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Barrit T, Planchet E, Lothier J, Satour P, Aligon S, Tcherkez G, Limami AM, Campion C, Teulat B. Nitrogen Nutrition Modulates the Response to Alternaria brassicicola Infection via Metabolic Modifications in Arabidopsis Seedlings. PLANTS (BASEL, SWITZERLAND) 2024; 13:534. [PMID: 38502050 PMCID: PMC10892011 DOI: 10.3390/plants13040534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/05/2024] [Accepted: 02/10/2024] [Indexed: 03/20/2024]
Abstract
Little is known about the effect of nitrogen nutrition on seedling susceptibility to seed-borne pathogens. We have previously shown that seedlings grown under high nitrate (5 mM) conditions are less susceptible than those grown under low nitrate (0.1 mM) and ammonium (5 mM) in the Arabidopsis-Alternaria brassicicola pathosystem. However, it is not known how seedling metabolism is modulated by nitrogen nutrition, nor what is its response to pathogen infection. Here, we addressed this question using the same pathosystem and nutritive conditions, examining germination kinetics, seedling development, but also shoot ion contents, metabolome, and selected gene expression. Nitrogen nutrition clearly altered the seedling metabolome. A similar metabolomic profile was observed in inoculated seedlings grown at high nitrate levels and in not inoculated-seedlings. High nitrate levels also led to specific gene expression patterns (e.g., polyamine metabolism), while other genes responded to inoculation regardless of nitrogen supply conditions. Furthermore, the metabolites best correlated with high disease symptoms were coumarate, tyrosine, hemicellulose sugars, and polyamines, and those associated with low symptoms were organic acids (tricarboxylic acid pathway, glycerate, shikimate), sugars derivatives and β-alanine. Overall, our results suggest that the beneficial effect of high nitrate nutrition on seedling susceptibility is likely due to nutritive and signaling mechanisms affecting developmental plant processes detrimental to the pathogen. In particular, it may be due to a constitutively high tryptophan metabolism, as well as down regulation of oxidative stress caused by polyamine catabolism.
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Affiliation(s)
- Thibault Barrit
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
| | - Elisabeth Planchet
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
| | - Jérémy Lothier
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
| | - Pascale Satour
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
| | - Sophie Aligon
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
| | - Guillaume Tcherkez
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Anis M. Limami
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
| | - Claire Campion
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
| | - Béatrice Teulat
- Institut Agro, University of Angers, INRAE, IRHS, SFR QUASAV, 49000 Angers, France; (T.B.); (E.P.); (J.L.); (P.S.); (S.A.); (G.T.); (A.M.L.); (C.C.)
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Makhazen DS, Veremeichik GN, Shkryl YN, Tchernoded GK, Grigorchuk VP, Bulgakov VP. Inhibition of the JAZ1 gene causes activation of camalexin biosynthesis in Arabidopsis callus cultures. J Biotechnol 2021; 342:102-113. [PMID: 34736953 DOI: 10.1016/j.jbiotec.2021.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/20/2021] [Accepted: 10/28/2021] [Indexed: 11/15/2022]
Abstract
Indole alkaloid camalexin has potential medicinal properties such as suppressing the viability of leukemic but not normal cells. Camalexin is not produced in plants and an external factor is required to activate its biosynthesis. In this work, we stimulated camalexin biosynthesis in Arabidopsis calli by blocking one of repressors of the jasmonate pathway, the jasmonate ZIM-domain protein 1 (JAZ1) by using amiRNA targeting JAZ1 gene transcripts. Inhibition of the JAZ1 gene led to an increase in camalexin content from trace amounts in control culture to 9 µg/g DW in the jaz1 line without affecting growth. In addition, JAZ1 silencing enhanced tolerance to cold stress with simultaneous increasing camalexin content up to 30 µg/g DW. Real-time quantitative PCR determination of marker gene expression showed that effects caused by the JAZ1 silencing might be realized through crosslinking JA, ROS, and abscisic acid signaling pathways. Thus, targeting the distal components of signaling pathways can be suggested as a tool for bioengineering of secondary metabolism, along with standard techniques for targeting biosynthetic genes or genes encoding transcription factors.
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Affiliation(s)
- D S Makhazen
- Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia.
| | - G N Veremeichik
- Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - Y N Shkryl
- Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - G K Tchernoded
- Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - V P Grigorchuk
- Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - V P Bulgakov
- Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
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Desmedt W, Mangelinckx S, Kyndt T, Vanholme B. A Phytochemical Perspective on Plant Defense Against Nematodes. FRONTIERS IN PLANT SCIENCE 2020; 11:602079. [PMID: 33281858 PMCID: PMC7691236 DOI: 10.3389/fpls.2020.602079] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 10/21/2020] [Indexed: 05/23/2023]
Abstract
Given the large yield losses attributed to plant-parasitic nematodes and the limited availability of sustainable control strategies, new plant-parasitic nematode control strategies are urgently needed. To defend themselves against nematode attack, plants possess sophisticated multi-layered immune systems. One element of plant immunity against nematodes is the production of small molecules with anti-nematode activity, either constitutively or after nematode infection. This review provides an overview of such metabolites that have been identified to date and groups them by chemical class (e.g., terpenoids, flavonoids, glucosinolates, etc.). Furthermore, this review discusses strategies that have been used to identify such metabolites and highlights the ways in which studying anti-nematode metabolites might be of use to agriculture and crop protection. Particular attention is given to emerging, high-throughput approaches for the identification of anti-nematode metabolites, in particular the use of untargeted metabolomics techniques based on nuclear magnetic resonance (NMR) and mass spectrometry (MS).
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Affiliation(s)
- Willem Desmedt
- Research Group Epigenetics and Defense, Department of Biotechnology, Ghent University, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Sven Mangelinckx
- Research Group Synthesis, Bioresources and Bioorganic Chemistry (SynBioC), Department of Green Chemistry and Technology, Ghent University, Ghent, Belgium
| | - Tina Kyndt
- Research Group Epigenetics and Defense, Department of Biotechnology, Ghent University, Ghent, Belgium
| | - Bartel Vanholme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
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Tahir J, Dijkwel P. β-Substituting alanine synthases: roles in cysteine metabolism and abiotic and biotic stress signalling in plants. FUNCTIONAL PLANT BIOLOGY : FPB 2016; 43:307-323. [PMID: 32480463 DOI: 10.1071/fp15272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/10/2015] [Indexed: 06/11/2023]
Abstract
Cysteine is required for the synthesis of proteins and metabolites, and is therefore an indispensable compound for growth and development. The β-substituting alanine synthase (BSAS) gene family encodes enzymes known as O-acetylserine thiol lyases (OASTLs), which carry out cysteine biosynthesis in plants. The functions of the BSAS isoforms have been reported to be crucial in assimilation of S and cysteine biosynthesis, and homeostasis in plants. In this review we explore the functional variation in this classic pyridoxal-phosphate-dependent enzyme family of BSAS isoforms. We discuss how specialisation and divergence in BSAS catalytic activities makes a more dynamic set of biological routers that integrate cysteine metabolism and abiotic and biotic stress signalling in Arabidopsis thaliana (L.) Heynh. and also other species. Our review presents a universal scenario in which enzymes modulating cysteine metabolism promote survival and fitness of the species by counteracting internal and external stress factors.
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Affiliation(s)
- Jibran Tahir
- Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | - Paul Dijkwel
- Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
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Bednarek P. Sulfur-containing secondary metabolites from Arabidopsis thaliana and other Brassicaceae with function in plant immunity. Chembiochem 2012; 13:1846-59. [PMID: 22807086 DOI: 10.1002/cbic.201200086] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Indexed: 11/10/2022]
Abstract
Biosynthesis of antimicrobial secondary metabolites in response to microbial infection is one of the features of the plant immune system. Particular classes of plant secondary metabolites involved in plant defence are often produced only by species belonging to certain phylogenetic clades. Brassicaceae plants have evolved the ability to synthesise a wide range of sulfur-containing secondary metabolites, including glucosinolates and indole-type phytoalexins. A subset of these compounds is produced by the model plant Arabidopsis thaliana. Genetic tools available for this species enabled verification of immune functions of glucosinolates and camalexin (A. thaliana phytoalexin), as well as characterisation of their respective biosynthetic pathways. Current knowledge of the biosynthesis of Brassicaceae sulfur-containing metabolites suggests that the key event in the evolution of these compounds is the acquisition of biochemical mechanisms originating from detoxification pathways into secondary metabolite biosynthesis. Moreover, it is likely that glucosinolates and Brassicaceae phytoalexins, traditionally considered as separate groups of compounds, have a common evolutionary origin and are interconnected on the biosynthetic level. This suggests that the diversity of Brassicaceae sulfur-containing phytochemicals reflect phylogenetic clade-specific branches of an ancient biosynthetic pathway.
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Affiliation(s)
- Paweł Bednarek
- Laboratory of Proteomics and Metabolomics, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, Poznań, Poland.
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Su T, Xu J, Li Y, Lei L, Zhao L, Yang H, Feng J, Liu G, Ren D. Glutathione-indole-3-acetonitrile is required for camalexin biosynthesis in Arabidopsis thaliana. THE PLANT CELL 2011; 23:364-80. [PMID: 21239642 PMCID: PMC3051237 DOI: 10.1105/tpc.110.079145] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 11/17/2010] [Accepted: 12/19/2010] [Indexed: 05/18/2023]
Abstract
Camalexin, a major phytoalexin in Arabidopsis thaliana, consists of an indole ring and a thiazole ring. The indole ring is produced from Trp, which is converted to indole-3-acetonitrile (IAN) by CYP79B2/CYP79B3 and CYP71A13. Conversion of Cys(IAN) to dihydrocamalexic acid and subsequently to camalexin is catalyzed by CYP71B15. Recent studies proposed that Cys derivative, not Cys itself, is the precursor of the thiazole ring that conjugates with IAN. The nature of the Cys derivative and how it conjugates to IAN and subsequently forms Cys(IAN) remain obscure. We found that protein accumulation of multiple glutathione S-transferases (GSTs), elevation of GST activity, and consumption of glutathione (GSH) coincided with camalexin production. GSTF6 overexpression increased and GSTF6-knockout reduced camalexin production. Arabidopsis GSTF6 expressed in yeast cells catalyzed GSH(IAN) formation. GSH(IAN), (IAN)CysGly, and γGluCys(IAN) were determined to be intermediates within the camalexin biosynthetic pathway. Inhibitor treatments and mutant analyses revealed the involvement of γ-glutamyl transpeptidases (GGTs) and phytochelatin synthase (PCS) in the catabolism of GSH(IAN). The expression of GSTF6, GGT1, GGT2, and PCS1 was coordinately upregulated during camalexin biosynthesis. These results suggest that GSH is the Cys derivative used during camalexin biosynthesis, that the conjugation of GSH with IAN is catalyzed by GSTF6, and that GGTs and PCS are involved in camalexin biosynthesis.
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Affiliation(s)
- Tongbing Su
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Juan Xu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yuan Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Lei Lei
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Luo Zhao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Hailian Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jidong Feng
- Functional Genomic Technology Center, China Agricultural University, Beijing 100193, China
| | - Guoqin Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Dongtao Ren
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- Address correspondence to
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Salvini M, Boccardi TM, Sani E, Bernardi R, Tozzi S, Pugliesi C, Durante M. Alpha-tryptophan synthase of Isatis tinctoria: gene cloning and expression. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2008; 46:715-723. [PMID: 18514538 DOI: 10.1016/j.plaphy.2008.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Indexed: 05/03/2023]
Abstract
Indole producing reaction is a crux in the regulation of metabolite flow through the pathways and the coordination of primary and secondary product biosynthesis in plants. Indole is yielded transiently from indole-3-glycerol phosphate and immediately condensed with serine to give tryptophan, by the enzyme tryptophan synthase (TS). There is evidence that plant TS, like the bacterial complex, functions as an alpha beta heteromer. In few species, e.g. maize, are known enzymes, related with the TS alpha-subunit (TSA), able to catalyse reaction producing indole, which is free to enter the secondary metabolite pathways. In this contest, we searched for TSA and TSA related genes in Isatis tinctoria, a species producing the natural blue dye indigo. The It-TSA cDNA and the full-length exons/introns genomic region were isolated. The phylogenetic analysis indicates that It-TSA is more closely related to Arabidopsis thaliana At-T14E10.210 TSA (95.7% identity at the amino acid level) with respect to A. thaliana At-T10P11.11 TSA1-like (63%), Zea mays indole-3-glycerol phosphate lyase (54%), Z. mays TSA (53%), and Z. mays indole synthase (50%). The It-TSA cDNA was also able to complement an Escherichia coli trpA mutant. To examine the involvement of It-TSA in the biosynthesis of secondary metabolism compounds, It-TSA expression was tested in seedling grown under different light conditions. Semi-quantitative RT-PCR showed an increase in the steady-state level of It-TSA mRNA, paralleled by an increase of indigo and its precursor isatan B. Our results appear to indicate an involvement for It-TSA in indigo precursor synthesis and/or tryptophan biosynthesis.
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Affiliation(s)
- M Salvini
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56124 Pisa, Italy; Dipartimento di Biologia delle Piante Agrarie-Sezione di Genetica, Università di Pisa, Via Matteotti 1/B, I-56124 Pisa, Italy
| | - T M Boccardi
- Dipartimento di Biologia delle Piante Agrarie-Sezione di Genetica, Università di Pisa, Via Matteotti 1/B, I-56124 Pisa, Italy
| | - E Sani
- Dipartimento di Biologia delle Piante Agrarie-Sezione di Genetica, Università di Pisa, Via Matteotti 1/B, I-56124 Pisa, Italy
| | - R Bernardi
- Dipartimento di Biologia delle Piante Agrarie-Sezione di Genetica, Università di Pisa, Via Matteotti 1/B, I-56124 Pisa, Italy
| | - S Tozzi
- Dipartimento di Agronomia e Gestione dell'Agro-Ecosistema, Università di Pisa, Via San Michele degli Scalzi 2, I-56124 Pisa, Italy
| | - C Pugliesi
- Dipartimento di Biologia delle Piante Agrarie-Sezione di Genetica, Università di Pisa, Via Matteotti 1/B, I-56124 Pisa, Italy
| | - M Durante
- Dipartimento di Biologia delle Piante Agrarie-Sezione di Genetica, Università di Pisa, Via Matteotti 1/B, I-56124 Pisa, Italy
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Alvarez S, He Y, Chen S. Comparative Investigations of the Glucosinolate–Myrosinase System in Arabidopsis Suspension Cells and Hypocotyls. ACTA ACUST UNITED AC 2008; 49:324-33. [DOI: 10.1093/pcp/pcn007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Ferrari S, Galletti R, Denoux C, De Lorenzo G, Ausubel FM, Dewdney J. Resistance to Botrytis cinerea induced in Arabidopsis by elicitors is independent of salicylic acid, ethylene, or jasmonate signaling but requires PHYTOALEXIN DEFICIENT3. PLANT PHYSIOLOGY 2007; 144:367-79. [PMID: 17384165 PMCID: PMC1913806 DOI: 10.1104/pp.107.095596] [Citation(s) in RCA: 284] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Oligogalacturonides (OGs) released from plant cell walls by pathogen polygalacturonases induce a variety of host defense responses. Here we show that in Arabidopsis (Arabidopsis thaliana), OGs increase resistance to the necrotrophic fungal pathogen Botrytis cinerea independently of jasmonate (JA)-, salicylic acid (SA)-, and ethylene (ET)-mediated signaling. Microarray analysis showed that about 50% of the genes regulated by OGs, including genes encoding enzymes involved in secondary metabolism, show a similar change of expression during B. cinerea infection. In particular, expression of PHYTOALEXIN DEFICIENT3 (PAD3) is strongly up-regulated by both OGs and infection independently of SA, JA, and ET. OG treatments do not enhance resistance to B. cinerea in the pad3 mutant or in underinducer after pathogen and stress1, a mutant with severely impaired PAD3 expression in response to OGs. Similarly to OGs, the bacterial flagellin peptide elicitor flg22 also enhanced resistance to B. cinerea in a PAD3-dependent manner, independently of SA, JA, and ET. This work suggests, therefore, that elicitors released from the cell wall during pathogen infection contribute to basal resistance against fungal pathogens through a signaling pathway also activated by pathogen-associated molecular pattern molecules.
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Affiliation(s)
- Simone Ferrari
- Dipartimento Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, 23-35020 Legnaro, Italy.
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Abstract
Camalexin (3-thiazol-2'-yl-indole) is the characteristic phytoalexin of Arabidopsis thaliana, which is induced by a great variety of plant pathogens. While particular pathogens, as well as a human tumour cell line, were growth inhibited by camalexin, some fungi show resistance due to active degradation. Camalexin originates from tryptophan and its biosynthesis involves the cytochrome P450 enzymes CYP79B2 and CYP71B15 (PAD3). Camalexin induction is a complex process, for which triggering by reactive oxygen species (ROS), salicylic acid signalling, and the glutathione status are important. Targets of the signalling cascade are the tryptophan and camalexin biosynthetic genes, which are strongly transcriptionally upregulated at the sites of pathogen infection. The important knowledge on camalexin, which is reviewed in this paper, will help to establish camalexin as a model for the investigation of the significance of phytoalexins in response pathogen challenge.
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Affiliation(s)
- Erich Glawischnig
- Lehrstuhl für Genetik, Technische Universität München, Am Hochanger 8, 85350 Freising, Germany.
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11
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Abstract
The biosynthesis of camalexin, the main phytoalexin of the model plant Arabidopsis thaliana, involves at least two CYP (cytochrome P450) steps. It is synthesized from tryptophan via indole-3-acetaldoxime in a reaction catalysed by CYP79B2 and CYP79B3. Based on the pad3 mutant phenotype, CYP71B15 (PAD3) had also been suggested as a camalexin biosynthetic gene. CYP71B15 catalyses the final step in camalexin biosynthesis, as recombinant CYP71B15 and microsomes from Arabidopsis leaves expressing functional PAD3 converted dihydrocamalexic acid into camalexin. The biosynthetic pathway is co-ordinately induced, strictly localized to the site of pathogen infection. This provides a model system to study the regulation of CYP enzymes involved in phytoalexin biosynthesis.
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Affiliation(s)
- E Glawischnig
- Lehrstuhl für Genetik, Technische Universität München, Am Hochanger 8, 85350 Freising, Germany.
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Bouizgarne B, El-Maarouf-Bouteau H, Madiona K, Biligui B, Monestiez M, Pennarun AM, Amiar Z, Rona JP, Ouhdouch Y, El Hadrami I, Bouteau F. A putative role for fusaric acid in biocontrol of the parasitic angiosperm Orobanche ramosa. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2006; 19:550-6. [PMID: 16673942 DOI: 10.1094/mpmi-19-0550] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Fusarium spp. are ubiquitous fungi found in soil worldwide as both pathogenic and nonpathogenic strains. The signals leading to disease or the absence of disease are poorly understood. We recently showed that fusaric acid (FA), a nonspecific toxin produced by most Fusarium spp., could elicit various plant defense responses at 100 nM without toxic effect. In this study, we checked for the effect of FA on root and root hairs, probable first site of contact between the fungi and the host. Large FA concentrations reduce root and root-hair growth and induce a rapid transient membrane hyperpolarization, followed by a large depolarization, due to the inhibition of H(+)-ATPase currents. Nanomolar concentrations of FA induced only an early transient membrane hyperpolarization of root hairs compatible with the induction of a signal transduction pathway. FA at 10(-7) M failed to induce salicylic acid- and jasmonic acid/ethylene-dependent defense-related genes but inhibited the germination of the angiosperm parasite Orobanche ramosa in contact of FA-pretreated Arabidopsis thaliana seedlings. These data suggest that FA at nontoxic concentrations could activate signal transduction components necessary for plant-defense responses that could contribute to biocontrol activity of Fusarium spp.
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Affiliation(s)
- Brahim Bouizgarne
- LEM (EA 3514), Université Paris 7, 2, place Jussieu, 750251 Paris 05, France
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Kriechbaumer V, Park WJ, Gierl A, Glawischnig E. Auxin biosynthesis in maize. PLANT BIOLOGY (STUTTGART, GERMANY) 2006; 8:334-9. [PMID: 16807825 DOI: 10.1055/s-2006-923883] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
For the biosynthesis of the phytohormone indole-3-acetic acid (IAA), a number of tryptophan-dependent and -independent pathways have been discussed. Maize is an appropriate model system to analyze IAA biosynthesis particularly because high quantities of IAA conjugates are stored in the endosperm. This allowed precursor feeding experiments in a kernel culture system followed by retrobiosynthetic NMR analysis, which strongly suggested that tryptophan-dependent IAA synthesis is the predominant route for auxin biosynthesis in the maize kernel. Two nitrilases ZmNIT1 and ZmNIT2 are expressed in seeds. ZmNIT2 efficiently hydrolyzes indole-3-acetonitrile (IAN) to IAA and thus could be involved in auxin biosynthesis. Redundant pathways, e.g., via indole-3-acetaldehyde could imply that multiple mutants will be necessary to obtain IAA-deficient plants and to conclusively identify relevant genes for IAA biosynthesis.
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Affiliation(s)
- V Kriechbaumer
- Lehrstuhl für Genetik, Technische Universität München, Am Hochanger 8, 85350 Freising, Germany
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Truman W, de Zabala MT, Grant M. Type III effectors orchestrate a complex interplay between transcriptional networks to modify basal defence responses during pathogenesis and resistance. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 46:14-33. [PMID: 16553893 DOI: 10.1111/j.1365-313x.2006.02672.x] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
To successfully infect a plant, bacterial pathogens inject a collection of Type III effector proteins (TTEs) directly into the plant cell that function to overcome basal defences and redirect host metabolism for nutrition and growth. We examined (i) the transcriptional dynamics of basal defence responses between Arabidopsis thaliana and Pseudomonas syringae and (ii) how basal defence is subsequently modulated by virulence factors during compatible interactions. A set of 96 genes displaying an early, sustained induction during basal defence was identified. These were also universally co-regulated following other bacterial basal resistance and non-host responses or following elicitor challenges. Eight hundred and eighty genes were conservatively identified as being modulated by TTEs within 12 h post-inoculation (hpi), 20% of which represented transcripts previously induced by the bacteria at 2 hpi. Significant over-representation of co-regulated transcripts encoding leucine rich repeat receptor proteins and protein phosphatases were, respectively, suppressed and induced 12 hpi. These data support a model in which the pathogen avoids detection through diminution of extracellular receptors and attenuation of kinase signalling pathways. Transcripts associated with several metabolic pathways, particularly plastid based primary carbon metabolism, pigment biosynthesis and aromatic amino acid metabolism, were significantly modified by the bacterial challenge at 12 hpi. Superimposed upon this basal response, virulence factors (most likely TTEs) targeted genes involved in phenylpropanoid biosynthesis, consistent with the abrogation of lignin deposition and other wall modifications likely to restrict the passage of nutrients and water to the invading bacteria. In contrast, some pathways associated with stress tolerance are transcriptionally induced at 12 hpi by TTEs.
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Affiliation(s)
- William Truman
- Department of Agricultural Science, Imperial College London, Wye Campus, High Street, Wye TN25 5AH, UK
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15
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Ruszkowska J, Wróbel JT. Tryptophan-derived sulfur-containing phytoalexins--a general overview. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 527:629-36. [PMID: 15206782 DOI: 10.1007/978-1-4615-0135-0_72] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Phytoalexins are low molecular weight antimicrobial compounds that are synthesized and accumulated in plants after their exposure to pathogenic microorganisms (bacteria, fungi, viruses and protozoans). They are extensively studied now as promising antifungal, potentially anticancer and plant diseases controlling agents. The article pertains to a group of indole-derived phytoalexins--brassinins, containing at least one sulfur atom in the side chain or in the ring(s), isolated from the cruciferous plants. Up today more than 20 compounds, closely related biogenetically, but exhibiting diversified biological activity have been identified. The survey summerises most promising recent results pertaining practical application of brassinins and camalexins.
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Affiliation(s)
- Joanna Ruszkowska
- Faculty of Chemistry, Warsaw University, L. Pasteur Str. 1, 02-093 Warsaw, Poland.
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16
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Glawischnig E, Hansen BG, Olsen CE, Halkier BA. Camalexin is synthesized from indole-3-acetaldoxime, a key branching point between primary and secondary metabolism in Arabidopsis. Proc Natl Acad Sci U S A 2004; 101:8245-50. [PMID: 15148388 PMCID: PMC419588 DOI: 10.1073/pnas.0305876101] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Characteristic for cruciferous plants is their production of N- and S-containing indole phytoalexins with disease resistance and cancer-preventive properties, previously proposed to be synthesized from indole independently of tryptophan. We show that camalexin, the indole phytoalexin of Arabidopsis thaliana, is synthesized from tryptophan via indole-3-acetaldoxime (IAOx) in a reaction catalyzed by CYP79B2 and CYP79B3. Cyp79B2/cyp79B3 double knockout mutant is devoid of camalexin, as it is also devoid of indole glucosinolates [Zhao, Y., Hull, A. K., Gupta, N. R., Goss, K. A., Alonso, J., Ecker, J. R., Normanly, J., Chory, J. & Celenza, J. L. (2002) Genes Dev. 16, 3100-3112], and isotope-labeled IAOx is incorporated into camalexin. These results demonstrate that only CYP79B2 and CYP79B3 contribute significantly to the IAOx pool from which camalexin and indole glucosinolates are synthesized. Furthermore, production of camalexin in the sur1 mutant devoid of glucosinolates excludes the possibility that camalexin is derived from indole glucosinolates. CYP79B2 plays an important role in camalexin biosynthesis in that the transcript level of CYP79B2, but not CYP79B3, is increased upon induction of camalexin by silver nitrate as evidenced by microarray analysis and promoter-beta-glucuronidase data. The structural similarity between cruciferous indole phytoalexins suggests that these compounds are biogenetically related and synthesized from tryptophan via IAOx by CYP79B homologues. The data show that IAOx is a key branching point between several secondary metabolic pathways as well as primary metabolism, where IAOx has been shown to play a critical role in IAA homeostasis.
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Affiliation(s)
- Erich Glawischnig
- Center for Molecular Plant Physiology and Department of Plant Biology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen, Denmark.
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17
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Ljun K, Hul AK, Kowalczyk M, Marchant A, Celenza J, Cohen JD, Sandberg G. Biosynthesis, conjugation, catabolism and homeostasis of indole-3-acetic acid in Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2002; 50:309-332. [PMID: 12175022 DOI: 10.1023/a:1016024017872] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- Karin Ljun
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå
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18
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Ljung K, Hull AK, Kowalczyk M, Marchant A, Celenza J, Cohen JD, Sandberg G. Biosynthesis, conjugation, catabolism and homeostasis of indole-3-acetic acid in Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2002; 49:249-272. [PMID: 12036253 DOI: 10.1023/a:1015298812300] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- Karin Ljung
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå
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19
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Pedras MSC, Nycholat CM, Montaut S, Xu Y, Khan AQ. Chemical defenses of crucifers: elicitation and metabolism of phytoalexins and indole-3-acetonitrile in brown mustard and turnip. PHYTOCHEMISTRY 2002; 59:611-625. [PMID: 11867093 DOI: 10.1016/s0031-9422(02)00026-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The metabolism of the cruciferous phytoalexins brassinin and cyclobrassinin, and the related compounds indole-3-carboxaldehyde, glucobrassicin, and indole-3-acetaldoxime was investigated in various plant tissues of Brassica juncea and B. rapa. Metabolic studies with brassinin showed that stems of B. juncea metabolized radiolabeled brassinin to indole-3-acetic acid, via indole-3-carboxaldehyde, a detoxification pathway similar to that followed by the "blackleg" fungus (Phoma lingam/Leptosphaeria maculans). In addition, it was established that tetradeuterated brassinin was incorporated into the phytoalexin brassilexin in B. juncea and B. rapa. On the other hand, the tetradeuterated indole glucosinolate glucobrassicin was not incorporated into brassinin, although the chemical structures of brassinins and indole glucosinolates suggest an interconnected biogenesis. Importantly, tetradeuterated indole-3-acetaldoxime was an efficient precursor of phytoalexins brassinin, brassilexin, and spirobrassinin. Elicitation experiments in tissues of Brassica juncea and B. rapa showed that indole-3-acetonitrile was an inducible metabolite produced in leaves and stems of B. juncea but not in B. rapa. Indole-3-acetonitrile displayed antifungal activity similar to that of brassilexin, was metabolized by the blackleg fungus at slower rates than brassinin, cyclobrassinin, or brassilexin, and appeared to be involved in defense responses of B. juncea.
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Affiliation(s)
- M Soledade C Pedras
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK, Canada S7N 5C9.
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Kruft V, Eubel H, Jänsch L, Werhahn W, Braun HP. Proteomic approach to identify novel mitochondrial proteins in Arabidopsis. PLANT PHYSIOLOGY 2001. [PMID: 11743114 DOI: 10.1104/pp.010474] [Citation(s) in RCA: 231] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
An Arabidopsis mitochondrial proteome project was started for a comprehensive investigation of mitochondrial functions in plants. Mitochondria were prepared from Arabidopsis stems and leaves or from Arabidopsis suspension cell cultures, and the purity of the generated fractions was tested by the resolution of organellar protein complexes applying two-dimensional blue-native/N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine (Tricine) sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Arabidopsis mitochondrial proteome was analyzed by two-dimensional isoelectric focusing/ Tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 650 different proteins in a pI range of pH 3 to 10 were separated on single gels. Solubilization conditions, pH gradients for isoelectric focusing, and gel staining procedures were varied, and the number of separable proteins increased to about 800. Fifty-two protein spots were identified by immunoblotting, direct protein sequencing, and mass spectrometry. The characterized proteins cooperate in various processes, such as respiration, citric acid cycle, amino acid and nucleotide metabolism, protection against O(2), mitochondrial assembly, molecular transport, and protein biosynthesis. More than 20% of the identified proteins were not described previously for plant mitochondria, indicating novel mitochondrial functions. The map of the Arabidopsis mitochondrial proteome should be useful for the analysis of knockout mutants concerning nuclear-encoded mitochondrial genes. Considerations of the total complexity of the Arabidopsis mitochondrial proteome are discussed. The data from this investigation will be made available at http://www.gartenbau.uni-hannover.de/genetik/AMPP.
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Affiliation(s)
- V Kruft
- Applied Biosystems, D-63225 Langen, Germany
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21
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Kruft V, Eubel H, Jänsch L, Werhahn W, Braun HP. Proteomic approach to identify novel mitochondrial proteins in Arabidopsis. PLANT PHYSIOLOGY 2001; 127:1694-1710. [PMID: 11743114 DOI: 10.1104/pp.127.4.1694] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
An Arabidopsis mitochondrial proteome project was started for a comprehensive investigation of mitochondrial functions in plants. Mitochondria were prepared from Arabidopsis stems and leaves or from Arabidopsis suspension cell cultures, and the purity of the generated fractions was tested by the resolution of organellar protein complexes applying two-dimensional blue-native/N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine (Tricine) sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Arabidopsis mitochondrial proteome was analyzed by two-dimensional isoelectric focusing/ Tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 650 different proteins in a pI range of pH 3 to 10 were separated on single gels. Solubilization conditions, pH gradients for isoelectric focusing, and gel staining procedures were varied, and the number of separable proteins increased to about 800. Fifty-two protein spots were identified by immunoblotting, direct protein sequencing, and mass spectrometry. The characterized proteins cooperate in various processes, such as respiration, citric acid cycle, amino acid and nucleotide metabolism, protection against O(2), mitochondrial assembly, molecular transport, and protein biosynthesis. More than 20% of the identified proteins were not described previously for plant mitochondria, indicating novel mitochondrial functions. The map of the Arabidopsis mitochondrial proteome should be useful for the analysis of knockout mutants concerning nuclear-encoded mitochondrial genes. Considerations of the total complexity of the Arabidopsis mitochondrial proteome are discussed. The data from this investigation will be made available at http://www.gartenbau.uni-hannover.de/genetik/AMPP.
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Affiliation(s)
- V Kruft
- Applied Biosystems, D-63225 Langen, Germany
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22
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Brader G, Palva ET. Jasmonate-dependent induction of indole glucosinolates in Arabidopsis by culture filtrates of the nonspecific pathogen Erwinia carotovora. PLANT PHYSIOLOGY 2001; 126:849-60. [PMID: 11402212 PMCID: PMC111174 DOI: 10.1104/pp.126.2.849] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Elicitors from the plant pathogen Erwinia carotovora trigger coordinate induction of the tryptophan (Trp) biosynthesis pathway and Trp oxidizing genes in Arabidopsis. To elucidate the biological role of such pathogen-induced activation we characterized the production of secondary defense metabolites such as camalexin and indole glucosinolates derived from precursors of this pathway. Elicitor induction was followed by a specific increase in 3-indolylmethylglucosinolate (IGS) content, but only a barely detectable accumulation of the indole-derived phytoalexin camalexin. The response is mediated by jasmonic acid as shown by lack of IGS induction in the jasmonate-insensitive mutant coi1-1. In accordance with this, methyl jasmonate was able to trigger IGS accumulation in Arabidopsis. In contrast, ethylene and salicylic acid seem to play a minor role in the response. They did not trigger alterations in IGS levels, and methyl jasmonate- or elicitor-induced IGS accumulation in NahG and ethylene-insensitive ein2-1 mutant plants was similar as in the wild type. The breakdown products of IGS and other glucosinolates were able to inhibit growth of E. carotovora. The results suggest that IGS is of importance in the defense against bacterial pathogens.
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Affiliation(s)
- G Brader
- Department of Biosciences, University of Helsinki, POB 56, FIN-00014 Helsinki, Finland
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23
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Frey M, Stettner C, Pare PW, Schmelz EA, Tumlinson JH, Gierl A. An herbivore elicitor activates the gene for indole emission in maize. Proc Natl Acad Sci U S A 2000; 97:14801-6. [PMID: 11106389 PMCID: PMC18999 DOI: 10.1073/pnas.260499897] [Citation(s) in RCA: 214] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Maize and a variety of other plant species release volatile compounds in response to herbivore attack that serve as chemical cues to signal natural enemies of the feeding herbivore. N-(17-hydroxylinolenoyl)-l-glutamine is an elicitor component that has been isolated and chemically characterized from the regurgitant of the herbivore-pest beet armyworm. This fatty acid derivative, referred to as volicitin, triggers the synthesis and release of volatile components, including terpenoids and indole in maize. Here we report on a previously unidentified enzyme, indole-3-glycerol phosphate lyase (IGL), that catalyzes the formation of free indole and is selectively activated by volicitin. IGL's enzymatic properties are similar to BX1, a maize enzyme that serves as the entry point to the secondary defense metabolites DIBOA and DIMBOA. Gene-sequence analysis indicates that Igl and Bx1 are evolutionarily related to the tryptophan synthase alpha subunit.
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Affiliation(s)
- M Frey
- Lehrstuhl für Genetik, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany.
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24
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Ouyang J, Shao X, Li J. Indole-3-glycerol phosphate, a branchpoint of indole-3-acetic acid biosynthesis from the tryptophan biosynthetic pathway in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2000; 24:327-33. [PMID: 11069706 DOI: 10.1046/j.1365-313x.2000.00883.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The phytohormone indole-3-acetic acid (IAA) plays a vital role in plant growth and development as a regulator of numerous biological processes. Its biosynthetic pathways have been studied for decades. Recent genetic and in vitro labeling evidence indicates that IAA in Arabidopsis thaliana and other plants is primarily synthesized from a precursor that is an intermediate in the tryptophan (Trp) biosynthetic pathway. To determine which intermediate(s) acts as the possible branchpoint for the Trp-independent IAA biosynthesis in plants, we took an in vivo approach by generating antisense indole-3-glycerol phosphate synthase (IGS) RNA transgenic plants and using available Arabidopsis Trp biosynthetic pathway mutants trp2-1 and trp3-1. Antisense transgenic plants display some auxin deficient-like phenotypes including small rosettes and reduced fertility. Protein gel blot analysis indicated that IGS expression was greatly reduced in the antisense lines. Quantitative analyses of IAA and Trp content in antisense IGS transgenic plants and Trp biosynthetic mutants revealed striking differences. Compared with wild-type plants, the Trp content in all the transgenic and mutant plants decreased significantly. However, total IAA levels were significantly decreased in antisense IGS transgenic plants, but remarkably increased in trp3-1 and trp2-1 plants. These results suggest that indole-3-glycerol phosphate (IGP) in the Arabidopsis Trp biosynthetic pathway serves as a branchpoint compound in the Trp-independent IAA de novo biosynthetic pathway.
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Affiliation(s)
- J Ouyang
- Institute of Genetics, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing 100101, China
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25
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Sicker D, Frey M, Schulz M, Gierl A. Role of natural benzoxazinones in the survival strategy of plants. INTERNATIONAL REVIEW OF CYTOLOGY 2000; 198:319-46. [PMID: 10804466 DOI: 10.1016/s0074-7696(00)98008-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Benzoxazinoid acetal glucosides are a unique class of natural products abundant in Gramineae, including the major agricultural crops maize, wheat, and rye. These secondary metabolites are also found in several dicotyledonous species. Benzoxazinoids serve as important factors of host plant resistance against microbial diseases and insects and as allelochemicals and endogenous ligands. Interdisciplinary investigations by biologists, biochemists, and chemists are stimulated by the intention to make agricultural use of the benzoxazinones as natural pesticides. These natural products are not only constituents of a plant defense system but also part of an active allelochemical system used in the competition with other plants. This review covers biological and chemical aspects of benzoxazinone research over the last decade with special emphasis on recent advances in the elucidation of the biosynthetic pathway.
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Affiliation(s)
- D Sicker
- Institute of Organic Chemistry, University of Leipzig, Germany
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26
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Hull AK, Vij R, Celenza JL. Arabidopsis cytochrome P450s that catalyze the first step of tryptophan-dependent indole-3-acetic acid biosynthesis. Proc Natl Acad Sci U S A 2000; 97:2379-84. [PMID: 10681464 PMCID: PMC15809 DOI: 10.1073/pnas.040569997] [Citation(s) in RCA: 294] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Plants synthesize numerous secondary metabolites that are used as developmental signals or as defense against pathogens. Tryptophan (Trp)-derived secondary metabolites include camalexin, indole glucosinolates, and indole-3-acetic acid (IAA); however, the steps in their synthesis from Trp or its precursors remain unclear. We have identified two Arabidopsis cytochrome P450s (CYP79B2 and CYP79B3) that can convert Trp to indole-3-acetaldoxime (IAOx), a precursor to IAA and indole glucosinolates.
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Affiliation(s)
- A K Hull
- Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA
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Pedras MS, Okanga FI, Zaharia IL, Khan AQ. Phytoalexins from crucifers: synthesis, biosynthesis, and biotransformation. PHYTOCHEMISTRY 2000; 53:161-176. [PMID: 10680168 DOI: 10.1016/s0031-9422(99)00494-x] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Phytoalexins play a significant role in the defense response of plants. These secondary metabolites, which are synthesized de novo in response to diverse forms of stress, including fungal infection, are part of the plants' chemical and biochemical defense mechanisms. Phytoalexins from crucifers are structurally and biogenetically related, but display significantly different biological activities. Here, we review work reporting the chemical structures, synthesis, biosynthesis and metabolism of cruciferous phytoalexins, as well as their biological activity towards different microorganisms.
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Affiliation(s)
- M S Pedras
- Department of Chemistry, University of Saskatchewan, Saskatoon, Canada.
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Zhou N, Tootle TL, Glazebrook J. Arabidopsis PAD3, a gene required for camalexin biosynthesis, encodes a putative cytochrome P450 monooxygenase. THE PLANT CELL 1999; 11:2419-28. [PMID: 10590168 PMCID: PMC144139 DOI: 10.1105/tpc.11.12.2419] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
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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Affiliation(s)
- N Zhou
- Center for Agricultural Biotechnology, University of Maryland Biotechnology Institute, College Park, Maryland 20742, USA
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Hammerschmidt R, Dann EK. The role of phytoalexins in plant protection. NOVARTIS FOUNDATION SYMPOSIUM 1999; 223:175-87; discussion 188-90. [PMID: 10549555 DOI: 10.1002/9780470515679.ch12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Plants resist pathogens with combinations of constitutive and induced defences. Of the induced defences, phytoalexin production has received much attention since the phytoalexin concept was introduced over 50 years ago. However, the specific role of phytoalexins in disease resistance is not clear for the majority of host-parasite systems. Much of the research on phytoalexins has relied on the identification of induced antifungal compounds and correlating their presence with resistance. Although an important first step, more definitive studies are needed. Approaches that use in situ localization and quantification have provided good evidence that phytoalexins can accumulate at the right time, concentration, and location to be effective in resistance. Studies on phytoalexin tolerance in pathogenic fungi have also shown a relationship between virulence and the ability of fungi to detoxify phytoalexins. Use of mutants deficient in phytoalexin synthesis and elucidating biosynthetic pathways provide other approaches to evaluating the role of phytoalexins. These approaches will be illustrated using the Arabidopsis-camalexin system and other selected examples. Studies on natural variation in phytoalexin production and the accumulation of phytoalexins under field conditions will be presented as another means of evaluating the role of these compounds in resistance to pathogens and other pests.
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Affiliation(s)
- R Hammerschmidt
- Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824-1312, USA
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Hammerschmidt R. PHYTOALEXINS: What Have We Learned After 60 Years? ANNUAL REVIEW OF PHYTOPATHOLOGY 1999; 37:285-306. [PMID: 11701825 DOI: 10.1146/annurev.phyto.37.1.285] [Citation(s) in RCA: 167] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
One of the best and longest-studied defense response of plants to infection is the induced accumulation of antimicrobial, low-molecular-weight secondary metabolites known as phytoalexins. Since the phytoalexin hypothesis was first proposed in 1940, a role for these compounds in defense has been revealed through several experimental approaches. Support has come, for example, through studies on the rate of phytoalexins in relation to cessation of pathogen development, quantification of phytoalexins at the infection site, and relationship of pathogen virulence to the phytoalexin tolerance. Evidence in support of phytoalexins in resistance as well some recent advances in phytoalexin biosynthesis are reviewed. Criteria for evaluating a role for phytoalexins in disease resistance are also discussed.
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Affiliation(s)
- Ray Hammerschmidt
- Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824; e-mail:
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