1
|
Liu F, Tang J, Li T, Zhang Q. The microRNA miR482 regulates NBS-LRR genes in response to ALT1 infection in apple. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 343:112078. [PMID: 38556113 DOI: 10.1016/j.plantsci.2024.112078] [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: 12/20/2023] [Revised: 02/01/2024] [Accepted: 03/28/2024] [Indexed: 04/02/2024]
Abstract
Plants are frequently attacked by a variety of pathogens and thus have evolved a series of defense mechanisms, one important mechanism is resistance gene (R gene)-mediated disease resistance, but its expression is tightly regulated. NBS-LRR genes are the largest gene family of R genes. microRNAs (miRNAs) target to a number of NBS-LRR genes and trigger the production of phased small interfering RNAs (phasiRNAs) from these transcripts. phasiRNAs cis or trans regulate NBS-LRR genes, which can result in the repression of R gene expression. In this study, we screened for upregulated miR482 in the susceptible apple cultivar 'Golden Delicious' (GD) after inoculation with the fungal pathogen Alternaria alternata f. sp. mali (ALT1). Additionally, through combined degradome sequencing, we identified a gene targeted by miR482, named MdTNL1, a gene encoding a TIR-NBS-LRR (Toll/interleukin1 receptor-nucleotide binding site-leucine-rich repeat) protein. This gene exhibited a significant down-regulation post ALT1 inoculation, suggesting an impact on gene expression mediated by miRNA regulation. miR482 could cleave MdTNL1 and generate phasiRNAs at the cleavage site. We found that overexpression of miR482 inhibited the expression of MdTNL1 and thus reduced the disease resistance of GD, while silencing of miR482 increased the expression of MdTNL1 and thus improved the disease resistance of GD. This work elucidates key mechanisms underlying the immune response to Alternaria infection in apple. Identification of the resistance genes involved will enable molecular breeding for prevention and control of Alternaria leaf spot disease in this important fruit crop.
Collapse
Affiliation(s)
- Feiyu Liu
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing, 100193 China
| | - Jinqi Tang
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing, 100193 China
| | - Tianzhong Li
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing, 100193 China
| | - Qiulei Zhang
- Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing, 100193 China.
| |
Collapse
|
2
|
Adeyemo A, Schmidt-Heydt M. Expansion of the multi-locus gene alignment approach to improve identification of the fungal species Alternaria alternata. Int J Food Microbiol 2024; 421:110746. [PMID: 38917488 DOI: 10.1016/j.ijfoodmicro.2024.110746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 04/19/2024] [Accepted: 05/13/2024] [Indexed: 06/27/2024]
Abstract
Alternaria alternata is part of a genus comprised of over 600 different species that occur all over the world and cause damage to humans, plants and thereby to the economy. Yet, even though some species are causing tremendous issues, the past years have shown that assigning newly found isolates to known species was rather inconsistent. Most identifications are usually done on the basis of spore morphology, chemotype and molecular markers. In this work we used strains isolated from the wild as well as commercial strains of the DSMZ (German collection of microorganisms and cell cultures) as a reference, to show, that the variation within the Alternaria alternata species is comparable to the variation between different species of the genus Alternaria in regards to spore morphology and chemotype. We compared the different methods of identification and discerned the concatenation of multiple molecular markers as the deciding factor for better identification. Up until this point, usually a concatenation of two or three traditional molecular markers was used. Some of those markers being stronger some weaker. We show that the concatenation of five molecular markers improves the likeliness of a correct assignment, thus a better distinction between the different Alternaria species.
Collapse
Affiliation(s)
- Adetoye Adeyemo
- Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Department of Safety and Quality of Fruit and Vegetables, Karlsruhe, Germany.
| | - Markus Schmidt-Heydt
- Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Department of Safety and Quality of Fruit and Vegetables, Karlsruhe, Germany.
| |
Collapse
|
3
|
Sedighi A, Mohammadi A. Phytotoxicity effect of a highly toxic isolate of Alternaria alternata metabolites from Iran. Toxicon X 2024; 21:100186. [PMID: 38380155 PMCID: PMC10878783 DOI: 10.1016/j.toxcx.2024.100186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 01/20/2024] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
Alternaria species produce several mycotoxins, such as alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), altertoxin (ATX), tentoxin (TTX) and tenuazonic acid (TeA). This research aimed to isolate and identify mycotoxins from highly toxic Alternaria alternata (w19) and A. tennuisima isolates and their phytotoxicity effects. Fungal metabolites were extracted from 21-day cultures of Alternaria in a Czapek broth medium with the organic solvent chloroform/acetone and identified using the HPLC method. Alternaria metabolites were infiltrated in vivo into several plant leaves for phytotoxicity detection. The study investigated the impact of temperature, time, and metabolite concentration on phytotoxicity using the detached leaf infiltration technique. Five mycotoxins (TTX, TeA, ALT, AOH, and AME) were detected in A. alternata W19 isolate with 959.24, 102.03, 24.01, 9.04, and 2.44 ppm, respectively. A. tennuisima produce these toxins in a lower concentration. Infiltration of fungal metabolites induced leaf chlorosis and necrosis, which differs based on temperature, concentration and plant species. Based on our knowledge, this is the first report of Alternaria mycotoxins in Iran and a highly toxic isolate of A. alternata with rapid phytotoxicity on a wide range of susceptible hosts.
Collapse
Affiliation(s)
- Atefeh Sedighi
- Dept. of Plant Protection, College of Agriculture, Univerity of Birjand, Birjand, Iran
| | - Abbas Mohammadi
- Dept. of Plant Protection, College of Agriculture, Univerity of Birjand, Birjand, Iran
| |
Collapse
|
4
|
Molnár A, Knapp DG, Lovas M, Tóth G, Boldizsár I, Váczy KZ, Kovács GM. Untargeted metabolomic analyses support the main phylogenetic groups of the common plant-associated Alternaria fungi isolated from grapevine (Vitis vinifera). Sci Rep 2023; 13:19298. [PMID: 37935846 PMCID: PMC10630412 DOI: 10.1038/s41598-023-46020-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/26/2023] [Indexed: 11/09/2023] Open
Abstract
Alternaria, a cosmopolitan fungal genus is a dominant member of the grapevine (Vitis vinifera) microbiome. Several Alternaria species are known to produce a variety of secondary metabolites, which are particularly relevant to plant protection and food safety in field crops. According to previous findings, the majority of Alternaria species inhabiting grapevine belong to Alternaria sect. Alternaria. However, the phylogenetic diversity and secondary metabolite production of the distinct Alternaria species has remained unclear. In this study, our aim was to examine the genetic and metabolic diversity of endophytic Alternaria isolates associated with the above-ground tissues of the grapevine. Altogether, 270 Alternaria isolates were collected from asymptomatic leaves and grape clusters of different grapevine varieties in the Eger wine region of Hungary. After analyses of the nuclear ribosomal DNA internal transcribed spacer (ITS) and RNA polymerase second largest subunit (rpb2) sequences, 170 isolates were chosen for further analyses. Sequences of the Alternaria major allergen gene (Alt a 1), endopolygalacturonase (endoPG), OPA10-2, and KOG1058 were also included in the phylogenetic analyses. Identification of secondary metabolites and metabolite profiling of the isolates were performed using high-performance liquid chromatography (HPLC)-high-resolution tandem mass spectrometry (HR-MS/MS). The multilocus phylogeny results revealed two distinct groups in grapevine, namely A. alternata and the A. arborescens species complex (AASC). Eight main metabolites were identified in all collected Alternaria isolates, regardless of their affiliation to the species and lineages. Multivariate analyses of untargeted metabolites found no clear separations; however, a partial least squares-discriminant analysis model was able to successfully discriminate between the metabolic datasets from isolates belonging to the AASC and A. alternata. By conducting univariate analysis based on the discriminant ability of the metabolites, we also identified several features exhibiting large and significant variation between A. alternata and the AASC. The separation of these groups may suggest functional differences, which may also play a role in the functioning of the plant microbiome.
Collapse
Affiliation(s)
- Anna Molnár
- Centre for Research and Development, Eszterházy Károly Catholic University, Leányka utca 6, Eger, 3300, Hungary.
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary.
| | - Dániel G Knapp
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- Department of Forestry and Wood Technology, Linnaeus University, Växjö, Sweden
| | - Miklós Lovas
- Centre for Research and Development, Eszterházy Károly Catholic University, Leányka utca 6, Eger, 3300, Hungary
| | - Gergő Tóth
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre U. 9, Budapest, 1092, Hungary
| | - Imre Boldizsár
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- Department of Pharmacognosy, Semmelweis University, Üllői út 26, Budapest, 1085, Hungary
| | - Kálmán Zoltán Váczy
- Centre for Research and Development, Eszterházy Károly Catholic University, Leányka utca 6, Eger, 3300, Hungary
| | - Gábor M Kovács
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- Plant Protection Institute, Centre for Agricultural Research, Budapest, 1525, Hungary
| |
Collapse
|
5
|
Waqas M, Prencipe S, Guarnaccia V, Spadaro D. Molecular Characterization and Pathogenicity of Alternaria spp. Associated with Black Rot of Sweet Cherries in Italy. J Fungi (Basel) 2023; 9:992. [PMID: 37888248 PMCID: PMC10607616 DOI: 10.3390/jof9100992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/30/2023] [Accepted: 10/05/2023] [Indexed: 10/28/2023] Open
Abstract
Black rot is limiting the production of sweet cherries in Italy. Dark brown to black patches and sunken lesions on fruits are the most common symptoms of Alternaria black rot on sweet cherry fruits. We isolated 180 Alternaria spp. from symptomatic cherry fruits 'Kordia', 'Ferrovia', and 'Regina' harvested in Northern Italy, over three years, from 2020 to 2022. The aim was to identify and characterize a selection of forty isolates of Alternaria spp. based on morphology, pathogenicity, and combined analysis of rpb2, Alt-a1, endoPG and OPA10-2. The colonies were dark greyish in the center with white margins. Ellipsoidal or ovoid shaped conidia ranging from 19.8 to 21.7 μm in length were observed under a microscope. Based on the concatenated session of four gene regions, thirty-three out of forty isolates were identified as A. arborescens species complex (AASC), and seven as A. alternata. Pathogenicity was evaluated on healthy 'Regina' sweet cherry fruits. All the tested strains were pathogenic on their host. This study represents the first characterization of Alternaria spp. associated with black rot of cherries in Italy and, to the best of our knowledge, it is also the first report of AASC as an agent of black rot of sweet cherries in Italy.
Collapse
Affiliation(s)
- Muhammad Waqas
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Largo Braccini 2, 10095 Grugliasco, TO, Italy; (M.W.); (S.P.); (V.G.)
| | - Simona Prencipe
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Largo Braccini 2, 10095 Grugliasco, TO, Italy; (M.W.); (S.P.); (V.G.)
| | - Vladimiro Guarnaccia
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Largo Braccini 2, 10095 Grugliasco, TO, Italy; (M.W.); (S.P.); (V.G.)
- AGROINNOVA—Interdepartmental Centre for Innovation in the Agro-environmental Sector, University of Torino, Largo Braccini 2, 10095 Grugliasco, TO, Italy
| | - Davide Spadaro
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Largo Braccini 2, 10095 Grugliasco, TO, Italy; (M.W.); (S.P.); (V.G.)
- AGROINNOVA—Interdepartmental Centre for Innovation in the Agro-environmental Sector, University of Torino, Largo Braccini 2, 10095 Grugliasco, TO, Italy
| |
Collapse
|
6
|
Species of the Genera Neopestalotiopsis and Alternaria as Dominant Pathogen Species Attacking Mastic Trees (Pistacia lentiscus var. Chia). MICROBIOLOGY RESEARCH 2023. [DOI: 10.3390/microbiolres14010010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Between 2018 and 2021, several mastic trees (Pistacia lentiscus var. Chia) sampled in the field and the nursery of the Chios Mastiha Growers Association (CMGA) were analyzed to determine the cause of dominant diseases. Symptoms included defoliation, leaf, and twig blight, wilting and/or apoplexy of trees and apoplexy of young hardwood cuttings. Moreover, brown discoloration had also been observed on older woody parts of the trees such as branches and tree trunks. Several pathogens have been isolated and identified as the causing agents. Neopestalotiopsis and Alternaria species were isolated consistently from necrotic tissues of mastic trees (branches, twigs, and leaves) in the field and the nursery. All fungal isolates’ pathogenicity was confirmed by applying Koch’s postulates on young mastic trees under glasshouse conditions. Fungal pathogens were identified by sequence analyses of the ITS, β-tubulin, and histone gene regions. Alternaria species were analyzed further by sequencing the endopolygalacturonase (endoPG) and the Alternaria major allergen (Alta1) genes. More specifically, the isolates were identified as Neopestalotiopsis clavispora, Alternaria arborescens, and A. alternata based on morphological features and sequence analyses. This is the first report of N. clavispora, A. arborescens, and A. alternata on P. lentiscus var. Chia.
Collapse
|
7
|
Improvement of Alternaria Leaf Blotch and Fruit Spot of Apple Control through the Management of Primary Inoculum. Microorganisms 2022; 11:microorganisms11010101. [PMID: 36677393 PMCID: PMC9866788 DOI: 10.3390/microorganisms11010101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/24/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
Alternaria spp. is the causal agent of apple leaf blotch and fruit spot, diseases of recent appearance in Spain. The overwinter inoculum of Alternaria spp. is the source of primary infections in apple, thus the aim of this work was to optimize the control of infection through two environmentally friendly inoculum-management strategies, the removal of winter fallen leaves and the treatment of leaves with the biological agent Trichoderma asperellum to inhibit or prevent inoculum development in commercial orchards. The results of commercial orchard trials showed that leaf aspiration and application of T. asperellum on the ground have efficacy to reduce fruit spot between 50 and 80% and leaf blotch of between 30 and 40% depending on the year. The efficacies on the reduction of leaf blotch were slightly lower than of fruit spot. Disease reduction has been related to a reduction of total spores released during the season. Results of dynamics of spore release indicate that factors influencing spore release were rainfall and temperature. In conclusion, the use of environmentally friendly strategies combined with standard fungicides, and with monitoring environmental conditions, might allow a reduction in the number of phytosanitary applications, thus achieving the goal of reducing their use.
Collapse
|
8
|
Li B, Cao Y, Ji Z, Zhang J, Meng X, Dai P, Hu T, Wang S, Cao K, Wang Y. Coinfection of Two Mycoviruses Confers Hypovirulence and Reduces the Production of Mycotoxin Alternariol in Alternaria alternata f. sp. mali. Front Microbiol 2022; 13:910712. [PMID: 35756001 PMCID: PMC9218907 DOI: 10.3389/fmicb.2022.910712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 04/28/2022] [Indexed: 11/22/2022] Open
Abstract
Alternaria leaf blotch caused by Alternaria alternata apple pathotype (Alternaria mali) is an important fungal disease that affects the production of apples worldwide. Mycoviruses harbored in plant pathogenic fungi can confer hypovirulence in their hosts and have attracted widespread attention as potential biocontrol tools. In this study, the coinfection of two mycoviruses, named A. alternata chrysovirus 1 strain QY2 (AaCV1-QY2) and A. alternata magoulivirus 1 (AaMV1), respectively, were isolated from A. alternata f. sp. mali strain QY21. Sequence analyses revealed that AaCV1-QY2 virus belonged to the genus Betachrysovirus and AaMV1 virus belonged to the genus Magoulvirus. These two mycoviruses were found to be associated with hypovirulence in A. alternata, among which AaCV1-QY2 might play a relatively leading role. Because the elimination of AaMV1 from the strain QY21 does not affect the hypovirulence trait, which indicates that the virus AaCV1-QY2 can independently induce slow growth and reduce host virulence. Moreover, the presence of viruses decreased the accumulation of the mycotoxin alternariol (AOH) in A. alternata strains. Intriguingly, AaCV1-QY2/AaMV1 mycoviruses can be horizontally transmitted to other A. alternata strains, and this coinfection can promote the interspecific transmission efficiency of AaCV1-QY2. To our knowledge, this study reports the first description of the member of Chrysovirus is related to hypovirulence in Alternaria spp. that facilitates the development of biocontrol measures of A. mali Roberts.
Collapse
Affiliation(s)
- Bo Li
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Yuhan Cao
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Zixuan Ji
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Jingyi Zhang
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Xianglong Meng
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Pengbo Dai
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Tongle Hu
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Shutong Wang
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Keqiang Cao
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Yanan Wang
- State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, China
| |
Collapse
|
9
|
Fungal Allergen and Mold Allergy Diagnosis: Role and Relevance of Alternaria alternata Alt a 1 Protein Family. J Fungi (Basel) 2022; 8:jof8030277. [PMID: 35330279 PMCID: PMC8954643 DOI: 10.3390/jof8030277] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/03/2022] [Accepted: 03/07/2022] [Indexed: 02/04/2023] Open
Abstract
Alternaria is a genus of worldwide fungi found in different habitats such as soil, the atmosphere, plants or indoor environments. Alternaria species are saprobic—largely involved in the decomposition of organic material—but they can also act as animal pathogens, causing disease in humans and animals, developing infections, toxicosis and allergic diseases. A. alternata is considered one of the most important sources of fungal allergens worldwide and it is associated with severe asthma and respiratory status. Among the A. alternata allergens, Alt a 1 is the main sensitizing allergen and its usefulness in diagnosis and immunotherapy has been demonstrated. Alt a 1 seems to define a protein family that can be used to identify related pathogenic fungi in plants and fruits, and to establish taxonomic relationships between the different fungal divisions.
Collapse
|