Suppression of CaCYP1, a novel cytochrome P450 gene, compromises the basal pathogen defense response of pepper plants.
A putative cytochrome P450 gene from chili pepper, Capsicum annuum L. Bukang cytochrome P450 (CaCYP1), was identified using cDNA microarray analysis of gene expression following induction of the leaf hypersensitive response by inoculation of pepper plants with the non-host pathogen Xanthomonas axonopodis pv. glycines 8ra. The full-length cDNA of CaCYP1 encoded a protein of 514 amino acid residues, which contained a putative hydrophobic membrane anchoring domain in the N-terminal region, and a heme-binding motif in the C-terminal region. Analysis of the deduced amino acid sequence of CaCYP1 revealed that it has high homology to Arabidopsis CYP89A5, the function of which is unknown. Expression of CaCYP1 was preferentially increased in pepper plants in response to non-host pathogen inoculation and also during the host resistance response. CaCYP1 expression also increased following treatment with salicylic acid and abscisic acid, while treatment with ethylene had a mild effect. Using a virus-induced gene silencing-based reverse genetics approach, we demonstrated that suppression of CaCYP1 results in enhanced susceptibility to bacterial pathogens. Interestingly, gene silencing of CaCYP1 in pepper plants resulted in the reduced expression of the defense-related genes CaLTP1, CaSIG4, and Cadhn. Our results indicated that CaCYP1, a novel cytochrome P450 in pepper plants, may play a role in plant defense response pathways that involve salicylic acid and abscisic acid signaling pathways.
Kim
Young-Cheol
YC
Plant Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Republic of Korea.
Kim
Soo-Yong
SY
Paek
Kyung-Hee
KH
Choi
Doil
D
Park
Jeong Mee
JM
D000596:Amino Acids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002212:Capsicum / Q000201:enzymology*; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing / Q000502:physiology*; D057927:Hydrophobic and Hydrophilic Interactions; D007113:Immunity, Innate / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data
D000596:Amino Acids; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D003577:Cytochrome P-450 Enzyme System