences, CSIRO Agriculture, Perth, 6014, WA, Australia
| | - Donald M Gardiner
- Queensland Bioscience Precinct, CSIRO Agriculture, Brisbane, 4067, QLD, Australia
| | - Peter N Dodds
- Black Mountain Laboratories, CSIRO Agriculture, Canberra, 2601, ACT, Australia
| | - Francesco Tini
- Queensland Bioscience Precinct, CSIRO Agriculture, Brisbane, 4067, QLD, Australia
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, 06121, Umbria, Italy
| | - Lorenzo Covarelli
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, 06121, Umbria, Italy
| | - Karam B Singh
- Centre for Environment and Life Sciences, CSIRO Agriculture, Perth, 6014, WA, Australia
| | - John M Manners
- Black Mountain Laboratories, CSIRO Agriculture, Canberra, 2601, ACT, Australia
| | - Jennifer M Taylor
- Black Mountain Laboratories, CSIRO Agriculture, Canberra, 2601, ACT, Australia
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Mostek A, Börner A, Weidner S. Comparative proteomic analysis of β-aminobutyric acid-mediated alleviation of salt stress in barley. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 99:150-61. [PMID: 26760953 DOI: 10.1016/j.plaphy.2015.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/14/2015] [Indexed: 05/23/2023]
Abstract
The non-protein amino acid β-aminobutyric acid (BABA) is known to induce plant resistance to a broad spectrum of biotic and abiotic stresses. This is the first study describing the effect of BABA seed priming on physiological and proteomic changes under salt stress conditions in barley (Hordeum vulgare). The aim of our study was to investigate the changes of fresh weight, dry weight and relative water content (RWC) as well as root proteome changes of two barley lines contrasting in salt tolerance (DH14, DH 187) in response to salt stress after seed priming in water or in 800 μM BABA. Seed priming with BABA significantly increased (p ≤ 0.05) RWC in both barley lines, which indicates considerably lower water loss in BABA-primed plants than in the non-primed control plants. Dry and fresh matter increased significantly in line DH 187, whereas no changes were detected in line DH14. BABA-primed plants of both lines showed different proteomic patterns than the non-primed control plants. The root proteins exhibiting significant abundance changes (1.75-fold change, p ≤ 0.05) were separated by two-dimensional polyacrylamide gel electrophoresis (2D- PAGE). Thirty-one spots, representing 24 proteins, were successfully identified by MALDI TOF/TOF mass spectrometry. The most prominent differences include the up-regulation of antioxidant enzymes (catalase, peroxidase and superoxide dismutase), PR proteins (chitinase, endo-1,3-β-glucosidase), and chaperones (cyclophilin, HSC 70). Our results indicate that BABA induces defence and detoxification processes which may enable faster and more effective responses to salt stress, increasing the chances of survival under adverse environmental conditions.
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Affiliation(s)
- Agnieszka Mostek
- Department of Biochemistry, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego Street 1a, 10-957 Olsztyn, Poland.
| | - Andreas Börner
- Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstrasse 3, 06466 Gatersleben, Germany
| | - Stanisław Weidner
- Department of Biochemistry, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego Street 1a, 10-957 Olsztyn, Poland
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24
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Mardi M, Karimi Farsad L, Gharechahi J, Salekdeh GH. In-Depth Transcriptome Sequencing of Mexican Lime Trees Infected with Candidatus Phytoplasma aurantifolia. PLoS One 2015; 10:e0130425. [PMID: 26132073 PMCID: PMC4489016 DOI: 10.1371/journal.pone.0130425] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 05/20/2015] [Indexed: 12/31/2022] Open
Abstract
Witches' broom disease of acid lime greatly affects the production of Mexican lime in Iran. It is caused by a phytoplasma (Candidatus Phytoplasma aurantifolia). However, the molecular mechanisms that underlie phytoplasma pathogenicity and the mode of interactions with host plants are largely unknown. Here, high-throughput transcriptome sequencing was conducted to explore gene expression signatures associated with phytoplasma infection in Mexican lime trees. We assembled 78,185 unique transcript sequences (unigenes) with an average length of 530 nt. Of these, 41,805 (53.4%) were annotated against the NCBI non-redundant (nr) protein database using a BLASTx search (e-value ≤ 1e-5). When the abundances of unigenes in healthy and infected plants were compared, 2,805 transcripts showed significant differences (false discovery rate ≤ 0.001 and log2 ratio ≥ 1.5). These differentially expressed genes (DEGs) were significantly enriched in 43 KEGG metabolic and regulatory pathways. The up-regulated DEGs were mainly categorized into pathways with possible implication in plant-pathogen interaction, including cell wall biogenesis and degradation, sucrose metabolism, secondary metabolism, hormone biosynthesis and signalling, amino acid and lipid metabolism, while down-regulated DEGs were predominantly enriched in ubiquitin proteolysis and oxidative phosphorylation pathways. Our analysis provides novel insight into the molecular pathways that are deregulated during the host-pathogen interaction in Mexican lime trees infected by phytoplasma. The findings can be valuable for unravelling the molecular mechanisms of plant-phytoplasma interactions and can pave the way for engineering lime trees with resistance to witches' broom disease.
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Affiliation(s)
- Mohsen Mardi
- Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Karaj, Tehran, Iran
| | - Laleh Karimi Farsad
- Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Karaj, Tehran, Iran
| | - Javad Gharechahi
- Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ghasem Hosseini Salekdeh
- Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Karaj, Tehran, Iran
- Department of Molecular Systems Biology at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
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Xanthomonas campestris pv. vesicatoria Secretes Proteases and Xylanases via the Xps Type II Secretion System and Outer Membrane Vesicles. J Bacteriol 2015; 197:2879-93. [PMID: 26124239 DOI: 10.1128/jb.00322-15] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 06/19/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Many plant-pathogenic bacteria utilize type II secretion (T2S) systems to secrete degradative enzymes into the extracellular milieu. T2S substrates presumably mediate the degradation of plant cell wall components during the host-pathogen interaction and thus promote bacterial virulence. Previously, the Xps-T2S system from Xanthomonas campestris pv. vesicatoria was shown to contribute to extracellular protease activity and the secretion of a virulence-associated xylanase. The identities and functions of additional T2S substrates from X. campestris pv. vesicatoria, however, are still unknown. In the present study, the analysis of 25 candidate proteins from X. campestris pv. vesicatoria led to the identification of two type II secreted predicted xylanases, a putative protease and a lipase which was previously identified as a virulence factor of X. campestris pv. vesicatoria. Studies with mutant strains revealed that the identified xylanases and the protease contribute to virulence and in planta growth of X. campestris pv. vesicatoria. When analyzed in the related pathogen X. campestris pv. campestris, several T2S substrates from X. campestris pv. vesicatoria were secreted independently of the T2S systems, presumably because of differences in the T2S substrate specificities of the two pathogens. Furthermore, in X. campestris pv. vesicatoria T2S mutants, secretion of T2S substrates was not completely absent, suggesting the contribution of additional transport systems to protein secretion. In line with this hypothesis, T2S substrates were detected in outer membrane vesicles, which were frequently observed for X. campestris pv. vesicatoria. We, therefore, propose that extracellular virulence-associated enzymes from X. campestris pv. vesicatoria are targeted to the Xps-T2S system and to outer membrane vesicles. IMPORTANCE The virulence of plant-pathogenic bacteria often depends on TS2 systems, which secrete degradative enzymes into the extracellular milieu. T2S substrates are being studied in several plant-pathogenic bacteria, including Xanthomonas campestris pv. vesicatoria, which causes bacterial spot disease in tomato and pepper. Here, we show that the T2S system from X. campestris pv. vesicatoria secretes virulence-associated xylanases, a predicted protease, and a lipase. Secretion assays with the related pathogen X. campestris pv. campestris revealed important differences in the T2S substrate specificities of the two pathogens. Furthermore, electron microscopy showed that T2S substrates from X. campestris pv. vesicatoria are targeted to outer membrane vesicles (OMVs). Our results, therefore, suggest that OMVs provide an alternative transport route for type II secreted extracellular enzymes.
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26
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Sperschneider J, Gardiner DM, Thatcher LF, Lyons R, Singh KB, Manners JM, Taylor JM. Genome-Wide Analysis in Three Fusarium Pathogens Identifies Rapidly Evolving Chromosomes and Genes Associated with Pathogenicity. Genome Biol Evol 2015; 7:1613-27. [PMID: 25994930 PMCID: PMC4494044 DOI: 10.1093/gbe/evv092] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Pathogens and hosts are in an ongoing arms race and genes involved in host–pathogen interactions are likely to undergo diversifying selection. Fusarium plant pathogens have evolved diverse infection strategies, but how they interact with their hosts in the biotrophic infection stage remains puzzling. To address this, we analyzed the genomes of three Fusarium plant pathogens for genes that are under diversifying selection. We found a two-speed genome structure both on the chromosome and gene group level. Diversifying selection acts strongly on the dispensable chromosomes in Fusarium oxysporum f. sp. lycopersici and on distinct core chromosome regions in Fusarium graminearum, all of which have associations with virulence. Members of two gene groups evolve rapidly, namely those that encode proteins with an N-terminal [SG]-P-C-[KR]-P sequence motif and proteins that are conserved predominantly in pathogens. Specifically, 29 F. graminearum genes are rapidly evolving, in planta induced and encode secreted proteins, strongly pointing toward effector function. In summary, diversifying selection in Fusarium is strongly reflected as genomic footprints and can be used to predict a small gene set likely to be involved in host–pathogen interactions for experimental verification.
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Affiliation(s)
- Jana Sperschneider
- CSIRO Agriculture Flagship, Centre for Environment and Life Sciences, Perth, Western Australia, Australia
| | - Donald M Gardiner
- CSIRO Agriculture Flagship, Queensland Bioscience Precinct, Brisbane, Queensland, Australia
| | - Louise F Thatcher
- CSIRO Agriculture Flagship, Centre for Environment and Life Sciences, Perth, Western Australia, Australia
| | - Rebecca Lyons
- CSIRO Agriculture Flagship, Queensland Bioscience Precinct, Brisbane, Queensland, Australia
| | - Karam B Singh
- CSIRO Agriculture Flagship, Centre for Environment and Life Sciences, Perth, Western Australia, Australia University of Western Australia Institute of Agriculture, University of Western Australia, Crawley, Western Australia, Australia
| | - John M Manners
- CSIRO Agriculture Flagship, Black Mountain Laboratories, Canberra, Australian Capital Territory, Australia
| | - Jennifer M Taylor
- CSIRO Agriculture Flagship, Black Mountain Laboratories, Canberra, Australian Capital Territory, Australia
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Munjal N, Jawed K, Wajid S, Yazdani SS. A constitutive expression system for cellulase secretion in Escherichia coli and its use in bioethanol production. PLoS One 2015; 10:e0119917. [PMID: 25768292 PMCID: PMC4358894 DOI: 10.1371/journal.pone.0119917] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 01/18/2015] [Indexed: 02/05/2023] Open
Abstract
The production of biofuels from lignocellulosic biomass appears to be attractive and viable due to the abundance and availability of this biomass. The hydrolysis of this biomass, however, is challenging because of the complex lignocellulosic structure. The ability to produce hydrolytic cellulase enzymes in a cost-effective manner will certainly accelerate the process of making lignocellulosic ethanol production a commercial reality. These cellulases may need to be produced aerobically to generate large amounts of protein in a short time or anaerobically to produce biofuels from cellulose via consolidated bioprocessing. Therefore, it is important to identify a promoter that can constitutively drive the expression of cellulases under both aerobic and anaerobic conditions without the need for an inducer. Using lacZ as reporter gene, we analyzed the strength of the promoters of four genes, namely lacZ, gapA, ldhA and pflB, and found that the gapA promoter yielded the maximum expression of the β-galactosidase enzyme under both aerobic and anaerobic conditions. We further cloned the genes for two cellulolytic enzymes, β-1,4-endoglucanase and β-1,4-glucosidase, under the control of the gapA promoter, and we expressed these genes in Escherichia coli, which secreted the products into the extracellular medium. An ethanologenic E. colistrain transformed with the secretory β-glucosidase gene construct fermented cellobiose in both defined and complex medium. This recombinant strain also fermented wheat straw hydrolysate containing glucose, xylose and cellobiose into ethanol with an 85% efficiency of biotransformation. An ethanologenic strain that constitutively secretes a cellulolytic enzyme is a promising platform for producing lignocellulosic ethanol.
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Affiliation(s)
- Neha Munjal
- Synthetic Biology and Biofuels Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Kamran Jawed
- Synthetic Biology and Biofuels Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Saima Wajid
- Centre for Biotechnology, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Syed Shams Yazdani
- Synthetic Biology and Biofuels Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
- DBT-ICGEB Centre for Advanced Bioenergy Research, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
- * E-mail:
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Malinovsky FG, Fangel JU, Willats WGT. The role of the cell wall in plant immunity. FRONTIERS IN PLANT SCIENCE 2014; 5:178. [PMID: 24834069 PMCID: PMC4018530 DOI: 10.3389/fpls.2014.00178] [Citation(s) in RCA: 270] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/14/2014] [Indexed: 05/17/2023]
Abstract
The battle between plants and microbes is evolutionarily ancient, highly complex, and often co-dependent. A primary challenge for microbes is to breach the physical barrier of host cell walls whilst avoiding detection by the plant's immune receptors. While some receptors sense conserved microbial features, others monitor physical changes caused by an infection attempt. Detection of microbes leads to activation of appropriate defense responses that then challenge the attack. Plant cell walls are formidable and dynamic barriers. They are constructed primarily of complex carbohydrates joined by numerous distinct connection types, and are subject to extensive post-synthetic modification to suit prevailing local requirements. Multiple changes can be triggered in cell walls in response to microbial attack. Some of these are well described, but many remain obscure. The study of the myriad of subtle processes underlying cell wall modification poses special challenges for plant glycobiology. In this review we describe the major molecular and cellular mechanisms that underlie the roles of cell walls in plant defense against pathogen attack. In so doing, we also highlight some of the challenges inherent in studying these interactions, and briefly describe the analytical potential of molecular probes used in conjunction with carbohydrate microarray technology.
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Affiliation(s)
- Frederikke G. Malinovsky
- DNRF Center DynaMo and Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of CopenhagenCopenhagen, Denmark
| | - Jonatan U. Fangel
- Department of Plant and Environmental Sciences, Faculty of Science, University of CopenhagenCopenhagen, Denmark
| | - William G. T. Willats
- Department of Plant and Environmental Sciences, Faculty of Science, University of CopenhagenCopenhagen, Denmark
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Abstract
Plants are invaded by an array of pathogens of which only a few succeed in causing disease. The attack by others is countered by a sophisticated immune system possessed by the plants. The plant immune system is broadly divided into two, viz. microbial-associated molecular-patterns-triggered immunity (MTI) and effector-triggered immunity (ETI). MTI confers basal resistance, while ETI confers durable resistance, often resulting in hypersensitive response. Plants also possess systemic acquired resistance (SAR), which provides long-term defense against a broad-spectrum of pathogens. Salicylic-acid-mediated systemic acquired immunity provokes the defense response throughout the plant system during pathogen infection at a particular site. Trans-generational immune priming allows the plant to heritably shield their progeny towards pathogens previously encountered. Plants circumvent the viral infection through RNA interference phenomena by utilizing small RNAs. This review summarizes the molecular mechanisms of plant immune system, and the latest breakthroughs reported in plant defense. We discuss the plant–pathogen interactions and integrated defense responses in the context of presenting an integral understanding in plant molecular immunity.
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30
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Scherm B, Balmas V, Spanu F, Pani G, Delogu G, Pasquali M, Migheli Q. Fusarium culmorum: causal agent of foot and root rot and head blight on wheat. MOLECULAR PLANT PATHOLOGY 2013; 14:323-41. [PMID: 23279114 PMCID: PMC6638779 DOI: 10.1111/mpp.12011] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
UNLABELLED Fusarium culmorum is a ubiquitous soil-borne fungus able to cause foot and root rot and Fusarium head blight on different small-grain cereals, in particular wheat and barley. It causes significant yield and quality losses and results in contamination of the grain with mycotoxins. This review summarizes recent research activities related to F. culmorum, including studies into its population diversity, mycotoxin biosynthesis, mechanisms of pathogenesis and resistance, the development of diagnostic tools and preliminary genome sequence surveys. We also propose potential research areas that may expand our basic understanding of the wheat-F. culmorum interaction and assist in the management of the disease caused by this pathogen. TAXONOMY Fusarium culmorum (W.G. Smith) Sacc. Kingdom Fungi; Phylum Ascomycota; Subphylum Pezizomycotina; Class Sordariomycetes; Subclass Hypocreomycetidae; Order Hypocreales; Family Nectriaceae; Genus Fusarium. DISEASE SYMPTOMS Foot and root rot (also known as Fusarium crown rot): seedling blight with death of the plant before or after emergence; brown discoloration on roots and coleoptiles of the infected seedlings; brown discoloration on subcrown internodes and on the first two/three internodes of the main stem; tiller abortion; formation of whiteheads with shrivelled white grains; Fusarium head blight: prematurely bleached spikelets or blighting of the entire head, which remains empty or contains shrunken dark kernels. IDENTIFICATION AND DETECTION: Morphological identification is based on the shape of the macroconidia formed on sporodochia on carnation leaf agar. The conidiophores are branched monophialides, short and wide. The macroconidia are relatively short and stout with an apical cell blunt or slightly papillate; the basal cell is foot-shaped or just notched. Macroconidia are thick-walled and curved, usually 3-5 septate, and mostly measuring 30-50 × 5.0-7.5 μm. Microconidia are absent. Oval to globose chlamydospores are formed, intercalary in the hyphae, solitary, in chains or in clumps; they are also formed from macroconidia. The colony grows very rapidly (1.6-2.2 cm/day) on potato dextrose agar (PDA) at the optimum temperature of 25 °C. The mycelium on PDA is floccose, whitish, light yellow or red. The pigment on the reverse plate on PDA varies from greyish-rose, carmine red or burgundy. A wide array of polymerase chain reaction (PCR) and real-time PCR tools, as well as complementary methods, which are summarised in the first two tables, have been developed for the detection and/or quantification of F. culmorum in culture and in naturally infected plant tissue. HOST RANGE Fusarium culmorum has a wide range of host plants, mainly cereals, such as wheat, barley, oats, rye, corn, sorghum and various grasses. In addition, it has been isolated from sugar beet, flax, carnation, bean, pea, asparagus, red clover, hop, leeks, Norway spruce, strawberry and potato tuber. Fusarium culmorum has also been associated with dermatitis on marram grass planters in the Netherlands, although its role as a causal agent of skin lesions appears questionable. It is also isolated as a symbiont able to confer resistance to abiotic stress, and has been proposed as a potential biocontrol agent to control the aquatic weed Hydrilla spp. USEFUL WEBSITES http://isolate.fusariumdb.org/; http://sppadbase.ipp.cnr.it/; http://www.broad.mit.edu/annotation/genome/fusarium_group/MultiHome.html; http://www.fgsc.net/Fusarium/fushome.htm; http://plantpath.psu.edu/facilities/fusarium-research-center; http://www.phi-base.org/; http://www.uniprot.org/; http://www.cabi.org/; http://www.indexfungorum.org/
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Affiliation(s)
- Barbara Scherm
- Dipartimento di Agraria-Sezione di Patologia Vegetale ed Entomologia and Centro Interdisciplinare per lo Sviluppo della Ricerca Biotecnologica e per lo Studio della Biodiversità della Sardegna e dell'Area Mediterranea, Università degli Studi di Sassari, Via E. De Nicola 9, I-07100 Sassari, Italy
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Wu S, Buthe A, Jia H, Zhang M, Ishii M, Wang P. Enzyme-enabled responsive surfaces for anti-contamination materials. Biotechnol Bioeng 2013; 110:1805-10. [PMID: 23335427 DOI: 10.1002/bit.24847] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 12/24/2012] [Accepted: 01/07/2013] [Indexed: 01/13/2023]
Abstract
Many real-life stains have origins from biological matters including proteins, lipids, and carbohydrates that act as gluing agents binding along with other particulates or microbes to exposed surfaces of automobiles, furniture, and fabrics. Mimicking naturally occurring self-defensive processes, we demonstrate in this work that a solid surface carrying partially exposed enzyme granules protected the surface in situ from contamination by biological stains and fingerprints. Attributed to the activities of enzymes which can be made compatible with a wide range of materials, such anti-contamination and self-cleaning functionalities are highly selective and efficient toward sticky chemicals. This observation promises a new mechanism in developing smart materials with desired anti-microbial, self-reporting, self-cleaning, or self-healing functions.
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Affiliation(s)
- Songtao Wu
- Department of Bioproducts and Biosystems Engineering and Biotechnology Institute, University of Minnesota, St. Paul, Minnesota 55108, USA
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Weng X, Huang Y, Hou C, Jiang D. Effects of an exogenous xylanase gene expression on the growth of transgenic rice and the expression level of endogenous xylanase inhibitor gene RIXI. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2013; 93:173-179. [PMID: 22674383 DOI: 10.1002/jsfa.5746] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 04/13/2012] [Accepted: 04/27/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Xylanases have attracted considerable interest in recent years owing to their various applications in industry and agriculture. The use of transgenic plants to produce xylanases is a less expensive alternative to biotechnological programmes. The aim of this study was to elucidate whether introducing a foreign xylanase gene ATX into rice had any adverse effect on plant growth and development. RESULTS A recombinant xylanase gene ATX was introduced into rice variety Zhonghua 11 through Agrobacterium-mediated transformation. The T₂ generation of transgenic rice was compared with the control (non-transgenic plants). Exogenous xylanase gene ATX was expressed in rice, and all examined transgenic lines exhibited xylanase activity. The transgenic lines (T₂, 'X1-3' and 'X2-5') appeared to grow and develop normally. There were no differences in net photosynthetic rate between transgenic rice lines ('X1-3' and 'X2-5') and wild type (WT) rice plants at the heading/flowering stage. Xylanases are key enzymes in the degradation of plant cell walls. Cell wall composition analysis showed that that there were no changes in cell wall polysaccharides in the root apex but some alterations in leaves in transgenic rice plants. The results also showed that the expression of exogenous xylanase gene ATX in rice would increase the expression of endogenous xylanase inhibitor gene RIXI, which could play a role in plant defence. Thus the stress resistance of transgenic rice plants might be improved. CONCLUSION Exogenous xylanase gene ATX could be successfully expressed in rice, and the exogenous protein had no apparent harmful effects on growth and development in transgenic rice plants.
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Affiliation(s)
- Xiaoyan Weng
- College of Life Science, Zhejiang University, Hangzhou 310058, China
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Buanafina MMDO, Langdon T, Dalton S, Morris P. Expression of a Trichoderma reesei β-1,4 endo-xylanase in tall fescue modifies cell wall structure and digestibility and elicits pathogen defence responses. PLANTA 2012; 236:1757-74. [PMID: 22878642 DOI: 10.1007/s00425-012-1724-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 07/10/2012] [Indexed: 05/04/2023]
Abstract
An endo-xylanase from Trichoderma reesei (xyn2) has been expressed in tall fescue targeted to the vacuole, apoplast or Golgi, constitutively under the control of the rice actin promoter, and to the apoplast under the control of a senescence enhanced gene promoter. Constitutive xylanase expression in the vacuole, apoplast, and golgi, resulted in only a small number of plants with low enzyme activities and in reduced plant growth in apoplast, and golgi targeted plants. Constitutive expression in the apoplast also resulted in increased levels of cell wall bound hydroxycinnamic acid monomers and dimers, but no significant effect on cell wall xylose or arabinose content. In situ constitutive xylanase expression in the Golgi also resulted in increased ferulate dimers. However, senescence induced xylanase expression in the apoplast was considerably higher and did not affect plant growth or the level of monomeric hydroxycinnamic acids or lignin in the cell walls. These plants also showed increased levels of ferulate dimers, and decreased levels of xylose with increased levels of arabinose in their cell walls. While the release of cell wall hydroxycinnamic acids on self digestion was enhanced in these plants in the presence of exogenously applied ferulic acid esterase, changes in cell wall composition resulted in decreases in both tissue digestibility and cellulase mediated sugar release. In situ detection of H(2)O(2) production mediated by ethylene release in leaves of plants expressing apoplast xylanase could be leading to increased dimerisation. High-level xylanase expression in the apoplast also resulted in necrotic lesions on the leaves. Together these results indicate that xylanase expression in tall fescue may be triggering plant defence responses analogous to foliar pathogen attack mediated by ethylene and H(2)O(2).
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Affiliation(s)
- Marcia M de O Buanafina
- Department of Biology, The Pennsylvania State University, 208 Mueller Laboratory, University Park, PA 16802, USA.
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Rodriguez Estrada AE, Jonkers W, Kistler HC, May G. Interactions between Fusarium verticillioides, Ustilago maydis, and Zea mays: an endophyte, a pathogen, and their shared plant host. Fungal Genet Biol 2012; 49:578-87. [PMID: 22587948 DOI: 10.1016/j.fgb.2012.05.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 05/03/2012] [Accepted: 05/04/2012] [Indexed: 11/15/2022]
Abstract
Highly diverse communities of microbial symbionts occupy eukaryotic organisms, including plants. While many well-studied symbionts may be characterized as either parasites or as mutualists, the prevalent but cryptic endophytic fungi are less easily qualified because they do not cause observable symptoms of their presence within their host. Here, we investigate the interactions of an endophytic fungus, Fusarium verticillioides with a pathogen, Ustilago maydis, as they occur within maize (Zea mays). We used experimental inoculations to evaluate metabolic mechanisms by which these three organisms might interact. We assessed the impacts of fungal-fungal interactions on endophyte and pathogen growth within the plant, and on plant growth. We find that F. verticillioides modulates the growth of U. maydis and thus decreases the pathogen's aggressiveness toward the plant. With co-inoculation of the endophyte with the pathogen, plant growth is similar to that which would be gained without the pathogen present. However, the endophyte may also break down plant compounds that limit U. maydis growth, and obtains a growth benefit from the presence of the pathogen. Thus, an endophyte such as F. verticillioides may function as both a defensive mutualist and a parasite, and express nutritional modes that depend on ecological context.
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Dong X, Meinhardt SW, Schwarz PB. Isolation and characterization of two endoxylanases from Fusarium graminearum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:2538-2545. [PMID: 22313372 DOI: 10.1021/jf203407p] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This paper reports the first isolation from cultures of two endoxylanases secreted by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schweinitz) Petch]. When F. graminearum is grown on wheat bran hydrated with a modified synthetic medium, high xylanase activity can be extracted. The two endoxylanases were identified by LC-MS/MS as the products of genes FGSG_6445 (Genbank gene id 2788192 ) (xylanase 1) and FGSG_3624 (GenBank accession no. AJ863566 ) (xylanase 2) with 61 and 51% sequence coverage, respectively. Both enzymes showed a pH optimum at pH 6, with xylanase 1 exhibiting a wider active pH range (5.5-9) than xlylanase 2 (5.5-7.5). Their temperature dependences were similar, >60% between 35 and 60 °C, with optimal temperatures of 45 °C for xylanase 1 and 50 °C for xylanase 2. Kinetic studies found that both enzymes had a lower K(m) for linear beachwood xylan than arabinoxylan. For xylanase 2, the V(max) increased with arabinoxylan, but decreased for xylanase 1.
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Affiliation(s)
- Xinrong Dong
- Department of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050, United States
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Jaroszuk-Ściseł J, Kurek E. Hydrolysis of fungal and plant cell walls by enzymatic complexes from cultures of Fusarium isolates with different aggressiveness to rye (Secale cereale). Arch Microbiol 2012; 194:653-65. [PMID: 22388990 DOI: 10.1007/s00203-012-0803-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 01/25/2012] [Accepted: 02/06/2012] [Indexed: 10/28/2022]
Abstract
The efficiency of hydrolysis of fungal (Fusarium spp.) cell wall and rye root cell wall by crude enzymatic complexes from (42-day-old) cultures of three F. culmorum isolates, a plant growth-promoting rhizosphere isolate (PGPF) DEMFc2, a deleterious rhizosphere isolate (DRMO) DEMFc5, and a pathogenic isolate DEMFc37, as well as two other, pathogenic isolates belonging to F. oxysporum and F. graminearum species was studied. In the enzymatic complexes originating from the Fusarium spp. cultures, the activities of the following cell wall-degrading enzymes were identified: glucanases, chitinases, xylanases, endocellulases, exocellulases, pectinases, and polygalacturonases. The preparation originating from a culture of the PGPF isolate was the least efficient in plant cell wall (PCW) hydrolysis. There were no significant differences in the efficiency of PCW hydrolysis between preparations from cultures of the DRMO and the pathogenic isolates. PGPF was the most efficient in liberating reducing sugars and N-acetylglucosamine (GlcNAc) from fungal cell walls (FCW). Xylanase activities of the enzymatic complexes were strongly positively (R > +0.9) correlated with their efficiency in hydrolyzing PCW, whereas chitinase activities were correlated with the efficiency in FCW hydrolysis.
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Affiliation(s)
- Jolanta Jaroszuk-Ściseł
- Department of Environmental Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University, Akademicka St. 19, 20-033 Lublin, Poland.
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Padilla-Hurtado B, Flórez-Ramos C, Aguilera-Gálvez C, Medina-Olaya J, Ramírez-Sanjuan A, Rubio-Gómez J, Acuña-Zornosa R. Cloning and expression of an endo-1,4-β-xylanase from the coffee berry borer, Hypothenemus hampei. BMC Res Notes 2012; 5:23. [PMID: 22233686 PMCID: PMC3283504 DOI: 10.1186/1756-0500-5-23] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 01/10/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The coffee berry borer, Hypothenemus hampei, reproduces and feeds exclusively on the mature endosperm of the coffee seed, which has a cell wall composed mainly of a heterogeneous mixture of hemicellulose polysaccharides, including arabinoxylans. Xylanases are digestive enzymes responsible for the degradation of xylan based polymers, hydrolyzing them into smaller molecules that are easier to assimilate by insects. We report the cloning, expression and enzymatic characterization of a xylanase gene that was identified in the digestive tract of the coffee berry borer. METHODS The complete DNA sequence encoding a H. hampei xylanase (HhXyl) was obtained using a genome walking technique in a cDNA library derived from the borer digestive tract. The XIP-I gene was amplified from wheat (Triticum aestivum variety Soisson). A Pichia pastoris expression system was used to express the recombinant form of these enzymes. The xylanase activity and XIP-I inhibitory activity was quantified by the 3,5-dinitrosalicylic (DNS). The biological effects of XIP-I on borer individuals were evaluated by providing an artificial diet enriched with the recombinant XIP-I protein to the insects. RESULTS The borer xylanase sequence contains a 951 bp open reading frame that is predicted to encode a 317-amino acid protein, with an estimated molecular weight of 34.92 kDa and a pI of 4.84. Bioinformatic analysis revealed that HhXyl exhibits high sequence homology with endo-β-D-xylanases of Streptomyces bingchenggensis from glycosyl hydrolase 10 (GH10). The recombinant xylanase showed maximal activity at pH 5.5 and 37°C. XIP-I expressed as a recombinant protein inhibited HhXyl activity in vitro and caused individual H. hampei mortality in bioassays when included as a supplement in artificial diets. CONCLUSION A xylanase from the digestive tract of the coffee berry borer was identified and functionally characterized. A xylanase inhibitor protein, XIP-I, from wheat was shown to be a potent inhibitor of this xylanase, suggesting that its deployment has potential as a strategy to control coffee berry borer colonization of coffee plants.
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Affiliation(s)
- Beatriz Padilla-Hurtado
- Disciplina de Mejoramiento Genético, Centro Nacional de Investigaciones de Café (CENICAFE), Planalto, Km 4 vía antigua Chinchiná-Manizales, Chinchiná, Colombia.
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Ligands of RLKs and RLPs Involved in Defense and Symbiosis. SIGNALING AND COMMUNICATION IN PLANTS 2012. [DOI: 10.1007/978-3-642-23044-8_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Daval S, Lebreton L, Gazengel K, Boutin M, Guillerm-Erckelboudt AY, Sarniguet A. The biocontrol bacterium Pseudomonas fluorescens Pf29Arp strain affects the pathogenesis-related gene expression of the take-all fungus Gaeumannomyces graminis var. tritici on wheat roots. MOLECULAR PLANT PATHOLOGY 2011; 12:839-54. [PMID: 21726382 PMCID: PMC3258481 DOI: 10.1111/j.1364-3703.2011.00715.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The main effects of antagonistic rhizobacteria on plant pathogenic fungi are antibiosis, fungistasis or an indirect constraint through the induction of a plant defence response. To explore different biocontrol mechanisms, an in vitro confrontation assay was conducted with the rhizobacterium Pseudomonas fluorescens Pf29Arp as a biocontrol agent of the fungus Gaeumannomyces graminis var. tritici (Ggt) on wheat roots. In parallel with the assessment of disease extension, together with the bacterial and fungal root colonization rates, the transcript levels of candidate fungal pathogenicity and plant-induced genes were monitored during the 10-day infection process. The bacterial inoculation of wheat roots with the Pf29Arp strain reduced the development of Ggt-induced disease expressed as attack frequency and necrosis length. The growth rates of Ggt and Pf29Arp, monitored through quantitative polymerase chain reaction of DNA amounts with a part of the Ggt 18S rDNA gene and a specific Pf29Arp strain detection probe, respectively, increased throughout the interactions. Bacterial antagonism and colonization had no significant effect on root colonization by Ggt. The expression of fungal and plant genes was quantified in planta by quantitative reverse transcription-polymerase chain reaction during the interactions thanks to the design of specific primers and an innovative universal reference system. During the early stages of the tripartite interaction, several of the fungal genes assayed were down-regulated by Pf29Arp, including two laccases, a β-1,3-exoglucanase and a mitogen-activated protein kinase. The plant host glutathione-S-transferase gene was induced by Ggt alone and up-regulated by Pf29Arp bacteria in interaction with the pathogen. We conclude that Pf29Arp antagonism acts through the alteration of fungal pathogenesis and probably through the activation of host defences.
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Affiliation(s)
- Stéphanie Daval
- INRA, Agrocampus Ouest, Université Rennes 1, UMR1099 BiO3P (Biology of Organisms and Populations Applied to Plant Protection), BP 35327, Le Rheu, France.
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Guo G, Liu Z, Xu J, Liu J, Dai X, Xie D, Peng K, Feng X, Duan S, Zheng K, Cheng L, Fu Y. Purification and characterization of a xylanase from Bacillus subtilis isolated from the degumming line. J Basic Microbiol 2011; 52:419-28. [DOI: 10.1002/jobm.201100262] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 08/12/2011] [Indexed: 11/08/2022]
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Nepi M, Bini L, Bianchi L, Puglia M, Abate M, Cai G. Xylan-degrading enzymes in male and female flower nectar of Cucurbita pepo. ANNALS OF BOTANY 2011; 108:521-7. [PMID: 21813563 PMCID: PMC3158684 DOI: 10.1093/aob/mcr165] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS Nectar is a very complex mixture of substances. Some components (sugars and amino acids) are considered primary alimentary rewards for animals and have been investigated and characterized in numerous species for many years. In contrast, nectar proteins have been the subject of few studies and little is known of their function. Only very recently have detailed studies and characterization of nectar proteins been undertaken, and then for only a very few species. This current work represents a first step in the identification of a protein profile for the floral nectar of Cucurbita pepo. In this regard, the species studied is of particular interest in that it is monoecious with unisexual flowers and, consequently, it is possible that nectar proteins derived from male and female flowers may differ. METHODS Manually excised spots from two-dimensional (2-D) electrophoresis were subjected to in-gel protein digestion. The resulting peptides were sequenced using nanoscale LC-ESI/MS-MS (liquid chromatography-electrospray ionization/tandem mass spectrometry). An MS/MS ions search was carried out in Swiss-Prot and NCBInr databases using MASCOT software. KEY RESULTS Two-dimensional electrophoresis revealed a total of 24 spots and a different protein profile for male and female flower nectar. Four main proteins recognized by 2-D electrophoresis most closely resemble β-d-xylosidases from Arabidopsis thaliana and have some homology to a β-d-xylosidase from Medicago varia. They were present in similar quantities in male and female flowers and had the same molecular weight, but with slightly different isoelectric points. CONCLUSIONS A putative function for xylosidases in floral nectar of C. pepo is proposed, namely that they may be involved in degrading the oligosaccharides released by the nectary cell walls in response to hydrolytic enzymes produced by invading micro-organisms. Several types of oligosaccharides have been reported to increase the pathogenic potential of micro-organisms. Thus, it is possible that such a mechanism may reduce the virulence of pathogens present in nectar.
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Affiliation(s)
- M Nepi
- BIOCONNET, Biodiversity and Conservation Network, Department of Environmental Sciences G. Sarfatti, University of Siena, Via Mattioli 4, 53100 Siena, Italy.
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Bakri Y, Arabi MIE, Jawhar M. Heterogeneity in the ITS of the ribosomal DNA of Pyrenophora graminea isolates differing in xylanase and amylase production. Microbiology (Reading) 2011. [DOI: 10.1134/s0026261711040023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Arnold DL, Jackson RW. Bacterial genomes: evolution of pathogenicity. CURRENT OPINION IN PLANT BIOLOGY 2011; 14:385-91. [PMID: 21444240 DOI: 10.1016/j.pbi.2011.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 05/06/2023]
Abstract
Bacterial pathogens continue to pose a major threat to economically important plant resources. Disease outbreaks can occur through rapid evolution of a pathogen to overcome host defences. The advent of genome sequencing, especially next-generation technologies, has seen a revolution in the study of plant pathogen evolution over the past five years. This review highlights recent developments in understanding bacterial plant pathogen evolution, enabled by genomics and specifically focusing on type III protein effectors. The genotypic changes and mechanisms involved in pathogen evolution are now much better understood. However, there is still much to be learned about the drivers of pathogen evolution, both in terms of plant resistance and bacterial lifestyle.
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Affiliation(s)
- Dawn L Arnold
- Department of Applied Sciences, University of the West of England, Bristol, BS16 1QY, United Kingdom.
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Nguyen QB, Itoh K, Van Vu B, Tosa Y, Nakayashiki H. Simultaneous silencing of endo-β-1,4 xylanase genes reveals their roles in the virulence of Magnaporthe oryzae. Mol Microbiol 2011; 81:1008-19. [DOI: 10.1111/j.1365-2958.2011.07746.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Miyashita M, Oda M, Ono Y, Komoda E, Miyagawa H. Discovery of a small peptide from combinatorial libraries that can activate the plant immune system by a jasmonic acid signaling pathway. Chembiochem 2011; 12:1323-9. [PMID: 21567702 DOI: 10.1002/cbic.201000694] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Indexed: 11/11/2022]
Abstract
Plants defend themselves by using an innate immune system that is activated in response to a variety of molecules derived from pathogens. These molecules have provided profound insights into the mechanisms of pathogen recognition and subsequent signaling pathways in plants. In the present study, we screened a combinatorial random hexapeptide library for peptides that activate the plant immune system, by using a cell-based high-throughput screening system in which H(2)O(2) generation was monitored. We discovered a novel small peptide (YGIHTH-amide, PIP-1) that triggered H(2)O(2) production in tobacco and tomato cells, but not in Arabidopsis cells. PIP-1 induced significant levels of phytoalexin biosynthesis and defense-related gene expression in tobacco cells; this is likely to be activated by a jasmonic acid pathway.
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Affiliation(s)
- Masahiro Miyashita
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
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Synthesis and characterization of chimeric proteins based on cellulase and xylanase from an insect gut bacterium. Appl Environ Microbiol 2011; 77:4859-66. [PMID: 21642416 DOI: 10.1128/aem.02808-10] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Insects living on wood and plants harbor a large variety of bacterial flora in their guts for degrading biomass. We isolated a Paenibacillus strain, designated ICGEB2008, from the gut of a cotton bollworm on the basis of its ability to secrete a variety of plant-hydrolyzing enzymes. In this study, we cloned, expressed, and characterized two enzymes, β-1,4-endoglucanase (Endo5A) and β-1,4-endoxylanase (Xyl11D), from the ICGEB2008 strain and synthesized recombinant bifunctional enzymes based on Endo5A and Xyl11D. The gene encoding Endo5A was obtained from the genome of the ICGEB2008 strain by shotgun cloning. The gene encoding Xyl11D was obtained using primers for conserved xylanase sequences, which were identified by aligning xylanase sequences in other species of Paenibacillus. Endo5A and Xyl11D were overexpressed in Escherichia coli, and their optimal activities were characterized. Both Endo5A and Xyl11D exhibited maximum specific activity at 50°C and pH 6 to 7. To take advantage of this feature, we constructed four bifunctional chimeric models of Endo5A and Xyl11D by fusing the encoding genes either end to end or through a glycine-serine (GS) linker. We predicted three-dimensional structures of the four models using the I-TASSER server and analyzed their secondary structures using circular dichroism (CD) spectroscopy. The chimeric model Endo5A-GS-Xyl11D, in which a linker separated the two enzymes, yielded the highest C-score on the I-TASSER server, exhibited secondary structure properties closest to the native enzymes, and demonstrated 1.6-fold and 2.3-fold higher enzyme activity than Endo5A and Xyl11D, respectively. This bifunctional enzyme could be effective for hydrolyzing plant biomass owing to its broad substrate range.
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Osorio S, Bombarely A, Giavalisco P, Usadel B, Stephens C, Aragüez I, Medina-Escobar N, Botella MA, Fernie AR, Valpuesta V. Demethylation of oligogalacturonides by FaPE1 in the fruits of the wild strawberry Fragaria vesca triggers metabolic and transcriptional changes associated with defence and development of the fruit. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:2855-73. [PMID: 21273336 DOI: 10.1093/jxb/erq465] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ectopic expression of the strawberry (Fragaria×ananassa) gene FaPE1 encoding pectin methyl esterase produced in the wild species Fragaria vesca partially demethylated oligogalacturonides (OGAs), which conferred partial resistance of ripe fruits to the fungus Botrytis cinerea. Analyses of metabolic and transcriptional changes in the receptacle of the transgenic fruits revealed channelling of metabolites to aspartate and aromatic amino acids as well as phenolics, flavanones, and sesquiterpenoids, which was in parallel with the increased expression of some genes related to plant defence. The results illustrate the changes associated with resistance to B. cinerea in the transgenic F. vesca. These changes were accompanied by a significant decrease in the auxin content of the receptacle of the ripe fruits of transgenic F. vesca, and enhanced expression of some auxin-repressed genes. The role of these OGAs in fruit development was revealed by the larger size of the ripe fruits in transgenic F. vesca. When taken together these results show that in cultivated F. ananassa FaPE1 participates in the de-esterification of pectins and the generation of partially demethylated OGAs, which might reinforce the plant defence system and play an active role in fruit development.
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Affiliation(s)
- Sonia Osorio
- Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, 29071 Málaga, Spain
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Aidemark M, Tjellström H, Sandelius AS, Stålbrand H, Andreasson E, Rasmusson AG, Widell S. Trichoderma viride cellulase induces resistance to the antibiotic pore-forming peptide alamethicin associated with changes in the plasma membrane lipid composition of tobacco BY-2 cells. BMC PLANT BIOLOGY 2010; 10:274. [PMID: 21156059 PMCID: PMC3017840 DOI: 10.1186/1471-2229-10-274] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 12/14/2010] [Indexed: 05/24/2023]
Abstract
BACKGROUND Alamethicin is a membrane-active peptide isolated from the beneficial root-colonising fungus Trichoderma viride. This peptide can insert into membranes to form voltage-dependent pores. We have previously shown that alamethicin efficiently permeabilises the plasma membrane, mitochondria and plastids of cultured plant cells. In the present investigation, tobacco cells (Nicotiana tabacum L. cv Bright Yellow-2) were pre-treated with elicitors of defence responses to study whether this would affect permeabilisation. RESULTS Oxygen consumption experiments showed that added cellulase, already upon a limited cell wall digestion, induced a cellular resistance to alamethicin permeabilisation. This effect could not be elicited by xylanase or bacterial elicitors such as flg22 or elf18. The induction of alamethicin resistance was independent of novel protein synthesis. Also, the permeabilisation was unaffected by the membrane-depolarising agent FCCP. As judged by lipid analyses, isolated plasma membranes from cellulase-pretreated tobacco cells contained less negatively charged phospholipids (PS and PI), yet higher ratios of membrane lipid fatty acid to sterol and to protein, as compared to control membranes. CONCLUSION We suggest that altered membrane lipid composition as induced by cellulase activity may render the cells resistant to alamethicin. This induced resistance could reflect a natural process where the plant cells alter their sensitivity to membrane pore-forming agents secreted by Trichoderma spp. to attack other microorganisms, and thus adding to the beneficial effect that Trichoderma has for plant root growth. Furthermore, our data extends previous reports on artificial membranes on the importance of lipid packing and charge for alamethicin permeabilisation to in vivo conditions.
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Affiliation(s)
- Mari Aidemark
- Department of Biology, Lund University, Sölvegatan 35, SE-223 62 LUND, Sweden
| | - Henrik Tjellström
- Plant Biology Department, Michigan State University, East Lansing, 48824, MI, USA
- Department of Plant and Environmental Sciences, Göteborg University, P.O. Box 461, SE-405 30 Göteborg, Sweden
| | - Anna Stina Sandelius
- Department of Plant and Environmental Sciences, Göteborg University, P.O. Box 461, SE-405 30 Göteborg, Sweden
| | - Henrik Stålbrand
- Department of Biochemistry, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Erik Andreasson
- Department of Plant Protection Biology, Swedish Agricultural University, P.O. Box 102, SE-230 53 Alnarp, Sweden
| | - Allan G Rasmusson
- Department of Biology, Lund University, Sölvegatan 35, SE-223 62 LUND, Sweden
| | - Susanne Widell
- Department of Biology, Lund University, Sölvegatan 35, SE-223 62 LUND, Sweden
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Nadal M, Garcia-Pedrajas MD, Gold SE. The snf1 gene of Ustilago maydis acts as a dual regulator of cell wall degrading enzymes. PHYTOPATHOLOGY 2010; 100:1364-72. [PMID: 21062173 DOI: 10.1094/phyto-01-10-0011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Many fungal plant pathogens are known to produce extracellular enzymes that degrade cell wall elements required for host penetration and infection. Due to gene redundancy, single gene deletions generally do not address the importance of these enzymes in pathogenicity. Cell wall degrading enzymes (CWDEs) in fungi are often subject to carbon catabolite repression at the transcriptional level such that, when glucose is available, CWDE-encoding genes, along with many other genes, are repressed. In Saccharomyces cerevisiae, one of the main players controlling this process is SNF1, which encodes a protein kinase. In this yeast, Snf1p is required to release glucose repression when this sugar is depleted from the growth medium. We have employed a reverse genetic approach to explore the role of the SNF1 ortholog as a potential regulator of CWDE gene expression in Ustilago maydis. We identified U. maydis snf1 and deleted it from the fungal genome. Consistent with our hypothesis, the relative expression of an endoglucanase and a pectinase was higher in the wild type than in the Δsnf1 mutant strain when glucose was depleted from the growth medium. However, when cells were grown in derepressive conditions, the relative expression of two xylanase genes was unexpectedly higher in the Δsnf1 strain than in the wild type, indicating that, in this case, snf1 negatively regulated the expression of these genes. Additionally, we found that, contrary to several other fungal species, U. maydis Snf1 was not required for utilization of alternative carbon sources. Also, unlike in ascomycete plant pathogens, deletion of snf1 did not profoundly affect virulence in U. maydis.
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Affiliation(s)
- Marina Nadal
- Department of Plant Pathology, University of Georgia, Athens 30602-7274, USA
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Szczesny R, Jordan M, Schramm C, Schulz S, Cogez V, Bonas U, Büttner D. Functional characterization of the Xcs and Xps type II secretion systems from the plant pathogenic bacterium Xanthomonas campestris pv vesicatoria. THE NEW PHYTOLOGIST 2010; 187:983-1002. [PMID: 20524995 DOI: 10.1111/j.1469-8137.2010.03312.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
*Type II secretion (T2S) systems of many plant-pathogenic bacteria often secrete cell wall-degrading enzymes into the plant apoplast. *Here, we show that the Xps-T2S system from the plant pathogen Xanthomonas campestris pv vesicatoria (Xcv) promotes disease and contributes to the translocation of effector proteins that are delivered into the plant cell by the type III secretion (T3S) system. *The Xcs-T2S system instead lacks an obvious virulence function. However, individual xcs genes can partially complement mutants in homologous xps genes, indicating that they encode functional components of T2S systems. Enzyme activity assays showed that the Xps system contributes to secretion of proteases and xylanases. We identified the virulence-associated xylanase XynC as a substrate of the Xps system. However, homologs of known T2S substrates from other Xanthomonas spp. are not secreted by the T2S systems from Xcv. Thus, T2S systems from Xanthomonas spp. appear to differ significantly in their substrate specificities. *Transcript analyses revealed that expression of xps genes in Xcv is activated by HrpG and HrpX, key regulators of the T3S system. By contrast, expression of xynC and extracellular protease and xylanase activities are repressed by HrpG and HrpX, suggesting that components and substrates of the Xps system are differentially regulated.
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Affiliation(s)
| | | | - Claudia Schramm
- Institut für Biologie, Bereich Genetik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Steve Schulz
- Institut für Biologie, Bereich Genetik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Virginie Cogez
- Institut für Biologie, Bereich Genetik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Ulla Bonas
- Institut für Biologie, Bereich Genetik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Daniela Büttner
- Institut für Biologie, Bereich Genetik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany
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