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Kasteel M, Ketelaar T, Govers F. Fatal attraction: How Phytophthora zoospores find their host. Semin Cell Dev Biol 2023; 148-149:13-21. [PMID: 36792439 DOI: 10.1016/j.semcdb.2023.01.014] [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: 12/14/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/15/2023]
Abstract
Oomycete plant pathogens, such as Phytophthora and Pythium species produce motile dispersal agents called zoospores that actively target host plants. Zoospores are exceptional in their ability to display taxis to chemical, electrical and physical cues to navigate the phyllosphere and reach stomata, wound sites and roots. Many components of root exudates have been shown attractive or repulsive to zoospores. Although some components possess very strong attractiveness, it seems that especially the mix of components exuded by the primary host is most attractive to zoospores. Zoospores actively approach attractants with swimming behaviour reminiscent of other microswimmers. To achieve a unified description of zoospore behaviour when sensing an attractant, we propose the following terms for the successive stages of the homing response: reorientation, approaching, retention and settling. How zoospores sense and process attractants is poorly understood but likely involves signal perception via cell surface receptors. Since zoospores are important for infection, undermining their activity by luring attractants or blocking receptors seem promising strategies for disease control.
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Affiliation(s)
- Michiel Kasteel
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands; Laboratory of Cell Biology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.
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Situ J, Xi P, Lin L, Huang W, Song Y, Jiang Z, Kong G. Signal and regulatory mechanisms involved in spore development of Phytophthora and Peronophythora. Front Microbiol 2022; 13:984672. [PMID: 36160220 PMCID: PMC9500583 DOI: 10.3389/fmicb.2022.984672] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
Oomycetes cause hundreds of destructive plant diseases, threatening agricultural production and food security. These fungus-like eukaryotes show multiple sporulation pattern including the production of sporangium, zoospore, chlamydospore and oospore, which are critical for their survival, dispersal and infection on hosts. Recently, genomic and genetic technologies have greatly promoted the study of molecular mechanism of sporulation in the genus Phytophthora and Peronophythora. In this paper, we characterize the types of asexual and sexual spores and review latest progress of these two genera. We summarize the genes encoding G protein, mitogen-activated protein kinase (MAPK) cascade, transcription factors, RNA-binding protein, autophagy-related proteins and so on, which function in the processes of sporangium production and cleavage, zoospore behaviors and oospore formation. Meanwhile, various molecular, chemical and electrical stimuli in zoospore behaviors are also discussed. Finally, with the molecular mechanism of sporulation in Phytophthora and Peronophythora is gradually being revealed, we propose some thoughts for the further research and provide the alternative strategy for plant protection against phytopathogenic oomycetes.
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Affiliation(s)
- Junjian Situ
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Pinggen Xi
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Long Lin
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Weixiong Huang
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Yu Song
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Zide Jiang
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Guanghui Kong
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
- *Correspondence: Guanghui Kong,
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Jin J, Shew HD. Components of Aggressiveness in Phytophthora nicotianae During Adaptation to Multiple Sources of Partial Resistance in Tobacco. PLANT DISEASE 2021; 105:1960-1966. [PMID: 33245258 DOI: 10.1094/pdis-09-20-1929-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Black shank is a devastating disease of tobacco caused by Phytophthora nicotianae. Host resistance has been an integral part of black shank management but after the loss of Php single-gene resistance following its widespread deployment in the 1990s, growers have relied on varieties with varying levels of partial resistance. Partial resistance is effective in suppressing disease, but continued exposure can result in an increase in pathogen aggressiveness that threatens durability of the resistance to P. nicotianae. Aggressiveness components in P. nicotianae were characterized following adaptation on two sources of partial resistance, Fla 301 and the Wz genomic region from Nicotiana rustica. An aggressive isolate of the two major races of P. nicotianae, race 0 and race 1, was adapted for either one/two or five/six generations on the two resistance sources, giving four sets of isolates based on race, number of generations of adaptation, and source of resistance. Across the four sets of isolates, adapted isolates infected higher proportions of tobacco root tips, produced more sporangia per infected root tip, and caused larger lesions than their respective nonadapted isolates of the same race and from the same resistance source. Adapted isolates also produced more aggressive zoospore progeny than the nonadapted isolates. Adaptation to partial resistance involves multiple aggressiveness components and results in the increased aggressiveness observed for P. nicotianae. These results improve our knowledge on the nature of P. nicotianae adaptation to partial resistance in tobacco and indicate that different resistance sources are likely to select for similar aggressiveness components in the pathogen.
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Affiliation(s)
- Jing Jin
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - H David Shew
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
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Bassani I, Larousse M, Tran QD, Attard A, Galiana E. Phytophthora zoospores: From perception of environmental signals to inoculum formation on the host-root surface. Comput Struct Biotechnol J 2020; 18:3766-3773. [PMID: 33304469 PMCID: PMC7718214 DOI: 10.1016/j.csbj.2020.10.045] [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: 08/28/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 12/13/2022] Open
Abstract
To explore moist soils and to target host plants, phytopathogenic Phytophthora species utilize the sensory and propulsion capabilities of the biflagellate unicellular zoospores they produce. Zoospore motion and interactions with the microenvironment are of primary importance for Phytophthora physiology. These are also of critical significance for plant pathology in early infection sequential events and their regulation: the directed zoospore migration toward the host, the local aggregation and adhesion at the host penetration site. In the soil, these early events preceding the root colonization are orchestrated by guidance factors, released from the soil particles in water films, or emitted within microbiota and by host plants. This signaling network is perceived by zoospores and results in coordinated behavior and preferential localization in the rhizosphere. Recent computational and structural studies suggest that rhizospheric ion and plant metabolite sensing is a key determinant in driving zoospore motion, orientation and aggregation. To reach their target, zoospores respond to various molecular, chemical and electrical stimuli. However, it is not yet clear how these signals are generated in local soil niches and which gene functions govern the sensing and subsequent responses of zoospores. Here we review studies on the soil, microbial and host-plant factors that drive zoospore motion, as well as the adaptations governing zoospore behavior. We propose several research directions that could be explored to characterize the role of zoospore microbial ecology in disease.
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Affiliation(s)
- Ilaria Bassani
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Marie Larousse
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Quang D Tran
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Nice 06108, France
| | - Agnès Attard
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Eric Galiana
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
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Galiana E, Cohen C, Thomen P, Etienne C, Noblin X. Guidance of zoospores by potassium gradient sensing mediates aggregation. J R Soc Interface 2019; 16:20190367. [PMID: 31387479 DOI: 10.1098/rsif.2019.0367] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The biflagellate zoospores of some phytopathogenic Phytophthora species spontaneously aggregate within minutes in suspension. We show here that Phytophthora parasitica zoospores can form aggregates in response to a K+ gradient with a particular geometric arrangement. Using time-lapse live imaging in macro- and microfluidic devices, we defined (i) spatio-temporal and concentration-scale changes in the gradient, correlated with (ii) the cell distribution and (iii) the metrics of zoospore motion (velocity, trajectory). In droplets, we found that K+-induced aggregates resulted from a single biphasic temporal sequence involving negative chemotaxis followed by bioconvection over a K+ gradient concentration scale [0-17 mM]. Each K+-sensing cell moved into a region in which potassium concentration is below the threshold range of 1-4 mM, resulting in swarming. Once a critical population density had been achieved, the zoospores formed a plume that migrated downward, with fluid advection in its wake and aggregate formation on the support surface. In the microfluidic device, the density of zoospores escaping potassium was similar to that achieved in droplets. We discuss possible sources of K+ gradients in the natural environment (zoospore population, microbiota, plant roots, soil particles), and implications for the events preceding inoculum formation on host plants.
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Affiliation(s)
- Eric Galiana
- Université Côte d'Azur, INRA, CNRS, ISA, Sophia Antipolis, France
| | - Celine Cohen
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Parc Valrose, 06108 Nice, France
| | - Philippe Thomen
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Parc Valrose, 06108 Nice, France
| | | | - Xavier Noblin
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Parc Valrose, 06108 Nice, France
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Jiang H, Hwang HW, Ge T, Cole B, Perkins B, Hao J. Leucine Regulates Zoosporic Germination and Infection by Phytophthora erythroseptica. Front Microbiol 2019; 10:131. [PMID: 30804912 PMCID: PMC6370700 DOI: 10.3389/fmicb.2019.00131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/21/2019] [Indexed: 11/20/2022] Open
Abstract
Pink rot (Phytophthora erythroseptica) of potato is a major concern in many potato production regions. The pathogen produces zoospores that serve as a primary inoculum for infection. To understand how the pink rot incidence is related to pathogen population, qualitative, and quantitative chemical analyses were conducted. It was demonstrated that P. erythroseptica zoospores required a minimal population of 103 zoospores/ml (threshold) for initiating germination and the subsequent infection; the percentage of zoosporic germination was positively correlated with the density of zoospores above the threshold. To elucidate the density-dependent behavior, zoospore exudate (ZE) was extracted from high-density (105/ml) zoospore suspension. Zoosporic inocula of P. erythroseptica at different concentrations were inoculated on potato tubers. Necrotic lesions were caused by inoculum with 100 zoospores per inoculation site; 5 zoospores per site did not cause lesions on the tuber. However, five zoospores did cause lesions when they were placed in ZE, suggesting ZE contained chemical compounds that regulate germination of zoospores. ZE was collected and analyzed using liquid chromatography mass spectroscopy (LC-MS). Results showed that the amino acid leucine was associated with zoosporic germination. Therefore, zoosporic germination and infection of P. erythroseptica were mediated by signaling molecules secreted from zoospores.
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Affiliation(s)
- He Jiang
- School of Food and Agriculture, The University of Maine, Orono, ME, United States
| | - Hye Weon Hwang
- Department of Chemistry, The University of Maine, Orono, ME, United States
| | - Tongling Ge
- School of Food and Agriculture, The University of Maine, Orono, ME, United States
| | - Barbara Cole
- Department of Chemistry, The University of Maine, Orono, ME, United States
| | - Brian Perkins
- School of Food and Agriculture, The University of Maine, Orono, ME, United States
| | - Jianjun Hao
- School of Food and Agriculture, The University of Maine, Orono, ME, United States
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Kong P, McDowell JM, Hong C. Zoospore exudates from Phytophthora nicotianae affect immune responses in Arabidopsis. PLoS One 2017; 12:e0180523. [PMID: 28662148 PMCID: PMC5491255 DOI: 10.1371/journal.pone.0180523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 06/17/2017] [Indexed: 11/19/2022] Open
Abstract
Zoospore exudates play important roles in promoting zoospore communication, homing and germination during plant infection by Phytophthora. However, it is not clear whether exudates affect plant immunity. Zoospore-free fluid (ZFF) and zoospores of P. nicotianae were investigated comparatively for effects on resistance of Arabidopsis thaliana Col-0 and mutants that affect signaling mediated by salicylic acid (SA) and jasmonic acid (JA): eds16 (enhanced disease susceptibility16), pad4 (phytoalexin deficient4), and npr1 (nonexpressor of pathogenesis-related genes1). Col-0 attracted more zoospores and had severe tissue damage when flooded with a zoospore suspension in ZFF. Mutants treated with ZFF alone developed disease symptoms similar to those inoculated with zoospores and requirements of EDS16 and PAD4 for plant responses to zoospores and the exudates was apparent. Zoospore and ZFFs also induced expression of the PR1 and PDF1.2 marker genes for defense regulated by SA and JA, respectively. However, ZFF affected more JA defense signaling, down regulating PR1 when SA signaling or synthesis is deficient, which may be responsible for Arabidopsis mutant plants more susceptible to infection by high concentration of P. nicotianae zoospores. These results suggest that zoospore exudates can function as virulence factors and inducers of plant immune responses during plant infection by Phytophthora.
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Affiliation(s)
- Ping Kong
- Hampton Roads Agricultural Research and Extension Center, Virginia Tech, Virginia Beach, Virginia, United States of America
- * E-mail:
| | - John M. McDowell
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Chuanxue Hong
- Hampton Roads Agricultural Research and Extension Center, Virginia Tech, Virginia Beach, Virginia, United States of America
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
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Kong P, Hong C. Soil bacteria as sources of virulence signal providers promoting plant infection by Phytophthora pathogens. Sci Rep 2016; 6:33239. [PMID: 27616267 PMCID: PMC5018965 DOI: 10.1038/srep33239] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 08/22/2016] [Indexed: 11/08/2022] Open
Abstract
Phytophthora species are known as "plant destroyers" capable of initiating single zoospore infection in the presence of a quorum of chemical signals from the same or closely related species of oomycetes. Since the natural oomycete population is too low to reach a quorum necessary to initiate a disease epidemic, creation of the quorum is reliant on alternate sources. Here, we show that a soil bacterial isolate, Bacillus megaterium Sb5, promotes plant infection by Phytophthora species. In the presence of Sb5 exudates, colonization of rhododendron leaf discs by 12 Phytophthora species/isolates was significantly enhanced, single zoospores of P. nicotianae infected annual vinca and P. sojae race 25 successfully attacked a non-host plant, Nicotiana benthamiana as well as resistant soybean cultivars with RPS1a or RPS3a. Sb5 exudates, most notably the fractions larger than 3 kDa, promoted plant infection by improving zoospore swimming, germination and plant attachment. Sb5 exudates also stimulated infection hypha growth and upregulated effector gene expression. These results suggest that environmental bacteria are important sources of virulence signal providers that promote plant infection by Phytophthora species, advancing our understanding of biotic factors in the environmental component of the Phytophthora disease triangle and of communal infection of plant pathogens.
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Affiliation(s)
- Ping Kong
- Hampton Roads Agricultural Research and Extension Center, Virginia Tech, 1444 Diamond Springs Road, Virginia Beach, VA 23455, USA
| | - Chuanxue Hong
- Hampton Roads Agricultural Research and Extension Center, Virginia Tech, 1444 Diamond Springs Road, Virginia Beach, VA 23455, USA
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Ochiai N, Dragiila MI, Parke JL. Pattern swimming of Phytophthora citricola zoospores: an example of microbial bioconvection. Fungal Biol 2010; 115:228-35. [PMID: 21354529 DOI: 10.1016/j.funbio.2010.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 12/08/2010] [Accepted: 12/13/2010] [Indexed: 11/30/2022]
Abstract
The genus Phytophthora, belonging to the class Oomycota, comprises a group of over fifty fungus-like plant pathogens in both managed and unmanaged ecosystems. A unique feature of the oomycete lifecycle is a zoosporic stage in which motile, unicellular propagules, serving as the primary agents of dispersal, are produced and released in the presence of water. In Petri dish suspensions, zoospores frequently exhibit 'pattern swimming', whereby they spontaneously form concentrated swimming masses, visible to the naked eye, even in the absence of a chemical or electrical gradient. The nature of this behaviour is unclear, but is of interest because of the potential for auto-attraction and implications for cohort recruitment during infection. Similar behaviour observed in a variety of motile bacteria, algae, and protists is attributed to 'bioconvection' that results from instability in fluid density due to the organisms' upward-swimming tendency and greater-than-water density. In this investigation, we determined that Phytophthora citricola zoospore 'pattern swimming' is unrelated to phototaxis, surface tension-driven (Marangoni) convection, or auto-attraction and that the observed convective pattern, directional swimming, and depth- and concentration dependence are consistent with bioconvection.
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Affiliation(s)
- Naoyuki Ochiai
- Department of Crop and Soil Science, Oregon State University, Corvallis, OR 97331, USA.
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Kong P, Tyler BM, Richardson PA, Lee BWK, Zhou ZS, Hong C. Zoospore interspecific signaling promotes plant infection by Phytophthora. BMC Microbiol 2010; 10:313. [PMID: 21138563 PMCID: PMC3016323 DOI: 10.1186/1471-2180-10-313] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 12/07/2010] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Oomycetes attack a huge variety of economically and ecologically important plants. These pathogens release, detect and respond to signal molecules to coordinate their communal behaviors including the infection process. When signal molecules are present at or above threshold level, single zoospores can infect plants. However, at the beginning of a growing season population densities of individual species are likely below those required to reach a quorum and produce threshold levels of signal molecules to trigger infection. It is unclear whether these molecules are shared among related species and what their chemistries are. RESULTS Zoospore-free fluids (ZFF) from Phytophthora capsici, P. hydropathica, P. nicotianae (ZFFnic), P. sojae (ZFFsoj) and Pythium aphanidermatum were cross tested for stimulating plant infection in three pathosystems. All ZFFs tested significantly increased infection of Catharanthus roseus by P. nicotianae. Similar cross activities were observed in infection of Lupinus polyphyllus and Glycine max by P. sojae. Only ZFFnic and ZFFsoj cross induced zoospore aggregation at a density of 2 × 10³ ml⁻¹. Pure autoinducer-2 (AI-2), a component in ZFF, caused zoospore lysis of P. nicotianae before encystment and did not stimulate plant infection at concentrations from 0.01 to 1000 μM. P. capsici transformants with a transiently silenced AI-2 synthase gene, ribose phosphate isomerase (RPI), infected Capsicum annuum seedlings at the same inoculum concentration as the wild type. Acyl-homoserine lactones (AHLs) were not detected in any ZFFs. After freeze-thaw treatments, ZFF remained active in promoting plant infection but not zoospore aggregation. Heat treatment by boiling for 5 min also did not affect the infection-stimulating property of ZFFnic. CONCLUSION Oomycetes produce and use different molecules to regulate zoospore aggregation and plant infection. We found that some of these signal molecules could act in an inter-specific manner, though signals for zoospore aggregation were somewhat restricted. This self-interested cooperation among related species gives individual pathogens of the same group a competitive advantage over pathogens and microbes from other groups for limited resources. These findings help to understand why these pathogens often are individually undetectable until severe disease epidemics have developed. The signal molecules for both zoospore aggregation and plant infection are distinct from AI-2 and AHL.
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Affiliation(s)
- Ping Kong
- Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Virginia Beach, VA 23455-3363, USA
| | - Brett M Tyler
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0477, USA
| | - Patricia A Richardson
- Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Virginia Beach, VA 23455-3363, USA
| | - Bobby WK Lee
- The Barnett Institute and Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Zhaohui S Zhou
- The Barnett Institute and Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Chuanxue Hong
- Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Virginia Beach, VA 23455-3363, USA
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