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The phytotoxin coronatine is a structural analog of octadecanoid signaling molecules, which are well known mediators of plant defense reactions. To isolate novel coronatine-regulated genes from Arabidopsis thaliana, differential mRNA display was performed. Transcript levels of CORI-7 (coronatine induced-7) were rapidly and transiently increased in coronatine-treated plants, and the corresponding cDNA was found to encode the sulfotransferase AtST5a. Likewise, upon wounding, an immediate and transient increase in AtST5a mRNA levels could be observed in both locally wounded and unwounded (systemic) leaves. Furthermore, application of octadecanoids and ethylene as compounds involved in plant wound defense reactions resulted in AtST5a gene activation, whereas pathogen defense-related signals (yeast elicitor and salicylic acid) were inactive. AtST5a and its close homologs AtST5b and AtST5c were purified as His6 -tagged proteins from Escherichia coli. The three enzymes were shown to catalyze the final step in the biosynthesis of the glucosinolate (GS) core structure, the sulfation of desulfoglucosinolates (dsGSs). They accept a broad range of dsGSs as substrates. However, in a competitive situation, AtST5a clearly prefers tryptophan- and phenylalanine-derived dsGSs, whereas long chain dsGSs derived from methionine are the preferred substrates of AtST5b and AtST5c. Treatment of Arabidopsis plants with low concentrations of coronatine resulted in an increase in the amounts of specific GSs, primarily glucobrassicin and neoglucobrassicin. Hence, it is suggested that AtST5a is the sulfotransferase responsible for the biosynthesis of tryptophan-derived GSs in vivo. The phytotoxin coronatine is a structural analog of octadecanoid signaling molecules, which are well known mediators of plant defense reactions. To isolate novel coronatine-regulated genes from Arabidopsis thaliana, differential mRNA display was performed. Transcript levels of CORI-7 (coronatine induced-7) were rapidly and transiently increased in coronatine-treated plants, and the corresponding cDNA was found to encode the sulfotransferase AtST5a. Likewise, upon wounding, an immediate and transient increase in AtST5a mRNA levels could be observed in both locally wounded and unwounded (systemic) leaves. Furthermore, application of octadecanoids and ethylene as compounds involved in plant wound defense reactions resulted in AtST5a gene activation, whereas pathogen defense-related signals (yeast elicitor and salicylic acid) were inactive. AtST5a and its close homologs AtST5b and AtST5c were purified as His6 -tagged proteins from Escherichia coli. The three enzymes were shown to catalyze the final step in the biosynthesis of the glucosinolate (GS) core structure, the sulfation of desulfoglucosinolates (dsGSs). They accept a broad range of dsGSs as substrates. However, in a competitive situation, AtST5a clearly prefers tryptophan- and phenylalanine-derived dsGSs, whereas long chain dsGSs derived from methionine are the preferred substrates of AtST5b and AtST5c. Treatment of Arabidopsis plants with low concentrations of coronatine resulted in an increase in the amounts of specific GSs, primarily glucobrassicin and neoglucobrassicin. Hence, it is suggested that AtST5a is the sulfotransferase responsible for the biosynthesis of tryptophan-derived GSs in vivo. Compared with the animal cell, very little is known regarding the structural and regulatory roles of the sulfate group in plants. The transfer of the active sulfate group from 3′-phosphoadenosine 5′-phosphosulfate (PAPS) 1The abbreviations used are: PAPS, 3′-phosphoadenosine 5′-phosphosulfate; GS, glucosinolate; dsGS, desulfoglucosinolate; dsGS-ST, desulfoglucosinolate:PAPS sulfotransferase; RT, reverse transcription; HPLC, high performance liquid chromatography; MeJA, jasmonic acid methyl ester; I3M, indole-3-methyl; 8MTO, 8-methylthiooctyl. to acceptor molecules is catalyzed by sulfotransferases. Members of the superfamily of sulfotransferases are known in prokaryotes as well as eukaryotes; however, the study of enzymes that catalyze the sulfation reaction in plants considerably lags behind that in animal systems. Cytosolic sulfotransferases from plants have been characterized in some detail (Ref. 1Varin L. Marsolais F. Richard M. Rouleau M. FASEB J. 1997; 11: 517-525Crossref PubMed Scopus (80) Google Scholar and references therein), and some cDNAs have been identified. These fall into three subgroups: the flavonol sulfotransferases described for Flaveria species (1Varin L. Marsolais F. Richard M. Rouleau M. FASEB J. 1997; 11: 517-525Crossref PubMed Scopus (80) Google Scholar), the steroid sulfotransferases identified in Brassica napus (2Rouleau M. Marsolais F. Richard M. Nicolle L. Voigt B. Adam G. Varin L. J. Biol. Chem. 1999; 274: 20925-20930Abstract Full Text Full Text PDF PubMed Scopus (95) Google Scholar, 3Marsolais F. Sebastia C.H. Rousseau A. Varin L. Plant Sci. 2004; 166: 1359-1370Crossref Scopus (25) Google Scholar), and a hydroxyjasmonic acid-specific sulfotransferase from Arabidopsis thaliana (4Gidda S.K. Miersch O. Levitin A. Schmidt J. Wasternack C. Varin L. J. Biol. Chem. 2003; 278: 17895-17900Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar). An additional sulfotransferase (RaR047, At2g03760) has been cloned from A. thaliana, and its mRNA level was found to be up-regulated by pathogens and salicylic acid; however, its physiological substrate is still unknown (5Lacomme C. Roby D. Plant Mol. Biol. 1996; 30: 995-1008Crossref PubMed Scopus (58) Google Scholar). In plants, sulfate groups occur in a number of secondary metabolites, notably the sulfoflavonoids (6Barron D. Varin L. Ibrahim R.K. Harborne J.B. Williams C.A. Phytochemistry. 1988; 27: 2375-2395Crossref Scopus (133) Google Scholar) and the glucosinolates (7Halkier B.A. Du L.C. Trends Plant Sci. 1997; 2: 425-431Abstract Full Text PDF Google Scholar). Glucosinolates (GSs) are secondary compounds found in at least 16 different plant families, 15 of which belong to the order Capparales (for review, see Ref. 8Fahey J.W. Zalcmann A.T. Talalay P. Phytochemistry. 2001; 56: 5-51Crossref PubMed Scopus (2302) Google Scholar). Within this order, much interest has been directed to the Brassicaceae family: the genus Brassica alone contains a large number of agriculturally important crops, including many vegetables (e.g. broccoli, Brussels sprouts, cauliflower, and cabbage) and one of the most important oilseed crops, oilseed rape (B. napus), the defatted seed meal of which is fed to animals. GSs in edible species or seed meal have attracted much attention because their breakdown products have been described to have anticancer but also goitrogenic and anti-nutritional activities. Although many functions such as sulfur and nitrogen storage have been assigned to GSs, defense against herbivores and pathogens seems to be their main function. Upon wounding, GSs are hydrolyzed by a thioglucosidase called myrosinase, and the released unstable aglycons rearrange to form isothiocyanates, thiocyanates, nitriles, and other compounds, the production of which depends on the GS itself, the reaction conditions, and the presence of certain cofactors (for review, see Ref. 9Rask L. Andreasson E. Ekbom B. Eriksson S. Pontoppidan B. Meijer J. Plant Mol. Biol. 2000; 42: 93-113Crossref PubMed Scopus (545) Google Scholar). These compounds have antimicrobial activity and are toxic or deterrent to non-specialist herbivores. Much progress has been made recently in identifying the gene products involved in the biosynthesis of GSs (Fig. 1): aldoxime-forming and aldoxime-oxidizing cytochrome P450 enzymes characterized by different substrate specificities have been identified (10Mikkelsen M.D. Hansen C.H. Wittstock U. Halkier B.A. J. Biol. Chem. 2000; 275: 33712-33717Abstract Full Text Full Text PDF PubMed Scopus (346) Google Scholar, 11Wittstock U. Halkier B.A. J. Biol. Chem. 2000; 275: 14659-14666Abstract Full Text Full Text PDF PubMed Scopus (210) Google Scholar, 12Barlier I. Kowalczyk M. Marchant A. Ljung K. Bhalerao R. Bennett M. Sandberg G. Bellini C. Proc. Natl. Acad. Sci. U. S. A. 2000; 97: 14819-14824Crossref PubMed Scopus (240) Google Scholar, 13Bak S. Feyereisen R. Plant Physiol. 2001; 127: 108-118Crossref PubMed Scopus (202) Google Scholar, 14Hansen C.H. Du L. Naur P. Olsen C.E. Axelsen K.B. Hick A.J. Pickett J.A. Halkier B.A. J. Biol. Chem. 2001; 276: 24790-24796Abstract Full Text Full Text PDF PubMed Scopus (138) Google Scholar, 15Reintanz B. Lehnen M. Reichelt M. Gershenzon J. Kowalczyk M. Sandberg G. Godde M. Uhl R. Palme K. Plant Cell. 2001; 13: 351-367Crossref PubMed Scopus (208) Google Scholar, 16Bak S. Tax F.E. Feldmann K.A. Galbraith D.W. Feyereisen R. Plant Cell. 2001; 13: 101-111Crossref PubMed Scopus (310) Google Scholar, 17Hansen C.H. Wittstock U. Olsen C.E. Hick A.J. Pickett J.A. Halkier B.A. J. Biol. Chem. 2001; 276: 11078-11085Abstract Full Text Full Text PDF PubMed Scopus (134) Google Scholar, 18Zhao Y. Hull A.K. Gupta N.R. Goss K.A. Alonso J. Ecker J.R. Normanly J. Chory J. Celenza J.L. Genes Dev. 2002; 16: 3100-3112Crossref PubMed Scopus (482) Google Scholar, 19Chen S. Glawischnig E. Jorgensen K. Naur P. Jorgensen B. Olsen C.E. Hansen C.H. Rasmussen H. Pickett J.A. Halkier B.A. Plant J. 2003; 33: 923-937Crossref PubMed Scopus (200) Google Scholar). C-S lyase, the enzyme catalyzing the subsequent step in GS biosynthesis, was identified recently as the SUPERROOT1 gene product (SUR1) (20Mikkelsen M.D. Naur P. Halkier B.A. Plant J. 2004; 37: 770-777Crossref PubMed Scopus (275) Google Scholar), and the gene encoding UDP-glucose:thiohydroximate glycosyltransferase was cloned from B. napus (21Marillia E.F. MacPherson J.M. Tsang E.W. Van Audenhove K. Keller W.A. GrootWassink J.W. Physiol. Plant. 2001; 113: 176-184Crossref PubMed Scopus (21) Google Scholar). The final step in the biosynthesis of the GS core structure is catalyzed by a desulfoglucosinolate:PAPS sulfotransferase (dsGS-ST), transferring the sulfate moiety from PAPS to the desulfoglucosinolate (dsGS). The enzymatic activity of dsGS-STs has been analyzed in partially purified protein fractions from Brassica juncea and cress (Lepidium sativum) (22Glendening T.M. Poulton J.E. Plant Physiol. 1990; 94: 811-818Crossref PubMed Scopus (35) Google Scholar, 23Jain J.C. GrootWassink J. Kolenovsky A.D. Underhill E.W. Phytochemistry. 1990; 29: 1425-1428Crossref Scopus (19) Google Scholar). The enzymes have similar biochemical characteristics with respect to native molecular mass, isoelectric point, pH, and temperature optima as well as inhibition by various sulfhydryl group reagents. Furthermore, the enzyme from cress was found to prefer desulfobenzylglucosinolate over desulfosinigrin. However, the corresponding proteins have not been purified to homogeneity; and until now, genes encoding dsGS-STs have not been identified. Here, we report the cloning and functional expression of a small family of such desulfoglucosinolate-specific sulfotransferases from A. thaliana. Chemicals—High quality PAPS (95% minimum) was from H. R. of acid was a from C. Wasternack of Plant an acid was purified from of as described by and PubMed Scopus Google Scholar). of was as described by and A. E.W. 2000; PubMed Scopus Google Scholar). and were from and Plant thaliana and were in a to plants were to a at and of 16 of at for at least Treatment of was a and of the of a specific The of of a were in this the of the was to of and of compounds in and was by plant until were plants were with the Plant was in liquid nitrogen and the of R. K. in Scholar) and and J. D.W. Scholar) were Plant was to A. Plant Cell. PubMed Scopus (80) Google Scholar). of were on and with a The for AtST5a mRNA to of the AtST5a cDNA and and the was the the in the was with the step was because the genes and could from of was by the as of were the as were as for at for for and for by a final at for products were by and the The were to signals by of the and of cDNAs from cDNA was by D. Roby (5Lacomme C. Roby D. Plant Mol. Biol. 1996; 30: 995-1008Crossref PubMed Scopus (58) Google Scholar). The AtST5a gene was identified by differential mRNA display as a gene in A. thaliana A. M. E.W. H. Plant Physiol. 2001; PubMed Scopus Google Scholar). The cDNA and was identified to be of the Arabidopsis number this still an The was by of cDNA Proc. Natl. Acad. Sci. U. S. A. 1988; PubMed Scopus Google Scholar) cDNA from coronatine plants as the corresponding of AtST5a was the of the Arabidopsis expression of Arabidopsis sulfotransferases as proteins in Escherichia the corresponding cDNA were from the and the cDNAs encoding AtST5b and by and cloned into the and and are upon The proteins were purified native to the The protein was with and in liquid and at for for sulfotransferase activity of the proteins were at in a of of PAPS substrate and purified protein dsGSs were from the and of A. thaliana and and purified by as described were but The reactions were by the of of to the that point, protein was also to the to and in the subsequent at the protein was by and the was to and in of was by an additional and the was analyzed by was on a a with a were as described S. Hansen C.H. Olsen C.E. Halkier B.A. 2002; PubMed Scopus Google Scholar). and of Glucosinolates in A. of GSs from plant and as dsGSs were as described by Reichelt M. Gershenzon J. Phytochemistry. 2003; PubMed Scopus Google Scholar). of were as an at the of the dsGSs were by as described S. Hansen C.H. Olsen C.E. Halkier B.A. 2002; PubMed Scopus Google Scholar). dsGSs were identified by their and by with the These were for the for the different of is by Reichelt M. Gershenzon J. Phytochemistry. 2003; PubMed Scopus Google Scholar). of a The structure of the phytotoxin coronatine is with of the octadecanoids acid and jasmonic acid E.W. T.M. U. F. PubMed Scopus (240) Google Scholar). mRNA display P. PubMed Scopus Google Scholar) was to novel coronatine-regulated genes in A. thaliana A. M. E.W. H. Plant Physiol. 2001; PubMed Scopus Google Scholar). this mRNA from coronatine or plants was genes were in and up-regulated genes were assigned as (coronatine The of the cDNA of CORI-7 was to that of the A. thaliana for a sulfotransferase family In A. thaliana, genes for sulfotransferases are known (Fig. M. J. J. 2004; PubMed Scopus Google Scholar). from seems to a encoding a that of corresponding to the of and to now, has been in the that CORI-7 a small with other sulfotransferases by the and genes (Fig. and to the by Marsolais F. Sebastia C.H. Rousseau A. Varin L. Plant Sci. 2004; 166: 1359-1370Crossref Scopus (25) Google Scholar, F. S.K. J. Varin L. 2000; Scopus Google Scholar), sulfotransferases are called AtST5a AtST5b and AtST5c small is to the flavonol sulfotransferase family known from different Flaveria species (Fig. The to this in A. thaliana are and by the and has been identified recently as and (4Gidda S.K. Miersch O. Levitin A. Schmidt J. Wasternack C. Varin L. J. Biol. Chem. 2003; 278: 17895-17900Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar). However, are very substrates for the of sulfotransferases the of is not to sulfate compounds (4Gidda S.K. Miersch O. Levitin A. Schmidt J. Wasternack C. Varin L. J. Biol. Chem. 2003; 278: 17895-17900Abstract Full Text Full Text PDF PubMed Scopus (157) Google of sulfotransferases in this to and C. Roby D. Plant Mol. Biol. 1996; 30: 995-1008Crossref PubMed Scopus (58) Google S.K. Miersch O. Levitin A. Schmidt J. Wasternack C. Varin L. J. Biol. Chem. 2003; 278: 17895-17900Abstract Full Text Full Text PDF PubMed Scopus (157) Google S.K. Miersch O. Levitin A. Schmidt J. Wasternack C. Varin L. J. Biol. Chem. 2003; 278: 17895-17900Abstract Full Text Full Text PDF PubMed Scopus (157) Google M. Marsolais F. Richard M. Nicolle L. Voigt B. Adam G. Varin L. J. Biol. Chem. 1999; 274: 20925-20930Abstract Full Text Full Text PDF PubMed Scopus (95) Google M. Marsolais F. Richard M. Nicolle L. Voigt B. Adam G. Varin L. J. Biol. Chem. 1999; 274: 20925-20930Abstract Full Text Full Text PDF PubMed Scopus (95) Google M. Marsolais F. Richard M. Nicolle L. Voigt B. Adam G. Varin L. J. Biol. Chem. 1999; 274: 20925-20930Abstract Full Text Full Text PDF PubMed Scopus (95) Google S. P. Ibrahim R.K. Plant Physiol. PubMed Scopus Google S. Varin L. P. Ibrahim R. Plant Physiol. PubMed Scopus Google L. Ibrahim R.K. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google L. Ibrahim R.K. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Y. K. J. Y. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google J.C. GrootWassink J. Kolenovsky A.D. Underhill E.W. Phytochemistry. 1990; 29: 1425-1428Crossref Scopus (19) Google T.M. Poulton J.E. Plant Physiol. 1990; 94: 811-818Crossref PubMed Scopus (35) Google Scholar in a of of from plants low CORI-7 mRNA levels (Fig. The at not the CORI-7 levels and salicylic acid not However, its mRNA levels and transiently increased upon application of coronatine jasmonic acid or the jasmonic acid acid In the ethylene acid a transient increase in the CORI-7 gene product (Fig. The increase in mRNA levels by or acid from that by jasmonic acid in that the was mRNA levels could be observed or acid the of jasmonic acid was of resulted in a and transient of CORI-7 mRNA and a in unwounded (Fig. Likewise, a transient whereas elicitor was not the levels of CORI-7 mRNA were by and signaling compounds and plant wound defense whereas pathogen defense-related signals (yeast elicitor and salicylic acid) were inactive. was used to the expression of the other genes application of coronatine and jasmonic acid methyl (Fig. were The AtST5a gene was up-regulated and by coronatine and MeJA, AtST5b was at by coronatine and was by MeJA, whereas AtST5c a by coronatine and a by of the cDNAs for the enzymes were cloned into the for expression of The proteins could be purified native by (Fig. the cDNA for (RaR047, by a sulfotransferase also described to be up-regulated by jasmonic acid (5Lacomme C. Roby D. Plant Mol. Biol. 1996; 30: 995-1008Crossref PubMed Scopus (58) Google Scholar), was cloned and in the In a range of known sulfotransferase substrates were AtST5a. However, sulfation of and and acid could not be it was that or similar compounds are substrates in vivo. GS levels increase in of the Brassicaceae family and (e.g. Phytochemistry. Scopus Google Scholar, Phytochemistry. Scopus Google Scholar, Pickett J.A. Phytochemistry. Scopus Google Scholar) we dsGSs, the immediate of GSs, as substrates. Upon of the enzymes with a of dsGSs of in the presence of of PAPS, of dsGSs was at the the of could be (Fig. and To products are GSs, the reaction product from by AtST5a was purified by and analyzed by The molecular of the product in was which is a of from the molecular of glucobrassicin and the of the used The of the product in and were in and with the from (Fig. of Arabidopsis dsGS-STs and by In are to reaction In and the substrate amounts are of of purified dsGSs was of dsGSs used in this in a of the reaction products by enzymes as the reaction product by AtST5a from was purified by and analyzed by are the of the reaction product and of the in of the are shown is the of by AtST5c and the of a GS core structure in the reaction was in the presence or of a sulfotransferase enzyme of the was or not from the but the reaction product by AtST5c the product a GS core a of the sulfation product from by AtST5c was with the enzyme (Fig. is a thioglucosidase that is specific for the of enzyme the GS core structure and not with dsGSs (Fig. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar). shown in the product from by AtST5c in the presence of myrosinase, a that this product is characterized by a GS core the three are functional this was review, similar regarding the of the enzymes as dsGS-STs were also by J. M. J. and J. at the on Arabidopsis activity is an of the steroid sulfotransferase from B. napus (Fig. is known to sulfate certain (2Rouleau M. Marsolais F. Richard M. Nicolle L. Voigt B. Adam G. Varin L. J. Biol. Chem. 1999; 274: 20925-20930Abstract Full Text Full Text PDF PubMed Scopus (95) Google it seems that is also a steroid of with a of dsGSs from the and in the presence of amounts of PAPS of PAPS of three dsGS-STs were to sulfate different of dsGSs, with different (Fig. These substrate specificities amounts of PAPS were (Fig. AtST5a clearly prefers dsGSs derived from to a whereas AtST5b and AtST5c prefer The substrate specificities were characterized by substrate the preferred substrate for enzyme was with a the the of AtST5a for The substrate specificities for AtST5b and AtST5c are similar but clearly The substrate identified for AtST5b is whereas AtST5c prefers Furthermore, additional substrates could be identified by the enzymes with from or of A. thaliana and and the dsGSs were shown to and not specificities of Arabidopsis in a the substrate specificities of the dsGS-STs are it is not that dsGSs, such as (e.g. and (e.g. and and such as were also as substrates. in certain chain reactions could the GS core structure is of on is known that of A. thaliana, B. B. and Brassica with jasmonic acid to an increase in GSs (e.g. Phytochemistry. Scopus Google Scholar, Pickett J.A. Phytochemistry. Scopus Google Scholar, and G. Plant Physiol. 1997; PubMed Scopus (25) Google Scholar, G. E. Plant Physiol. 2001; PubMed Scopus Google Scholar, M.D. Glawischnig E. Andreasson E. Halkier B.A. Plant Physiol. 2003; PubMed Scopus Google Scholar). coronatine is to be a structural analog of jasmonic acid we analyzed the of the phytotoxin on GS biosynthesis in A. thaliana The of the GSs found in plants were in with recently S. Hansen C.H. Olsen C.E. Halkier B.A. 2002; PubMed Scopus Google Scholar, Reichelt M. Gershenzon J. Phytochemistry. 2003; PubMed Scopus Google Scholar) with the of glucobrassicin the of which was in described in the not increase was not to and because plants the level of of coronatine resulted in a increase in the of and a increase in the of and an additional increase whereas the of the other GSs tryptophan-derived was or (Fig. were (Fig. M.D. Glawischnig E. Andreasson E. Halkier B.A. Plant Physiol. 2003; PubMed Scopus Google Scholar), that both compounds, at different concentrations coronatine the biosynthesis of and in a similar have described the cloning and functional of a small family of The of this was identified the mRNA differential display A. thaliana with plants with that AtST5a with AtST5b and AtST5c of the sulfotransferases in the Arabidopsis (Fig. The three genes are on and AtST5a and AtST5b are in However, to AtST5b is to AtST5c with AtST5a. with known sulfotransferases from other species that the family is to the family of flavonol sulfotransferases (Fig. F. Sebastia C.H. Rousseau A. Varin L. Plant Sci. 2004; 166: 1359-1370Crossref Scopus (25) Google Scholar). from A. thaliana are not known (6Barron D. Varin L. Ibrahim R.K. Harborne J.B. Williams C.A. Phytochemistry. 1988; 27: 2375-2395Crossref Scopus (133) Google Scholar). are AtST5b and AtST5c to other with similar substrate enzymes prefer long chain dsGSs derived from whereas AtST5a clearly prefers dsGSs derived from the and is in high concentrations in A. thaliana the whereas phenylalanine-derived GSs are in many of A. thaliana U. Halkier B.A. J. Biol. Chem. 2000; 275: 14659-14666Abstract Full Text Full Text PDF PubMed Scopus (210) Google Scholar, S. Hansen C.H. Olsen C.E. Halkier B.A. 2002; PubMed Scopus Google Scholar, Reichelt M. Gershenzon J. Phytochemistry. 2003; PubMed Scopus Google Scholar, M. B. E. J. Gershenzon J. Phytochemistry. 2002; PubMed Scopus (202) Google Scholar). the of AtST5a in is biosynthesis of However, it be that three enzymes are of a range of different and not substrate specificities (Fig. and biosynthesis of specific GSs seems to be at the the preferred substrates for AtST5b and and are in small amounts in the of A. thaliana whereas the main GS in this is is derived from the of which is a substrate for AtST5b and plants in which genes are regarding functional of plants resulted in a specific increase in tryptophan-derived and (Fig. whereas at the the genes for and AtST5c were up-regulated (Fig. to a of GS is known that the aldoxime-forming enzymes and which are involved in the biosynthesis of tryptophan-derived GSs and and GSs and are up-regulated by with M.D. Glawischnig E. Andreasson E. Halkier B.A. Plant Physiol. 2003; PubMed Scopus Google Scholar). The that GSs are still by and coronatine that their biosynthesis is very at the level of chain not chain the GS it could be by and step in GS biosynthesis is catalyzed by a C-S one additional gene identified as up-regulated by a C-S lyase, as A. M. E.W. H. Plant Physiol. 2001; PubMed Scopus Google Scholar, M. K. J. Biol. Chem. 2003; 278: Full Text Full Text PDF PubMed Scopus (35) Google Scholar). Although the C-S involved in GS biosynthesis was identified as the SUPERROOT1 gene which is not to (20Mikkelsen M.D. Naur P. Halkier B.A. Plant J. 2004; 37: 770-777Crossref PubMed Scopus (275) Google Scholar), the that be involved in biosynthesis by coronatine or be D. Roby for the cDNA C. Wasternack for the of acid; and D. L. and S. for M. and J. are to M. Reichelt and J. Gershenzon of for the to glucosinolate
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