Rapid induction by fungal elicitor of the synthesis of cinnamyl-alcohol dehydrogenase, a specific enzyme of lignin synthesis.
A fivefold increase in the extractable activity of cinnamyl-alcohol dehydrogenase, an enzyme of phenylpropanoid metabolism specific for lignin synthesis, was observed within 10 h of treatment of cell-suspension cultures of bean (Phaseolus vulgaris L.) with a high-molecular-mass elicitor preparation heat-released from mycelial cell walls of the bean pathogen Colletotrichum lindemuthianum. Elicitor caused a rapid, marked but transient increase in the synthesis of cinnamyl-alcohol dehydrogenase with maximum rates 2-3 h after elicitation, concomitant with the phase of rapid increase in enzyme activity. There is a close correspondence between increased polysomal mRNA activity encoding cinnamyl-alcohol dehydrogenase, as measured by incorporation of [35S]methionine into immunoprecipitable enzyme subunits in vitro, and the stimulation of enzyme synthesis in vivo in response to elicitor. This marked increase in polysomal mRNA activity represents an increase as a proportion of total cellular mRNA activity, indicating that elicitor does not stimulate synthesis of this enzyme by selective recruitment from the total pool of cellular mRNA. Elicitor stimulation of cinnamyl-alcohol dehydrogenase activity and enzyme synthesis is more rapid than previously observed for other proteins involved inducible defense mechanisms, such as enzymes of phytoalexin biosynthesis or the apoproteins of cell-wall hydroxyproline-rich glycoproteins.
Grand
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C
Plant Biology Laboratory, Salk Institute for Biological Studies, San Diego, California.
Sarni
F
F
Lamb
C J
CJ
D000429:Alcohol Oxidoreductases / Q000096:biosynthesis*; D004790:Enzyme Induction / Q000187:drug effects; D007887:Fabaceae; D005658:Fungi / Q000378:metabolism*; D007163:Immunosorbent Techniques; D008031:Lignin / Q000096:biosynthesis*; D010944:Plants / Q000201:enzymology*; D010946:Plants, Medicinal; D011132:Polyribosomes / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis
D012333:RNA, Messenger; D008031:Lignin; D000429:Alcohol Oxidoreductases; C018656:cinnamyl alcohol dehydrogenase