Abstract
Phytoalexins are low molecular weight antimicrobial compounds that are synthesized in response to pathogen attack. The phytoalexin camalexin, an indole derivative, is produced by Arabidopsis in response to infection with the bacterial pathogen Pseudomonas syringae. The phytoalexin deficient 3 (pad3) mutation, which causes a defect in camalexin production, has no effect on resistance to P. syringae but compromises resistance to the fungal pathogen Alternaria brassicicola. We have now isolated PAD3 by map-based cloning. The predicted PAD3 protein appears to be a cytochrome P450 monooxygenase, similar to those from maize that catalyze synthesis of the indole-derived secondary metabolite 2,4-dihydroxy-1, 4-benzoxazin-3-one. The expression of PAD3 is tightly correlated with camalexin synthesis and is regulated by PAD4 and PAD1. On the basis of these findings, we conclude that PAD3 almost certainly encodes an enzyme required for camalexin biosynthesis. Moreover, these results strongly support the idea that camalexin does not play a major role in plant resistance to P. syringae infection, although it is involved in resistance to a fungal pathogen.
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- Altschul S. F., Gish W., Miller W., Myers E. W., Lipman D. J. Basic local alignment search tool. J Mol Biol. 1990 Oct 5;215(3):403–410. doi: 10.1016/S0022-2836(05)80360-2. [DOI] [PubMed] [Google Scholar]
- Bak S., Kahn R. A., Nielsen H. L., Moller B. L., Halkier B. A. Cloning of three A-type cytochromes P450, CYP71E1, CYP98, and CYP99 from Sorghum bicolor (L.) Moench by a PCR approach and identification by expression in Escherichia coli of CYP71E1 as a multifunctional cytochrome P450 in the biosynthesis of the cyanogenic glucoside dhurrin. Plant Mol Biol. 1998 Feb;36(3):393–405. doi: 10.1023/a:1005915507497. [DOI] [PubMed] [Google Scholar]
- Bent A. F., Kunkel B. N., Dahlbeck D., Brown K. L., Schmidt R., Giraudat J., Leung J., Staskawicz B. J. RPS2 of Arabidopsis thaliana: a leucine-rich repeat class of plant disease resistance genes. Science. 1994 Sep 23;265(5180):1856–1860. doi: 10.1126/science.8091210. [DOI] [PubMed] [Google Scholar]
- Bowling S. A., Clarke J. D., Liu Y., Klessig D. F., Dong X. The cpr5 mutant of Arabidopsis expresses both NPR1-dependent and NPR1-independent resistance. Plant Cell. 1997 Sep;9(9):1573–1584. doi: 10.1105/tpc.9.9.1573. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Camilleri C., Lafleuriel J., Macadré C., Varoquaux F., Parmentier Y., Picard G., Caboche M., Bouchez D. A YAC contig map of Arabidopsis thaliana chromosome 3. Plant J. 1998 Jun;14(5):633–642. doi: 10.1046/j.1365-313x.1998.00159.x. [DOI] [PubMed] [Google Scholar]
- Chapple Clint. MOLECULAR-GENETIC ANALYSIS OF PLANT CYTOCHROME P450-DEPENDENT MONOOXYGENASES. Annu Rev Plant Physiol Plant Mol Biol. 1998 Jun;49(NaN):311–343. doi: 10.1146/annurev.arplant.49.1.311. [DOI] [PubMed] [Google Scholar]
- Creelman Robert A., Mullet John E. BIOSYNTHESIS AND ACTION OF JASMONATES IN PLANTS. Annu Rev Plant Physiol Plant Mol Biol. 1997 Jun;48(NaN):355–381. doi: 10.1146/annurev.arplant.48.1.355. [DOI] [PubMed] [Google Scholar]
- Culbertson M. R. RNA surveillance. Unforeseen consequences for gene expression, inherited genetic disorders and cancer. Trends Genet. 1999 Feb;15(2):74–80. doi: 10.1016/s0168-9525(98)01658-8. [DOI] [PubMed] [Google Scholar]
- Dong X., Mindrinos M., Davis K. R., Ausubel F. M. Induction of Arabidopsis defense genes by virulent and avirulent Pseudomonas syringae strains and by a cloned avirulence gene. Plant Cell. 1991 Jan;3(1):61–72. doi: 10.1105/tpc.3.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feys BJF., Benedetti C. E., Penfold C. N., Turner J. G. Arabidopsis Mutants Selected for Resistance to the Phytotoxin Coronatine Are Male Sterile, Insensitive to Methyl Jasmonate, and Resistant to a Bacterial Pathogen. Plant Cell. 1994 May;6(5):751–759. doi: 10.1105/tpc.6.5.751. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Frey M., Chomet P., Glawischnig E., Stettner C., Grün S., Winklmair A., Eisenreich W., Bacher A., Meeley R. B., Briggs S. P. Analysis of a chemical plant defense mechanism in grasses. Science. 1997 Aug 1;277(5326):696–699. doi: 10.1126/science.277.5326.696. [DOI] [PubMed] [Google Scholar]
- Glazebrook J., Ausubel F. M. Isolation of phytoalexin-deficient mutants of Arabidopsis thaliana and characterization of their interactions with bacterial pathogens. Proc Natl Acad Sci U S A. 1994 Sep 13;91(19):8955–8959. doi: 10.1073/pnas.91.19.8955. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Glazebrook J., Rogers E. E., Ausubel F. M. Isolation of Arabidopsis mutants with enhanced disease susceptibility by direct screening. Genetics. 1996 Jun;143(2):973–982. doi: 10.1093/genetics/143.2.973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Glazebrook J., Rogers E. E., Ausubel F. M. Use of Arabidopsis for genetic dissection of plant defense responses. Annu Rev Genet. 1997;31:547–569. doi: 10.1146/annurev.genet.31.1.547. [DOI] [PubMed] [Google Scholar]
- Glazebrook J., Zook M., Mert F., Kagan I., Rogers E. E., Crute I. R., Holub E. B., Hammerschmidt R., Ausubel F. M. Phytoalexin-deficient mutants of Arabidopsis reveal that PAD4 encodes a regulatory factor and that four PAD genes contribute to downy mildew resistance. Genetics. 1997 May;146(1):381–392. doi: 10.1093/genetics/146.1.381. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Greenberg J. T., Guo A., Klessig D. F., Ausubel F. M. Programmed cell death in plants: a pathogen-triggered response activated coordinately with multiple defense functions. Cell. 1994 May 20;77(4):551–563. doi: 10.1016/0092-8674(94)90217-8. [DOI] [PubMed] [Google Scholar]
- Hammond-Kosack K. E., Jones J. D. Resistance gene-dependent plant defense responses. Plant Cell. 1996 Oct;8(10):1773–1791. doi: 10.1105/tpc.8.10.1773. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Konieczny A., Ausubel F. M. A procedure for mapping Arabidopsis mutations using co-dominant ecotype-specific PCR-based markers. Plant J. 1993 Aug;4(2):403–410. doi: 10.1046/j.1365-313x.1993.04020403.x. [DOI] [PubMed] [Google Scholar]
- Melanson D., Chilton M. D., Masters-Moore D., Chilton W. S. A deletion in an indole synthase gene is responsible for the DIMBOA-deficient phenotype of bxbx maize. Proc Natl Acad Sci U S A. 1997 Nov 25;94(24):13345–13350. doi: 10.1073/pnas.94.24.13345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Penninckx I. A., Eggermont K., Terras F. R., Thomma B. P., De Samblanx G. W., Buchala A., Métraux J. P., Manners J. M., Broekaert W. F. Pathogen-induced systemic activation of a plant defensin gene in Arabidopsis follows a salicylic acid-independent pathway. Plant Cell. 1996 Dec;8(12):2309–2323. doi: 10.1105/tpc.8.12.2309. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Radwanski E. R., Last R. L. Tryptophan biosynthesis and metabolism: biochemical and molecular genetics. Plant Cell. 1995 Jul;7(7):921–934. doi: 10.1105/tpc.7.7.921. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reuber T. L., Plotnikova J. M., Dewdney J., Rogers E. E., Wood W., Ausubel F. M. Correlation of defense gene induction defects with powdery mildew susceptibility in Arabidopsis enhanced disease susceptibility mutants. Plant J. 1998 Nov;16(4):473–485. doi: 10.1046/j.1365-313x.1998.00319.x. [DOI] [PubMed] [Google Scholar]
- Rogers E. E., Glazebrook J., Ausubel F. M. Mode of action of the Arabidopsis thaliana phytoalexin camalexin and its role in Arabidopsis-pathogen interactions. Mol Plant Microbe Interact. 1996 Nov;9(8):748–757. doi: 10.1094/mpmi-9-0748. [DOI] [PubMed] [Google Scholar]
- Ryals J. A., Neuenschwander U. H., Willits M. G., Molina A., Steiner H. Y., Hunt M. D. Systemic Acquired Resistance. Plant Cell. 1996 Oct;8(10):1809–1819. doi: 10.1105/tpc.8.10.1809. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Siebert P. D., Chenchik A., Kellogg D. E., Lukyanov K. A., Lukyanov S. A. An improved PCR method for walking in uncloned genomic DNA. Nucleic Acids Res. 1995 Mar 25;23(6):1087–1088. doi: 10.1093/nar/23.6.1087. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thomma B. P., Eggermont K., Penninckx I. A., Mauch-Mani B., Vogelsang R., Cammue B. P., Broekaert W. F. Separate jasmonate-dependent and salicylate-dependent defense-response pathways in Arabidopsis are essential for resistance to distinct microbial pathogens. Proc Natl Acad Sci U S A. 1998 Dec 8;95(25):15107–15111. doi: 10.1073/pnas.95.25.15107. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thomma B. P., Nelissen I., Eggermont K., Broekaert W. F. Deficiency in phytoalexin production causes enhanced susceptibility of Arabidopsis thaliana to the fungus Alternaria brassicicola. Plant J. 1999 Jul;19(2):163–171. doi: 10.1046/j.1365-313x.1999.00513.x. [DOI] [PubMed] [Google Scholar]
- Tsuji J., Jackson E. P., Gage D. A., Hammerschmidt R., Somerville S. C. Phytoalexin Accumulation in Arabidopsis thaliana during the Hypersensitive Reaction to Pseudomonas syringae pv syringae. Plant Physiol. 1992 Apr;98(4):1304–1309. doi: 10.1104/pp.98.4.1304. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Whalen M. C., Innes R. W., Bent A. F., Staskawicz B. J. Identification of Pseudomonas syringae pathogens of Arabidopsis and a bacterial locus determining avirulence on both Arabidopsis and soybean. Plant Cell. 1991 Jan;3(1):49–59. doi: 10.1105/tpc.3.1.49. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhao J., Last R. L. Coordinate regulation of the tryptophan biosynthetic pathway and indolic phytoalexin accumulation in Arabidopsis. Plant Cell. 1996 Dec;8(12):2235–2244. doi: 10.1105/tpc.8.12.2235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhou N., Tootle T. L., Tsui F., Klessig D. F., Glazebrook J. PAD4 functions upstream from salicylic acid to control defense responses in Arabidopsis. Plant Cell. 1998 Jun;10(6):1021–1030. doi: 10.1105/tpc.10.6.1021. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zook M. Biosynthesis of camalexin from tryptophan pathway intermediates in cell-suspension cultures of Arabidopsis. Plant Physiol. 1998 Dec;118(4):1389–1393. doi: 10.1104/pp.118.4.1389. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zook M., Hammerschmidt R. Origin of the thiazole ring of camalexin, a phytoalexin from Arabidopsis thaliana. Plant Physiol. 1997 Feb;113(2):463–468. doi: 10.1104/pp.113.2.463. [DOI] [PMC free article] [PubMed] [Google Scholar]