Sudden Oak Death and Associated Diseases Caused by <i>Phytophthora ramorum</i>

Davidson, Jennifer; Werres, Sabine; Garbelotto, Matteo; Hansen, E. M.; Rizzo, David M.

doi:10.1094/php-2003-0707-01-dg

Cited by 163 publications

(132 citation statements)

References 15 publications

Supporting

Mentioning

124

Contrasting

Order By: Relevance

“…This could indicate divergence in the specificity of the coldbox-binding protein. Alternatively, the NIF genes from P. ramorum may be expressed differently than the P. infestans genes; unfortunately, our ability to test this is impaired by quarantine restrictions concerning this invasive pathogen in California (15). Another limitation on comparative studies is a dearth of functional data on oomycete promoters, especially binding sites for general transcription factors.…”

Section: Discussionmentioning

confidence: 99%

Activation of Zoosporogenesis-Specific Genes in Phytophthora infestans Involves a 7-Nucleotide Promoter Motif and Cold-Induced Membrane Rigidity

Tani

Judelson

2006

Eukaryot Cell

View full text Add to dashboard Cite

Infections of plants by the oomycete Phytophthora infestans typically result from zoospores, which develop from sporangia at cold temperatures. To help understand the relevant cold-induced signaling pathway, factors regulating the transcription of the zoosporogenesis-specific NIF (nuclear LIM-interactor-interacting factor) gene family were examined. Sequences required for inducing PinifC3 were identified by analyzing truncated and mutated promoters using the ␤-glucuronidase reporter in stable transformants. A 7-nucleotide (nt) sequence located 139 bases upstream of the major transcription start point (GGACGAG) proved essential for the induction of PinifC3 when sporangia were shifted from ambient to cold temperatures. The motif, named the cold box, also conferred cold inducibility to a promoter normally activated only during sexual development. An identical motif was detected in the two other zoosporogenesis-specific NIF genes from P. infestans and three Phytophthora sojae orthologues, and a closely related sequence was found in Phytophthora ramorum orthologues. The 7-nt motif was also found in the promoters of other zoosporogenesis-induced genes. The presence of a cold box-interacting protein in nuclear extracts of P. infestans sporangia was demonstrated using electrophoretic mobility shift assays. Furthermore, zoospore release and cold box-regulated transcription were stimulated by the membrane rigidizer dimethyl sulfoxide and inhibited by the membrane fluidizer benzyl alcohol. The data therefore delineate a pathway in which sporangia perceive cold temperatures through membrane rigidity, which activates signals that drive both zoosporogenesis and cold-box-mediated transcription.

show abstract

Section: Discussionmentioning

confidence: 99%

Activation of Zoosporogenesis-Specific Genes in Phytophthora infestans Involves a 7-Nucleotide Promoter Motif and Cold-Induced Membrane Rigidity

Tani

Judelson

2006

Eukaryot Cell

View full text Add to dashboard Cite

show abstract

“…The pathogen was first isolated in 1993 in Germany and The Netherlands from rhododendrons in nurseries and formally described in 2001 (Werres et al 2001). Since then, P. ramorum has been detected in at least nine European countries, where it is reported to cause twig blight of Rhododendron, Viburnum, Camellia, Kalmia, Pieris, Vaccinium and other important nursery plant species (http://www.eppo.org ; Davidson et al 2003). Recently the pathogen was also isolated from multiple tree species in the vicinity of infected rhododendrons in the UK and The Netherlands (http:// www.defra.gov.uk).…”

Section: Introductionmentioning

confidence: 99%

AFLP and phylogenetic analyses of North American and European populations of Phytophthora ramorum

Ivors

Hayden

Bonants³

et al. 2004

Mycological Research

142

127

View full text Add to dashboard Cite

The genetic structure within and between USA and European populations of the emerging phytopathogen Phytophthora ramorum was examined. Four primer combinations were used for amplified fragment length polymorphism (AFLP) fingerprinting of 67 USA isolates from California and Oregon, and 18 European isolates from Belgium, Germany, The Netherlands, Spain and the UK. In addition, three DNA regions (ITS, cox II, and nad 5) of additional Phytophthora species were amplified by polymerase chain reaction, sequenced, and analysed to provide better phylogenetic understanding of P. ramorum within the genus Phytophthora. AFLP banding patterns indicate that the 85 isolates form two distinct lineages within a monophyletic group, distinct from the closely related outgroup species P. lateralis. With the exception of two isolates from an Oregon nursery, European and USA isolates clustered separately within individual clades. The AFLP profiles also indicate that a single clonal lineage dominates the North American population, while the European population consists of an array of mainly unique, closely related AFLP types. Sequences from the three DNA regions were identical among all P. ramorum isolates, and phylogenetic analysis indicates that P. ramorum is closely related to P. lateralis and P. hibernalis.

show abstract

“…This pathogen also causes ramorum leaf blight and dieback on a range of other plant species (9) and can have a profound and devastating effect on forest ecosystems. A distinct population of the same pathogen (6,35) is found in a number of European countries (10,20,23,37), mostly causing dieback and leaf blight on a range of ornamental plants in nurseries and landscaped areas (2).…”

mentioning

confidence: 99%

On-Site DNA Extraction and Real-Time PCR for Detection of Phytophthora ramorum in the Field

Tomlinson¹,

Boonham²,

Hughes³

et al. 2005

Appl Environ Microbiol

118

View full text Add to dashboard Cite

Phytophthora ramorum is a recently described pathogen causing oak mortality (sudden oak death) in forests in coastal areas of California and southern Oregon and dieback and leaf blight in a range of tree, shrub, and herbaceous species in the United States and Europe. Due to the threat posed by this organism, stringent quarantine regulations are in place, which restrict the movement of a number of hosts. Fast and accurate diagnostic tests are required in order to characterize the distribution of P. ramorum, prevent its introduction into pathogen-free areas, and minimize its spread within affected areas. However, sending samples to a laboratory for testing can cause a substantial delay between sampling and diagnosis. A rapid and simple DNA extraction method was developed for use at the point of sampling and used to extract DNAs from symptomatic foliage and stems in the field. A sensitive and specific single-round real-time PCR (TaqMan) assay for P. ramorum was performed using a portable real-time PCR platform (Cepheid SmartCycler II), and a costeffective method for stabilizing PCR reagents was developed to allow their storage and transportation at room temperature. To our knowledge, this is the first description of a method for DNA extraction and molecular testing for a plant pathogen carried out entirely in the field, independent of any laboratory facilities.Phytophthora ramorum is the causal agent of extensive oak mortality (commonly known as sudden oak death) in coastal forests in California (27) and southern Oregon (12,25). This pathogen also causes ramorum leaf blight and dieback on a range of other plant species (9) and can have a profound and devastating effect on forest ecosystems. A distinct population of the same pathogen (6, 35) is found in a number of European countries (10,20,23,37), mostly causing dieback and leaf blight on a range of ornamental plants in nurseries and landscaped areas (2). There have also recently been a number of incidences of lethal bark cankers caused by P. ramorum in native and nonnative trees in Europe (7). P. ramorum has a broad and expanding host range (3,4,10,11,19,20,28,31), and as a result of the threat posed to forest ecosystems, the movement of a variety of its host species is subject to restrictions in Europe and the United States. Emergency European Community phytosanitary measures for P. ramorum were introduced in 2002 (1), and in the United States quarantine restrictions at both the federal and state levels control the movement of a variety of plant species from infested areas in California and Oregon (31). The availability of rapid and accurate detection methods for P. ramorum is critical to allow its prevalence to be monitored and to expedite management or eradication steps to prevent its introduction and minimize its spread.The identification of P. ramorum is not possible based on host symptoms alone due to the considerable variation in their expression and because a range of other causes can produce similar symptoms. These include infections by several other Phyt...

show abstract

Sudden Oak Death and Associated Diseases Caused by Phytophthora ramorum

Cited by 163 publications

References 15 publications

Activation of Zoosporogenesis-Specific Genes in Phytophthora infestans Involves a 7-Nucleotide Promoter Motif and Cold-Induced Membrane Rigidity

Activation of Zoosporogenesis-Specific Genes in Phytophthora infestans Involves a 7-Nucleotide Promoter Motif and Cold-Induced Membrane Rigidity

AFLP and phylogenetic analyses of North American and European populations of Phytophthora ramorum

On-Site DNA Extraction and Real-Time PCR for Detection of Phytophthora ramorum in the Field

Contact Info

Product

Resources

About