scholarly journals Pine defense responses to eggs of an herbivorous sawfly are elicited by an annexin-like protein

2021 ◽  
Author(s):  
Janik Hundacker ◽  
Norbert Bittner ◽  
Christoph Weise ◽  
Gunnar Bröhan ◽  
Martti Varama ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Defense Responses ◽  
Egg Parasitoids ◽  
Low Molecular Weight ◽  
Terpene Biosynthesis ◽  
Insect Eggs ◽  
Defensive Responses ◽  
Egg Deposition ◽  
Ros Homeostasis ◽  
Pathogenesis Related

Known elicitors of plant defenses against eggs of herbivorous insects are low-molecular-weight organic compounds associated with the eggs. However, previous studies provided evidence that also proteinaceous compounds present in secretion associated with eggs of the herbivorous sawfly Diprion pini can elicit defensive responses in Pinus sylvestris. Pine responses induced by the proteinaceous secretion are known to result in enhanced emission of (E)-β-farnesene, which attracts egg parasitoids killing the eggs. Here, we aimed to identify the defense-eliciting protein and elucidate its function. After isolating the defense-eliciting protein from D. pini egg secretion by ultrafiltration and gel electrophoresis, we identified it by MALDI-ToF mass spectrometry as an annexin-like protein, which we named “diprionin”. Further GC-MS analyses showed that pine needles treated with heterologously expressed diprionin released enhanced quantities of (E)-β-farnesene. Our bioassays confirmed attractiveness of diprionin-treated pine to egg parasitoids. Expression of several pine candidate genes involved in terpene biosynthesis and regulation of ROS homeostasis was similarly affected by diprionin and natural sawfly egg deposition. However, the two treatments had different effects on expression of pathogenesis related genes (PR1, PR5). Diprionin is the first egg-associated proteinaceous elicitor of indirect plant defense against insect eggs described so far.

scholarly journals Defense of Scots pine against sawfly eggs (Diprion pini) is primed by exposure to sawfly sex pheromones

2019 ◽  
Vol 116 (49) ◽  
pp. 24668-24675 ◽  
Author(s):  
Norbert Bittner ◽  
Janik Hundacker ◽  
Ander Achotegui-Castells ◽  
Olle Anderbrant ◽  
Monika Hilker
Keyword(s):  
Sex Pheromones ◽  
Herbivorous Insect ◽  
Plant Responses ◽  
Insect Eggs ◽  
Pine Sawfly ◽  
Defensive Responses ◽  
Egg Deposition ◽  
Pathogenesis Related Protein ◽  
Pathogenesis Related ◽  
Insect Sex Pheromones

Plants respond to insect infestation with defenses targeting insect eggs on their leaves and the feeding insects. Upon perceiving cues indicating imminent herbivory, such as damage-induced leaf odors emitted by neighboring plants, they are able to prime their defenses against feeding insects. Yet it remains unknown whether plants can amplify their defenses against insect eggs by responding to cues indicating imminent egg deposition. Here, we tested the hypothesis that a plant strengthens its defenses against insect eggs by responding to insect sex pheromones. Our study shows that preexposure of Pinus sylvestris to pine sawfly sex pheromones reduces the survival rate of subsequently laid sawfly eggs. Exposure to pheromones does not significantly affect the pine needle water content, but results in increased needle hydrogen peroxide concentrations and increased expression of defense-related pine genes such as SOD (superoxide dismutase), LOX (lipoxygenase), PAL (phenylalanine ammonia lyase), and PR-1 (pathogenesis related protein 1) after egg deposition. These results support our hypothesis that plant responses to sex pheromones emitted by an herbivorous insect can boost plant defensive responses to insect egg deposition, thus highlighting the ability of a plant to mobilize its defenses very early against an initial phase of insect attack, the egg deposition.

Normal Mature Human Enamel Protein

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 986-987 ◽  
Author(s):  
A. Belcourt
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Electrophoresis ◽  
Protein Concentration ◽  
Polyacrylamide Gel Electrophoresis ◽  
Organic Matrix ◽  
Low Molecular Weight ◽  
Human Enamel ◽  
Weak Density ◽  
Enamel Protein

Pure enamel was prepared using an original microdissection technic. Protein concentration was 375 μg per gram of enamel. Polyacrylamide gel electrophoresis showed a single fast-migrating zone containing a thin double band. Ultracentrifugation studies suggested that the proteins were of low molecular weight or of weak density. Absorption spectra showed a strong absorbance at 260nm. Amino acid analyses yielded a composition of 25% Gly, 13.5% Glu, 11% Ser, 11% Pro, 2% Cys and 2% Hyp. A glucidic content of 15% was estimated and glucose, galactose, mannose and fucose were identified. The organic matrix of enamel seemed to be constituted of two major glycoproteins probably fibrous but different from keratin.

scholarly journals A Faster and a Stronger Defense Response: One of the Key Elements in Grapevine Explaining Its Lower Level of Susceptibility to Esca?

2013 ◽  
Vol 103 (10) ◽  
pp. 1028-1034 ◽  
Author(s):  
Carole Lambert ◽  
Ian Li Kim Khiook ◽  
Sylvia Lucas ◽  
Nadège Télef-Micouleau ◽  
Jean-Michel Mérillon ◽  
...  
Keyword(s):  
Defense Response ◽  
Defense Mechanisms ◽  
Defense Responses ◽  
Cabernet Sauvignon ◽  
Susceptible Cultivar ◽  
Pathogenesis Related ◽  
Leaf Level ◽  
Plant Pathogen Interaction ◽  
Related Proteins ◽  
Stilbene Compounds

Wood diseases like Esca are among the most damaging afflictions in grapevine. The defense mechanisms in this plant–pathogen interaction are not well understood. As some grapevine cultivars have been observed to be less susceptible to Esca than others, understanding the factors involved in this potentially stronger defense response can be of great interest. To lift part of this veil, we elicited Vitis vinifera plants of two cultivars less susceptible to Esca (‘Merlot’ and ‘Carignan’) and of one susceptible cultivar (‘Cabernet Sauvignon’), and monitored their defense responses at the leaf level. Our model of elicitation consisted in grapevine cuttings absorbing a culture filtrate of one causal agent of Esca, Phaemoniella chlamydospora. This model might reflect the early events occurring in Esca-affected grapevines. The two least susceptible cultivars showed an earlier and stronger defense response than the susceptible one, particularly with regard to induction of the PAL and STS genes, and a higher accumulation of stilbene compounds and some pathogenesis-related proteins.

scholarly journals OsWRKY62 and OsWRKY76 interact with Importin α1s for Negative Regulation of Defensive Responses in Nucleus

2021 ◽  
Author(s):  
Xiaohui Xu ◽  
Han Wang ◽  
Jiqin Liu ◽  
Shuying Han ◽  
Miaomiao Lin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nuclear Localization ◽  
Nuclear Export ◽  
Nuclear Translocation ◽  
Nuclear Export Signal ◽  
Defense Responses ◽  
Nuclear Localization Signals ◽  
Defensive Responses ◽  
Export Signal ◽  
Positively Charged

Abstract Background: OsWRKY62 and OsWRKY76, two close members of WRKY transcription factors, function together as transcriptional repressors. OsWRKY62 is predominantly localized in the cytosol. What are the regulatory factors for OsWRKY62 nuclear translocation?Results: In this study, we characterized they interacted with rice importin, OsIMα1a and OsIMα1b, for nuclear translocation. Chimeric OsWRKY62.1-GFP, which is predominantly localized in the cytoplasm, was translocated to the nucleus of Nicotiana benthamiana leaf cells in the presence of OsIMα1a or OsIMαDIBB1a lacking the auto-inhibitory importin β-binding domain. OsIMαDIBB1a interacted with the WRKY domain of OsWRKY62.1, which has specific bipartite positively charged concatenated amino acids functioning as a nuclear localization signal. Similarly, we found that OsIMαDIBB1a interacted with the AvrPib effector of rice blast fungus Magnaporthe oryzae, which contains a scattered distribution of positively charged amino acids. Furthermore, we identified a nuclear export signal in OsWRKY62.1 that inhibited nuclear transportation. Overexpression of OsIMα1a or OsIMα1b enhanced resistance to M. oryzae, whereas knockout mutants decreased resistance to the pathogen. However, overexpressing both OsIMα1a and OsWRKY62.1 were slightly more susceptible to M. oryzae than OsWRKY62.1 alone. Ectopic overexpression of OsWRKY62.1 with an extra nuclear export signal compromised the enhanced susceptibility of OsWRKY62.1 to M. oryzae.Conclusion: These results indicated that OsWRKY62 localization is a consequence of competition binding between rice importins and exportins. OsWRKY62, OsWRKY76, and AvrPib effector translocate to nucleus in association with importin α1s through new types of nuclear localization signals for negatively regulating defense responses.

scholarly journals Molecular Insights into Defense Responses of Vietnamese Maize Varieties to Fusarium verticillioides Isolates

2021 ◽  
Vol 7 (9) ◽  
pp. 724
Author(s):  
Trang Minh Tran ◽  
Maarten Ameye ◽  
Sofie Landschoot ◽  
Frank Devlieghere ◽  
Sarah De Saeger ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Fusarium Verticillioides ◽  
Gene Expression Profiles ◽  
Defense Responses ◽  
Ear Rot ◽  
In Planta ◽  
Resistant Lines ◽  
Maize Varieties ◽  
Pathogenesis Related ◽  
Related Proteins

Fusarium ear rot (FER) caused by Fusarium verticillioides is one of the main fungal diseases in maize worldwide. To develop a pathogen-tailored FER resistant maize line for local implementation, insights into the virulence variability of a residing F. verticillioides population are crucial for developing customized maize varieties, but remain unexplored. Moreover, little information is currently available on the involvement of the archetypal defense pathways in the F. verticillioides–maize interaction using local isolates and germplasm, respectively. Therefore, this study aims to fill these knowledge gaps. We used a collection of 12 F. verticillioides isolates randomly gathered from diseased maize fields in the Vietnamese central highlands. To assess the plant’s defense responses against the pathogens, two of the most important maize hybrid genotypes grown in this agro-ecological zone, lines CP888 and Bt/GT NK7328, were used. Based on two assays, a germination and an in-planta assay, we found that line CP888 was more susceptible to the F. verticillioides isolates when compared to line Bt/GT NK7328. Using the most aggressive isolate, we monitored disease severity and gene expression profiles related to biosynthesis pathways of salicylic acid (SA), jasmonic acid (JA), abscisic acid (ABA), benzoxazinoids (BXs), and pathogenesis-related proteins (PRs). As a result, a stronger induction of SA, JA, ABA, BXs, and PRs synthesizing genes might be linked to the higher resistance of line Bt/GT NK7328 compared to the susceptible line CP888. All these findings could supply valuable knowledge in the selection of suitable FER resistant lines against the local F. verticllioides population and in the development of new FER resistant germplasms.

scholarly journals Relationship Between Localized Acquired Resistance (LAR) and the Hypersensitive Response (HR): HR Is Necessary for LAR to Occur and Salicylic Acid Is Not Sufficient to Trigger LAR

1999 ◽  
Vol 12 (8) ◽  
pp. 655-662 ◽  
Author(s):  
Laurent Costet ◽  
Sylvain Cordelier ◽  
Stéphan Dorey ◽  
Fabienne Baillieul ◽  
Bernard Fritig ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Hypersensitive Response ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Pr Proteins ◽  
Tobacco Plants ◽  
Tobacco Leaves ◽  
Pathogenesis Related ◽  
Tobacco Mosaic Virus Infection ◽  
Mosaic Virus Infection

In tobacco plants reacting hypersensitively to pathogen infection, localized acquired resistance (LAR) is induced in a sharp zone surrounding hypersensitive response (HR) lesions. Using a fungal glycoprotein inducing HR and LAR when infiltrated at 50 nM into tobacco leaves, we have shown previously that a plant signal(s) is released by HR cells and diffuses to induce LAR. Here we address two questions: does LAR occur when HR is not induced, and is salicylic acid the (or one of the) mobile LAR signal? We found that application to tobacco leaves of 0.25 nM glycoprotein triggered defense responses without HR and without an H2O2 burst. The analyzed responses include changes in expression of O-methyltransferase (OMT), 3-hydroxy-3-methylglutarylCoA reductase, pathogenesis-related (PR) proteins, and changes in levels of the signal salicylic acid. No defense responses and no increased resistance to tobacco mosaic virus infection were found beyond the elicitor-infiltrated tissue, providing strong evidence that there is no LAR without HR. Treatments of NahG tobacco leaves with 50 nM elicitor induced the HR and, in the sharp zone surrounding the HR lesion, a strong activation of OMT and of basic PR proteins, but not of acidic PR-1 proteins. This indicates that a signal different from salicylic acid is diffusing.

Bifunctionally engineered polyethylenimines as efficient DNA carriers and antibacterials against resistant pathogens

2018 ◽  
Vol 33 (3) ◽  
pp. 363-379
Author(s):  
Z Ahmadi ◽  
D Jha ◽  
B Kumar ◽  
HK Gautam ◽  
Pradeep Kumar
Keyword(s):  
Gel Electrophoresis ◽  
Mammalian Cells ◽  
Biomedical Applications ◽  
Pathogenic Bacteria ◽  
Low Molecular Weight ◽  
High Cell ◽  
Gene Delivery Vectors ◽  
Efficient Gene ◽  
Resistant Strains ◽  
Better Than

In this study, we have designed and developed two series of bifunctional conjugates by tethering polyethylenimine with streptomycin. By varying the amount of streptomycin, conjugates, polyethylenimine-streptomycin, have been synthesized and characterized spectroscopically. Gel electrophoresis assay revealed a slight decrease in the cationic charge density on the conjugates as these retarded the mobility of pDNA at higher w/w ratios. Further, transfection studies showed that both the series of conjugates transfected the mammalian cells efficiently with low-molecular weight polyethylenimine-streptomycin conjugates were more competent (∼9-fold enhancement with respect to native bPEI) exhibiting high cell viability too. Besides, both the series of conjugates displayed excellent antibacterial activity on pathogenic bacteria, even better than native streptomycin on resistant strains. Altogether, these results ensure the promising potential of the projected bifunctional conjugates as safe and efficient gene delivery vectors as well as antibacterials for future biomedical applications.

scholarly journals Serological grouping ofTreponema hyodysenteriae

1990 ◽  
Vol 105 (1) ◽  
pp. 79-85 ◽  
Author(s):  
D. J. Hampson ◽  
J. R. L. Mhoma ◽  
B. G. Combs ◽  
J. I. Lee
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Vaccine Development ◽  
Polyacrylamide Gel Electrophoresis ◽  
Cross Reactivity ◽  
Low Molecular Weight ◽  
Serological Response ◽  
Double Immunodiffusion ◽  
Sds Page ◽  
Treponema Hyodysenteriae

SUMMARYTwo Australian isolates ofTreponema hyodysenteriaewhich did not fit within the current serological grouping system for these bacteria wrere examined by agarose gel double immunodiffusion tests (AGDP). Isolate Vic1 was serologically unique, and we propose that it becomes the type organism for a new sixth serological group ofT. hyodysenteriae(Group F). Isolate Q1 was unusual in that lipopolysaccharide (LPS) extracted from it reacted strongly in AGDP with serum raised against the type organism for serogroup D (A1), and also weakly with serum raised against the type organism for serogroup B (WA1). The nature of this cross-reactivity was examined by using cross-absorbed antisera in AGDP, and by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis.The pattern of serological cross-reactivity between Q1, A1 and WA1 was complex and was not fully defined, but the isolate Q1 apparently shared low molecular weight ‘serogroup’ LPS antigens with A1, and shared higher molecular weight LPS antigens with WA1. On this basis Q1 was designated as belonging to serogroup D, although it was recommended that this be qualified as D (B) to indicate the presence of weak cross-reactivity with serogroup B. Such serological cross-reactivity may have significance in relation to the development of immunity toT. hyodysenteriae. Isolate Q1 may be a potentially useful organism for vaccine development because of its ability to induce a good serological response to LPS of treponemes from both serogroups D and B.

scholarly journals The Absence of Nops Secretion in Sinorhizobium fredii HH103 Increases GmPR1 Expression in Williams Soybean

2009 ◽  
Vol 22 (11) ◽  
pp. 1445-1454 ◽  
Author(s):  
Francisco Javier López-Baena ◽  
José Antonio Monreal ◽  
Francisco Pérez-Montaño ◽  
Beatriz Guasch-Vidal ◽  
Ramón A. Bellogín ◽  
...  
Keyword(s):  
Plant Defense ◽  
Type Iii Secretion ◽  
Transcriptional Regulators ◽  
Defense Responses ◽  
Secretion System ◽  
Plant Defense Responses ◽  
Sinorhizobium Fredii ◽  
Pathogenesis Related ◽  
Complete Set ◽  
Soybean Roots

Sinorhizobium fredii HH103 secretes through the type III secretion system at least eight nodulation outer proteins (Nops), including the effector NopP. These proteins are necessary for an effective nodulation of soybean. In this work, we show that expression of the nopP gene depended on flavonoids and on the transcriptional regulators NodD1 and TtsI. Inactivation of nopP led to an increase in the symbiotic capacity of S. fredii HH103 to nodulate Williams soybean. In addition, we studied whether Nops affect the expression of the pathogenesis-related genes GmPR1, GmPR2, and GmPR3 in soybean roots and shoots. In the presence of S. fredii HH103, expression of pathogenesis-related (PR) gene PR1 was induced in soybean roots 4 days after inoculation and it increased 8 days after inoculation. The absence of Nops provoked a higher induction of PR1 in both soybean roots and shoots, suggesting that Nops function early, diminishing plant defense responses during rhizobial infection. However, the inactivation of nopP led to a decrease in PR1 expression. Therefore, the absence of NopP or that of the complete set of Nops seems to have opposite effects on the symbiotic performance and on the elicitation of soybean defense responses.

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