Increased sesquiterpenoid biosynthesis and an apparent decrease in sterol biosynthesis in elicitor-treated tobacco cell suspension cultures
Addition of fungel elicitor prepared from Phytophthora parasitica to tobacco cell suspension cultures leads to an increased production of the phytoalexin capsidiol. Capsidiol is a sesquiterpenoid which is most likely synthesized from farnesylpyrophosphat (FPP) by a bicyclic cyclase reaction. Because FPP is also a substrate for squalene synthetase and therefore a precursor of sterol biosynthesis, the question arises whether or not the accumulation of capsidiol in elicitor-treated cells occurs at the expense of sterol biosynthesis. (/sup 14/C)-acetate was given to elicitor-treated and control (no treatment) cell cultures and incorporation into sterols and capsidiol determined. No labeled capsidiol was detected in control cells. In elicitor-treated cells about 12-15% of the radioactivity taken up by the cells was incorporated into capsidiol. In contrast, control cells incorporated 4 times more radioactivity into sterols than elicitor-treated cells. Similar results were obtained using (/sup 3/H)-mevalonate as a precursor of capsidiol and sterol biosynthesis. Likely explanations for the apparently decline in sterol biosynthesis in elicitor-treated cells include: (1) inhibition of squalene synthetase; (2) induction of capsidiol synthesizing enzymes; and (3) metabolic channeling of FPP into capsidiol versus sterols. These possibilities will be discussed further together with other results.
- Research Organization:
- Univ. of Kentucky, Lexington
- OSTI ID:
- 5840474
- Report Number(s):
- CONF-8707108-
- Journal Information:
- Plant Physiol., Suppl.; (United States), Journal Name: Plant Physiol., Suppl.; (United States) Vol. 83:4; ISSN PPYSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fungal elicitor induces sesquiterpenoid biosynthesis in tobacco cell suspension cultures
Effect of medium modification and selected precursors on sterol production by short-term callus cultures of Euphorbia tirucalli
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL EFFECTS
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
CARBON 14 COMPOUNDS
ENZYMES
FUNGI
HYDROXY COMPOUNDS
IMMUNE REACTIONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIGASES
ORGANIC COMPOUNDS
PATHOGENS
PLANTS
STEROIDS
STEROLS
SYNTHESIS
TERPENES
TOBACCO
TRACER TECHNIQUES
TRITIUM COMPOUNDS