Planta DOI 10.1007/s00425-015-2254-z

ORIGINAL ARTICLE

A small, differentially regulated family of farnesyl diphosphate synthases in maize (Zea mays) provides farnesyl diphosphate for the biosynthesis of herbivore-induced sesquiterpenes Annett Richter • Irmgard Seidl-Adams • Tobias G. Ko¨llner • Claudia Schaff • James H. Tumlinson • Jo¨rg Degenhardt

Received: 2 April 2014 / Accepted: 26 January 2015  Springer-Verlag Berlin Heidelberg 2015

Abstract Main conclusion Of the three functional FPPS identified in maize, fpps3 is induced by herbivory to produce FDP important for the formation of the volatile sesquiterpenes of plant defense. Sesquiterpenes are not only crucial for the growth and development of a plant but also for its interaction with the environment. The biosynthesis of sesquiterpenes proceeds over farnesyl diphosphate (FDP), which is either used as a substrate for protein prenylation, converted to squalene, or to volatile sesquiterpenes. To elucidate the regulation of sesquiterpene biosynthesis in maize, we identified and characterized the farnesyl diphosphate synthase (FPPS) gene family which consists of three genes. Synteny analysis indicates that fpps2 and fpps3 originate from a genome duplication in an ancient tetraploid ancestor. The three FPPSs encode active enzymes that produce predominantly FDP from the

isopentenyl diphosphate and dimethylallyl diphosphate substrates. Only fpps1 and fpps3 are induced by elicitor treatment, but induced fpps1 levels are much lower and only increased to the amounts of fpps3 levels in intact leaves. Elicitor-induced fpps3 levels in leaves increase to more than 15-fold of background levels. In undamaged roots, transcript levels of fpps1 are higher than those of fpps3, but only fpps3 transcripts are induced in response to herbivory by Diabrotica virgifera virgifera. A kinetic of transcript abundance in response to herbivory in leaves provided further evidence that the regulation of fpps3 corresponds to that of tps23, a terpene synthase, that converts FDP to the volatile (E)-ß-caryophyllene. Our study indicates that the differential expression of fpps1 and fpps3 provides maize with FDP for both primary metabolism and terpene-based defenses. The expression of fpps3 seems to coincide with the herbivore-induced emission of volatile sesquiterpenes that were demonstrated to be important defense signals. Keywords Farnesyl diphosphate  Plant defense  Sesquiterpenes  Terpene biosynthesis  Volatile terpenes

Electronic supplementary material The online version of this article (doi:10.1007/s00425-015-2254-z) contains supplementary material, which is available to authorized users. A. Richter  C. Schaff  J. Degenhardt (&) Institute of Pharmacy, Martin Luther University Halle, Hoher Weg 8, 06120 Halle, Germany e-mail: [email protected] I. Seidl-Adams  J. H. Tumlinson Chemical Ecology, The Pennsylvania State University, University Park, State College, PA 16802, USA T. G. Ko¨llner Max Planck Institute for Chemical Ecology, Hans-Kno¨ll-Strasse 8, 07745 Jena, Germany

Abbreviations DMADP Dimethylallyl diphosphate FARM First aspartate-rich motif FDP Farnesyl diphosphate FPPS Farnesyl diphosphate synthase GDP Geranyl diphosphate GGDP Geranylgeranyl diphosphate GGPPS Geranylgeranyl diphosphate synthase IDP Isopentenyl diphoshphate LG Linolenoyl-L-glutamine SARM Second aspartate-rich motif TPS Terpene synthase

123

Planta

Introduction Terpenes are a large and structurally diverse group of compounds with many crucial roles in plant growth and development. Hormones like gibberellic acid, abscisic acid, and steroid derivates are of terpene origin, as well as the phytol chain of chlorophyll and plastoquinone, or the farnesylation of proteins during intracellular signal transduction (Correll and Edwards 1994). Most terpenes, however, are crucial for the interaction of plants with their environment (Harborne 1991). They act as defense against herbivores and pathogens, or as volatile signals. In maize, herbivore damage results in the emission of volatile monoterpenes and sesquiterpenes that attract natural enemies of attacking herbivores. In response to damage by lepidopteran larvae, maize leaves emit a complex volatile blend dominated by the sesquiterpenes (E)-ß-farnesene, (E)-a-bergamotene, and (E)-b-caryophyllene which attract parasitic wasps (Turlings et al. 1990; Schnee et al. 2006; Ko¨llner et al. 2008). Maize roots attacked by larvae of the beetle Diabrotica virgifera virgifera only release a single sesquiterpene, (E)-ß-caryophyllene, which attracts entomopathogenic nematodes (Rasmann et al. 2005; Ko¨llner et al. 2008). The high diversity of plant terpenes is contrasted by their relatively short biosynthetic pathways. Sesquiterpenes are formed from the activated isoprene units isopentenyl diphosphate (IDP) and its isomer dimethylallyl diphosphate (DMADP), which are provided by the mevalonate pathway in the cytosol. One DMADP unit and two IDP units are fused by a farnesyl diphosphate synthase (FPPS) to farnesyl diphosphate (FDP), the central intermediate of sesquiterpene biosynthesis. FDP is also the substrate for the farnesylation of regulatory proteins by farnesyltransferases (Galichet and Gruissem 2003). These modifications play a role in hormone signal transduction, plant development (Cutler et al. 1996; Yalovsky et al. 2000), and basal defense responses (Goritschnig et al. 2008). Two molecules of FDP are condensed into squalene (Popjak et al. 1961), a triterpene intermediate in the biosynthesis pathway of sterols and other triterpenoids. Volatile sesquiterpenes are formed by terpene synthases that convert FDP to a large structural diversity of hydrocarbons. In maize, the terpene synthases TPS10 and TPS23 form the major sesquiterpenes of herbivore-damaged leaves and roots, respectively (Schnee et al. 2006; Ko¨llner et al. 2008). Farnesyl diphosphate synthases (FPPS, EC 2.5.1.10) are central to each of these biosynthetic pathways and were identified in many organisms including humans (Wilkin et al. 1990), E. coli (Fujisaki et al. 1990), S. cerevisiae (Anderson et al. 1989), rat (Jiang et al. 2001), birds (Reed and Rilling 1975), and many plant species. They share a

123

high sequence similarity and at least five conserved domains (Koyama et al. 1993), including the two aspartaterich motifs FARM (DDXX(XX)D) in region II and SARM (DDXXD) in region VI. These motifs are crucial for substrate binding (Ashby and Edwards 1990; Koyama et al. 1993). A structure derived from FPPS of avian liver identified 10 a-helices, which form a core by antiparallel orientations (Tarshis et al. 1994). The helices containing the DDXXD motives are located in the catalytic center. FPPS is encoded by small gene families of two members in A. thaliana (Cunillera et al. 1996), Artemisia tridentata (Hemmerlin et al. 2003), rice (Sanmiya et al. 1997, 1999), and in tomato (Gaffe et al. 2000). In maize, only one gene encoding FPPS was identified (Li and Larkins 1996), but further research identified a long and a shorter transcript of this gene. The longer transcript coded for an enzyme with FPPS activity in vitro (Cervantes-Cervantes et al. 2006). To study the regulation of sesquiterpene biosynthesis in maize, we identified a family of three fpps genes. Two of the genes may be the result of a genome duplication event which gave rise to an ancient tetraploid ancestor. All genes encode active FPPSs, but fpps1 and fpps3 display a complex, organ-specific expression pattern where only one copy is induced in response to herbivory and corresponds to the expression pattern of sesquiterpene synthase TPS23. Materials and methods Plant material and treatment Maize (Zea mays L.) seeds of the inbred line B73 (KWS, Einbeck, Germany) and the hybrid line Delprim (Delley, Switzerland) were grown for 2 weeks in climate-controlled chambers under a 16/8 h and 22/18 C day/night cycle (1 mmol m-2 s-1 photosynthetically active radiation). The third leaf of two-week-old seedlings was used to conduct the induction experiments. For the elicitor induction experiments, the third leaf was cut off and incubated in 2 mL tap water with 2.3 lM indanone-derivate for 24 h (Schu¨ler et al., 2001). Treatment was started in the afternoon. For wound induction experiments, the leaf was treated similarly but without the indanone-derivate. The time course experiments started at 9:00 a.m. with a placement of a 2-week-old seedling in 250 lL of either elicitor solution (25 mM phosphate buffer pH 7.8 with 4 lL of linolenoyl-1 L-glutamine at 100 ng lL in 100 mM phosphate buffer pH 7.8) or phosphate buffer only. After 30 min, the leaf was transferred to ddH2O. Starting at 10:30 a.m., leaves of both treatments were collected every 90 min and frozen in liquid N2. For the herbivore treatment of roots, secondinstar larvae of Diabrotica virgifera virgifera were provided by CABI BioSience (Dele´mont, Switzerland). Each

Planta

maize plant was subjected to four second-instar or thirdinstar larvae for 48 h (Ko¨llner et al. 2008). Transcript measurement by quantitative Real Time PCR For quantitative Real Time PCR (qRT-PCR), total RNA was isolated from B73 and Delprim with the RNeasy Plant Mini Kit (Qiagen, Hilden, Germany), the GeneJETTM, or the RNA Purification Kit (Fermentas, St. Leon-Rot, Germany) according to manufacturer’s instructions. Subsequent treatment of the isolated RNA with RQ1 RNAse-free DNAse (Promega, Mannheim, Germany) removed residual genomic DNA. The First Strand cDNA Kit (Fermentas) was used to synthesize cDNA from 1 lg purified RNA. For qRT-PCR, 10 lL Maxima SYBR Green/ROX qPCR Master Mix (Fermentas), 0.5 lL gene-specific forward Primer, 0.5 lL reverse Primer, 5 lL template (1:5 diluted), and 4 lL PCR-grade water were mixed. PCR was performed on a CFX96 Real Time System (BioRAD) under following conditions: 10 min at 95 C, 40 cycles of 30 s at 95 C, 30 s at 62 C, and 40 s at 72 C. To get a melting curve, additional cycles followed at 95 C for 10 s and 56–95 C for 30 s each. Maize adenine phosphate transferase 1 (APT1) was used as reference gene. For each analyzed gene, a cDNA pool from all plants was diluted from 39 to 1/279 to generate a standard curve. With the program BioRad CFX Manager, the DCT (D-threshold cycle) for each gene was calculated relative to the reference gene. The CT values were derived from an average of at least three biological samples with three technical replicates each. Primer sequences are listed in Supplementary Table S1. Statistical analysis Significant differences of expression levels between unwounded, mechanically wounded, and elicitor treated leaves were analyzed by one-way ANOVA (SigmaPlot; Systat Software Inc. 2008). All analyses were performed with normal distributed errors/values and equal variance. If the values were not normally distributed, simple transformations (log 10, square root, reciprocal, exponential) were performed prior to ANOVA calculations. To test pairwise significance of differences between all samples, a Post-Hoc test were conducted with the Holm-Sidak method. Isolation of FPPS cDNAs To isolate the open reading frames of fpps2 and fpps3 from cDNA without getting chimeric versions of both genes, specific primers in the UTR region were constructed based on the sequence data base www.maizesequence.org. For the isolation of the 50 and 30 flanking regions, 50 and 30

RACE libraries from line B73 were constructed from the inbred line with the SMARTerTM RACE cDNA Amplification Kit (Clontech, Mountain View, CA, USA). To get the complete amplicon of both FPPS genes, the libraries were screened with the Advantage cDNA PCR Kit (Clontech) and the primer sets GRMZM2G147721 and GRMZM2G098569 (Supplementary Table S1) according to the manufacturer’s instruction. All PCR fragments were cloned into the pCR4-TOPO vector for sequencing. Phylogenetical analysis For dendrogram analysis, we used the MUSCLE Codon algorithm (gap open -2.9, gap extend 0, hydrophobicity multiplier 1.2, clustering method, upgmb) of MEGA5 (Tamura et al. 2011) to compute a codon alignment. Based on this alignment, the tree was reconstructed with MEGA5 using the Maximum Likelihood method. Initial tree(s) for the heuristic search were obtained automatically as follows: when the number of common sites was either below 100 or less than one-fourth of the total number of sites, the maximum parsimony method was used; otherwise, BIONJ method with MCL distance matrix was used. A discrete Gamma distribution was used to model evolutionary rate differences among sites [5 categories (?G, parameter = 1.2345)]. The rate variation model allowed for some sites to be evolutionarily invariable [(?I), 0.4169 % sites]. Codon positions included were 1st ? 2nd ? 3rd ? Noncoding. A bootstrap resampling analysis with 1,000 replicates was performed to evaluate the tree topology. Evolutionary analyses were conducted in MEGA5 (Tamura et al. 2011). Accession numbers of FPPSs and GGPPSs are listed in Supplementary Table S2. Heterologous expression and assay for prenyl transferase activity The open reading frames of the putative farnesyl diphosphate synthases fpps2 and fpps3 were cloned into the bacterial expression vector pASK-IBA37plus and pASKIBA33plus (IBAGmbH, Go¨ttingen, Germany). To amplify these genes, special primers with a BsaI restriction site ´ Signer’’ (IBA GmbH) were created with the ‘‘Primer D (Supplementary Table S1). The cloning of the FPPS fragments into the vector yielded a fusion protein with a His-tag (6xHis) at the N-terminus (pASK-IBA37plus) or C-terminus (pASKIBA33plus) of each protein. The vector pASK-IBA37plus without insert was expressed in the empty vector control. A starter culture of 3 mL LB medium with 100 lg mL-1 ampicillin was grown overnight at 37 C and used to inoculate 100 mL of LB medium with 100 lg mL-1 ampicillin. FPPS expression was induced by addition of anhydrotetracycline (end concentration: 200 lg/L) after the

123

Planta

bacteria were grown to an OD of 0.6. After induction, the culture was shaken for 20 h at 18 C and centrifuged (5 min, 5,000g, 4 C). The bacterial pellet was resuspended in 3 mL cold extraction buffer (50 mM MOPSO, 10 % glycerol, 5 mM magnesium-chloride, 5 mM DTT, 5 mM sodium ascorbate, 0.5 mM PMSF, pH 7.0). Cells were disrupted with an ultrasonicator (3 9 30 s, Bandelin UW2070, Berlin, Germany) and the cell debris removed by a centrifugation step at 14.000g. Protein concentrations in the supernatant were determined with Protein Assay Dye (Bradford) Reagent (5x; Bio-Rad, Munich, Germany) and adjusted to similar amounts when necessary. The bovine serum (Bio-Rad) was used as standard protein. The supernatants were purified by affinity chromatography with Ninitrilotriacetic acid agarose columns (Qiagen) as described in the manufacturer’s manual. For the elution step, an imidazole concentration of 250 mM was used. Protein purity was verified by SDS/PAGE gel electrophoresis with unstained protein markers (Thermo Scientific 26614; Fermentas SM0669) and Coomassie staining (Carl Roth). The molecular weight of 40.7 kDa for FPPS2 and 40.8 kDA for FPPS3 was calculated with ExPASy (web.expasy.org). Before prenyltransferase assays were performed, the purified proteins were desalted into assay buffer [25 mM MOPSO, 10 % glycerol (v/v), 10 mM MgCl2, 5 mM DTT, 5 mM sodium ascorbate, pH 7.5] with a PD-10 Desalting Column (Amersham Biosciences). Enzyme activity assays were performed in a 2 mL glass reaction vial with 500 lL extracted enzyme, 60 lM IDP, and 60 lM DMADP (Echelon Research Laboratories, Salt Lake City, UT, USA) incubated at 35 C in a water bath for 45 min as described in the results section. For the expression of FPPS2 and FPPS3 without His-tags and the corresponding empty vector controls, the 6xHis-tag of pASK-IBA37plus was removed. After heterologous expression, no affinity chromatography with Ni-nitrilotriacetic agarose columns was performed. FPPS product determination by liquid chromatography–tandem MS The isoprenoids were analyzed on an Agilent 1260 HPLC system (Agilent Technologies) coupled to an API 5000 triple-quadrupole mass spectrometer (AB Sciex Instruments). The method was modified to Nagel et al. (2012) and a ZORBAX Extended C-18 column (1.8 lm, 4.6 9 50 mm, Agilent Technologies) was used. For the mobile phase, the solvents A (5 mM ammonium bicarbonate in water) and B (acetonitrile) were set with a flow rate at 1.2 mL/min and a column temperature at 20 C. The separation used a gradient starting at 5 % of solvent B, increasing to 70 % B in 5 min and 100 % B after an additional minute with 30 s hold. Before the next injection, solvent B was reduced to 5 % in 30 s (1 min hold). The injection volume for standards and

123

samples was 1 lL. Settings for the mass spectrometer, negative electrospray ionization mode (EI), ion source gas 1 (GS1) at 60 psi, ion source gas 2 (GS2) at 70 psi, temperature of 700 C, and curtain gas (CUR), was set at 30 psi, collision gas at 7 psi, with all gases being nitrogen, and ion spray voltage at -4,200 V. Multiple reaction monitoring (MRM) was used to monitor analyte parent ion-to-product ion formation: m/z 312.9/79 for GDP, m/z 380.9/78.8 for FDP, m/ z 449/78.9 for GGDP, m/z 244.8/79.1 for IDP, and DMADP. The dataset was analyzed with Analyst Software 1.6 Build 3773 (AB Sciex), and authentic standards were used as described by Nagel et al. (2012). GC–MS analysis Volatile terpenes produced during the enzyme assay with both the recombinant FPPS3 and TPS23 were collected on a polydimethylsiloxane-coated SPME fiber (Supelco, Bellefonte, PA, USA) which was exposed to the head space of the assay mixture. The assay was conducted in a 2-mL glass reaction vial with 250 lL of each extracted enzyme, 60 lM IDP, and 60 lM DMADP (Echelon Research Laboratories) incubated at 35 C in a water bath for 45 min. The volatile terpenes collected on the SPME fiber were analyzed by gas chromatography (GC-2010, Shimadzu, Duisburg, Germany) coupled to a mass spectrometer (GCMS-QP 2010 Plus, Shimadzu). The injection temperature was 220 C, and hydrogen was used as a carrier gas with a flow rate of 1 mL/ min. To separate the volatiles, a EC5-MS column (30 m length, 0.25 mm inner diameter and 0.25 lm film) (Grace, Deerfield, IL, USA) was used under the following conditions: 80 C for 3 min, first ramp 7 C/min to 200 C, second ramp 100 C/min to 300 C, and final 2 min hold. Products were identified by comparison of retention times and mass spectra with authentic reference compounds. Shimadzu software ‘‘GCMS Postrun Analysis’’ was used with the mass spectra libraries ‘‘Wiley8’’ (Hewlett & Packard) and ‘‘Adams’’ (Adams 2007). To determine the products of FPPS2 and FPPS3 without His-tag, 30 lL 37 % HCL was added after incubation with the prenyl diphosphate substrates. After 15 min, the dephosphorylated products were collected from the headspace with a polydimethylsiloxane-coated SPME fiber (Supelco) and analyzed as above. Authentic standards were used as described by Ko¨llner et al. (2008).

Results Maize contains three putative farnesyl diphosphate synthases To study the importance of FPPS in herbivore-induced terpene biosynthesis, we isolated two genomic sequences

Planta

activity because no signal peptides for the translocation in organelles were identified.

with similarity to the previously described ZmFPPS1 (GRMZM2G168681_P01) in induced leaf material of the maize inbred line B73 (Li and Larkins 1996; CervantesCervantes et al. 2006). Two additional genes encoding open reading frames with 85–86 % amino acid identity to fpps1 were found and designated fpps2 and fpps3, respectively (Fig. 1). While fpps1 is situated on chromosome 8 at 63 Mb, the two putative prenyl transferases are localized on chromosome 3 at 205 Mb (FPPS3, GRMZM2 G098569_T01) and on chromosome 8 at 153 Mb (FPPS2, GRMZM2G147721_T01). They share 94 % identity at the nucleotide level and are encoded by 11 exons with identical intron/exon boundaries while fpps1 is encoded by 12 exons. The two putative prenyl transferases contain the characteristic aspartate-rich motifs FARM (DD(XX)1–2D…RRG) and SARM (FQ…DDXXD) which are essential for catalytic function (Koyama 1999; Hemmi et al. 2003; Cervantes-Cervantes et al. 2006). The chain-length-determining (CLD) region classifies them as type I FPPS with two aromatic amino acids in the fourth and fifth positions upstream of the first DDXXD motif (Hemmi et al. 2003). FPPS1 displays a phenylalanine residue in these positions. Both aromatic residues together with FARM correlate with synthesis of the short chain prenyl diphosphate FDP (Ohnuma et al. 1996). Sequence analysis of the N-terminus suggested that the genes encode enzymes with cytoplasmic

The open reading frames encoding the putative farnesyl diphosphate synthases FPPS2 and FPPS3 were each cloned into expression vectors with a His-tag either at the N-terminus or at the C-terminus. After expression in E. coli, the enzymes were purified by affinity chromatography (Supplementary Fig. S1) and analyzed for their prenyl synthase activities in the presence of the substrates IDP and DMADP. To detect the prenyl diphosphate products, the enzyme assays were analyzed by LC–MS (Fig. 2). Similar to the empty vector control, FPPS2 and FPPS3 expressions with the C-terminal His-tag did not show any activity (Fig. 2b; data not shown). With N-terminal His-tag, both FPPS2 and FPPS3 converted DMADP and IDP and produced FDP at 5.7 ng/lL (FPPS2) and 7.6 ng/lL (FPPS3) (Fig. 2c, d). Alternatively, the heterologously expressed (E)-b-caryophyllene synthase TPS23 (Ko¨llner et al. 2008) was added to the activity assay. TPS23 converts the FDP product into (E)-b-caryophyllene which can be detected by GC–MS (Supplementary Fig. S2c). Both enzymes produced FDP also in the absence of a His-tag (Supplementary Fig. S2a,b). No GDP synthase activity was detected for

Fig. 1 Alignment of the amino acid sequences of FPPS1, FPPS2, and FPPS3. Amino acid differences between the FPPSs are highlighted in gray. Bold lines indicate the conserved aspartate-rich motifs FARM (DD(XX)1-2D…RRG) and SARM (DDXXD) which are essential for

the catalytic function (Koyama 1999; Hemmi et al. 2003; CervantesCervantes et al. 2006). Two aromatic amino acids of the chain-lengthdetermining region (CLD) in the 4th and 5th N-terminal positions of the FARM motif are marked with dark gray

FPPS3 and FPPS2 encode active farnesyl diphosphate synthases

123

Planta

1.5e4 4.0

3.4

4.6 4.5e3

b

3.0e3

0.5e5

1.5e3 2.8

3.4

4.0

4.6

c

3.4 4.5e3

3.8

4.2

4.6

5.0

3.8

4.2

4.6

5.0

4.6

5.0

f

g

FDP 3.0e3

1.0e6

1.5e3

0.5e5

GGDP Intensity (CPS)

FPPS3

2.2 1.5e6

2.8

d

3.4

4.0

3.4

4.6 4.5e3

FDP

3.8

4.2

h

In roots, both FPPS1 and FPPS3 contribute to FPPS activity

3.0e3

1.0e6

1.5e3

0.5e5 2.2

2.8

3.4

4.0

4.6

Retention time (min)

GGDP 3.4

3.8

4.2

4.6

5.0

Retention time (min)

Fig. 2 Activities of FPPS2 and FPPS3 after heterologous expression with a N-terminal His-tag. Purified recombinant protein of FPPS2 (c, g), FPPS3 (d, h), or empty vector control (b, f), was incubated with the substrates IDP and DMADP. Products were identified by MRM with m/z 380.9/78.8 for FDP (a–d) and m/z 449/78.9 for GGDP (e–h). The dataset was analyzed by Analyst Software 1.6

either FPPS2 or FPPS3 (data not shown). FPPS3 with a His-tag at the N-terminus displayed a low level of geranyl geranyl diphosphate synthase activity (0.144 ng/lL; Fig. 2h), whereas FPPS2 produces barely detectable amounts (0.006 ng/lL, Fig. 2g). These results demonstrate that FPPS2 and FPPS3 are similar to FPPS1 in that they have both a FPPS activity and a rather minor GGPPS activity (Cervantes-Cervantes et al. 2006). FPPS3 is strongly induced in leaves after elicitor treatment To study the regulation of the prenyl transferases in response to herbivore attack, we determined transcript levels after treatment with Spodoptera littoralis (Supplementary Fig. S3). In further experiments, we used a more reproducible technique consisting of mechanical wounding (scratching) combined with an indanone-derivate elicitor treatment (Schu¨ler et al. 2001). To determine the influence of the elicitor treatment by itself, we also compared it to mechanical wounding only. The leaves were treated once at 2 p.m. and harvested at 2 p.m. the following afternoon

123

Roots respond to attack by Diabrotica virgifera virgifera with the formation of sesquiterpene (E)-ß-caryophyllene. To determine whether this terpene signal also correlates with the induction of FPPS activity, the transcript levels of the three genes were compared in undamaged, mechanically wounded, and D. virgifera-infested roots. Transcripts of fpps1 were formed at similar levels in undamaged roots, mechanically damaged roots, and D. virgifera-infested

Control 2

Wound

Elicitor

0.2

0.2

*** ***

1.5

1

0.1

0

0.1

FPPS1

0.5

0

Del_I

3.4

1.0e6

2.2 Intensity (CPS)

2.8

Del_mech

0.5e5

1.5e6

GGDP

3.0e4

1.0e6

1.5e6

e

Del_K

FDP

2.2

FPPS2

4.5e4

1.5e6

for quantitative reverse transcriptase PCR analysis (Fig. 3). The transcript levels of fpps1 were very low in undamaged control plants and mechanically damaged plants. Elicitor treatment resulted in a small but significant induction (P = 0.001; t = 15.5). The transcript levels of the fpps2 were also very low but showed no induction after elicitor treatment. The transcript level of fpps3 in undamaged plants was already higher than those of the other FDP synthases (P B 0.001; t = 4.6), but mechanical damage increased the levels significantly and elicitor treatment raised the levels approximately 15-fold (P B 0.001; t = 6.9). To test whether this regulatory pattern is unique to the maize variety Delprim, we repeated the experiment with the inbred line B73. At slightly higher overall levels, the induction patterns of the three genes were very similar. In response to the indanone-derivate elicitor, a 70-fold induction of fpps3 was observed (Supplementary Fig. S4).

Del_K Del_m… Del_I

Intensity (CPS) Intensity (CPS)

a

GGDP (MRM 449/78.9)

Transcript level rel. toAPT1

authentic standard empty vector

FDP (MRM 380.9/78.8)

FPPS2

***

0 FPPS1

FPPS2

FPPS3

Fig. 3 Transcript abundance of fpps1, fpps2, and fpps3 genes in leaves. Transcript levels were determined in leaves of 14-day-old plants of the variety Delprim that were undamaged, wounded mechanically, and wounded and treated with the elicitor indanonederivate for 24 h. The expression was calculated relative to the reference gene APT1. Significance was calculated by one-way ANOVA of three technical replicates of four biological samples. Significant differences among treatments for each gene were indicated for P B 0.001 (***)

Planta

roots, while transcripts of the fpps2 were hardly detectable (Fig. 4a). In D. virgifera-infested roots, the transcript levels of fpps3 were similar to those of fpps1, but fpps3 levels were much lower in undamaged roots (P B 0.001; t = 9.297) and mechanically damaged roots (P = 0.007; t = 3.249). In the same tissue samples, transcript levels of tps23 were hardly detectable in control roots and undamaged roots but strongly induced after D. virgifera attack (P = 0.017; t = 4.08) (Fig. 4b). The regulation pattern of tps23 was similar to that of fpps3 but distinctively different to that of fpps1.

Adams et al. (2014). The induction kinetics of fpps3 and tps23 were very similar (Fig. 5) and more pronounced in response to the elicitor. After induction at 9:00 a.m., an increase of fpps3 and tps23 transcripts was detectable by 10:30 a.m. and peaked approximately at noon. While the transcript levels of fpps3 declined sharply after by 1:30 p.m., at 4.5 h after induction, the levels of tps23 stayed relatively stable and decreased after 3:00 p.m., at 6 h after induction. On average, the transcript levels after elicitor treatment had a similar kinetics but were 1.5-fold higher.

The expression pattern of FPPS3 correlates with that of the terpene synthase TPS23

Discussion

The terpene synthase TPS23 produces an important defense signal after herbivore damage on both aboveground and belowground tissues (Ko¨llner et al. 2008). TPS23 is induced in leaves after elicitor treatment in a pattern very similar to FPPS3 (Supplementary Fig. 5). Since the herbivore-induced FPPS3 most likely supplies the terpene synthase TPS23 with its substrate, we tested whether the induction kinetics of both enzymes correlate. We conducted a time course experiment with 8 time points within 10 h after leaf herbivory. Herbivory was mimicked by leaf damage and treatment with buffer or the elicitor linolenoylL-glutamine in an attempt to make the kinetics comparable to those of the genes fpps3 and tps10 presented by Seidl-

FDP is produced by a small family of farnesyl diphosphate synthases in maize. The availability of FDP for sesquiterpene biosynthesis is controlled by a family of three prenyl transferases. Two of the enzymes, FPPS2 and FPPS3, share 94 % amino acid identity, while FPPS1 is more distant with 79.6–80 %. In their genomic structure, fpps1 has an additional intron that is not present in fpps2 or fpps3. The location of fpps3 on chromosome 3 is inverted syntenic to a part of chromosome 8 where fpps2 is situated. This synteny between chromosome 3 and 8 was identified in studies that also described synteny between rice chromosome 1 and

1

a

Buffer

Elicitor

0.6

a ***

4 3 2 1 0

Control Wounded Diabrotica virgifera

Transcript level rel. to APT1

FPPS1

FPPS2 20

FPPS3

b ***

15 10

Transcript level rel. toAPT1

Transcript level rel. to APT1

0.8

5

0.4 0.2 0 9:30 10:30 noon 1:30 3:00 4:30 6:00 7:30 AM AM PM PM PM PM PM

1.6

b

1.2 0.8 0.4

5

0

0

TPS23

Fig. 4 Transcript abundance of fpps1, fpps2, fpps3, and tps23 genes in roots. Transcript levels of the prenyl transferase genes (a) and the (E)-b-caryophyllene synthase tps23 (b) were determined in roots of 14 day-old plants of the variety Delprim that were undamaged, wounded mechanically 24 h before analysis, and incubated with larvae of D. virgifera for 48 h. The expression was calculated relative to the reference gene APT1. Significance was calculated by one-way ANOVA of three technical replicates of four biological samples. Significant differences among treatments for each gene were indicated for P B 0.001 (***)

9:30 10:30 noon 1:30 3:00 4:30 6:00 7:30 AM AM PM PM PM PM PM

Fig. 5 Kinetics of transcript abundance of fpps3 and tps23 in response to mechanical wounding and elicitor treatment. Transcript levels of fpps3 (a) and tps23 (b) were determined in leaves of 14-dayold plants of the variety Delprim, which were wounded mechanically and treated with buffer (solid bars) or wounded and treated with the elicitor linolenoyl-L-glutamine (hatched bars) at 9:00 a.m. The expressions of fpps3 and tps23 were calculated relative to the reference gene APT1. Averages and standard errors were calculated by one-way ANOVA of three technical replicates of three biological samples

123

Planta

maize chromosomes 3, 6, and 8 (Helentjaris et al. 1988; Gale and Devos 1998; Wilson et al. 1999; Gaut 2001; Ahn et al. 1993; Salse et al. 2004; Odland et al. 2006; Wei et al. 2007). Therefore, the generation of fpps2 and fpps3 might date back to the formation of an ancient tetraploid ancestor in maize about 50–70 mya ago. All FPPS produce some GGDP, but at 1,000-fold (FPPS2) or 50-fold (FPPS3) lower levels than FDP. This clearly characterizes the enzymes as FPPS. A dendrogram including genes with similarity to FPPS and GGPPS from maize, rice, and Arabidopsis indicates a monophyletic clade for both enzymes. These clades have diverged into small families in each of the species (Fig. 6). All putative prenyl transferases included in this analysis contain the characteristic FARM [DD(XX)1-2D] and SARM (DDXXD) motifs, but only putative FPPS contain two aromatic amino acids in the fourth and fifth positions before FARM, which determine the product specificity of the FPPS. A family of two putative FPPS was identified in rice (Sanmiya et al. 1996, 1999). While the enzymatic activities of the encoded enzymes were not determined, their differential targeting to either the chloroplasts or the cytosol suggest specific functions (Sanmiya et al. 1999). Although the rice protein localized in the chloroplast is closely related to the genes of the maize FPPS family, no signal peptides were found in the maize proteins. For Maize fpps1, a short and long cDNA were identified (CervantesCervantes et al. 2006). Comparisons to the open reading frames of FPPS of other species suggests that both cDNAs encode enzymes lacking a signal peptide and the short clone is missing an additional 10 amino acids at the N-terminus. Indeed, when the short cDNA of fpps1 was expressed in vitro, it was only marginally active, most likely because the N-terminal end contains functionally

fpps2 (maize) fpps3 (maize) putative Fpps1 (rice) fpps1 (maize) 93 98 putative Fpps2 (rice) 97 Fpps2 (Arabidopsis) 100 Fpps1 (Arabidopsis) putative Fpps3 (rice) Ggpps2 (Arabidopsis) Ggpps4 (Arabidopsis) putative ggpps1 (maize) putative ggpps2 (maize) putative ggpps3 (maize) putative ggpps4 (maize) 98 68 97

79 93

73 47

tps23

47

0,5

Fig. 6 Dendrogram analysis of prenyltransferase genes from maize and other plant species. The tree was inferred from a MUSCLE codon alignment using the Maximum Likelihood method. The tree with the highest log likelihood (-12,878,0323) is shown. The percentage of trees in which the associated taxa clustered together is shown next to the branches (bootstrap trials 1,000). The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. For accession numbers see Supplementary Table S2

123

important domains (Cervantes-Cervantes et al. 2006). Direct proof of the localization of the maize FPPS family members could be obtained with transgenic maize overexpressing the enzymes coupled to a fluorescent dye. In Arabidopsis, the FPPS gene family consists of only two genes. The enzyme encoded by At4g17190 is localized in the cytosol and may be involved in phytosterol biosynthesis, while one of the two products of At5g47770 is localized in mitochondria and may contribute to ubiquinone biosynthesis (Delourme et al. 1994; Cunillera et al. 1996; Lange and Ghassemian 2003). In contrast, the GGPPS of Arabidopsis forms a large family with twelve members and including one pseudogene (Beck et al. 2013). Associated with diterpene biosynthesis, these enzymes are mostly expressed in the plastids, except for three genes, which are expressed in the ER and the mitochondria (Okada et al. 2000). FPPS3 is responsible for sesquiterpene production after herbivore attacks Of the three prenyl transferases, fpps2 was transcribed only in trace amounts. Transcript levels of fpps3 were more than 15-fold higher than those of fpps1. Although fpps1 was previously shown to be induced by herbivory (CervantesCervantes et al. 2006), its expression is much lower than that of fpps3 in both damaged or undamaged leaves. Since both enzymes appear to be localized in the cytosol, FPPS3 is likely to dominate the production of the FDP substrate in response to herbivore damage. Similar pattern was observed by attack of leaves with S. littoralis and an elicitor treatment that mimics herbivory. The treatment with elicitor provides transcript data with a higher time resolution since the feeding behavior of the herbivore is more variable. In roots, the transcript levels of fpps1 surpass those of fpps3 both in damaged and control plants. While the transcript levels of fpps3 are still controlled by herbivory, the transcript levels of fpps1 are uniformly high. Therefore, FPPS1 might provide FDP for the biosynthesis of constitutive sesquiterpenes and triterpenes in the root. Such triterpenes have been described in Avena sativum where they are involved in the defense against pathogens (Geisler et al. 2013). Gossypol, a dimer of sesquiterpenes in the roots of Gossypium hirsutum has antimicrobial properties (Tan et al. 2000). In maize, similar sesquiterpene phytoalexins were described in shoot tissue, but their presence has not been verified in roots (Huffaker et al. 2011). Delprim is a maize cultivar, whose roots emit the sesquiterpene (E)-b-caryophyllene in response to feeding by the larvae of Diabrotica virgifera virgifera (Rasmann et al. 2005). Like in leaves, the transcript levels of fpps3 were induced by root damage. In undamaged roots, fpps3

Planta

levels were only marginal in comparison to those of fpps1. After feeding by D. virgifera, levels of fpps3 and fpps1 did not show a significant difference. Therefore, FDP production for (E)-b-caryophyllene biosynthesis in D. virgiferainfested roots is probably provided by both FPPS unless the expression of the enzymes is spatially separated in different root tissues. Further studies are required to understand these patterns of terpene synthesis. Tissue-specific transcription of fpps1 has already been shown for endosperm (Li and Larkins 1996). A similar expression was shown for the farnesyl diphosphate synthase 1 (FPS1) in A.thaliana, which is expressed in seedlings, roots, and flowers (Cunillera et al. 1996, 1997; Closa et al. 2010). The up-regulation of FPPS activity after herbivory might also be an important control mechanism for the production of terpene-based defenses in other plants including Withania somnifera (Gupta et al. 2011). In plants, these herbivore defenses are often mediated by jasmonic acid derivates, a group of plant stress hormones released after herbivory (Howe and Jander 2008). Treatment of ginseng with methyl jasmonate increased FPPS transcript levels, which suggests that FPPS activity is regulated by herbivory in ginseng as well (Kim et al. 2010). Similarly, the prenyl transferase PaIDS1 that forms GDP and GGDP in the conifer Picea abies is induced by both herbivory and treatment with Methyl jasmonate (Schmidt and Gershenzon 2008). An earlier step of terpene biosynthesis is also catalyzed by a small gene family, the 1-desoxy-D-xylulose-5-phosphate synthases (DXS). These enzymes catalyze the first reaction of the MEP pathway, which provides IDP units to monoterpene and diterpene biosynthesis (Eisenreich et al. 2001). In maize and M.truncatula, dxs1 is preferentially expressed above ground in photosynthetic tissues but barely in roots (Walter et al. 2002). Conversely, dxs2 transcripts were detected only in traces in the aboveground parts of the plant but at high levels in the roots, especially after colonization by mycorrhiza. This correlates somewhat with the differentially distribution of fpps1 and fpps3 transcripts in maize leaves and roots. FPPS3 expression is tightly correlated with the volatileproducing terpene synthase tps23 A time course of fpps3 expression in response to simulated herbivory revealed expression kinetics is similar to that of the terpene synthase tps23 in cut seedlings. This enzyme produces almost exclusively (E)-ß-caryophyllene, an important signal in plant defense both above and below ground (Rasmann et al. 2005; Ko¨llner et al. 2008). After simulated herbivory, the transcript levels of both enzymes increase within an hour. After 4 h, fpps3 transcripts

decreased somewhat earlier than those of tps23, which could be due to differences in mRNA stability. The two genes appear to be regulated by the same signal transduction pathway that originates with the exposure to mechanical damage and insect elicitors. Similar regulation of fpps3 and tps23 ensures that sufficient FDP intermediate is available for the formation of the volatile terpenes. A tight regulation of FDP concentration in the cytoplasm will also be necessary to ensure the correct post-translational farnesylation of proteins, which mediate protein–protein interactions and protein–membrane interactions (Novelli and ´ Apice 2012). Most likely, the constitutively expressed D fpps1 and the basal expression levels of fpps3 provide steady levels of FDP for these regulatory processes, while the herbivore-inducible FPPS3 provides the precursor for the production of terpene signals. In addition to the differential regulation by the FPPS gene family members, FDP concentration appears to be regulated by a feedback mechanism sensing the availability of FDP. Transgenic maize plants overexpressing a (E)-bcaryophyllene synthase under control of an ubiquitin promoter can produce up to 130 ng g-1 fresh weight of (E)-bcaryophyllene in roots, which is five-fold more than a typical (E)-b-caryophyllene producing maize variety (Degenhardt et al. 2009a, b). In these plants, five-fold higher amounts of FDP need to be available for FDP formation. Since these plants produce the terpene without herbivore induction, only fpps1 but not fpps3 might be involved in this feedback mechanism. Similar observations were made in Arabidopsis, where overexpression of terpene synthases resulted in the emission of terpenes that are not produced by Arabidopsis (Ko¨llner et al. 2005, 2008; Schnee et al. 2006; Fontana et al. 2009; Huang et al. 2012). Most likely, this apparently very flexible feedback mechanism ensures that FDP is always available for protein farnesylation in maize. In addition, ubiquinone, sterols, and other triterpenes are derived from FDP. The concentration of this important intermediate needs to be maintained despite large differences in FDP demand by secondary metabolite production. To fully understand this regulatory mechanism, the expression of both fpps1 and fpps3 needs to be determined specifically for each of the major leaf and root tissues. Due to the important roles of terpene volatiles in plant defenses, many strategies to increase plant resistance in an agricultural setting have been pursued (Degenhardt et al. 2003, 2009b; Hassanali et al. 2008). Most of these strategies are based on an increase in volatile terpene signals. Our study demonstrates that FDP synthases, especially fpps3 of maize, are a crucial regulatory step of terpene biosynthesis that may be as important as the regulation of terpene synthase activities themselves.

123

Planta

Author contribution AR and JD conceived and designed the study. AR conducted all experiments except for the time course analysis which was provided by I S-A. CS prepared some of the plant material and TGK helped with LC-MS analysis. The paper was written by AR and JD with support by all other authors. All authors read and approved the manuscript. Acknowledgments The authors would like to thank Matthias Erb for D. virgifera-treated root material. We are indebted to Raimund Nagel and Michael Reichelt for help with LC-MS analysis. A. Richter and J. Degenhardt were supported by project B7 of the Collaborative Research Center 648 of the German Research Foundation (DFG). I. Seidl-Adams was supported by two travel Grants of the Collaborative Research Center 648 of the German Research Foundation (DFG).

References Adams RP (2007) Identification of essential oil components by gas chromatography/mass spectrometry, 4th edn. Allured Publ. Corp, Carol Stream Ahn S, Anderson J, Sorrells M, Tanksley S (1993) Homoeologous relationships of rice, wheat and maize chromosomes. Mol Gen Genet 241 (5–6):483–490 Anderson MS, Yarger J, Burck C, Poulter C (1989) Farnesyl diphosphate synthetase. Molecular cloning, sequence, and expression of an essential gene from Saccharomyces cerevisiae. J Biol Chem 264:19176–19184 Ashby MN, Edwards P (1990) Elucidation of the deficiency in two yeast coenzyme Q mutants. Characterization of the structural gene encoding hexaprenyl pyrophosphate synthetase. J Biol Chem 265:13157–13164 ´ , Rodrı´guez-Concepcio´n Beck G, Coman D, Herren E, Ruiz-Sola MA M, Gruissem W, Vranova´ E (2013) Characterization of the GGPP synthase gene family in Arabidopsis thaliana. Plant Mol Biol 82:393–416 Cervantes-Cervantes M, Gallagher CE, Zhu C, Wurtzel ET (2006) Maize cDNAs expressed in endosperm encode functional farnesyl diphosphate synthase with geranylgeranyl diphosphate synthase activity. Plant Physiol 141:220–231 Closa M, Vranova´ E, Bortolotti C, Bigler L, Arro´ M, Ferrer A, Gruissem W (2010) The Arabidopsis thaliana FPP synthase isozymes have overlapping and specific functions in isoprenoid biosynthesis, and complete loss of FPP synthase activity causes early developmental arrest. Plant J 63:512–525 Correll CC, Edwards PA (1994) Mevalonic acid-dependent degradation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in vivo and in vitro. J Biol Chem 269:633–638 Cunillera N, Arro´ M, Delourme D, Karst F, Boronat A, Ferrer A (1996) Arabidopsis thaliana contains two differentially expressed farnesyl-diphosphate synthase genes. J Biol Chem 271:7774–7780 Cunillera N, Boronat A, Ferrer A (1997) The Arabidopsis thaliana FPS1 gene generates a novel mRNA that encodes a mitochondrial farnesyl-diphosphate synthase isoform. J Biol Chem 272:15381–15388 Cutler S, Ghassemian M, Bonetta D, Cooney S, McCourt P (1996) A protein farnesyl transferase involved in abscisic acid signal transduction in Arabidopsis. Science 273(5279):1239–1241 Degenhardt J, Gershenzon J, Baldwin IT, Kessler A (2003) Attracting friends to feast on foes: engineering terpene emission to make

123

crop plants more attractive to herbivore enemies. Curr Opin Biotechnol 14:169–176. doi:10.1016/s0958-1669(03)00025-9 Degenhardt J, Hiltpold I, Kollner TG, Frey M, Gierl A, Gershenzon J, Hibbard BE, Ellersieck MR, Turlings TCJ (2009a) Restoring a maize root signal that attracts insect-killing nematodes to control a major pest. Proc Natl Acad Sci USA 106:13213–13218. doi:10. 1073/pnas.0906365106 Degenhardt J, Koellner TG, Gershenzon J (2009b) Monoterpene and sesquiterpene synthases and the origin of terpene skeletal diversity in plants. Phytochemistry 70:1621–1637. doi:10.1016/ j.phytochem.2009.07.030 Delourme D, Fo Lacroute, Karst F (1994) Cloning of an Arabidopsis thaliana cDNA coding for farnesyl diphosphate synthase by functional complementation in yeast. Plant Mol Biol 26:1867–1873 Eisenreich W, Rohdich F, Bacher A (2001) Deoxyxylulose phosphate pathway to terpenoids. Trends Plant Sci 6:78–84 Fontana A, Reichelt M, Hempel S, Gershenzon J, Unsicker SB (2009) The effects of arbuscular mycorrhizal fungi on direct and indirect defense metabolites of Plantago lanceolata L. J Chem Ecol 35:833–843. doi:10.1007/s10886-009-9654-0 Fujisaki S, Hara H, Nishimura Y, Horiuchi K, Nishino T (1990) Cloning and nucleotide sequence of the ispA gene responsible for farnesyl diphosphate synthase activity in Escherichia coli1. J Biochem 108:995–1000 Gaffe J, Bru J-P, Causse M, Vidal A, Stamitti-Bert L, Carde J-P, Gallusci P (2000) LEFPS1, a tomato farnesyl pyrophosphate gene highly expressed during early fruit development. Plant Physiol 123:1351–1362 Gale MD, Devos KM (1998) Comparative genetics in the grasses. Proc Natl Acad Sci USA 95:1971–1974 Galichet A, Gruissem W (2003) Protein farnesylation in plants— conserved mechanisms but different targets. Curr Opin Plant Biol 6:530–535 Gaut BS (2001) Patterns of chromosomal duplication in maize and their implications for comparative maps of the grasses. Genome Res 11:55–66 Geisler K, Hughes RK, Sainsbury F, Lomonossoff GP, Rejzek M, Fairhurst S, Olsen C-E, Motawia MS, Melton RE, Hemmings AM, Bak S, Osbourn A (2013) Biochemical analysis of a multifunctional cytochrome P450 (CYP51) enzyme required for synthesis of antimicrobial triterpenes in plants. Proc Natl Acad Sci USA 110:E3360–E3367 Goritschnig S, Weihmann T, Zhang Y, Fobert P, McCourt P, Li X (2008) A novel role for protein farnesylation in plant innate immunity. Plant Physiol 148:348–357 Gupta P, Akhtar N, Tewari SK, Sangwan RS, Trivedi PK (2011) Differential expression of farnesyl diphosphate synthase gene from Withania somnifera in different chemotypes and in response to elicitors. Plant Growth Regul 65:93–100 Harborne JB (1991) Recent advances in the ecological chemistry of plant terpenoids. In: Harborne JB, Tomas-Barberan FA (eds) Ecological chemistry and biochemistry of plant terpenoids. Clarendon Press, Oxford, pp 399–426 Hassanali A, Herren H, Khan ZR, Pickett JA, Woodcock CM (2008) Integrated pest management: the push-pull approach for controlling insect pests and weeds of cereals, and its potential for other agricultural systems including animal husbandry. Phil Trans R Soc B Biol Sci 363:611–621 Helentjaris T, Weber D, Wright S (1988) Identification of the genomic locations of duplicate nucleotide sequences in maize by analysis of restriction fragment length polymorphisms. Genetics 118:353–363 Hemmerlin AA, Rivera SB, Erickson HK, Poulter CD (2003) Enzymes encoded by the farnesyl diphosphate synthase gene family in the big sagebrush Artemisia tridentata ssp. spiciformis. J Biol Chem 278:32132–32140

Planta Hemmi H, Noike M, Nakayama T, Nishino T (2003) An alternative mechanism of product chain-length determination in type III geranylgeranyl diphosphate synthase. Eur J Biochem 270: 2186–2194 Howe GA, Jander G (2008) Plant immunity to insect herbivores. Annu Rev Plant Biol 59:41–66 Huang M, Sanchez-Moreiras AM, Abel C, Sohrabi R, Lee S, Gershenzon J, Tholl D (2012) The major volatile organic compound emitted from Arabidopsis thaliana flowers, the sesquiterpene (E)-ß-caryophyllene, is a defense against a bacterial pathogen. New Phytol 193:997–1008 Huffaker A, Kaplan F, Vaughan MM, Dafoe NJ, Ni X, Rocca JR, Alborn HT, Teal PE, Schmelz EA (2011) Novel acidic sesquiterpenoids constitute a dominant class of pathogeninduced phytoalexins in maize. Plant Physiol 156:2082–2097 Jiang F, Yang L, Cai X, Cyriac J, Shechter I, Wang Z (2001) Farnesyl diphosphate synthase is abundantly expressed and regulated by androgen in rat prostatic epithelial cells. J Steroid Biochem 78(2):123–130 Kim OT, Kim SH, Ohyama K, Muranaka T, Choi YE, Lee HY, Kim MY, Hwang B (2010) Upregulation of phytosterol and triterpene biosynthesis in Centella asiatica hairy roots overexpressed ginseng farnesyl diphosphate synthase. Plant Cell Rep 29:403–411 Ko¨llner TG, Held M, Lenk C, Hiltpold I, Turlings TCJ, Gershenzon J, Degenhardt J (2008) A maize (E)-beta-caryophyllene synthase implicated in indirect defense responses against herbivores is not expressed in most American maize varieties. Plant Cell 20:482–494. doi:10.1105/tpc.107.051672 Koyama T (1999) Molecular analysis of prenyl chain elongating enzymes. Biosci Biotechnol Biochem 63:1671–1676 Koyama T, Obata S, Osabe M, Takeshita A, Yokoyama K, Uchida M, Ogura T (1993) Thermostable farnesyl diphosphate synthase of Bacillus stearothermophilus: molecular cloning, sequence determination, overproduction, and purification. J Biochem 113:355– 363 Lange BM, Ghassemian M (2003) Genome organization in Arabidopsis thaliana: a survey for genes involved in isoprenoid and chlorophyll metabolism. Plant Mol Biol 51:925–948 Li CP, Larkins BA (1996) Identification of a maize endospermspecific cDNA encoding farnesyl pyrophosphate synthetase. Gene 171:193–196 Nagel R, Gershenzon J, Schmidt A (2012) Nonradioactive assay for detecting isoprenyl diphosphate synthase activity in crude plant extracts using liquid chromatography coupled with tandem mass spectrometry. Anal Biochem 422:33–38 ´ Apice MR (2012) Protein farnesylation and disease. Novelli G, D J Inherited Metab Dis 35:917–926 Odland W, Baumgarten A, Phillips R (2006) Ancestral rice blocks define multiple related regions in the maize genome. Crop Sci 46(Supplement_1):S-41–S-48 Ohnuma S-I, Nakazawa T, Hemmi H, Hallberg A-M, Koyama T, Ogura K, Nishino T (1996) Conversion from farnesyl diphosphate synthase to geranylgeranyl diphosphate synthase by random chemical mutagenesis. J Biol Chem 271:10087–10095 Okada K, Saito T, Nakagawa T, Kawamukai M, Kamiya Y (2000) Five geranylgeranyl diphosphate synthases expressed in different organs are localized into three subcellular compartments in Arabidopsis. Plant Physiol 122:1045–1056 Popjak G, Goodman DS, Cornforth J, Cornforth RH, Ryhage R (1961) Studies on the biosynthesis of cholesterol XV. Mechanism of squalene biosynthesis from farnesyl pyrophosphate and from mevalonate. J Biol Chem 236:1934–1947 Rasmann S, Ko¨llner TG, Degenhardt J, Hiltpold I, Toepfer S, Kuhlmann U, Gershenzon J, Turlings TC (2005) Recruitment of entomopathogenic nematodes by insect-damaged maize roots. Nature 434:732–737

Reed BC, Rilling HC (1975) Crystallization and partial characterization of prenyltransferase from avian liver. Biochemistry 14:50–54 Salse JRM, Pie´gu B, Cooke R, Delseny M (2004) New in silico insight into the synteny between rice (Oryza sativa L.) and maize (Zea mays L.) highlights reshuffling and identifies new duplications in the rice genome. Plant J 38:396–409 Sanmiya K, Iwasaki T, Matsuoka M, Miyao M, Yamamoto N (1997) Cloning of a cDNA that encodes farnesyl diphosphate synthase and the blue-light-induced expression of the corresponding gene in the leaves of rice plants. Biochim Biophys Acta 1350:240–246 Sanmiya K, Ueno O, Matsuoka M, Yamamoto N (1999) Localization of farnesyl diphosphate synthase in chloroplasts. Plant Cell Physiol 40:348–354 Schmidt A, Gershenzon J (2008) Cloning and characterization of two different types of geranyl diphosphate synthases from Norway spruce (Picea abies). Phytochemistry 69:49–57. doi:10.1016/j. phytochem.2007.06.022 Schnee C, Koellner TG, Held M, Turlings TCJ, Gershenzon J, Degenhardt J (2006) The products of a single maize sesquiterpene synthase form a volatile defense signal that attracts natural enemies of maize herbivores. Proc Natl Acad Sci USA 103:1129–1134. doi:10.1073/pnas.0508027103 Schu¨ler G, Go¨rls H, Boland W (2001) 6-Substituted indanoyl isoleucine conjugates mimic the biological activity of coronatine. Eur J Org Chem 2001:1663–1668 Seidl-Adams I, Richter A, Boomer KB, Yoshinaga N, Degenhardt J, Tumlinson JH (2014) Emission of herbivore elicitor-induced sesquiterpenes is regulated by stomatal aperture in maize (Zea mays) seedlings. Plant, Cell Environ 38:23–34 Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S (2011) MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 28:2731–2739 Tan XP, Liang WQ, Liu CJ, Luo P, Heinstein P, Chen XY (2000) Expression pattern of (?)-delta-cadinene synthase genes and biosynthesis of sesquiterpene aldehydes in plants of Gossypium arboreum L. Planta 210:644–651 Tarshis L, Yan M, Poulter CD, Sacchettini JC (1994) Crystal structure of recombinant farnesyl diphosphate synthase at 2.6-Angstrom resolution. Biochemistry 33:10871–10877 Turlings TC, Tumlinson JH, Lewis W (1990) Exploitation of herbivore-induced plant odors by host-seeking parasitic wasps. Science 250(4985):1251–1253 Walter MH, Hans J, Strack D (2002) Two distantly related genes encoding 1-deoxy-d-xylulose 5-phosphate synthases: differential regulation in shoots and apocarotenoid-accumulating mycorrhizal roots. Plant J 31:243–254 Wei F, Coe E, Nelson W, Bharti AK, Engler F, Butler E, Kim H, Goicoechea JL, Chen M, Lee S (2007) Physical and genetic structure of the maize genome reflects its complex evolutionary history. PLoS Genet 3:e123 Wilkin DJ, Kutsunai S, Edwards P (1990) Isolation and sequence of the human farnesyl pyrophosphate synthetase cDNA. Coordinate regulation of the mRNAs for farnesyl pyrophosphate synthetase, 3-hydroxy-3-methylglutaryl coenzyme A reductase, and 3-hydroxy-3-methylglutaryl coenzyme A synthase by phorbol ester. J Biol Chem 265:4607–4614 Wilson WA, Harrington SE, Woodman WL, Lee M, Sorrells ME, McCouch SR (1999) Inferences on the genome structure of progenitor maize through comparative analysis of rice, maize and the domesticated panicoids. Genetics 153:453–473 Yalovsky S, Kulukian A, Rodrı´guez-Concepcio´n M, Young CA, Gruissem W (2000) Functional requirement of plant farnesyltransferase during development in Arabidopsis. Plant Cell 12:1267–1278

123

A small, differentially regulated family of farnesyl diphosphate synthases in maize (Zea mays) provides farnesyl diphosphate for the biosynthesis of herbivore-induced sesquiterpenes.

Of the three functional FPPS identified in maize, fpps3 is induced by herbivory to produce FDP important for the formation of the volatile sesquiterpe...
702KB Sizes 0 Downloads 7 Views