scholarly journals A Thermally Stable Protein EPP1 of Corn Borer Ostrinia furnacalis Regulates Hemocytic Encapsulation

2021 ◽  
pp. 1-15
Author(s):  
Jian Hu ◽  
Xiangping Feng ◽  
Li Yao ◽  
Meng Meng ◽  
Yan Du ◽  
...  
Keyword(s):  
Polyclonal Antibodies ◽  
Repetitive Sequences ◽  
Secretory Protein ◽  
Thermally Stable ◽  
Ostrinia Furnacalis ◽  
Corn Borer ◽  
Asian Corn Borer ◽  
A Cell ◽  
Fat Bodies ◽  
Cellular Immune

Encapsulation is a vital cellular immune reaction of host insects against endoparasitoids; however, how encapsulation is regulated is still unclear. Utilizing a cell line, SYSU-<i>Of</i>Hem C, derived from larval hemocytes of the Asian corn borer <i>Ostrinia furnacalis</i> to assay for encapsulation response<i>,</i> an encapsulation-promoting protein (<i>Of</i>EPP1) was isolated from the plasma of <i>O. furnacalis</i> larvae. <i>Of</i>EPP1 is a novel secretory protein, which exists only in <i>O. furnacalis</i> to date. The <i>OfEpp1</i> gene is intronless and encodes a protein containing several groups of short repetitive sequences and a high proportion of proline residues (18.3%). <i>Of</i>EPP1 is a thermally stable protein that is mainly expressed in fat bodies, and its accumulation could be induced by the injection of foreign objects (Sephadex beads). Eukaryotically expressed recombinant <i>Of</i>EPP1 promoted hemocytes to encapsulate Sephadex beads, while prokaryotically expressed protein did not, indicating that posttranscriptional modification affects the function of <i>Of</i>EPP1. The encapsulation-promoting function of <i>Of</i>EPP1 could be neutralized by the addition of polyclonal antibodies against <i>Of</i>EPP1 or disrupted by the injection of dsRNA targeting <i>OfEpp1.</i> Eukaryotically expressed <i>Of</i>EPP1 promoted the aggregation, but not spreading, of both granulocytes and plasmatocytes. Immunocytochemistry analysis showed that eukaryotically expressed <i>Of</i>EPP1 could bind to the surface of hemocytes. Therefore, we speculate that <i>Of</i>EPP1 possibly promotes hemocytic encapsulation by binding to the surface of hemocytes as a ligand to induce their aggregation. This study provides evidence clarifying the mechanism of encapsulation in insects.

scholarly journals A Short-Type Peptidoglycan Recognition Protein 1 (PGRP1) Is Involved in the Immune Response in Asian Corn Borer, Ostrinia furnacalis (Guenée)

2021 ◽  
Vol 22 (15) ◽  
pp. 8198
Author(s):  
Dongxu Shen ◽  
Jiayue Ji ◽  
Shasha Zhang ◽  
Jiahui Liu ◽  
Chunju An
Keyword(s):  
Immune Response ◽  
Micrococcus Luteus ◽  
Binding Activity ◽  
Ostrinia Furnacalis ◽  
Corn Borer ◽  
Peptidoglycan Recognition Protein ◽  
Asian Corn Borer ◽  
Recognition Protein ◽  
Fat Bodies ◽  
Insect Immune Response

The insect immune response is initiated by the recognition of invading microorganisms. Peptidoglycan recognition proteins (PGRPs) function primarily as pattern recognition receptors by specifically binding to peptidoglycans expressed on microbial surfaces. We cloned a full-length cDNA for a PGRP from the Asian corn borer Ostrinia furnacalis (Guenée) and designated it as PGRP1. PGRP1 mRNA was mainly detected in the fat bodies and hemocytes. Its transcript levels increased significantly upon bacterial and fungal challenges. Purified recombinant PGRP1 exhibited binding activity to the gram-positive Micrococcus luteus, gram-negative Escherichia coli, entomopathogenic fungi Beauveria bassiana, and yeast Pichia pastoris. The binding further induced their agglutination. Additionally, PGRP1 preferred to bind to Lys-type peptidoglycans rather than DAP-type peptidoglycans. The addition of recombinant PGRP1 to O. furnacalis plasma resulted in a significant increase in phenoloxidase activity. The injection of recombinant PGRP1 into larvae led to a significantly increased expression of several antimicrobial peptide genes. Taken together, our results suggest that O. furnacalis PGRP1 potentially recognizes the invading microbes and is involved in the immune response in O. furnacalis.

scholarly journals Trichogramma ostriniae Is More Effective Than Trichogramma dendrolimi As a Biocontrol Agent of the Asian Corn Borer, Ostrinia furnacalis

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 70
Author(s):  
Yu Wang ◽  
Yang-Yang Hou ◽  
Giovanni Benelli ◽  
Nicolas Desneux ◽  
Asad Ali ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Developmental Time ◽  
Economic Losses ◽  
Ostrinia Furnacalis ◽  
Female Progeny ◽  
Corn Borer ◽  
High Preference ◽  
Asian Corn Borer ◽  
Biocontrol Potential ◽  
Trichogramma Dendrolimi

The Asian corn borer (ACB), Ostrinia furnicalis, is a serious corn pest in south-east Asia, causing huge economic losses every year. Trichogramma dendrolimi and Trichogramma ostriniae, two egg parasitoids, have previously been identified as key biological control agents. To determine the age impact of ACB eggs on their effective biocontrol potential, herein we compared the biological parameters (i.e., number of parasitized eggs, emergence, developmental time, and sex ratio) of both parasitoids on ACB eggs of various ages (i.e., 0–4, 4–8, 8–12, 12–16, 16–24, 24–36, and 36–48 h old), respectively. Our results showed that the age of ACB eggs had a significant impact on the parasitization activity of T. dendrolimi in both choice and no-choice conditions. Trichogramma dendrolimi preferred to parasitize 0–8-h-old ACB eggs, and its parasitization dramatically declined on ACB eggs older than 8 h under choice and no-choice conditions. On the other hand, T. ostriniae showed high preference to parasitize all tested ACB egg ages. The age of ACB eggs had no significant impact on the parasitization of T. ostriniae under choice and no-choice conditions. Furthermore, the female progeny of T. dendrolimi decreased as the age of ACB increased, while no differences were found in female progeny of T. ostriniae. Trichogramma ostriniae also developed faster on each ACB egg age group in comparison with T. dendrolimi. Overall, the age of ACB eggs had a significant impact on T. dendrolimi performance, leading us to conclude that T. ostriniae is more effective than T. dendrolimi as a biocontrol agent of the ACB.

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