The Involvement of Two P450 Enzymes, CYP83B1 and CYP83A1, in Auxin Homeostasis and Glucosinolate Biosynthesis

Bak, Søren; Feyereisen, René

doi:10.1104/pp.127.1.108

Cited by 227 publications

(156 citation statements)

References 52 publications

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“…The ref2 mutant has decreased lignin content and Ϸ3-fold-reduced sinapate ester levels (29). The ref2 mutant is defective in CYP83A1, one of the two oxime-metabolizing cytochrome P450s in glucosinolate biosynthesis (30,31). It has been suggested that accumulation of oximes or their degradation products perturbs the biosynthesis of phenylpropanoids (29).…”

Section: Discussionmentioning

confidence: 99%

Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome

Kristensen

Morant

Olsen

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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198

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Focused and nontargeted approaches were used to assess the impact associated with introduction of new high-flux pathways in Arabidopsis thaliana by genetic engineering. Transgenic A. thaliana plants expressing the entire biosynthetic pathway for the tyrosine-derived cyanogenic glucoside dhurrin as accomplished by insertion of CYP79A1, CYP71E1, and UGT85B1 from Sorghum bicolor were shown to accumulate 4% dry-weight dhurrin with marginal inadvertent effects on plant morphology, free amino acid pools, transcriptome, and metabolome. In a similar manner, plants expressing only CYP79A1 accumulated 3% dry weight of the tyrosine-derived glucosinolate, p-hydroxybenzylglucosinolate with no morphological pleitropic effects. In contrast, insertion of CYP79A1 plus CYP71E1 resulted in stunted plants, transcriptome alterations, accumulation of numerous glucosides derived from detoxification of intermediates in the dhurrin pathway, and in loss of the brassicaceae-specific UV protectants sinapoyl glucose and sinapoyl malate and kaempferol glucosides. The accumulation of glucosides in the plants expressing CYP79A1 and CYP71E1 was not accompanied by induction of glycosyltransferases, demonstrating that plants are constantly prepared to detoxify xenobiotics. The pleiotrophic effects observed in plants expressing sorghum CYP79A1 and CYP71E1 were complemented by retransformation with S. bicolor UGT85B. These results demonstrate that insertion of high-flux pathways directing synthesis and intracellular storage of high amounts of a cyanogenic glucoside or a glucosinolate is achievable in transgenic A. thaliana plants with marginal inadvertent effects on the transcriptome and metabolome.DNA microarrays ͉ metabolic engineering ͉ metabolite profiling ͉ channeling ͉ substantial equivalence M etabolic engineering offers the possibility to design plants that produce desired compounds (1-3). Knowledge of the impact of insertion of metabolic pathways on preexisting metabolic pathways is typically scarce, and is assessed by targeted approaches, but not by more global and unbiased approaches. We have previously reported transfer of the entire pathway for synthesis of the tyrosine-derived cyanogenic glucoside dhurrin from Sorghum bicolor to Arabidopsis thaliana by coexpression of three S. bicolor cDNAs: two multifunctional cytochromes P450, CYP79A1 and CYP71E1, and a family 1 glucosyltransferase, UGT85B1 (Fig. 1). The transgenic A. thaliana plants accumulated up 4% of plant dry matter of dhurrin (4). Transgenic A. thaliana plants in which only CYP79A1 was introduced accumulated up to 3% dry matter of the tyrosine derived p-hydroxybenzylglucosinolate, a glucosinolate that does not occur naturally in A. thaliana (5). The accumulation of tyrosine derived p-hydroxybenzylglucosinolate in A. thaliana is the result of metabolic crosstalk, where the p-hydroxyphenylacetaldoxime produced by CYP79A1 is efficiently used by the post-oximemetabolizing enzymes CYP83B1 or CYP83A1 in the endogenous glucosinolate biosynthetic pathway (5, 6) (Fig. 1).In this study,...

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Section: Discussionmentioning

confidence: 99%

Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome

Kristensen

Morant

Olsen

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

198

149

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“…MYB28 (At5g61420, also called PRODUCTION OF METHIONINE-DERIVED GLUCOSINOLATE1), which is a positive regulator for the production of aliphatic GSLs at basal levels in Arabidopsis (Hirai et al, 2007), was down-regulated by both JA and RGA (Supplemental Table S8). In addition, two cytochrome P450 family genes encoding CYP79B2 and CYP83A1, which are involved in the production of indole and aliphatic GSLs (Hull et al, 2000;Bak and Feyereisen, 2001), were also down-regulated by RGA. Identification of these genes involved in GSL production suggests that the interaction between the JA pathway and DELLA proteins may control amino acid metabolism during stamen development.…”

Section: Expression Of Rga-regulated Genes In Different Floral Organsmentioning

confidence: 99%

Global Identification of DELLA Target Genes during Arabidopsis Flower Development

Hou

Shen

et al. 2008

Plant Physiology

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Gibberellin (GA) plays important roles in regulating many aspects of plant development. GA derepresses its signaling pathway by promoting the degradation of DELLA proteins, a family of nuclear growth repressors. Although the floral organ identity is established in flowers of the GA-deficient mutant ga1-3, the growth of all floral organs is severely retarded. In particular, abortive anther development in ga1-3 results in male sterility. Genetic analysis has revealed that various combinations of null mutants of DELLA proteins could gradually rescue floral organ defects in ga1-3 and that RGA is the most important DELLA protein involved in floral organ development. To elucidate the early molecular events controlled by RGA during flower development, we performed whole-genome microarray analysis to identify genes in response to the steroid-inducible activation of RGA in ga1-3 rgl2 rga 35S:RGA-GR. Although DELLA proteins were suggested as transcriptional repressors, similar numbers of genes were down-regulated or up-regulated by RGA during floral organ development. More than one-third of RGA down-regulated genes were specifically or predominantly expressed in stamens. A significant number of RGA-regulated genes are involved in phytohormone signaling or stress response. Further expression analysis through activation of RGA by steroid induction combined with cycloheximide identified eight genes as immediate targets of RGA. In situ hybridization and transgenic studies further showed that the expression pattern and function of several selected genes were consistent with the predictions from microarray analysis. These results suggest that DELLA regulation of floral organ development is modulated by multiple phytohormones and stress signaling pathways.

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“…AJ270. The deduced amino acid sequences of orf3, 4,5,6,7, and 8 displayed 82.8, 85.9, 96.4, 98.6, 98.6, and 73.2% identity to those of NHase regulator 2, NHase regulator 1, amidase, NHase R-subunit, NHase -subunit, and NHase activator of Rhodococcus sp. N-771, respectively.…”

Section: Effects Of Various Compounds On the Enzyme Activitymentioning

confidence: 99%

“…N-771, respectively. The deduced amino acid sequences of orf4, 5,6,7, and 8 displayed 98.0, 96.4, 98.6, 98.6, and 98.0% identity with those of Rhodococcus sp. AJ270, respectively.…”

Section: Effects Of Various Compounds On the Enzyme Activitymentioning

confidence: 99%

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A Gene Cluster Responsible for Alkylaldoxime Metabolism Coexisting with Nitrile Hydratase and Amidase in Rhodococcus globerulus A-4^,

et al. 2003

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An enzyme "alkylaldoxime dehydratase (OxdRG)" was purified and characterized from Rhodococcus globerulus A-4, in which nitrile hydratase (NHase) and amidase coexisted with the enzyme. The enzyme contains heme b as a prosthetic group, requires reducing reagents for the reaction, and is most active at a neutral pH and at around 30°C, similar to the phenylacetaldoxime dehydratase from Bacillus sp. OxB-1 (OxdB). However, some differences were seen in subunit structure, substrate specificity, and effects of activators and inhibitors. The corresponding gene, oxd, encoding a 1059-base pair ORF consisting of 353 codons, was cloned, sequenced, and overexpressed in Escherichia coli. The predicted polypeptide showed 30.3% identity to OxdB. The gene is mapped just upstream of the gene cluster encoding the enzymes involved in the metabolism of aliphatic nitriles, i.e., NHase and amidase, and their regulatory and activator proteins. We report here the existence of an aldoxime dehydratase genetically linked with NHase and amidase, and responsible for the metabolism of alkylaldoxime in R. globerulus.Aldoximes derived from amino acids are considered to be intermediates in the biosynthesis of cyanogenic glucosides and glucosinolates in plants (1). However, information on aldoxime metabolism is quite limited and the genetics and enzymology have not been well characterized. One oximemetabolizing enzyme (cytochrome P450 CYP71E1) has been reported to catalyze the conversion of aldoxime to R-hydroxynitrile in the pathway for biosynthesis of cyanogenic glucoside dhurrin in Sorghum bicolor (2-4). Other cytochrome P450s, namely, CYP83 homologues (A1 and B1), have also been identified as oxime-metabolizing enzymes, which catalyze the conversion of indoleacetaldoxime to the corresponding aci-nitro compound, the first step in the biosynthesis of indole glucosinolates in Arabidopsis thaliana. However, the level of activity is quite low, and the mechanisms involved have not been studied. Indoleacetaldoxime is known to be a metabolic branch point between the production of indoleacetic acid and indole glucosinolates in A. thaliana (5-7), but the enzymes responsible for the metabolism have yet to be purified and characterized.Asano et al. have isolated various nitrile-degrading microorganisms, e.g., Rhodococcus rhodochrous (formerly Arthrobacter sp.) strains J-1 and I-9 (K22, AKU 629) (8) and Pseudomonas chlororaphis B23 (9). They first purified, characterized, and named nitrile hydratase (NHase, EC. 4.2.1.84) from R. rhodochrous J-1 (10-12). They also found that P. chlororaphis B23 accumulates large quantities of amides from nitriles and is suitable for the industrial production of acrylamide from acrylonitrile (9, 12). Moreover, nicotinamide and 5-cyanovaleramide are also industrially produced by NHase (13,14). Despite its important uses, the physiological function of NHase in nature remains unclear.We have studied the metabolism of aldoximes from a physiological as well as an applicative perspective, and have isolated Bacillus sp. O...

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The Involvement of Two P450 Enzymes, CYP83B1 and CYP83A1, in Auxin Homeostasis and Glucosinolate Biosynthesis

Cited by 227 publications

References 52 publications

Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome

Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome

Global Identification of DELLA Target Genes during Arabidopsis Flower Development

A Gene Cluster Responsible for Alkylaldoxime Metabolism Coexisting with Nitrile Hydratase and Amidase in Rhodococcus globerulus A-4^,

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The Involvement of Two P450 Enzymes, CYP83B1 and CYP83A1, in Auxin Homeostasis and Glucosinolate Biosynthesis

Cited by 227 publications

References 52 publications

Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome

Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome

Global Identification of DELLA Target Genes during Arabidopsis Flower Development

A Gene Cluster Responsible for Alkylaldoxime Metabolism Coexisting with Nitrile Hydratase and Amidase in Rhodococcus globerulus A-4,

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A Gene Cluster Responsible for Alkylaldoxime Metabolism Coexisting with Nitrile Hydratase and Amidase in Rhodococcus globerulus A-4^,