Lack of specificity in accumulation of sterols by<i>Phytophthora cactorum</i>

Gonzales, Robert A.; Parks, Leo W.

doi:10.1007/bf02534969

Cited by 13 publications

(6 citation statements)

References 22 publications

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“…The interaction between light and cholesterol supplementation observed in this species by Hendrix (1967) is consistent with the hypothesis that sterol uptake in the mycelial phase is restricted. However, this is in contrast with the results obtained with Phytophthora cactorum Gonzales & Parks (1981), who observed that cholesterol was accumulated by the mycelia grown in liquid culture when the sterol was offered. Differences in sterol absorption from liquid as opposed to agar cultures have been observed (Nes et al, 1983;Nes & Stafford, 1983) but did not appear to contribute to the differences noted in our results.…”

Section: Discussioncontrasting

confidence: 99%

Metabolic Changes during Development of Phytophthora palmivora Examined by Gas Chromatography/Mass Spectrometry

Grant

Greenaway²,

Whatley³

1988

Microbiology

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Metabolic profiles from four stages of differentiation of the fungus Phytophthora palmivora were obtained by gas chromatography/mass spectrometry. The profiles showed the presence of sterols in the asexual reproduction stage of the organism, and confirmed their virtual absence from the mycelial stages. The zoospore stage was characterized by the presence of polyunsaturated fatty acids of C20 and C22 chain length. The transition from zoospore to cyst was also marked by the appearance of disaccharides and by a decrease in the amount of phosphate present. There were also distinctive shifts in the proportions and the total amounts of amino acids present, with gamma-aminobutyrate and alanine increasing as germination took place. These distinctive profiles identify some of the metabolic changes which accompany differentiation in this fungus.

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Section: Discussioncontrasting

confidence: 99%

Metabolic Changes during Development of Phytophthora palmivora Examined by Gas Chromatography/Mass Spectrometry

Grant

Greenaway²,

Whatley³

1988

Microbiology

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“…The genus Phytophthora and other members of the oomycete order Peronosporales are sterol auxotrophs (Nes, 1987). They lack sterol biosynthetic activity and accumulate sterols available from their environment in their membranes (Gonzales and Parks, 1981). The nutritional dependence on external sterol supplies is expected to make Phytophthora especially vulnerable to perturbation by sterol-binding proteins.…”

Section: Resultsmentioning

confidence: 99%

The sterol‐binding activity of PATHOGENESIS‐RELATED PROTEIN 1 reveals the mode of action of an antimicrobial protein

et al. 2017

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SUMMARYPathogenesis-related proteins played a pioneering role 50 years ago in the discovery of plant innate immunity as a set of proteins that accumulated upon pathogen challenge. The most abundant of these proteins, PATHOGENESIS-RELATED 1 (PR-1) encodes a small antimicrobial protein that has become, as a marker of plant immune signaling, one of the most referred to plant proteins. The biochemical activity and mode of action of PR-1 proteins has remained elusive, however. Here, we provide genetic and biochemical evidence for the capacity of PR-1 proteins to bind sterols, and demonstrate that the inhibitory effect on pathogen growth is caused by the sequestration of sterol from pathogens. In support of our findings, sterol-auxotroph pathogens such as the oomycete Phytophthora are particularly sensitive to PR-1, whereas sterol-prototroph fungal pathogens become highly sensitive only when sterol biosynthesis is compromised. Our results are in line with previous findings showing that plants with enhanced PR-1 expression are particularly well protected against oomycete pathogens.

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“…The fact that most oomycetes cannot synthesize their own sterols for their growth and reproduction and hence are sterol auxotrophs led to the proposition that oomycetes secrete elicitins to bind and sequester sterols from the host plant and shuttle these sterols back to meet their own demand (Dahlin et al, 2017;Gonzales & Parks, 1981;Ponchet et al, 1999).…”

Section: Oomyce Te S Are S Terol Auxotroph S and S En S Itive To The ...mentioning

confidence: 99%

The function of plant PR1 and other members of the CAP protein superfamily in plant–pathogen interactions

Han

Xiong

Schneiter

et al. 2023

Molecular Plant Pathology

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The pathogenesis‐related (PR) proteins of plants have originally been identified as proteins that are strongly induced upon biotic and abiotic stress. These proteins fall into 17 distinct classes (PR1–PR17). The mode of action of most of these PR proteins has been well characterized, except for PR1, which belongs to a widespread superfamily of proteins that share a common CAP domain. Proteins of this family are not only expressed in plants but also in humans and in many different pathogens, including phytopathogenic nematodes and fungi. These proteins are associated with a diverse range of physiological functions. However, their precise mode of action has remained elusive. The importance of these proteins in immune defence is illustrated by the fact that PR1 overexpression in plants results in increased resistance against pathogens. However, PR1‐like CAP proteins are also produced by pathogens and deletion of these genes results in reduced virulence, suggesting that CAP proteins can exert both defensive and offensive functions. Recent progress has revealed that plant PR1 is proteolytically cleaved to release a C‐terminal CAPE1 peptide, which is sufficient to activate an immune response. The release of this signalling peptide is blocked by pathogenic effectors to evade immune defence. Moreover, plant PR1 forms complexes with other PR family members, including PR5, also known as thaumatin, and PR14, a lipid transfer protein, to enhance the host's immune response. Here, we discuss possible functions of PR1 proteins and their interactors, particularly in light of the fact that these proteins can bind lipids, which have important immune signalling functions.

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Lack of specificity in accumulation of sterols byPhytophthora cactorum

Cited by 13 publications

References 22 publications

Metabolic Changes during Development of Phytophthora palmivora Examined by Gas Chromatography/Mass Spectrometry

Metabolic Changes during Development of Phytophthora palmivora Examined by Gas Chromatography/Mass Spectrometry

The sterol‐binding activity of PATHOGENESIS‐RELATED PROTEIN 1 reveals the mode of action of an antimicrobial protein

The function of plant PR1 and other members of the CAP protein superfamily in plant–pathogen interactions

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