Lipids

, Volume 35, Issue 3, pp 243–247

Biochemical modifications and transcriptional alterations attendant to sterol feeding in Phytophthora parasitica

Authors

  • W. David Dotson
    • Department of MicrobiologyNorth Carolina State University
  • Shirley R. Tove
    • Department of MicrobiologyNorth Carolina State University
    • Department of MicrobiologyNorth Carolina State University
Article

DOI: 10.1007/s11745-000-0519-9

Cite this article as:
Dotson, W.D., Tove, S.R. & Parks, L.W. Lipids (2000) 35: 243. doi:10.1007/s11745-000-0519-9

Abstract

Phytophthora species are eukaryotic sterol auxotrophs that possess the ability to grow, albeit poorly, in the complete absence of sterols. Growth of Phytophthora is often improved substantially when an exogenous source of sterol is provided. Additionally, sterols may be required for sexual and asexual sporulation in Phytophthora. Our research has been focused on identifying and characterizing the immediate physiological effects following sterol addition to cultures of P. parasitica. Through gas chromatographic analysis of extracts from P. parasitica cultures that were fed various sterols, we have ob-tained evidence for sterol C5 desaturase and Δ7 reductase activities in this organism. Zoo blots were probed with DNA sequences encoding these enzymes, from Saccharomyces cerevisiae and Arabidopsis thaliana. Hybridization of a S. cerevisiae ERG3 probe to P. parasitica DNA was observed, implicating sequence similarity between the sterol C5 desaturase encoding genes. Differential display experiments, using RNA from P. parasitica, have demonstrated a pattern of altered gene expression between cultures grown in the presence and absence of sitosterol. Characterization of sterol-related metabolic effects and sterol functions in Phytophthora should lead to improved measures for control of this important group of plant pathogens.

Abrreviations

Brassicasterol

(22E)-ergosta-5,22-dien-3β-ol

DDRT-PCR

differential display reverse transcriptase polymerase chain reaction

ergosterol

(22E)-ergosta-5,7,22-trien-3β-ol

GC

gas chromatography

HT11VN

modified oligo-dT anchored primers

lamosterol

lanosta-8,24-dient-3β-ol

PB

Phytophthora basal medium

RRT

Telative retention time

shosterol

stigmast-5-en-3β-ol

TLC

thin-layer chromatography

zymosterol

5α-cholesta-8,24-dien-3β-ol

Copyright information

© AOCS Press 2000