Signaling in the elicitation process is mediated through the octadecanoid pathway leading to jasmonic acid.

Abstract

Fungal cell wails and fragments thereof (elicitors) induce the formation of low and high molecular weight defense compounds in plant cell suspension cultures. This induced synthesis requires a signal molecule transmitting the message between the elicitor plant cell wail receptor and gene activation. We demonstrate in this study that cis-jasmonic acid is rapidly synthesized in plant cell cultures ofdiverse taxonomic origin (gymnosperms and mono-and dicotyledonous plants) after challenge with a fungal elicitor preparation. The rapid decline ofcis-jasmonic acid in some ofthese issues is attributed to rapid metabolism of this pentacyclic acid. The induction of alkaloids by several different molecules provoking the elicitation process is strictly correlated with the synthesis of jasmonates. Elicitation leads to a rapid release of a-linolenic acid from the lipid pool of the plant cell. a-Linolenic acid and 12-oxophytodienoic acid, the formation of which is also induced, are known to be distant precursors ofjasmonic acid. We assume cis-jasmonic acid and its precursors to be the signaling molecules in the elicitation process.

JIPs and RIPs: the regulation of plant gene expression by jasmonates in response to environmental cues and pathogens.

“…Thus, the coordinate interplay between JIP60 and marked ribosomes could take place only in the immediate vicinity of wounded or pathogenattacked, structurally damaged cells. Although distant plant organs and tissues could import MeJA from its site of continuous production, they would not be necessarily destined to down-regulate their protein biosynthetic machinery because they would be able to rapidly metabolize this compound (Sembdner et al, 1990;Gundlach et al, 1992;Müller et al, 1993). By lowering the effective MeJA concentration, intact plant tissues could thus protect themselves efficiently against the wasteful degradation of their ribosomes.…”

“…Recently, jasmonates have been proposed to be stress-related compounds (Farmer and Ryan, 1990;Parthier, 1990Parthier, , 1991Enyedi et al, 1992;Farmer et al, 1992;Gundlach et al, 1992;Müller et al, 1993). MeJA, in particular, is a signal molecule that is released in plants in response to various stresses, such as wounding or pathogen attack , To whom correspondence should be addressed at the lnstitute of Plant Sciences, Department of Genetics, Swiss Federal lnstitute of Technology Zurich (ETH), ETH-Zentrum, Universitatsstrasse 2, CH-8092, Zurich, Switzerland.…”

“…MeJA, in particular, is a signal molecule that is released in plants in response to various stresses, such as wounding or pathogen attack , To whom correspondence should be addressed at the lnstitute of Plant Sciences, Department of Genetics, Swiss Federal lnstitute of Technology Zurich (ETH), ETH-Zentrum, Universitatsstrasse 2, CH-8092, Zurich, Switzerland. treatment of plant tissues or plant cell cultures with funga1 elicitors (Dittrich et al, 1992;Gundlach et al, 1992;Müller et al, 1993), or subjection of tissues to osmotica or desiccation . Jasmonates are thought to be transported both locally and systemically within wounded plants (Anderson, 1985;Farmer and Ryan, 1990;Enyedi et al, 1992;Farmer et al, 1992;Hildmann et al, 1992).…”

The Role of Octadecanoids and Functional Mimics in Soybean Defense Responses

“…Using a yeast-derived cell wall preparation, the transient accumulation of jasmonic acid (JA) and methyl jasmonate (JAMe) has been reported concomitantly with the production of benzo [c]phenanthridine alkaloids in cell cultures of Eschscholtzia californica (Gundlach et al, 1992). The postulated role as a signal transducer in elicitor-induced defense reactions of plant cell cultures (Gundlach et al, 1992;Müller et al, 1993) was corroborated by similar results obtained with rice (Oryza sativa L.) cell suspension cultures elicited with N-acetylchitoheptaose (Nojiri et al, 1996) and tobacco (Nicotiana tabacum L.) cell cultures challenged with a species-specific elicitor from the tobacco pathogen Phytophthora parasitica var. nicotianae (Rickauer et al, 1997).…”

Differential Expression of a Novel Gene in Response to Coronatine, Methyl Jasmonate, and Wounding in the Coi1Mutant of Arabidopsis1

“…JA and its methyl ester, MeJA, and related compounds derived from linolenic acid are recognized as signaling molecules synthesized by plants in response to wounding and herbivore and pathogen attack (Creelman et al, 1992;Farmer and Ryan, 1992;Mueller et al, 1993). These substances can activate the expression of several genes, leading to the accumulation of their products, which are referred to as jasmonate-induced proteins.…”