Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Spodoptera”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1997

Expression of human immunodeficiency virus genes using baculovirus expression system.

The structural protein genes of HIV-1 and HIV-2 have been expressed in Spodoptera frugiperda (SF) cells using baculovirus expression system. The noncoding flanking sequences of HIV structural genes were removed and a putative ribosome binding site was placed in front of the open reading frame of each gene by using crossover linker mutagenesis. The coding sequences of the gag, pol, env, and vif proteins were inserted into Autographa californica nuclear polyhedrosis virus (AcNPV) so that HIV genes were under the control of the AcNPV polyhedrin promoter. All recombinant AcNPV-infected SF cells express high levels of HIV structural proteins. Detailed strategies of recombinant AcNPV construction for high level protein expression are presented.

Animals↗
PubMed1997

Improved heterologous expression of the white-rot fungal ligninase H8 by crossover linker mutagenesis.

Using the crossover-linker mutagenesis method, the 5' noncoding region of the lambda ML-1 cDNA, which encodes the ligninase H8 isozyme of the white-rot fungus, Phanerochaete chrysosporium, was deleted with the simultaneous insertion of the putative Spodoptera frugiperda ribosome-binding sequence (RBS) (TATAAAT) directly in front of the translation-initiation codon of this gene. A recombinant baculovirus, pVL-Mu-H8, carrying the ligninase-H8 gene was successfully constructed, as determined by both sequence analysis and dot blot hybridization. A more than 18-fold increase in the expression of ligninase H8, compared to the previous pEV11-1A.3 recombinant baculovirus, was detected in the Sf-21 insect cells. This enzyme was detected within 3 d postinfection and was biologically active, capable of oxidizing the model lignin compound, veratryl alcohol. The molecular weight of the overexpressed 42 kD protein was similar to that of the native fungal ligninase-H8 isozyme and it also reacted specifically with the anti-H8 monoclonal antibody (MAb 2D4.9) in Western blot analysis.

Animals↗
PubMed1997

Functional properties of CYP2D6 1 (wild-type) and CYP2D6 7 (His324Pro) expressed by recombinant baculovirus in insect cells.

The debrisoquine/sparteine or CYP2D6 genetic polymorphism of drug oxidation is a common cause for interindividual variability in drug response. We recently identified a mutant allele, designated CYP2D6-E or CYP2D6*7, which is associated with the poor metabolizer phenotype and occurs in Caucasian populations with a frequency of about 1%. In contrast to other loss-of-function alleles, a full length protein with a single amino acid substitution. His324Pro, is encoded by the CYP2D6*7 allele. To functionally analyze this mutant protein form of CYP2D6, recombinant baculoviruses were constructed to express the CYP2D6 cDNA. Up to 0.33 nmol of spectrally detected P450/mg of cell protein were produced in Spodoptera frugiperda cells, whereas Trichoplusia ni 5B1-4 cells reproducibly produced 0.8 nmol/mg (4% of total cell protein). Insect cell membranes were functionally characterized with cumene hydroperoxide or after reconstitution with purified rat NADPH:cytochrome P450 reductase. Km values for the substrates bufuralol and sparteine and other enzymatic properties were almost identical to those of human liver microsomes. The H324P mutation was introduced into the cDNA by site-directed mutagenesis and recombinant baculovirus was obtained. Expression under a variety of conditions demonstrated that mutant protein amounts comparable to the wild-type enzyme were produced. However, no spectrally detectable P450 was formed and no catalytic activity was detected. Furthermore, in contrast to the wild-type protein the mutant protein was almost exclusively located in a detergent-insoluble insect cell fraction. These results demonstrate that the H324P mutation is responsible for the in vivo poor metabolizer phenotype associated with the CYP2D6*7 allele by preventing normal protein folding and heme incorporation.

Animals↗
PubMed2002

Extraction and quantification of "condensed tannins" as a measure of plant anti-herbivore defence? Revisiting an old problem.

Contents of phenolic compounds in leaf extracts often serve as a measure of plant anti-herbivore defence. This method suffers from the multifunctionality of phenolics and from problems with their colorimetric quantification. Here we present further evidence for the pertinence of these problems. Contents of condensed tannins (CCT) were spectrophotometrically quantified in leaf extracts of 11 closely related mimosoid species, and Spodoptera littoralis caterpillars were reared on artificial diet containing these extracts. The relationship of CCT with caterpillar growth differed considerably among plant species, since both positive and negative correlations were detected. There was, however, a negative correlation of CCT with fungal spore germination, indicating a role of these compounds in resistance to fungi. Detailed knowledge on the structure and biological function of defensive compounds and on the overall composition of leaves is required to estimate a plant's defensive efficacy against a particular group of enemies.

Animal Feed↗
PubMed2000

Kinetic properties of the channels formed by the bacillus thuringiensis insecticidal crystal protein Cry1C in the plasma membrane of Sf9 cells.

Spectrofluorimetric measurements were conducted to quantify, in real-time, membrane permeability changes resulting from the treatment of Sf9 insect cells (Spodoptera frugiperda, Lepidoptera) with different Bacillus thuringiensis Cry insecticidal proteins. Coumarin-derived CD222 and Merocyanin-540 probes were respectively used to monitor extracellular K(+) and membrane potential variations upon Sf9 cells incubation with Cry toxins. Our results establish that Cry1C induces, after a delay, the depolarization of the cell membrane and the full depletion of intracellular K(+). These changes were not observed upon Sf9 cells treated with Cry1A family toxins. Both the rate of the K(+) efflux and the delay before its onset were dependent on toxin concentration. Both parameters were sensitive to temperature but only the delay was affected by pH. Cry1C-induced K(+) efflux was inhibited by lanthanum ions in a dose-dependent manner. This study provides the first kinetic and quantitative characterization of the ion fluxes through the channels formed by a Cry toxin in the plasma membrane of a susceptible insect cell line.

Animals↗
PubMed2005

A homologue of cathepsin L identified in conditioned medium from Sf9 insect cells.

Gelatin zymography revealed the presence of proteolytic activity in conditioned medium (CM) from a serum-free, non-infected Spodoptera frugiperda, Sf9 insect cell culture. Two peptidase bands at about 49 and 39 kDa were detected and found to be proform and active form of the same enzyme. The 49-kDa form was visible on zymogram gels in samples of CM taken on days 4 and 5 of an Sf9 culture, while the 39-kDa form was seen on days 6 and 7. On basis of the inhibitor profile and substrate range, the enzyme was identified as an Sf9 homologue of cathepsin L, a papain-like cysteine peptidase. After lowering the pH of Sf9 CM to 3.5, an additional peptidase band at 22 kDa appeared. This peptidase showed the same inhibitor profile, substrate range and optimum pH (5.0) as the 39-kDa form, indicating that Sf9 cathepsin L has two active forms, at 39 and 22 kDa. Addition of the cysteine peptidase inhibitor E-64c to an Sf9 culture inhibited all proteolytic activities of Sf9 cathepsin L but did not influence the proliferation of Sf9 cells.

Animals↗
PubMed2001

Investigation of sequential behavior of carboxyl protease and cysteine protease activities in virus-infected Sf-9 insect cell culture by inhibition assay.

Proteases produced during the culture of Spodoptera frugiperda Sf-9 cells infected with Autographa californica nuclear polyhedrosis virus (AcNPV) were assayed with various protease inhibitors. This inhibitory analysis revealed that: (1) carboxyl and cysteine proteases were predominantly produced by the insect cells infected with recombinant AcNPV, the gene of which encoded a variant of green fluorescent protein in a portion of the polyhedrin gene of the baculovirus, and (2) the protease activity was almost completely blocked by pepstatin A (carboxyl protease inhibitor) and E64 (cysteine protease inhibitor) in an additive manner in the presence of EDTA. Utilizing the additive property of the inhibitors, the inhibition-based protease assay discriminated between the two protease activities and elucidated the sequential behavior of the carboxyl and cysteine proteases produced in the virus-infected Sf-9 cell culture. The carboxyl protease(s) existed in the virus-infected cells all the time and their level in the medium continuously increased. Uninfected cells also contained a carboxyl protease activity, the level of which was similar to that of the virus-infected cells. At a certain time after virus infection, the cysteine protease activity was largely increased in the virus-infected cells and a significant amount of the protease(s) was released into the medium, due to the cell membranes losing their integrity. The behavior of intracellular and extracellular cysteine protease activities coincided with that of a recombinant protein whose expression was under the control of the viral polyhedrin promoter. Similar examinations with wt-AcNPV-infected and uninfected insect cells showed that the inhibition-based protease assay was useful for analyzing the carboxyl protease and cysteine protease activities emerging in the insect cell (Sf-9)/baculovirus expression system.

Animals↗
PubMed2002

Isolation and characterization of a strain of Bacillus thuringiensis ssp. kurstaki containing a new delta-endotoxin gene.

A strain of Bacillus thuringiensis that showed significantly high toxicity to Plutella xylostella and Spodoptera exigua was isolated from a Korean soil sample and characterized. The isolate, named B. thuringiensis K1, was determined to belong to ssp. kurstaki (H3a3b3c) type by an H antisera agglutination test and produced bipyramidal inclusions. Plasmid pattern of K1 was different from that of the reference strain, ssp. kurstaki HD-1, but the parasporal inclusion protein profile of K1 had two major bands that were similar in size to those of ssp. kurstaki HD-1. To verify the delta-endotoxin gene types of K1, PCR analysis with specific cry gene primers was performed to show that K1 contained a new cry gene in addition to cry1Aa, cry1Ab, cry1Ac, cry1E and cry2 genes. PCR-amplified region of the new cry gene, cryX, showed 79% similarity to cry1Fa1 gene (GenBank Accession No. M63897). In an insect toxicity assay, K1 had higher toxicity against Plutella xylostella and S. exigua than ssp. kurstaki HD-1.

Animals↗
PubMed2003

Occurrence and linkage between secreted insecticidal toxins in natural isolates of Bacillus thuringiensis.

Little is known about the occurrence and linkage between secreted insecticidal virulence factors in natural populations of Bacillus thuringiensis (Bt). We carried out a survey of 392 Bt strains isolated from various samples originating from 31 countries. The toxicity profile of the culture supernatants of these strains was determined individually against Anthonomus grandis (Coleoptera) and Spodoptera littoralis (Lepidoptera). We analyzed beta-exotoxin I production and searched for the genes encoding Vip1-2, Vip3, and Cry1I toxins in 125 of these strains. Our results showed that these insecticidal toxins were widespread in Bt but that their distribution was nonrandom, with significant linkage observed between vip3 and cry1I and between vip1-2 and beta-exotoxin I. Strains producing significant amounts of beta-exotoxin I were more frequently isolated from invertebrate samples than from dust, water, soil, or plant samples.

Adenosine↗
PubMed2001

Exchange of domain I from Bacillus thuringiensis Cry1 Toxins Influences protoxin stability and crystal formation.

Influence of domain I exchange on the stability and production of Bacillus thuringiensis Cry1 protoxins as well as on the shape of inclusion and toxicity to Spodoptera exigua and Plutella xylostella larvae was investigated. Chimeric genes were prepared by exchanging the regions coding for domain I between Cry1Aa, Cry1Ab, Cry1Ac, Cry1C, and Cry1E. The AcCC chimera accumulated into bipyramidal inclusion bodies, whereas CEE produced round-shaped inclusion bodies, and ECC and AaEE protoxins produced small granules. AbEE and EAaAa did not produce any inclusion body and were visualized by immunodetection only. AcCC, CEE, ECC, and AaEE were stable to trypsin, whereas AbEE and EAaAa were not. Bioassays showed that the chimeras were not toxic in vivo. However, S. exigua larvae fed with the activated AcCC toxin displayed a lower growth rate.

Animals↗
PubMed2001

Highly toxic and broad-spectrum insecticidal Bacillus thuringiensis engineered by using the transposon Tn917 and protoplast fusion.

The chromosome of the Bacillus thuringiensis strain S184 that was toxic against the third instar larvae of Spodoptera litura with the LC(50) of 9.74 microg/ml was successfully integrated into two genes of cyt1Aa and cry11Aa using the transposon Tn917, yielding the primary engineered strain TnX. The strain TnX was highly toxic to the third instar larvae of Culex pipiens fatigans with the LC(50) of 5.12 ng/ml which was 1.82-fold higher than that of B. thuringiensis subsp. israelensis, but lowly toxic to lepidopterous larvae. By the protoplast fusion of the strain TnX and the strain S184-Tet(r) (resistance to tetracycline), the target engineered strain TnY was obtained. Against the third instar larvae of S. litura, the strain TnY LC(50) was of 4.68 micro g/ml and increased by 2.08-fold in comparison with the parent strain S184. Against the third instar larvae of C. pipiens fatigans, the strain TnY LC(50) was of 103.20 ng/ml. The two target genes of cyt1Aa and cry11Aa integrated into the chromosome were extremely stable and had little possibility of a second transposition. It was unclear whether some factors existing in the parent strain, S184, contributed to the high toxicity of the strains TnX and TnY.

Animals↗
PubMed2005

Proteomic analysis of TRPC5- and TRPC6-binding partners reveals interaction with the plasmalemmal Na(+)/K(+)-ATPase.

Mammalian transient receptor potential canonical (TRPC) genes encode a family of nonselective cation channels that are activated following stimulation of G-protein-coupled membrane receptors linked to phospholipase C. In Drosophila photoreceptor cells, TRP channels are found in large, multimolecular signaling complexes in association with the PDZ-containing scaffolding protein, INAD. A similar mammalian TRPC "signalplex" has been proposed, but has yet to be defined. In the present study, affinity-purified polyclonal antibodies against TRPC5 and TRPC6 were used to immunoprecipitate signalplex components from rat brain lysates. Immunoprecipitated proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, digested with trypsin, and sequenced by mass spectrometry. Proteins identified in the immunoprecipitates included cytoskeletal proteins spectrin, myosin, actin, drebrin, tubulin, and neurabin; endocytic vesicle-associated proteins clathrin, dynamin and AP-2; and the plasmalemmal Na(+)/K(+)-ATPase (NKA) pump. Several of these interactions were confirmed by reciprocal immunoprecipitation followed by Western blot analysis. In lysates from rat kidney, TRPC6, but not TRPC3, was found to coimmunoprecipitate with the NKA pump. Likewise, TRPC6, stably expressed in human embryonic kidney (HEK) cells, coimmunoprecipitated with endogenous NKA and colocalized with the pump to the plasmalemma when examined by immunofluorescence microscopy. Cell surface biotinylation experiments in intact HEK cells, confirmed that both the Na(+) pump and TRPC6 were present in the surface membrane and appeared to interact. Lastly, TRPC6 coimmunoprecipitated with the NKA pump when the proteins were coexpressed in Spodoptera frugiperda insect cells using recombinant baculoviruses. These observations suggest that TRPC6 and the Na(+) pump are part of a functional complex that may be involved in ion transport and homeostasis in both the brain and kidney.

Animals↗
PubMed2001

5-HT-receptor-induced changes of the intracellular cAMP level monitored by a hyperpolarization-activated cation channel.

The HvCNG channel from the moth Heliothis virescens is highly sensitive to cAMP concentrations ranging between 0.1 microM and 5 microM. This HvCNG channel was over-expressed in Spodoptera frugiperda (Sf.9) cells to measure endogenous cAMP levels. Hyperpolarization-activated inward currents were measured in the whole-cell patch-clamp configuration with pipettes filled with different cAMP concentrations to calibrate the system. Varying the cAMP concentration between 0 microM and 100 microM in the pipette, the half-maximal activation voltage ( V1/2) was shifted by +28.5+/-1.7 mV. The activation time constant (tau(a)) was used as a parameter for cAMP quantification because it was independent of the expression level of HvCNG channels. tau(a) changed from 1106+/-60 ms at 0 microM cAMP to 265+/-7 ms at a saturating concentration of 1 mM cAMP. A dose-response relationship yielded values of 0.6 microM for the half-maximal cAMP concentration and 1.5 for the Hill coefficient. Activation of endogenous adenylyl cyclases by 50 microM forskolin induced an elevation of the cAMP level by about 1.6+/-0.2 microM. Co-expressions of HvCNG channels in combination with the mouse 5-HT4a- or 5-HT1A- receptors and the corresponding Gs- or Gi-proteins were successful and allowed us to also verify receptor-induced changes of the cAMP level. Stimulation of m5-HT4a-receptors by 0.1 microM 5-HT induced an increase of cAMP of about 4.6+/-1.5 microM, whereas cAMP levels decreased from a control value of 1+/-0.2 microM to 0.41+/-0.1 microM after stimulation of the m5-HT1A-receptors.

Adenylyl Cyclases↗
PubMed2002

Functional expression of a cDNA encoding pea (Pisum sativum L.) raffinose synthase, partial purification of the enzyme from maturing seeds, and steady-state kinetic analysis of raffinose synthesis.

Raffinose (O-alpha- D-galactopyranosyl-(1-->6)- O-alpha- D-glucopyranosyl-(1<-->2)- O-beta- D-fructofuranoside) is a widespread oligosaccharide in plant seeds and other tissues. Raffinose synthase (EC 2.4.1.82) is the key enzyme that channels sucrose into the raffinose oligosaccharide pathway. We here report on the isolation of a cDNA encoding for raffinose synthase from maturing pea ( Pisum sativum L.) seeds. The coding region of the cDNA was expressed in Spodoptera frugiperda Sf21 insect cells. The recombinant enzyme, a protein of glycoside hydrolase family 36, displayed similar kinetic properties to raffinose synthase partially purified from maturing seeds by anion-exchange and size-exclusion chromatography. Apart from the natural galactosyl donor galactinol ( O-alpha- D-galactopyranosyl-(1-->1)- L- myo-inositol), p-nitrophenyl alpha- D-galactopyranoside, an artificial substrate, was utilized as a galactosyl donor. An equilibrium constant of 4.1 was determined for the galactosyl transfer reaction from galactinol to sucrose. Steady-state kinetic analysis suggested that raffinose synthase is a transglycosidase operating by a ping-pong reaction mechanism and may also act as a glycoside hydrolase. The enzyme was strongly inhibited by 1-deoxygalactonojirimycin, a potent inhibitor for alpha-galactosidases (EC 3.2.1.22). The physiological implications of these observations are discussed.

Algorithms↗
PubMed2005

Systemic induction of volatile release in cotton: how specific is the signal to herbivory?

Plants attacked by herbivorous insects release chemical signals that attract natural enemies of the herbivores to the damaged plants. Feeding of Spodoptera exigua larvae on the lower leaves of cotton (Gossypium hirsutum L.) for multiple feeding periods of 9-12 h with a 12 h, interval in between when the caterpillars are removed overnight, will induce a systemic release of volatile compounds that is comparable to the volatiles released in response to continuous feeding damage on the lower leaves for several days. The systemic volatile release in response to herbivory can be mimicked by mechanically damaging the lower leaves and applying caterpillar oral secretion to the injured leaves over 4 days. Cotton plants that are only mechanically damaged systemically release significantly less beta-pinene, myrcene, (Z)-3-hexenyl acetate, (E)-beta-farnesene and (E,E)-alpha-farnesene after 4 days compared to plants damaged mechanically with application of caterpillar regurgitant. However, multiple 9-12 h mechanical damage alone induces a significantly higher systemic release of (Z)-3-hexenyl acetate, myrcene, (E)-beta-ocimene, and (E)-beta-farnesene after 4 days compared to undamaged control plants. This indicates that multiple mechanical damage alone cannot mimic completely the response induced by mechanically injuring the leaves and applying caterpillar regurgitant. A specific elicitor in the regurgitant of the caterpillar enhances the amount of several systemically released volatiles. Thus, the systemic release of volatile compounds by herbivore-damaged cotton plants appears to be regulated by at least two different mechanisms.

Animals↗
PubMed2000

Demonstration and characterization of (E)-nerolidol synthase from maize: a herbivore-inducible terpene synthase participating in (3E)-4,8-dimethyl-1,3,7-nonatriene biosynthesis.

Upon herbivore attack, maize (Zea mays L.) emits a mixture of volatile compounds that attracts herbivore enemies to the plant. One of the major components of this mixture is an unusual acyclic C11 homoterpene, (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), which is also emitted by many other species following herbivore damage. Biosynthesis of DMNT has been previously shown to proceed via the sesquiterpene alcohol, (E)-nerolidol. Here we demonstrate an enzyme activity that converts farnesyl diphosphate, the universal precursor of sesquiterpenes, to (3S)-(E)-nerolidol in cell-free extracts of maize leaves that had been fed upon by Spodoptera littoralis. The properties of this (E)-nerolidol synthase resemble those of other terpene synthases. Evidence for its participation in DMNT biosynthesis includes the direct incorporation of deuterium-labeled (E)-nerolidol into DMNT and the close correlation between increases in (E)-nerolidol synthase activity and DMNT emission after herbivore damage. Since farnesyl diphosphate has many other metabolic fates, (E)-nerolidol synthase may represent the first committed step of DMNT biosynthesis in maize. However, the formation of this unusual acyclic terpenoid appears to be regulated at both the level of (E)-nerolidol synthase and at later steps in the pathway.

Alkyl and Aryl Transferases↗
PubMed2001

The influence of intact-plant and excised-leaf bioassay designs on volicitin- and jasmonic acid-induced sesquiterpene volatile release in Zea mays.

Induced plant responses to insect attack include the release of volatile chemicals. These volatiles are used as host-location signals by foraging parasitoids, which are natural enemies of insect herbivores. A plant's response to herbivory can be influenced by factors present in insect oral secretions. Volicitin (N-(17-hydroxylinolenoyl)-L-glutamine), identified in beet armyworm (Spodoptera exigua) oral secretions, stimulates volatile release in corn (Zea mays L.) seedlings in a manner similar to beet armyworm herbivory. Volicitin is hypothesized to trigger release of induced volatiles, at least in part, by modulating levels of the wound hormone, jasmonic acid (JA). We compare the sesquiterpene volatile release of damaged leaves treated with aqueous buffer only or with the same buffer containing volicitin or JA. Leaves were damaged by scratching with a razor and test solutions were applied to the scratched area. The leaves were either excised from the plant or left intact shortly after this treatment. Plants were treated at three different times (designated as Evening, Midnight, and Morning) and volatiles were collected in the subsequent photoperiod. JA and volicitin treatments stimulated the release of volatile sesquiterpenes, namely beta-caryophyllene, (E)-alpha-bergamotene, and (E)-beta-farnesene. In all cases, JA stimulated significant sesquiterpene release above mechanical damage alone. Volicitin induced an increase in sesquiterpene volatiles for all excised-leaf bioassays and the Midnight intact plants. Volicitin treatments in the Evening and Morning intact plants produced more sesquiterpenes than the untreated controls, while mechanical damage alone produced an intermediate response that did not differ from either treatment group. Excised leaves produced a 2.5- to 8.0-fold greater volatile response than similarly treated intact plants. Excision also altered the ratio of JA-and volicitin-induced sesquiterpene release by preferentially increasing (E)-beta-farnesene levels relative to beta-caryophyllene. The inducibility of volatile release varied with time of treatment. On average, sesquiterpene release was highest in the Midnight excised leaves and lowest in the Morning intact plants. The duration of induced volatile release also differed between treatments. On average, JA produced a sustained release of sesquiterpenes over time, with over 20% of the combined sesquiterpenes released in the third and final volatile collection period. In contrast, less than 8% of the combined sesquiterpenes induced by volicitin were emitted during this period. The large quantitative differences between intact plants and detached leaves suggest that the results of assays using excised tissues should be cautiously interpreted when considering intact-plant models.

Animals↗
PubMed2002

Evidence for regulation of resistance in Arabidopsis to Egyptian cotton worm by salicylic and jasmonic acid signaling pathways.

Signaling cross-talk between wound- and pathogen-response pathways influences resistance of plants to insects and disease. To elucidate potential interactions between salicylic acid (SA) and jasmonic acid (JA) defense pathways, we exploited the availability of characterized mutants of Arabidopsis thaliana (L.) Heynh. and monitored resistance to Egyptian cotton worm (Spodoptera littoralis Boisd.; Lepidoptera: Noctuidae). This generalist herbivore is sensitive to induced plant defense pathways and is thus a useful model for a mechanistic analysis of insect resistance. As expected, treatment of wild-type Arabidopsis with JA enhanced resistance to Egyptian cotton worm. Conversely, the coil mutant, with a deficiency in the JA response pathway, was more susceptible to Egyptian cotton worm than wild-type Arabidopsis. By contrast, the nprl mutant, with defects in systemic disease resistance, exhibited enhanced resistance to Egyptian cotton worm. Pretreatment with SA significantly reduced this enhanced resistance of nprl plants but had no influence on the resistance of wild-type plants. However, exogenous SA reduced the amount of JA that Egyptian cotton worm induced in both npr1 mutant and wild-type plants. Thus, this generalist herbivore engages two different induced defense pathways that interact to mediate resistance in Arabidopsis.

Animals↗