(Z)-3-Hexenol induces defense genes and downstream metabolites in maize.
In response to insect feeding, corn plants (Zea mays cv. Delprim) release elevated levels of volatile organic compounds (VOCs), including the C(6)-volatile (Z)-3-hexenol. The level of mRNA accumulation for a series of defense genes was monitored in response to application of (Z)-3-hexenol (50 nmol) to undamaged plants. The induction of transcripts for hpl (hydroperoxide lyase), fps (farnesyl pyrophosphate synthase), pal (phenylalanine ammonia-lyase), lox (lipoxygenase), igl (indole-3-glycerol phosphate lyase) and mpi (maize proteinase inhibitor) were compared with metabolites generated from the respective pathways. While headspace VOC analysis showed an increase in (Z)-3-hexenyl acetate and methyl salicylate with lox and pal induction, respectively, MPI accumulation was not observed with an increase in mpi transcripts. Moreover, (Z)-3-hexenol treatment did not elevate sesquiterpene emissions or activate fps transcription. Chemical labeling and bioassay experiments established that exogenous (Z)-3-hexenol can be taken up and converted to a less active acetylated form. These data indicate that (Z)-3-hexenol can serve as a signaling molecule that triggers defense responses in maize and can rapidly be turned over in planta.
Farag
Mohamed A
MA
Department of Chemistry & Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA.
Fokar
Mohamed
M
Abd
Haggag
H
Zhang
Huiming
H
Allen
Randy D
RD
Paré
Paul W
PW
D000085:Acetates / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D000441:Hexanols / Q000378:metabolism / Q000494:pharmacology*; D007211:Indoles / Q000378:metabolism; D008084:Lipoxygenase / Q000235:genetics / Q000378:metabolism; D054883:Oxylipins; D010650:Phenylalanine Ammonia-Lyase / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D018411:Spodoptera / Q000502:physiology; D014835:Volatilization; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism / Q000469:parasitology
D000085:Acetates; D003517:Cyclopentanes; D000441:Hexanols; D007211:Indoles; D054883:Oxylipins; D010940:Plant Proteins; D012333:RNA, Messenger; D012717:Sesquiterpenes; C051918:3-hexen-1-ol; C023578:proteinase inhibitor I (plants); C072239:methyl jasmonate; D008084:Lipoxygenase; D010650:Phenylalanine Ammonia-Lyase