1
|
Rosli H, Batzer JC, Hernández E, Beruski G, Dixon PM, Gleason ML. Precipitation Impacts Dissemination of Three Sooty Blotch and Flyspeck Taxa on Apple Fruit. PLANT DISEASE 2020; 104:2398-2405. [PMID: 32689919 DOI: 10.1094/pdis-11-19-2340-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The spatial dissemination of three prevalent taxa of sooty blotch and flyspeck (SBFS) fungi under several levels of precipitation was compared during 2015 and 2016 in an Iowa apple orchard. Overhead irrigation was used to supplement ambient precipitation in order to insure SBFS spore dissemination and colony development. There were five irrigation levels, involving 1-min-long periods of irrigation that were imposed either once or twice per hour at intervals of 3, 6, or 12 h, as well as a nonirrigated control. Preselected apple fruit were inoculated with one of the three SBFS taxa to serve as sources of inoculum. Dissemination from these inoculated apple fruit was assessed at harvest by counting SBFS colonies on water-sprayed and nontreated fruit. As a further control, additional fruit were enclosed in fruit bags throughout the fruit development period. In both 2015 and 2016, the number of colonies of the SBFS fungus Peltaster gemmifer per apple increased sharply as the duration of irrigation increased, whereas the number of colonies of Microcyclosporella mali increased to a lesser extent and Stomiopeltis sp. RS1 showed no increase. In 2015, the linear relationship between the duration of irrigation-imposed precipitation levels and the number of colonies on the water-sprayed apple fruit was similar for P. gemmifer (slope = 0.09), Stomiopeltis sp. RS1 (slope = 0.07), and Microcyclosporella mali (slope = 0.13); whereas, in 2016, the slope was higher for P. gemmifer (0.28) than for Stomiopeltis sp. RS1 (-0.09) or M. mali (0.06). The results indicated that dissemination of P. gemmifer increased sharply in response to increased irrigation-imposed precipitation, and that dissemination patterns differed considerably among the three SBFS taxa. The apparent advantage of P. gemmifer in precipitation-triggered dissemination may stem from its ability to produce spores rapidly by budding. To our knowledge, this is the first article to assess splash dispersal by SBFS fungi in the field and the first to document taxon-specific patterns of dissemination in this pathogen complex.
Collapse
Affiliation(s)
- Hafizi Rosli
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - Jean C Batzer
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
| | - Edward Hernández
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
| | - Gustavo Beruski
- Department of Biosystems Engineering, ESALQ, University of São Paulo, Piracicaba, Brazil
| | - Philip M Dixon
- Department of Statistics, Iowa State University, Ames, IA, U.S.A
| | - Mark L Gleason
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, U.S.A
| |
Collapse
|
2
|
Gleason ML, Zhang R, Batzer JC, Sun G. Stealth Pathogens: The Sooty Blotch and Flyspeck Fungal Complex. ANNUAL REVIEW OF PHYTOPATHOLOGY 2019; 57:135-164. [PMID: 31150591 DOI: 10.1146/annurev-phyto-082718-100237] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Sooty blotch and flyspeck (SBFS) fungi produce superficial, dark-colored colonies on fruits, stems, and leaves of many plant genera. These blemishes are economically damaging on fruit, primarily apple and pear, because they reduce the sale price of fresh fruit. Fungicide spray programs can control SBFS but are costly and impair human and environmental health; thus, less chemically intensive management strategies are needed. Although the scientific study of SBFS fungi began nearly 200 years ago, recent DNA-driven studies revealed an unexpectedly diverse complex: more than 100 species in 30 genera of Ascomycota and Basidiomycota. Analysis of evolutionary phylogenetics and phylogenomics indicates that the evolution of SBFS fungi from plant-penetrating ancestors to noninvasive ectophytic parasites was accompanied by a massive contraction of pathogenicity-related genes, including plant cell wall-degrading enzymes and effectors, and an expansion of cuticle-degradation genes. This article reviews progress in understanding SBFS taxonomy and ecology and improving disease management. We also highlight recent breakthroughs in reconstructing the evolutionary origins of these unusual plant pathogens and delineating adaptations to their ectophytic niche.
Collapse
Affiliation(s)
- Mark L Gleason
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi Province, China;
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011, USA
| | - Rong Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi Province, China;
| | - Jean C Batzer
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011, USA
| | - Guangyu Sun
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi Province, China;
| |
Collapse
|
3
|
Rosli H, Batzer JC, Harrington TC, Gleason ML. Peltaster gemmifer: A new species in the sooty blotch and flyspeck species complex from the United States. Mycologia 2018; 110:822-834. [PMID: 30240341 DOI: 10.1080/00275514.2018.1486679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Sooty blotch and flyspeck (SBFS) fungi infect the cuticle of fruit, including apple fruit, and produce pigmented colonies. A new member of this fungal complex in the genus Peltaster is described on the basis of molecular and morphological evidence. The SBFS complex is a diverse group of ectophytic fungi that reside primarily within the order Capnodiales. Sooty blotch and flyspeck isolates from apple orchards in the central United States were subjected to parsimony and Bayesian analyses based on the internal transcribed spacer regions of nuc rDNA, the partial translation elongation factor 1-α gene, and the partial mitochondrial small subunit rRNA gene. Phylogenetic analysis delineated a new species, Peltaster gemmifer, from P. cerophilus and P. fructicola. Peltaster gemmifer conidiophores bear primary conidia that produce secondary conidia either through budding or through microcyclic conidiation; these were not seen in cultures of P. cerophilus and P. fructicola. On cellulose membrane that was placed on water agar amended with apple juice, P. gemmifer produced brown to black pycnothyria in a superficial brownish mycelial mat, similar to the colonies produced on apple fruit. Findings from the present study add to the >80 named and putative SBFS species so far described worldwide.
Collapse
Affiliation(s)
- Hafizi Rosli
- a School of Biological Sciences, Universiti Sains Malaysia , 11800 Penang , Malaysia
| | - Jean C Batzer
- b Department of Plant Pathology and Microbiology , ATRB Building, 2213 Pammel Drive, Iowa State University , Ames , Iowa 50011
| | - Thomas C Harrington
- b Department of Plant Pathology and Microbiology , ATRB Building, 2213 Pammel Drive, Iowa State University , Ames , Iowa 50011
| | - Mark L Gleason
- b Department of Plant Pathology and Microbiology , ATRB Building, 2213 Pammel Drive, Iowa State University , Ames , Iowa 50011
| |
Collapse
|
4
|
|
5
|
Xu C, Chen H, Gleason ML, Xu JR, Liu H, Zhang R, Sun G. Peltaster fructicola genome reveals evolution from an invasive phytopathogen to an ectophytic parasite. Sci Rep 2016; 6:22926. [PMID: 26964666 PMCID: PMC4786788 DOI: 10.1038/srep22926] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 02/24/2016] [Indexed: 11/26/2022] Open
Abstract
Sooty blotch and flyspeck (SBFS) fungi are unconventional plant pathogens that cause economic losses by blemishing the surface appearance of infected fruit. Here, we introduce the 18.14-Mb genome of Peltaster fructicola, one of the most prevalent SBFS species on apple. This undersized assembly contains only 8,334 predicted protein-coding genes and a very small repertoire of repetitive elements. Phylogenomics and comparative genomics revealed that P. fructicola had undergone a reductive evolution, during which the numbers of orphan genes and genes involved in plant cell wall degradation, secondary metabolism, and secreted peptidases and effectors were drastically reduced. In contrast, the genes controlling 1,8-dihydroxynaphthalene (DHN)-melanin biosynthesis and appressorium-mediated penetration were retained substantially. Additionally, microscopic examination of the surfaces of infected apple indicated for the first time that P. fructicola can not only dissolve epicuticular waxes but also partially penetrate the cuticle proper. Our findings indicate that genome contraction, characterized mainly by the massive loss of pathogenicity-related genes, has played an important role in the evolution of P. fructicola (and by implication other SBFS species) from a plant-penetrating ancestor to a non-invasive ectophyte, displaying a novel form of trophic interaction between plants and fungi.
Collapse
Affiliation(s)
- Chao Xu
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Huan Chen
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Mark L. Gleason
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011, USA
| | - Jin-Rong Xu
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Rong Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Guangyu Sun
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| |
Collapse
|
6
|
|