Topical Toxicity of Tomato Sesquiterpenes to the Beet Armyworm and the Role of These Compounds in Resistance Derived from an Accession of Lycopersicon hirsutum f. typicum

1994 ◽  
Vol 42 (3) ◽  
pp. 807-810 ◽  
Author(s):  
Sanford D. Eigenbrode ◽  
John T. Trumble ◽  
Jocelyn G. Millar ◽  
Kristine K. White
Keyword(s):  
Beet Armyworm ◽  
Lycopersicon Hirsutum

scholarly journals Mutations in Potato virus Y Genome-Linked Protein Determine Virulence Toward Recessive Resistances in Capsicum annuum and Lycopersicon hirsutum

2004 ◽  
Vol 17 (3) ◽  
pp. 322-329 ◽  
Author(s):  
Benoît Moury ◽  
Caroline Morel ◽  
Elisabeth Johansen ◽  
Laurent Guilbaud ◽  
Sylvie Souche ◽  
...  
Keyword(s):  
Amino Acid ◽  
Capsicum Annuum ◽  
Potato Virus ◽  
Potato Virus Y ◽  
Cdna Clones ◽  
Lycopersicon Hirsutum ◽  
Potato Virus A ◽  
Single Nucleotide Change ◽  
Protein Encoding

The recessive resistance genes pot-1 and pvr2 in Lycopersicon hirsutum and Capsicum annuum, respectively, control Potato virus Y (PVY) accumulation in the inoculated leaves. Infectious cDNA molecules from two PVY isolates differing in their virulence toward these resistances were obtained using two different strategies. Chimeras constructed with these cDNA clones showed that a single nucleotide change corresponding to an amino acid substitution (Arg119His) in the central part of the viral protein genome-linked (VPg) was involved in virulence toward the pot-1 resistance. On the other hand, 15 nucleotide changes corresponding to five putative amino acid differences in the same region of the VPg affected virulence toward the pvr21 and pvr22 resistances. Substitution models identified six and five codons within the central and C terminal parts of the VPg for PVY and for the related potyvirus Potato virus A, respectively, which undergo positive selection. This suggests that the role of the VPg-encoding region is determined by the protein and not by the viral RNA apart from its protein-encoding capacity.

scholarly journals Management of the Beet Armyworm (Lepidoptera: Noctuidae) in Cotton: Role of Natural Enemies

1994 ◽  
Vol 77 (4) ◽  
pp. 440 ◽  
Author(s):  
John R. Ruberson ◽  
Gary A. Herzog ◽  
William R. Lambert ◽  
W. Joe Lewis
Keyword(s):  
Natural Enemies ◽  
Beet Armyworm ◽  
Lepidoptera Noctuidae

scholarly journals Antibiosis to Beet Armyworm (Spodoptera exigua) in Lycopersicon Accessions

HortScience ◽  
1993 ◽  
Vol 28 (9) ◽  
pp. 932-934 ◽  
Author(s):  
Sanford D. Eigenbrode ◽  
John T. Trumble
Keyword(s):  
Spodoptera Exigua ◽  
Leaf Surface ◽  
Glandular Trichomes ◽  
Beet Armyworm ◽  
Lycopersicon Hirsutum ◽  
Tomato Cultivar ◽  
Type Iv ◽  
Leaf Surfaces ◽  
Susceptible Tomato ◽  
Neonate Larvae

Four accessions of Lycopersicon hirsutum f. glabratum Mull. and eight accessions of L. hirsutum f. typicum Humb. & Bonpl. were evaluated for their resistance to the beet armyworm [Spodoptera exigua (Hübner)]. Survival of S. exigua neonate larvae for up to 96 hours on foliage of all these accessions differed significantly from their survival on a susceptible tomato cultivar. Spodoptera exigua survival did not differ significantly between the two forms of L. hirsutum. Antibiosis to S. exigua in L. hirsutum f. glabratum appears similar to the levels found to other Lepidoptera. Accessions of L. hirsutum f. typicum included the very susceptible PI 199381 and the two most resistant accessions, LA 2329 and LA 1777. Insect resistance had not been reported previously in four of the L. hirsutum f. typicum accessions. Spodoptera exigua survival was significantly negatively correlated with the density of type IV glandular trichomes on the leaf surfaces, calculated across all 12 accessions. This relationship did not occur within L. hirsutum f. glabratumor L. hirsutum f. typicum accessions, nor was it significant if PI 199381 was excluded from the analysis. Leaf-surface exudates of L. hirsutum f. glabratum accessions were dominated by the methylketones 2-undecanone and 2-tridecanone. Leaf-surface exudates of L. hirsutum f. typicum were dominated by three sesquiterpenes-zingiberene, δ elemene, and γ elemene. Resistance was not correlated with the amounts of these specific compounds within or across botanical form. Spodoptera exigua survival in L. hirsutum f. typicum (excluding PI 199381) correlated negatively with the total estimated amount of leaf-surface volatiles extracted. PI 199381 may be useful as a susceptible parent for intraspecific crosses to examine S. exigua resistance in L. hirsutum.

scholarly journals Hetero-oligomerization of Bacillus thuringiensis Cry1A proteins enhance binding to the ABCC2 transporter of Spodoptera exigua

2021 ◽  
Author(s):  
Daniel Pinos ◽  
Noelia Joya ◽  
Salvador Herrero ◽  
Juan Ferré ◽  
Patricia Hernández Martinez
Keyword(s):  
Bacillus Thuringiensis ◽  
Spodoptera Exigua ◽  
Ex Vivo ◽  
Specific Binding ◽  
Beet Armyworm ◽  
Oligomeric State ◽  
Bt Crops ◽  
Domain I

The ABC transporters are membrane proteins that can act as putative receptors for Cry proteins from Bacillus thuringiensis (Bt) in the midgut of different insects. For the beet armyworm, Spodoptera exigua, ABCC2 and ABCC3 have been found to interact with Cry1A proteins, the main insecticidal proteins used in Bt-crops, as well as Bt-based pesticides. The ABCC2 has shown to have specific binding towards Cry1Ac and is involved in the toxic process of Cry1A proteins, but the role of this transporter and how it relates with the Cry1A proteins is still unknown. Here, we have characterized the interactions between the SeABCC2 and the main proteins that bind to the receptor. By labelling the Cry1Aa protein, we have found that virtually all of the binding is in an oligomeric state, a conformation that allowed higher levels of specific binding that could not be achieved by the monomeric protein on its own. Furthermore, we have observed that Cry1A proteins can hetero-oligomerize in the presence of the transporter, which is reflected in an increase in binding and toxicity to SeABCC2-expressing cells. This synergism can be one of the reasons why B. thuringiensis co-expresses different Cry1 proteins that can apparently have similar binding preferences. The results from in vitro competition and ex vivo competition showed that Cry1Aa, Cry1Ab and Cry1Ac share functional binding sites. By using Cry1Ab-Cry1Ac chimeras, the presence of domain I from Cry1A proteins was revealed to be critical for oligomer formation.

scholarly journals ER bodies are induced by Pseudomonas syringae and negatively regulate immunity

2021 ◽  
Author(s):  
Jose Rufian ◽  
James Elmore ◽  
Eduardo R Bejarano ◽  
Carmen R. Beuzón ◽  
Gitta Coaker
Keyword(s):  
Immune Responses ◽  
Pseudomonas Syringae ◽  
Bacterial Infections ◽  
De Novo ◽  
Cell Types ◽  
Beet Armyworm ◽  
Bacterial Toxin ◽  
Main Components ◽  
New Evidence

ER bodies are endoplasmic reticulum-derived organelles present in plants belonging to the Brassicales order. In Arabidopsis thaliana, ER bodies are ubiquitous in cotyledons and roots, and present only in certain cell types in rosette leaves. However, both wounding and jasmonic acid treatment induce the formation of ER bodies in leaves. Formation of this structure is dependent on the transcription factor NAI1. The main components of the ER bodies are β-glucosidases (BGLUs), enzymes that hydrolyze specialized compounds. In Arabidopsis, PYK10 (BGLU23) and BGLU18 are the most abundant ER body proteins. In this work, we found that ER bodies are downregulated as a consequence of the immune responses induced by bacterial flagellin perception. Arabidopsis mutants defective in ER body formation show enhanced responses upon flagellin perception and enhanced resistance to bacterial infections. Furthermore, the bacterial toxin coronatine induces the formation of de novo ER bodies in leaves and its virulence function is partially dependent on this structure. Finally, we show that performance of the polyphagous beet armyworm herbivore, Spodoptera exigua, increases in plants lacking ER bodies. Altogether, we provide new evidence for the role of the ER bodies in plant immune responses.

scholarly journals Terpenoids from Weedy Ricefield Flatsedge (Cyperus iria L.) Are Developmentally Regulated and Stress-Induced, and have Antifungal Properties

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3149 ◽  
Author(s):  
Yifan Jiang ◽  
Bonnie Ownley ◽  
Feng Chen
Keyword(s):  
Developmental Stages ◽  
Total Concentration ◽  
Beet Armyworm ◽  
Ecological Niches ◽  
Drought Treatment ◽  
Developmentally Regulated ◽  
Biotic Stresses ◽  
Anti Fungal ◽  
Spatial Specificity

Ricefield flatsedge (Cyperus iria L.), a troublesome weed in rice production, actively adapts to ecological niches. In this study, terpenoids were identified as the dominant compounds from organic extracts of C. iria leaves. To understand the role of terpenoid production in plant development and resistance to abiotic and biotic stresses, the dynamics of terpenoid production at different developmental stages, and the regulation of these compounds by stresses were determined. Terpenoid production exhibited temporal and spatial specificity. During vegetative growth, the total concentration of sesquiterpenoids increased and reached a maximum at 70 d after germination, and then decreased until the emergence of inflorescence. Monoterpenoids were only detected from leaves 90 d after germination. During reproductive growth, the total concentration of sesquiterpenoids increased dramatically and mainly accumulated in inflorescences, indicating that the sesquiterpenoids were primarily produced in newly formed and actively growing tissues. The total amount of monoterpenoids, mostly accumulated in flowers, increased until 130 d after germination. Furthermore, accumulation of sesquiterpenoids in leaves was promoted significantly by methyl jasmonate (MeJA) and drought treatment. Infestation by beet armyworm (Spodoptera exigua, BAW) promoted the emission of total sesquiterpenoids significantly and induced the production of more monoterpenoids and sesquiterpenoids specifically. Furthermore, volatiles from C. iria leaves had an anti-fungal effect on Fusarium graminearum. The implications of our findings on the biosynthetic pathways leading to the production of sesquiterpenoids in C. iria as well as their potential as fungicides are discussed.

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