Ethylene: Indicator but Not Inducer of Phytoalexin Synthesis in Soybean

Paradies, Inge; Konze, Jörg R.; Elstner, Erich F.; Paxton, J. D.

doi:10.1104/pp.66.6.1106

Cited by 62 publications

(26 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Congruently, flg22 perception leads to EIN3 accumulation (31). This model may explain the longestablished observation that PAMP perception triggers increased ethylene biosynthesis (14)(15)(16). Our results show an unexpected layer of regulation by ethylene to maintain optimal levels of innate immune receptors.…”

Section: Discussionmentioning

confidence: 53%

“…Flagellin induces production of SA (11,12) but also leads to repression of auxin perception (13). A classical response associated with PAMP treatment is an increase in the biosynthesis of the gaseous hormone ethylene (ET) (14)(15)(16). Here, we show a simple and direct link between the hormone ET and the earliest events in PAMP-triggered immunity (PTI) against pathogenic bacteria.…”

mentioning

confidence: 89%

See 1 more Smart Citation

Direct transcriptional control of the Arabidopsis immune receptor FLS2 by the ethylene-dependent transcription factors EIN3 and EIL1

Boutrot

Segonzac

Chang

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

211

195

View full text Add to dashboard Cite

In plant innate immunity, the leucine-rich repeat receptor kinase FLS2 recognizes the bacterial pathogen-associated molecular pattern (PAMP) flagellin. The molecular mechanisms underlying PAMP perception are not fully understood. Here, we reveal that the gaseous phytohormone ethylene is an integral part of PAMPtriggered immunity. Plants mutated in the key ethylene-signaling protein EIN2 are impaired in all FLS2-mediated responses, correlating with reduced FLS2 transcription and protein accumulation. The EIN3 and EIN3-like transcription factors, which depend on EIN2 activity for their accumulation, directly control FLS2 expression. Our results reveal a direct role for ethylene in regulation of an innate immune receptor.innate immunity | receptor kinase

show abstract

Section: Discussionmentioning

confidence: 53%

mentioning

confidence: 89%

Direct transcriptional control of the Arabidopsis immune receptor FLS2 by the ethylene-dependent transcription factors EIN3 and EIL1

Boutrot

Segonzac

Chang

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

211

195

View full text Add to dashboard Cite

show abstract

“…Excised leaves were allowed to absorb cycloheximide or buffer (control) during the first 6 h. Elicitor, or ACC were then added and their effect measured after an additional 18 h. The reported data (Table IV) show that chitinase activities of elicited leaves was enhanced by elicitor by a factor of about 15 or 2, depending on the enzymic assay, and by ACC by a factor of 12 or 1.5. The presence of cycloheximide (10-4_10-6 M) prevented the enhance- (5,19,23,27). Elicitation of phenylalanine ammonia lyase for instance, was related to an increase in ACC synthase activity in parsley cells (5), although ethylene alone had no effect on phenylalanine ammonia lyase in this system.…”

Section: Resultsmentioning

confidence: 91%

Cell Surfaces in Plant-Microorganism Interactions

Roby¹,

Toppan²,

Esquerré-Tugayé³

1986

Plant Physiol.

View full text Add to dashboard Cite

MATERIALS AND METHODSTreatment of melon leaves or seedlings with elicitors of Colletotrichum lagenarium, a fungal pathogen of melon, increases chitinase activity. In treated leaves, chitinase is enhanced within the first 6 hours and becomes 2 to 10 times higher than in control leaves after 24 hours. Ethylene is increased simultaneously and is correlated with chitinase elicitation. In the presence of aminoethoxyvinylglycine, an inhibitor of ethylene synthesis, both elicitor-induced ethylene and elicitor-induced chitinase are inhibited. This inhibition is overcome by added exogenous ethylene. On the other hand, 1-aminocyclopropane-1-carboxylic acid the direct precursor of ethylene, triggers chitinase activity. Chitinase elicitation is thought to be a protein synthesis dependent process, as it does not occur in the presence of cycloheximide.For many years, fungal elicitors have been studied mainly for their ability to induce in plants the biosynthesis and accumulation of antimicrobial compounds called phytoalexins (3,34). Because the accumulation of phytoalexins is only one of the several mechanisms displayed by plants against pathogens (31) it has been proposed that elicitors might have a more general effect on plant defense. This hypothesis has been partly checked in previous papers by demonstrating that elicitors of Colletotrichum lagenarium induce the synthesis of ethylene and of hydroxyproline-rich glycoproteins in melon plants (10,27,30).In this paper, we report the effect of C. lagenarium glycopeptide elicitors on the chitinase activity of melon plants. Chitinase is thought to be a defense enzyme since chitin is not present in plants but is an important component of fungal cell walls and insect cuticles. Its ability to hydrolyze the cell wall of fungal pathogens (28,33) and to release elicitors (12, 13) strongly supports the role of chitinase as an antifungal enzyme. The chitinase activity of melon and of other plants is highly stimulated upon infection with fungal pathogens (21,24,25,28) Colletotrichum lagenarium was grown on a liquid culture medium (8). ELICITOR TREATMENTThe fungal elicitor mainly used in these studies was the elicitor 1, obtained by gel filtration and ion exchange chromatography of the ethanol-soluble elicitor fraction recovered from a crude autoclaved extract of the mycelium (30). Alternatively, the ethanol-soluble fraction was used in some experiments. These elicitors are fungal glycopeptides (mol wt = 5-10,000) whose activity is correlated with their sugar portion (30); accordingly their amounts were expressed as Mg glucose equivalents for the purpose ofconvenience. Two different assays using excised leaves or whole seedlings were used to measure the elicitor activity. In the assay using seedlings, the elicitor (50 Ml corresponding to 50 Mg Glc eq) was given to 28-d-old seedlings through a wound made by gently squeezing the center area of the cotyledon with pliers; the elicited area was then covered with a piece of Parafilm to avoid drying out of the wound. In some experiment...

show abstract

“…However, apparently, ethylene alone, at least at physiological levels, does not induce Rl or N2 transcript abundance. Although wounding and pathogen infection generally cause stress ethylene production (Paradies et al, 1980;Felix and Boiler, 1995), the relationship between M-JA and ethylene production is less evident. Perhaps ethylene potentiates M-JA function in the wounding signal transduction pathway that mediates specific induction of soybean CysPI genes, as has been shown for induction of pathogenesis-related protein gene expression (Xu et al, 1994) …”

Section: Wounding and M-ja Induction Of Cyspi Gene Expression Requirementioning

confidence: 99%

Differential Expression of Soybean Cysteine Proteinase Inhibitor Genes during Development and in Response to Wounding and Methyl Jasmonate

et al. 1996

View full text Add to dashboard Cite

Three cysteine proteinase inhibitor cDNA clones (pL1, pR1, and pN2) have been isolated from a soybean (Glycine max 1. Merr.) embryo library. The proteins encoded by the clones are between 60 and 70% identical and contain the consensus QxVxC motif and W residue i n the appropriate spatial context for interaction with the cysteine proteinase papain. L7, R7, and N2 mRNAs were differentially expressed in different organs of plants (juvenile and mature) and seedlings, although NZ mRNA was constitutive only i n flowers. R I and N2 transcripts were induced by wounding or methyl jasmonate (M-JA) treatment in local and systemic leaves coincident with increased papain inhibitory activity, indicating a role for R I and N2 in plant defense. The L I transcript was constitutively expressed in leaves and was induced slightly by M-JA treatment in roots. Unlike the chymotrypsin/trypsin proteinase inhibitor II gene (H. Peiia-Cortes, J. Fisahn, 1. Willmitzer [19951 Proc Natl Acad Sci USA 92: 41 06-41 13), expression of the soybean genes was only marginally induced by abscisic acid and only in certain tissues. Norbornadiene, a competitive inhibitor of ethylene binding, abolished the wounding or M-JA induction of R I and N2mRNAs but not the accumulation of the wound-inducible vspA transcript. Presumably, ethylene binding to its receptor is involved in the wound inducibility of R I and N2 but not vspA mRNAs. Bacterial recombinant L I and R1 proteins, expressed as glutathione S-transferase fusion proteins, exhibited substantial inhibitory activities against vicilin peptidohydrolase, the major thiol endopeptidase i n mung bean seedlings. Recombinant R I protein had much greater cysteine proteinase inhibitor activity than recombinant L I protein, consistent with the wound inducibility of the R7 gene and its presumed role in plant defense.Injury to plants due to phytophagous insects or mechanical damage induces accumulation of proteinase inhibitor proteins (Ryan, 1981(Ryan, , 1990. Inhibitor proteins with specificity against Ser proteinases have been well characterized and there is direct evidence of their involvement in host plant defense against herbivorous insects (Johnson et al.,

show abstract

Ethylene: Indicator but Not Inducer of Phytoalexin Synthesis in Soybean

Cited by 62 publications

References 17 publications

Direct transcriptional control of the Arabidopsis immune receptor FLS2 by the ethylene-dependent transcription factors EIN3 and EIL1

Direct transcriptional control of the Arabidopsis immune receptor FLS2 by the ethylene-dependent transcription factors EIN3 and EIL1

Cell Surfaces in Plant-Microorganism Interactions

Differential Expression of Soybean Cysteine Proteinase Inhibitor Genes during Development and in Response to Wounding and Methyl Jasmonate

Contact Info

Product

Resources

About