Identification of a cytochrome P450 cDNA (CYP98A5) from Phaseolus vulgaris, inducible by 3,5-dichlorosalicylic acid and 2,6-dichloro isonicotinic acid.
To investigate the involvement of cytochrome P450s in the metabolism of plants treated with xenobiotic agrochemicals, bean leaves were treated with 3,5-dichlorosalicylic acid (DC-SA), a priming agent of plant defense and 2,6-dichloroisonicotinic acid (DC-INA), a chemical inducer of systemic acquired resistance. Through the use of directed differential display reverse transcription polymerase chain reactions, a differentially expressed cDNA amplicon, found to be up-regulated by both DC-SA and DC-INA treatment, was identified as a cytochrome P450 cDNA, CYP98A5. The nucleotide sequence indicates extensive homology to 3'-hydroxylases of p-coumaroyl esters. Dot blot analysis of leaves treated with various SA and isonicotinic acid derivatives showed enhanced expression of CYP98A5 due to DC-SA and DC-INA. Northern blot analysis of a time-dependent induction study of CYP98A5 in treated bean leaves indicated that DC-SA induces CYP98A5 mRNA transcripts earlier than DC-INA. Both inducers resulted in high transcript levels 24-48 h after treatment. The up-regulation of CYP98A5 is supportive of the conditioning and sensitizing effects of DC-SA and DC-INA to elicit a more rapid and effective defense response.
Department of Biochemistry, University of Johannesburg, Kingsway Campus, Auckland Park 2006, South Africa.
Adriaan E
AE
Basson
Ian A
IA
Dubery
D000595:Amino Acid Sequence; D001483:Base Sequence; D002723:Chlorobenzoates; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018744:DNA, Plant / Q000235:genetics / Q000302:isolation & purification; D004790:Enzyme Induction / Q000187:drug effects; D017343:Genes, Plant / Q000187:drug effects; D007539:Isonicotinic Acids / Q000494:pharmacology*; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D012459:Salicylates / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid
D002723:Chlorobenzoates; D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D007539:Isonicotinic Acids; D012333:RNA, Messenger; D018749:RNA, Plant; D012459:Salicylates; C077261:2,6-dichloroisonicotinic acid; D003577:Cytochrome P-450 Enzyme System; C110890:cytochrome P-450 CYP98A1 (Sorghum bicolor); C514856:3,5-dichlorosalicylic acid