Function of Fungal Haustoria in Epiphytic and Endophytic Infections

Spencer‐Phillips, P. T. N.

doi:10.1016/s0065-2296(08)60077-4

Cited by 29 publications

(22 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In support, recently described asymptomatic infections of the annual Vicia sativa by P. cinnamomi from another Mediterranean ecosystem. Although the formation of haustoria per se is not a definitive trait of biotrophs, as non-haustorial biotrophs do exist (Spencer-Phillips 1997), globose structures consistent with haustoria of other plant pathogen systems were observed for P. cinnamomi in this study. This agrees with previous studies on P. cinnamomi structures considered to be haustoria (Cahill & Weste 1983;Cahill et al 1989;Wetherbee et al 1985) although only Wetherbee et al (1985) provided evidence at the level of the electron microscope.…”

Section: A C C E P T E D Accepted Manuscriptsupporting

confidence: 58%

Survival of Phytophthora cinnamomi as oospores, stromata, and thick-walled chlamydospores in roots of symptomatic and asymptomatic annual and herbaceous perennial plant species

et al. 2013

View full text Add to dashboard Cite

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT RESEARCH HIGHLIGHTS• P. cinnamomi survival propagules in annuals/herbaceous perennials in nature • Formation of stromata by Phytophthora cinnamomi, novel for the species • Dense oospore clusters of P. cinnamomi, forming viable colonies in new hosts • Thick walled chlamydospores inside naturally infected roots • Presence of haustoria suggest a biotrophic mode in asymptomatic host species M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT ABSTRACTStudies were conducted to determine how Phytophthora cinnamomi survives during hot and dry Mediterranean summers in areas with limited surviving susceptible hosts.Two Western Australian herbaceous perennials Chamaescilla corymbosa and Stylidium diuroides and one Western Australian annual Trachymene pilosa were collected weekly from a naturally infested site from the Eucalyptus marginata (jarrah) forest from winter to spring and less frequently during summer 2011/12. Selfed oospores, thick walled chlamydospores and stromata of P. cinnamomi were observed in each species. Oospores and thick-walled chlamydospores germinated in planta confirming their viability. This is the first report of autogamy by P. cinnamomi in naturally infected plants. Stromata, reported for the first time for P. cinnamomi, were densely aggregated inside host cells, and germinated in planta with multiple germ tubes with hyphae capable of producing oospores and chlamydospores.Trachymene pilosa was completely asymptomatic, S. diuroides did not develop root lesions but some plants wilted, whilst C. corymbosa remained asymptomatic above ground but lesions developed on some tubers. The presence of haustoria suggests that P. cinnamomi grows biotrophically in some hosts. Asymptomatic, biotrophic growth of P. cinnamomi in some annual and herbaceous perennials and the production of a range of survival structures have implications for pathogen persistence over summer and its management. KEYWORDSPhytophthora cinnamomi, survival structures, life cycle, facultative homothallic, biotrophic growth, endophyte, haustoria M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 2 INTRODUCTIONPhytophthora cinnamomi is a soil-borne root pathogen with a broad host range and necrotrophic mode of infection (Cahill et al. 2008; Zentmyer 1980) and results in the death of many susceptible plant species and the degradation of ecosystems worldwide including 15 global biodiversity hotspots (Dunstan et al. 2010). Phylogenetically and taxonomically, this pathogen belongs to the class Oomycetes in which swimming zoos...

show abstract

Section: A C C E P T E D Accepted Manuscriptsupporting

confidence: 58%

Survival of Phytophthora cinnamomi as oospores, stromata, and thick-walled chlamydospores in roots of symptomatic and asymptomatic annual and herbaceous perennial plant species

et al. 2013

View full text Add to dashboard Cite

show abstract

“…It would also increase the chance of contact with stomata, hence optimising the potential for production of conidiophore primordia and the dispersal of spores. The possibility that the pattern of branching reflects the phloem loading mechanism operating in the infected tissue now merits investigation (Spencer-Phillips, 1997;Ott et al, 2003). There may also be different branching patterns in different parts of the same host tissue, perhaps tending towards herringbone in regions of low nutrient supply, but dichotomous in areas where the nutrient supply is greater (such as adjacent to veins).…”

Section: The Endophytic Myceliummentioning

confidence: 99%

“…Increased apoplastic invertase would increase the concentration of glucose available for pathogen nutrition, and reduce the amount of sucrose removed from infected leaves by phloem loading. This may be particularly significant in downy mildew infections of hosts where sucrose is the main translocate, and is exported from leaves by an apoplastic pathway (Spencer-Phillips, 1997). A resulting effect would be the "sugar feeding" that has been reported for some downy mildew diseases (Bhatia and Thakur, 1994).…”

Section: Physiology and Biochemistrymentioning

confidence: 99%

“…It should be remembered, however, that downy mildews do not always form haustoria (Fraymouth, 1956), and their intercellular hyphae also provide an interface for nutrient uptake and general inter-communication, as in other non-haustorial biotrophs (Spencer-Phillips, 1997). Indeed Dick (2002a) has pointed out that the development of haustoria may have evolved separately even within the oomycetes, so that haustoria may have a different physiology and function in each of the genera Albugo, Peronospora and Sclerospora.…”

Section: Introductionmentioning

confidence: 99%

“…In fungal systematics, similar morphological features used previously for taxonomic and nomenclature purposes do not fit with contemporary phylogenic concepts based on molecular data. In relation to physiological function, the debate concerning the apoplastic versus symplastic pathways for phloem loading provides another example that is potentially relevant to strategies for nutrient acquisition by biotrophic fungi (Spencer-Phillips, 1997). These alternative pathways were championed by opposing research teams, with each group working with their favoured model plant species.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations