Alternative oxidase (AOX) and phenolic metabolism in methyl jasmonate-treated hairy root cultures of Daucus carota L.
Methyl-jasmonate (MJ)-treated hairy roots of Daucus carota L. were used to study the influence of alternative oxidase (AOX) in phenylpropanoid metabolism. Phenolic acid accumulation, as well as total flavonoids and lignin content of the MJ-treated hairy roots were decreased by treatment with salicylhydroxamic acid (SHAM), a known inhibitor of AOX. The inhibitory effect of SHAM was concentration dependent. Treatment with propyl gallate (PG), another inhibitor of AOX, also had a similar inhibitory effect on accumulation of phenolic acid, total flavonoids and lignin. The transcript levels of two DcAOX genes (DcAOX2a and DcAOX1a) were monitored at selected post-elicitation time points. A notable rise in the transcript levels of both DcAOX genes was observed preceding the MJ-induced enhanced accumulation of phenolics, flavonoids and lignin. An appreciable increase in phenylalanine ammonia-lyase (PAL) transcript level was also observed prior to enhanced phenolics accumulation. Both DcAOX genes showed differential transcript accumulation patterns after the onset of elicitation. The transcript levels of DcAOX1a and DcAOX2a attained peak at 6hours post elicitation (hpe) and 12hpe, respectively. An increase in the transcript levels of both DcAOX genes preceding the accumulation of phenylpropanoid-derivatives and lignin showed a positive correlation between AOX activity and phenylpropanoid biosynthesis. The results provide important new insight about the influence of AOX in phenylpropanoid biosynthesis.
EU Marie Curie Chair, ICAAM, University of Évora, 7002-554 Évora, Portugal. dsircar.iitkgp@gmail.com
Debabrata
D
Sircar
Hélia G
HG
Cardoso
Chiranjit
C
Mukherjee
Adinpunya
A
Mitra
Birgit
B
Arnholdt-Schmitt
D000085:Acetates / Q000494:pharmacology*; D003517:Cyclopentanes / Q000494:pharmacology*; D018552:Daucus carota / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000032:analysis / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D062385:Hydroxybenzoates / Q000032:analysis / Q000378:metabolism; D008031:Lignin / Q000032:analysis / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins / Q000494:pharmacology*; D010636:Phenols / Q000032:analysis / Q000378:metabolism*; D010650:Phenylalanine Ammonia-Lyase / Q000235:genetics* / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D020005:Propanols / Q000032:analysis / Q000378:metabolism; D011435:Propyl Gallate / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D012457:Salicylamides / Q000494:pharmacology; D000099188:Alternative Oxidase
D000085:Acetates; D003517:Cyclopentanes; D005419:Flavonoids; D062385:Hydroxybenzoates; D008031:Lignin; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D054883:Oxylipins; D010636:Phenols; D010650:Phenylalanine Ammonia-Lyase; D010937:Plant Growth Regulators; D010940:Plant Proteins; D020005:Propanols; D011435:Propyl Gallate; D012333:RNA, Messenger; D018749:RNA, Plant; D012457:Salicylamides; D000099188:Alternative Oxidase; C439395:1-phenylpropanol; C005703:salicylhydroxamic acid; C072239:methyl jasmonate; C017616:phenolic acid