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Li Y, Lou H, Fu H, Su H, Hao C, Luo J, Cai N, Jin Y, Han J, Deng Z, Cao Y, Ma X. Identifying the role of cellulase gene CsCEL20 upon the infection of Xanthomonas citri subsp. citri in citrus. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2025; 45:10. [PMID: 39781329 PMCID: PMC11704107 DOI: 10.1007/s11032-024-01531-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2024] [Accepted: 12/17/2024] [Indexed: 01/12/2025]
Abstract
Citrus canker is a devastating disease caused by Xanthomonas citri subsp. citri (Xcc), which secretes the effector PthA4 into host plants to trigger transcription of the susceptibility gene CsLOB1, resulting in pustule formation. However, the molecular mechanism underlying CsLOB1-mediated susceptibility to Xcc remains elusive. This study identified CsCEL20 as a target gene positively regulated by CsLOB1. Cell expansion and cell wall degradation were observed in sweet orange leaves after Xcc infection. A total of 69 cellulase genes were retrieved within the Citrus sinensis genome, comprising 40 endoglucanase genes and 29 glucosidase genes. Transcriptomic analysis revealed that expression levels of CsCEL8, CsCEL9, CsCEL20, and CsCEL26 were induced by Xcc invasion in sweet orange leaves, but not in the resistant genotype Citron C-05. Among them, CsCEL20 exhibited the highest expression level, with an over 430-fold increase following Xcc infection. Additionally, RT-qPCR analysis confirmed that CsCEL20 expression was induced in susceptible genotypes (Sweet orange, Danna citron, Lemon) upon Xcc invasion, but not in resistant genotypes (Citron C-05, Aiguo citron, American citron). A Single-Nucleotide Polymorphism (SNP) at -423 bp was identified in the CEL20 promoters and exhibits a difference between eight susceptible citrus genotypes and three resistant ones. Moreover, CsCEL20 expression was upregulated in CsLOB1-overexpression transgenic lines compared to the wild type. Dual-luciferase reporter assays indicated that CsLOB1 can target the -505 bp to -168 bp region of CsCEL20 promoter to trans-activate its expression. These findings suggest that CsCEL20 may function as a candidate gene for citrus canker development and may be a promising target for biotechnological breeding of Xcc-resistant citrus genotypes. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-024-01531-3.
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Affiliation(s)
- Yi Li
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Huijie Lou
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Hongyan Fu
- Hunan Horticultural Research Institute, Hunan Academy of Agricultural Sciences, Changsha, 410125 China
| | - Hanying Su
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Chenxing Hao
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Jianming Luo
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Nan Cai
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Yan Jin
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Jian Han
- Hunan Horticultural Research Institute, Hunan Academy of Agricultural Sciences, Changsha, 410125 China
| | - Ziniu Deng
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- Nanling Institute of Citrus Industry, Chenzhou, 423000 China
| | - Yunlin Cao
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
| | - Xianfeng Ma
- Engineering Research Center of Education Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128 China
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Chen L, Bin M, Lin J, Shen W, Zhang X. Characterization of MPK family members in the genus Citrus (Rutaceae) and analysis of the function of AbMPK13 in the response to citrus canker in Atalantia buxifolia. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 219:109418. [PMID: 39708698 DOI: 10.1016/j.plaphy.2024.109418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2024] [Revised: 11/20/2024] [Accepted: 12/16/2024] [Indexed: 12/23/2024]
Abstract
Citrus bacterial canker has deleterious effects on global citrus production. The mitogen-activated protein kinase (MAPK) signaling cascade regulates plant defense against pathogen infection. Here, we identified 11 MAPKs in Atalantia buxifolia, a wild citrus species with high stress tolerance. Phylogenetic and gene structure analysis of the identified MAP kinases (MPKs) was conducted, and conserved motifs were identified. MPK expression was altered in Xanthomonas citri subsp. citri (Xcc)-resistant Atalantia buxifolia and Xcc-sensitive sweet orange after Xcc infection. AbMPK13 expression was significantly up-regulated after Xcc infection. AbMPK13 was localized to the cytoplasm, and its overexpression enhanced the resistance of sweet orange to Xcc and activated the salicylic acid (SA) signaling pathway. These findings clarify the role of MPKs in the citrus canker resistance of A. buxifolia.
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Affiliation(s)
- Lijuan Chen
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Science and Technology Research on Fruit Tree, Guangzhou, 510640, China
| | - Minliang Bin
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Science and Technology Research on Fruit Tree, Guangzhou, 510640, China; College of Life Sciences, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642, China
| | - Jue Lin
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Science and Technology Research on Fruit Tree, Guangzhou, 510640, China
| | - Wenzhong Shen
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Science and Technology Research on Fruit Tree, Guangzhou, 510640, China
| | - Xinxin Zhang
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Science and Technology Research on Fruit Tree, Guangzhou, 510640, China.
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Liu L, Liu X, Liu L, Zhu T, Ye R, Chen H, Zhou L, Wu G, Tan L, Han J, Li R, Ma X, Deng Z. Clarification of the infection pattern of Xanthomonas citri subsp. citri on citrus fruit by artificial inoculation. PLANT METHODS 2024; 20:65. [PMID: 38725004 PMCID: PMC11080196 DOI: 10.1186/s13007-024-01190-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/19/2024] [Indexed: 05/13/2024]
Abstract
BACKGROUND Citrus canker is a significant bacterial disease caused by Xanthomonas citri subsp. citri (Xcc) that severely impedes the healthy development of the citrus industry. Especially when citrus fruit is infected by Xcc, it will reduce or even lost its commercial value. However, due to the prolonged fruiting cycle and intricate structure, much less research progress had been made in canker disease on fruit than on leaf. In fact, limited understanding has been achieved on canker development and the response to Xcc infection in fruit. RESULTS Herein, the progression of canker disease on sweet orange fruit was tracked in the field. Results indicated that typical lesions initially appear on the sepal, style residue, nectary disk, epicarp, and peduncle of young fruits after petal fall. The susceptibility of fruits to Xcc infection diminished as the fruit developed, with no new lesions forming at the ripening stage. The establishment of an efficient method for inoculating Xcc on fruit as well as the artificial inoculation throughout the fruit's developmental cycle clarified this infection pattern. Additionally, microscopic observations during the infection process revealed that Xcc invasion caused structural changes on the surface and cross-section of the fruit. CONCLUSIONS An efficient system for inoculation on citrus fruit with Xcc was established, by which it can serve for the evaluation of citrus germplasm for canker disease resistance and systematic research on the interactions between Xcc and citrus fruits.
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Affiliation(s)
- Lian Liu
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Xin Liu
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Lingyi Liu
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Tao Zhu
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Rongchun Ye
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Hao Chen
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Linglei Zhou
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Guang Wu
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China
| | - Limei Tan
- Chenzhou Institute of Agricultural Science, Chenzhou, 423000, China
- NanLing Institute of Citrus Industry, Chenzhou, 423000, China
| | - Jian Han
- Hunan Academy of Agricultural Sciences, Hunan Horticultural Research Institute, Changsha, 410125, China
| | - Ronghua Li
- Comprehensive Experimental Station of Navel Sweet Orange in South Hunan, Chenzhou, 424200, China
| | - Xianfeng Ma
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China.
- Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, 410128, China.
| | - Ziniu Deng
- National Center for Citrus Improvement-Changsha, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China.
- NanLing Institute of Citrus Industry, Chenzhou, 423000, China.
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Cardoso JLS, Souza AA, Vieira MLC. Molecular basis for host responses to Xanthomonas infection. PLANTA 2022; 256:84. [PMID: 36114308 DOI: 10.1007/s00425-022-03994-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 09/05/2022] [Indexed: 06/15/2023]
Abstract
This review highlights the most relevant and recent updated information available on the defense responses of selected hosts against Xanthomonas spp. Xanthomonas is one of the most important genera of Gram-negative phytopathogenic bacteria, severely affecting the productivity of economically important crops worldwide, colonizing either the vascular system or the mesophyll tissue of the host. Due to its rapid propagation, Xanthomonas poses an enormous challenge to farmers, because it is usually controlled using huge quantities of copper-based chemicals, adversely impacting the environment. Thus, developing new ways of preventing colonization by these bacteria has become essential. Advances in genomic and transcriptomic technologies have significantly elucidated at molecular level interactions between various crops and Xanthomonas species. Understanding how these hosts respond to the infection is crucial if we are to exploit potential approaches for improving crop breeding and cutting productivity losses. This review focuses on our current knowledge of the defense response mechanisms in agricultural crops after Xanthomonas infection. We describe the molecular basis of host-bacterium interactions over a broad spectrum with the aim of improving our fundamental understanding of which genes are involved and how they work in this interaction, providing information that can help to speed up plant breeding programs, namely using gene editing approaches.
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Affiliation(s)
- Jéssica L S Cardoso
- Genetics Department, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, SP, 13418-900, Brazil
| | - Alessandra A Souza
- Citrus Research Center "Sylvio Moreira", Agronomic Institute (IAC), Cordeirópolis, SP, 13490-000, Brazil
| | - Maria Lucia C Vieira
- Genetics Department, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, SP, 13418-900, Brazil.
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Long Y, Luo R, Xu Z, Cheng S, Li L, Ma H, Bao M, Li M, Ouyang Z, Wang N, Duan S. A Fluorescent Reporter-Based Evaluation Assay for Antibacterial Components Against Xanthomonas citri subsp. citri. Front Microbiol 2022; 13:864963. [PMID: 35602035 PMCID: PMC9114712 DOI: 10.3389/fmicb.2022.864963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Xanthomonas citri subsp. citri (Xcc) is the agent of citrus bacterial canker (CBC) disease, which has significantly reduced citrus quantity and quality in many producing areas worldwide. Copper-based bactericides are the primary products for CBC control and management, but the problems derived from copper-resistant and environmental contamination have become issues of anxiety. Thus, there is a need to find alternative antibacterial products instead of relying on a single type of agent. This study developed a method to evaluate the inhibition of antibacterial agents using the fluorescence-labeled recombinant Xcc strain (Xcc-eYFP). The optimization of timelines and parameters for the evaluation of antibacterial agents involved the use of a Spark™ multimode microplate reader. This evaluation and screening method can be applied to bactericides, cocktail-mixture formulations, antagonistic bacteria, and derived metabolites. The results showed that the minimum inhibitory concentration (MIC) of commercial bactericides determined by fluorescence agrees with the MIC values determined by the conventional method. A screened cocktail-mixture bactericide presents more activity than the individual agents during the protective effects. Notably, this method has been further developed in the screening of Xcc-antagonistic bacterial strains. In summary, we provide a validated strategy for screening and evaluation of different antibacterial components for inhibition against Xcc for CBC control and management.
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Affiliation(s)
- Yunfei Long
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Ruifang Luo
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Zhou Xu
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Shuyuan Cheng
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Ling Li
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Haijie Ma
- College of Agricultural and Food Sciences, Zhejiang A&F University, Hangzhou, China
| | - Minli Bao
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Min Li
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Zhigang Ouyang
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
| | - Nian Wang
- Department of Microbiology and Cell Science, Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Shuo Duan
- China-USA Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, China
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Duan S, Long Y, Cheng S, Li J, Ouyang Z, Wang N. Rapid Evaluation of the Resistance of Citrus Germplasms Against Xanthomonas citri subsp. citri. PHYTOPATHOLOGY 2022; 112:765-774. [PMID: 34495678 DOI: 10.1094/phyto-04-21-0175-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Xanthomonas citri subsp. citri (Xcc) is the causal agent of citrus bacterial canker (CBC), one of the most devastating citrus diseases. Most commercial citrus varieties are susceptible to CBC. However, some citrus varieties and wild citrus germplasms are CBC resistant and are promising in genetic increases in citrus resistance against CBC. We aimed to evaluate citrus germplasms for resistance against CBC. First, we developed a rapid evaluation method based on enhanced yellow fluorescent protein (eYFP)-labeled Xcc. The results demonstrated that eYFP does not affect the growth and virulence of Xcc. Xcc-eYFP allows measurement of bacterial titers but is more efficient and rapid than the plate colony counting method. Next, we evaluated citrus germplasms collected in China. Based on symptoms and bacterial titers, we identified that two citrus germplasms ('Ichang' papeda and 'Huapi' kumquat) are resistant, whereas eight citrus germplasms ('Chongyi' wild mandarin, 'Mangshan' wild mandarin, 'Ledong' kumquat, 'Dali' citron, 'Yiliang' citron, 'Longyan' kumquat, 'Bawang' kumquat, and 'Daoxian' wild mandarin) are tolerant. In summary, we have developed a rapid evaluation method to test the resistance of citrus plants against CBC. This method was successfully used to identify two highly canker-resistant citrus germplasms and eight citrus germplasms with canker tolerance. These results could be leveraged in traditional breeding contexts or be used to identify canker resistance genes to increase the disease resistance of commercial citrus varieties via biotechnological approaches.
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Affiliation(s)
- Shuo Duan
- Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, Jiangxi 341000, China
| | - Yunfei Long
- Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, Jiangxi 341000, China
| | - Shuyuan Cheng
- Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, Jiangxi 341000, China
| | - Jinyun Li
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, Lake Alfred, FL 33850, U.S.A
| | - Zhigang Ouyang
- Citrus Huanglongbing Joint Laboratory, National Navel Orange Engineering Research Center, Gannan Normal University, Ganzhou, Jiangxi 341000, China
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, Lake Alfred, FL 33850, U.S.A
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Iantas J, Savi DC, Schibelbein RDS, Noriler SA, Assad BM, Dilarri G, Ferreira H, Rohr J, Thorson JS, Shaaban KA, Glienke C. Endophytes of Brazilian Medicinal Plants With Activity Against Phytopathogens. Front Microbiol 2021; 12:714750. [PMID: 34539608 PMCID: PMC8442585 DOI: 10.3389/fmicb.2021.714750] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022] Open
Abstract
Plant diseases caused by phytopathogens are responsible for significant crop losses worldwide. Resistance induction and biological control have been exploited in agriculture due to their enormous potential. In this study, we investigated the antimicrobial potential of endophytic fungi of leaves and petioles of medicinal plants Vochysia divergens and Stryphnodendron adstringens located in two regions of high diversity in Brazil, Pantanal, and Cerrado, respectively. We recovered 1,304 fungal isolates and based on the characteristics of the culture, were assigned to 159 phenotypes. One isolate was selected as representative of each phenotype and studied for antimicrobial activity against phytopathogens. Isolates with better biological activities were identified based on DNA sequences and phylogenetic analyzes. Among the 159 representative isolates, extracts from 12 endophytes that inhibited the mycelial growth (IG) of Colletotrichum abscissum (≥40%) were selected to expand the antimicrobial analysis. The minimum inhibitory concentrations (MIC) of the extracts were determined against citrus pathogens, C. abscissum, Phyllosticta citricarpa and Xanthomonas citri subsp. citri and the maize pathogen Fusarium graminearum. The highest activity against C. abscissum were from extracts of Pseudofusicoccum stromaticum CMRP4328 (IG: 83% and MIC: 40 μg/mL) and Diaporthe vochysiae CMRP4322 (IG: 75% and MIC: 1 μg/mL), both extracts also inhibited the development of post-bloom fruit drop symptoms in citrus flowers. The extracts were promising in inhibiting the mycelial growth of P. citricarpa and reducing the production of pycnidia in citrus leaves. Among the isolates that showed activity, the genus Diaporthe was the most common, including the new species D. cerradensis described in this study. In addition, high performance liquid chromatography, UV detection, and mass spectrometry and thin layer chromatography analyzes of extracts produced by endophytes that showed high activity, indicated D. vochysiae CMRP4322 and P. stromaticum CMRP4328 as promising strains that produce new bioactive natural products. We report here the capacity of endophytic fungi of medicinal plants to produce secondary metabolites with biological activities against phytopathogenic fungi and bacteria. The description of the new species D. cerradensis, reinforces the ability of medicinal plants found in Brazil to host a diverse group of fungi with biotechnological potential.
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Affiliation(s)
- Jucélia Iantas
- Postgraduate Program of Microbiology, Parasitology and Pathology, Department of Pathology, Federal University of Paraná, Curitiba, Brazil
| | - Daiani Cristina Savi
- Department of Biomedicine, Centro Universitário Católica de Santa Catarina, Joinville, Brazil
- Postgraduate Program of Genetics, Federal University of Paraná, Curitiba, Brazil
| | - Renata da Silva Schibelbein
- Postgraduate Program of Microbiology, Parasitology and Pathology, Department of Pathology, Federal University of Paraná, Curitiba, Brazil
| | - Sandriele Aparecida Noriler
- Postgraduate Program of Microbiology, Parasitology and Pathology, Department of Pathology, Federal University of Paraná, Curitiba, Brazil
| | | | - Guilherme Dilarri
- Department of General and Applied Biology, Biosciences Institute, State University of São Paulo, Rio Claro, Brazil
| | - Henrique Ferreira
- Department of General and Applied Biology, Biosciences Institute, State University of São Paulo, Rio Claro, Brazil
| | - Jürgen Rohr
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, United States
| | - Jon S. Thorson
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, United States
- Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY, United States
| | - Khaled A. Shaaban
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, United States
- Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY, United States
| | - Chirlei Glienke
- Postgraduate Program of Microbiology, Parasitology and Pathology, Department of Pathology, Federal University of Paraná, Curitiba, Brazil
- Postgraduate Program of Genetics, Federal University of Paraná, Curitiba, Brazil
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8
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Deciphering the Role of Ion Channels in Early Defense Signaling against Herbivorous Insects. Cells 2021; 10:cells10092219. [PMID: 34571868 PMCID: PMC8470099 DOI: 10.3390/cells10092219] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 12/14/2022] Open
Abstract
Plants and insect herbivores are in a relentless battle to outwit each other. Plants have evolved various strategies to detect herbivores and mount an effective defense system against them. These defenses include physical and structural barriers such as spines, trichomes, cuticle, or chemical compounds, including secondary metabolites such as phenolics and terpenes. Plants perceive herbivory by both mechanical and chemical means. Mechanical sensing can occur through the perception of insect biting, piercing, or chewing, while chemical signaling occurs through the perception of various herbivore-derived compounds such as oral secretions (OS) or regurgitant, insect excreta (frass), or oviposition fluids. Interestingly, ion channels or transporters are the first responders for the perception of these mechanical and chemical cues. These transmembrane pore proteins can play an important role in plant defense through the induction of early signaling components such as plasma transmembrane potential (Vm) fluctuation, intracellular calcium (Ca2+), and reactive oxygen species (ROS) generation, followed by defense gene expression, and, ultimately, plant defense responses. In recent years, studies on early plant defense signaling in response to herbivory have been gaining momentum with the application of genetically encoded GFP-based sensors for real-time monitoring of early signaling events and genetic tools to manipulate ion channels involved in plant-herbivore interactions. In this review, we provide an update on recent developments and advances on early signaling events in plant-herbivore interactions, with an emphasis on the role of ion channels in early plant defense signaling.
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