Induced phenylpropanoid metabolism during suberization and lignification: a comparative analysis.
Induction of the biosynthesis of phenylpropanoids was monitored at the enzyme level through measurement of the temporal change in the activity of two marker enzymes of phenylpropanoid metabolism, phenylalanine ammonia-lyase, (PAL, E.C. 4.1.3.5) and 4-coumaryl-CoA ligase (4-CL, E.C. 6.2.1.12) and two marker enzymes for hydroxycinnamyl alcohol biosynthesis, cinnamoyl-CoA:NADP+ oxidoreductase (CCR, E.C. 1.2.1.44) and cinnamyl alcohol dehydrogenase (CAD, E.C. 1.1.1.195) in both suberizing potato (Solanum tuberosum) tubers and lignifying loblolly pine (Pinus taeda) cell cultures. While measurable activities of PAL, 4-CL and CAD increased upon initiation of suberization in potato tubers, that of CCR did not. By contrast, all four enzymes were induced upon initiation of lignification in pine cell cultures. The lack of CCR induction in potato by wound treatment is consistent with the channelling of hydroxycinnamoyl-CoA derivatives away from monolignol formation and toward other hydroxycinnamoyl derivatives such as those that accumulate during suberization.
Bernards
M A
MA
Department of Plant Sciences, University of Western Ontario, London ON, Canada. bernards@julian.uwo.ca
Susag
L M
LM
Bedgar
D L
DL
Anterola
A M
AM
Lewis
N G
NG
D000429:Alcohol Oxidoreductases / Q000096:biosynthesis / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000096:biosynthesis / Q000378:metabolism; D003066:Coenzyme A Ligases / Q000096:biosynthesis / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism*; D008031:Lignin / Q000096:biosynthesis / Q000378:metabolism*; D008055:Lipids; D008563:Membrane Lipids / Q000096:biosynthesis / Q000378:metabolism*; D010650:Phenylalanine Ammonia-Lyase / Q000096:biosynthesis / Q000378:metabolism; D028223:Pinus / Q000201:enzymology* / Q000378:metabolism; D011198:Solanum tuberosum / Q000201:enzymology* / Q000378:metabolism
D003373:Coumaric Acids; D008055:Lipids; D008563:Membrane Lipids; C065875:suberin; D008031:Lignin; D000429:Alcohol Oxidoreductases; C018656:cinnamyl alcohol dehydrogenase; D000445:Aldehyde Oxidoreductases; C019904:cinnamoyl CoA reductase; D010650:Phenylalanine Ammonia-Lyase; D003066:Coenzyme A Ligases; C019943:4-coumarate-CoA ligase