Parasitism by Cotesia plutellae inhibits imaginal wing disc development ofdiamondback moth, Plutella xylostella

Sungwoo Bae,김용균 한국응용곤충학회 2008 Journal of Asia-Pacific Entomology Vol.11 No.2

Cotesia plutellae is an endoparasitoid that parasitizes the diamondback moth Plutella xylostella. Parasitized P. xylostella exhibits immunosuppression and developmental retardation, resulting in death before pupation after parasitoid emergence. Except digestive organ, most host internal organs of parasitized P. xylostella show poor development, suggesting nutrient deprivation by the parasitoid. Here we report another significant morphological aberration in the development of parasitized P. xylostella. Imaginal wing disc development was markedly inhibited, while nonparasitized larvae developed two pairs of wing discs (approximately 0.5 mm diameter) in the thorax at their final instar. Since P. xylostella wing disk development can begin at the late larval stage depending on their nutritional status, C. plutellae parasitism may prevent wing disc development indirectly by disrupting host nutrient usage. Also, the hypotrophied wing disc of parasitized P. xylostella may be associated with immunosuppression due to its structural association with the hematopoietic organ in most lepidopteran wing discs. This study showed a high correlation between wing disc development and total hemocyte population in P. xylostella. Cotesia plutellae is an endoparasitoid that parasitizes the diamondback moth Plutella xylostella. Parasitized P. xylostella exhibits immunosuppression and developmental retardation, resulting in death before pupation after parasitoid emergence. Except digestive organ, most host internal organs of parasitized P. xylostella show poor development, suggesting nutrient deprivation by the parasitoid. Here we report another significant morphological aberration in the development of parasitized P. xylostella. Imaginal wing disc development was markedly inhibited, while nonparasitized larvae developed two pairs of wing discs (approximately 0.5 mm diameter) in the thorax at their final instar. Since P. xylostella wing disk development can begin at the late larval stage depending on their nutritional status, C. plutellae parasitism may prevent wing disc development indirectly by disrupting host nutrient usage. Also, the hypotrophied wing disc of parasitized P. xylostella may be associated with immunosuppression due to its structural association with the hematopoietic organ in most lepidopteran wing discs. This study showed a high correlation between wing disc development and total hemocyte population in P. xylostella.

Attenuation of antiviral activity of the diamondback moth, Plutella xylostella, by a polydnaviral product, CpBV-IkB

Sungwoo Bae,Yonggyun Kim 한국응용곤충학회 2008 한국응용곤충학회 학술대회논문집 Vol.2008 No.05

The diamondback moth, Plutella xylostella, is reluctant to a baculovirus, Autographa california nucleopolyhedrosis virus (AcNPV) at its oral administration. However, parasitization by an endoparasitoid wasp, Cotesia plutellae, enhances the viral susceptibility. This study analyzed an antiviral activity of P. xylostella in response to the viral infection and determined the parasitic factor inhibiting the antiviral mechanism. For the analysis of antiviral activity of P. xylostella, a recombinant AcNPV expressing enhanced green fluorescence (AcNPV-EGFP) was orally adminstered to lavae of P. xylostella. After 24 h, EGFP expression was observed in the midgut tissue at a confocal-FITC mode. At the same time, a characteristic midgut melanotic response (MMR) was observed in some midgut regions under a phase contrast microscope. Thereafter, the EGFP signal was attenuated, while MMR spread on most midgut region. When the MMR was scored from 0 to 5 by the intensity of melanized cell density, it increased in time- and dose-dependent manners at the viral administration per os. These results suggest that the MMR is an antiviral activity of P. xylostella. This antiviral activity was significantly attenuated by C. plutellae parasitism. The parasitized P. xylostella showed significant decrease in the MMR score compared to nonparasitized larvae when they were orally administered with the same dose of AcNPV. To determine the parasitic factor(s) inhibiting the antiviral activity from the symbiotic polydnavirus of C. plutellae (C. plutellae bracovirus: CpBV), CpBV-IkB, which is a viral homolog of NFkB inhibitor and has been considered as an antiviral factor as in other polydnaviruses, was tested. A recombinant AcNPV expressing CpBV-IkB (AcNPV-IkB) was constructed and administered to P. xylostella larvae. As expected, AcNPV-IkB significantly decreased the antiviral activity measured by the MMR score compared to AcNPV-EGFP treatment. This study suggests that CpBV-IkB plays an antiviral parasitic role in the molecular interactions between P. xylostella and C. plutellae.

Effects of three different cultivars of cruciferous plants on the age‐stage, two‐sex life table traits of Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Waqar Jaleel,Shafqat SAEED,Qamar Saeed,Muhammad Nadir NAQQASH,Muhammad Umair SIAL,Qurat Ul AINE,Lei YANYUAN,Zhao RUI,Yurong HE,Lihua LU 한국곤충학회 2019 Entomological Research Vol.49 No.4

Plutella xylostella is an important pest of cruciferous crops worldwide. However, information regarding the age‐stage, two‐sex life parameters of P. xylostella, which is vital for designing more effective control methods, is currently lacking. The present study reports age‐stage, two‐sex life table parameters for P. xylostella on napa cabbage (Brassica oleracea var. napa), white cabbage (B. oleracea var. capitata), and cauliflower (B. oleracea var. botrytis) under laboratory conditions at 25 ± 2°C, 50–60% relative humidity, and a 16‐h light : 8‐h dark photoperiod. The time for development from an egg to a male or female adult P. xylostella on white cabbage (mean [± SE] 41.15 ± 0.54 and 39.50 ± 0.54 days, respectively) was significantly longer than that on cauliflower and napa cabbage. Furthermore, P. xylostella fecundity on cauliflower (261.90 ± 4.53 eggs female) was significantly highest than on napa cabbage and white cabbage. Intrinsic rate of increase (r) and finite rate of increase (λ) were highest on cauliflower 0.182 day−1 and 1.199 day−1 respectively as comparison to napa cabbage and white cabbage. The highest gross reproductive rate (GRR) and net reproductive rates (R0) of P. xylostella 65.87 and 52.58 respectively on cauliflower then those of other hosts. The findings of the present study indicate that cauliflower is the most suitable cultivar (host) for the development of P. xylostella. Based on these findings, crops like cauliflower can be used as trap crops when napa cabbage and white cabbage are the main crops.

Parasitism by Cotesia plutellae inhibits imaginal wing disc development of diamondback moth, Plutella xylostella

Bae, Sung-Woo,Kim, Yong-Gyun 한국응용곤충학회 2008 Journal of Asia-Pacific Entomology Vol. No.

Cotesia plutellae is an endoparasitoid that parasitizes the diamondback moth Plutella xylostella. Parasitized P. xylostella exhibits immunosuppression and developmental retardation, resulting in death before pupation after parasitoid emergence. Except digestive organ, most host internal organs of parasitized P. xylostella show poor development, suggesting nutrient deprivation by the parasitoid. Here we report another significant morphological aberration in the development of parasitized P. xylostella. Imaginal wing disc development was markedly inhibited, while nonparasitized larvae developed two pairs of wing discs (approximately 0.5 mm diameter) in the thorax at their final instar, Since P. xylostella wing disk development can begin at the late larval stage depending on their nutritional status, C. plutellae parasitism may prevent wing disc development indirectly by disrupting host nutrient usage. Also, the hypotrophied wing disc of parasitized P. xylostella may be associated with immunosuppression due to its structural association with the hematopoietic organ in most lepidopteran wing discs. This study showed a high correlation between wing disc development and total hemocyte population in P. xylostella.

Cotesia plutellae Bracovirus Suppresses Expression of an Antimicrobial Peptide, Cecropin, in the Diamondback Moth, Plutella xylostella, Challenged by Bacteria

Barandoc, Karen P.,Kim, Jae-Hyun,Kim, Yong-Gyun 한국미생물학회 2010 The journal of microbiology Vol.48 No.1

An endoparasitoid wasp, Cotesia plutellae, induces significant immunosuppression of host insect, Plutella xylostella. This study was focused on suppression in humoral immune response of P. xylostella parasitized by C. plutellae. An EST database of P. xylostella provided a putative cecropin gene (PxCec) which is 627 bp long and encodes 66 amino acids. A signal peptide (22 amino acids) is predicted and two putative O-glycosylation sites in threonine are located at positions 58 and 64. Without bacterial infection, PxCec was expressed in pupa and adult stages but not in the egg and larval stages. Upon bacterial challenge, however, the larvae expressed PxCec as early as 3 h post infection (PI) and maintained high expression levels at 12-24 h PI. By 48 h PI, its expression noticeably diminished. All tested tissues of bacteria-infected P. xylostella showed PxCec expression. However, other microbes, such as virus and fungus, did not induce the PxCec expression. Parasitization by C. plutellae suppressed the expression of PxCec in response to bacterial challenge. Among the parasitic factors of C. plutellae, its symbiotic virus (C. plutellae bracovirus: CpBV) alone was able to inhibit the expression of PxCec of P. xylostella challenged by bacteria. These results indicate that PxCec expression is regulated by both immune and developmental processes in P. xylostella. The parasitization by C. plutellae inhibited the expression of PxCec by the wasp's symbiotic virus.

Combined Application of Trichogramma ostriniae and Bacillus thuringiensis for Eco-friendly Control of Plutella xylostella

Hwang, In-Cheon,Park, Chan,Kang, Dong-Kyun,Jin, Na-Young,Jung, Sun-Young,Seo, Mi-Ja,Kim, Jang-Eok,Youn, Young-Nam,Yu, Yong-Man The Korean Society for Applied Biological Chemistr 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.3

Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), is one of the most destructive insect pests of cruciferous crops. This study is to determine the effect of a combined treatment of Bacillus thuringiensis (Berliner) and Trichogramma ostriniae (Peng and Chen) (Hymenoptera: Trichogrammatidae) applied for an eco-friendly control of Diamondback moth, P. xylostella. Results of the investigation of the resistance ratio of four field populations of P. xylostella to B. thuringiensis shows that Hoengseong populations were highly resistance to the 17.1-fold of B. thuringiensis subsp. aizawai and to the 36.0-fold of B. thuringiensis subsp. kurstaki. B. thuringiensis was proven to give no detrimental effects on adult survival and eggs parasitism of the wasp based on contact toxicity test. Survival rates of P. xylostella were 31.67% and 14.17% on single treatment of T. ostriniae and B. thuringiensis, respectively. But, survival rate of P. xylostella was 1.07% on a combined treatment of egg parasitoid and B. thuringiensis. The combined treatment of both biological control agents significantly decreased the crops damage rate, though none of the biological control agents alone showed any significant control efficacy.

Analysis of the immune-inducible genes of Plutella xylostella using expressed sequence tags and cDNA microarray

Eum, J.H.,Seo, Y.R.,Yoe, S.M.,Kang, S.W.,Han, S.S. Pergamon Press ; Elsevier Science Ltd ; Pergamon 2007 DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY Vol.31 No.11

In the present study, the complex gene expression responses of Plutella xylostella to microbial challenges and injury were surveyed using a newly constructed expressed sequence tag (EST) clone collection and cDNA microarray analysis. A total of 1132 P. xylostella ESTs were cloned, annotated and categorized by their putative functions; these included proteases, protease inhibitors, recognition molecules and anti-microbial peptides. GeneOntology revealed that 4% of the P. xylostella ESTs corresponded to immunity-related genes potentially involved in innate immunity. We then used microarray analysis to identify 44 genes that were differentially expressed with at least a two-fold expression difference in P. xylostella before and after pathogen challenge. Together, our EST categorization and microarray profiling analyses allowed us to identify 70 genes that should be considered candidate immune response genes, providing important new insights into the molecular events that occur during the innate immune response in P. xylostella.

Genetic Analysis of the Diamondback Moth, Plutella xylostella, Collected from China Using Mitochondrial COI Gene Sequence

Li, Jianhong,Choi, Yong Soo,Kim, Iksoo,Sohn, Hung Dae,Jin, Byung Rae Korean Society of Sericultural Science 2004 International Journal of Industrial Entomology Vol.9 No.1

The diamondback moth, Plutella xylostella, is notorious because of its extensive potential and actual dispersal ability. Previously, the Korean populations of P. xylostella was extensively collected and analyzed for their genetic population structure using a portion of mitochondrial DNA (mtDNA). One of the postulated characteristics on population genetic structure of the species includes the presence of heterogeneous haplotypes, possibly possessed by some dispersed ones from neighboring countries. In this study, we sequenced ten P. xylostella collected from China (∼2,000 km away from the middle part of Korea) to know the genetic relationships of these to the Korean P. xylostella. Sequence analysis of the identical portion of COI gene resulted in five haplotypes with the sequence divergence ranging from 0.5% (two nucleotides) to 1.1 % (five nucleotides) among them and from 0.7% (three) to 2.5% (11) to the pre-existing 52 Korean haplotypes. Phylogenetic analysis showed that the Chinese P. xylostella were neither clearly separated from the Korean haplotypes nor clustered with one heterogeneous Korean haplotype. This result reinforces the significance of gene flow in this species and suggests to exclude the possibility that the heterogeneous Korean haplotypes may have emigrated from China, where our samples were obtained, although further extensive investigation is required.

N-terminal tail of a viral histone H4 encoded in <i>Cotesia plutellae</i> bracovirus is essential to suppress gene expression of host histone H4

Gad, W.,Kim, Y. Blackwell Publishing Ltd 2009 INSECT MOLECULAR BIOLOGY Vol.18 No.1

<P>Abstract</P><P>An endoparasitoid wasp, <I>Cotesia plutellae</I>, possesses a symbiotic bracovirus (CpBV), which facilitates parasitism of a specific host, such as larvae of the diamondback moth, <I>Plutella xylostella</I>. A viral histone H4 (CpBV-H4) has been found in the CpBV genome and its gene product plays a role in impairing the host insect cellular immune response. Based on its high similarity to histone H4 of <I>P. xylostella</I> apart from its extended N-terminal tail, it has been suspected to alter host gene expression. Histone subunits were purified from parasitized <I>P. xylostella</I> larvae and found to contain both host and viral H4s, confirming a previous report of a possible epigenetic mode of action. Moreover, this study showed that the host H4 levels in the parasitized larvae clearly decreased during the parasitization period, whereas CpBV-H4 levels maintained a significant level without significant changes. To understand the decrease of host H4 levels, transcription levels of host H4 were monitored by quantitative reverse-transcriptase PCR (RT-PCR) and showed a significant decrease in parasitized <I>P. xylostella </I>larvae, whereas no significant change of the mRNA level was detected in nonparasitized larvae. This transcriptional control of host H4 expression was also observed by inducing transient expression of CpBV-H4 in nonparasitized <I>P. xylostella</I>. Moreover, co-injection of CpBV-H4 and its specific double-stranded RNA recovered the host H4 expression level. To identify a functional domain of CpBV-H4 involved in the transcriptional control, the extended N-terminal tail of CpBV-H4 was removed by preparing a truncated viral H4 construct in an expression vector by deleting the N-terminal tail of 38 amino acid residues and inducing its expression in nonparasitized <I>P. xylostella </I>larvae. The truncated CpBV-H4 clearly lost its inhibitory effects on host H4 transcription. Moreover, the presence of CpBV-H4 affects the spreading of host haemocytes by an epigenetic effect, which is at least partly restored in larvae expressing the truncated version of CpBV-H4. This study suggests that the viral H4 encoded in CpBV can alter host gene expression with its extended N-terminal tail.</P>

Insecticidal Capacity of Recombinant Baculoviruses to Plutella xylostella and Spodoptera exigua larvae

Myung-Pyo Jung,Hong-Hyun Park,Jae Young Choi,Yeon Ho Je 한국응용곤충학회 2012 한국응용곤충학회 학술대회논문집 Vol.2012 No.05

This study was conducted to investigate the insecticidal capacity of recombinant baculoviruses to Plutella xylostella and Spodoptera exigua larvae. For recombinant viruses, Bacillus thuringiensis cry1-5 crystal protein gene was introduced into the genome by fusion of polyhedrin-cry1-5 under the control of polyhedrin gene promoter. Recombinant AcPolh5-3006BiKTT and AcPolh5-3006 AvTox2 based on BiKTT and AvTox2, respectively, were constructed under the control of early promoter from Cotesia plutellae bracovirus. Mortality of S. exigua larvae was significantly higher when they fed on cabbage coated with ApEGFP (wild type) over 5.0×106 PIBs/ml. For AcPolh5-3006BiKTT and AcPolh5-3006AvTox2, mortality of P. xylostella and S. exigua larvae was significantly higher when they fed on cabbage coated with recombinant baculoviruses over 5.0×106 PIBs/ml and 1.0×104 PIBs/ml, respectively. The value of LD50 was lower in the treatments with AcPolh5-3006BiKTT (P. xylostella:1.2×106, S. exigua:1.3×104) or AcPolh5-3006AvTox2 (P. xylostella:2.3×106, S. exigua:1.4×104) than the treatments with ApEGFP (P. xylostella: not estimated, S. exigua:5.0×105). Survival time (ST50) of P. sylostella larvae was much shorter at AcPolh5-3006BiKTT (29.6h) than AcPolh5-3006AvTox2 (46.2h) while that of S. exigua larvae was much shorter at AcPolh5-3006AvTox2 (95.1h) than AcPolh5-3006BiKTT (101.9h) or ApEGFp (130.7h). The two recombinant baculoviruses were more effective in S. exigua larvae but slower speed of action.