Immunosuppressive Activity of Cultured Broth of Entompathogenic Bacteria on the Beet Armyworm, Spodoptera exigua, and Their Mixture Effects with Bt Biopesticide on Insecticidal Pathogencity

파밤나방(Spodoptera exigua)에 대한 곤충병원세균류 배양액의 곤충면역억제활성 및 비티 생물농약과 혼합효과

  • Kim, Jea-Min (Plant Medicine, School of Bioresource Sciences, Andong National University) ;
  • Nalini, Madanagopal (Plant Medicine, School of Bioresource Sciences, Andong National University) ;
  • Kim, Yong-Gyun (Plant Medicine, School of Bioresource Sciences, Andong National University)
  • 김지민 (안동대학교 자연과학대학 생명자원과학부 식물의학) ;
  • ;
  • 김용균 (안동대학교 자연과학대학 생명자원과학부 식물의학)
  • Published : 2008.06.30


Entomopathogenic bacteria (Xenorhabdus nematophila, X. sp. and Photorhabdus temperata subsp. temperata) isolated from entomopathogenic nematodes express potent insecticidal activity in insect hemocoel. They are also known to suppress insect immune mediation by inhibiting phospholipase $A_2$, leading to host immunosuppression. This study analyzed effects of their cultured broths on inhibiting insect immunosuppression. For this, we removed all bacterial cells using $0.2\;{\mu}m$ pore sized membrane from the bacteria-cultured broth. All three sterilized cultured media, in dose-dependent manners, significantly inhibited hemocyte-spreading behavior of 5th instar larvae of Spodoptera exigua. However, they showed differential inhibitory activities among different bacterial species, in which X. nematophila showed the most potent inhibitory activity. This immunosuppressive effect was applied to increase the pathogenicity of Bacillus thuringiensis (Bt). All three bacterial cultured broths including bacterial cells significantly potentiated Bt pathogenicity against young S. exigua larvae when each of them was orally administered in a mixture of low dose of Bt. Finally, we tested the effect of oral administration of the cultured media containing the immunosuppressive compound(s) secreted by the bacteria. The membrane-sterilized cultured broths were mixed with the low dose of Bt and then orally administered to the young S. exigua. Only the cultured medium of X. nematophila showed increase of Bt pathogenicity. These results indicated that the; cultured media of the three bacteria possessed immunosuppressive factor(s), which may act to potentiate Bt toxicity to young S. exigua larvae.


  1. Clark, K.D., Y. Kim and M.R. Strand (2005) Plasmatocyte sensitivity to plasmatocyte spreading peptide (PSP) fluctuates with the larval molting cycle. J. Insect Physiol. 51:587-596
  2. Dennis, E.A. (1997) The growing phospholipase A2 superfamily of signal transduction enzymes. Trends. Biochem. Sci. 22:1-2
  3. Dunphy, G.B. and J.M. Webster (1984) Interaction of Xenorhabdus nematophilus subsp. nematophilus with the haemolymph of Galleria mellonella. J. Insect Physiol. 30:883-889
  4. ffrench-Constant, R.H., N. Waterfield and P. Daborn (2005) Insecticidal toxins from Photorhabdus and Xenorhabdus. pp. 239-253, In Comprehensive Molecular Insect Science (eds. L.I. Gilbert, I. Kostas and S.S. Gill), Elsevier, New York
  5. Ji, D., Y. Yi and Y. Kim (2004a) 16S rDNA sequence and biochemical characters of a Korean isolate of Xenorhabdus nematophila. J. Asia-Pacific Entomol. 7:105-111
  6. Lord, J.C., S. Anderson and D.W. Stanley (2002) Eicosanoids mediate Manduca sexta cellular response to the fungal pathogen Beauveria bassiana: a role for lipoxygenase pathway. Arch. Insect Biochem. Physiol. 51:46-54
  7. Stanley, D. (2006) Prostaglandins and other eicosanoids in insects: biological significance. Annu. Rev. Entomol. 51:25-44
  8. Forst, S., B. Dowds, N. Boemare and E. Stackebrandt (1997) Xenorhabdus and Photorhabdus spp.: bugs that kill bugs. Annu. Rev. Microbiol. 51:47-72
  9. Kwon, S. and Y. Kim (2007) Immunosuppressive action of pyriproxyfen, a juvenile hormone analog, enhances pathogenicity of Bacillus thuringiensis subsp. kurstaki against diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae). Biol. Control 42:72-76
  10. Bae, S. and Y. Kim (2003) Lysozyme of the beet armyworm, Spodoptera exigua: activity induction and cDNA structure. Comp. Biochem. Physiol. 135B:511-519
  11. Buyukguzel, E., H. Tunaz, D. Stanley and K. Buyukguzel (2007) Eicosanoids mediate Galleria mellonella cellular immune response to viral infection. J. Insect Physiol 53:99-105
  12. Gahan, L.J., F. Gould and D.G. Heckel (2001) Identification of a gene associated with Bt resistance in Heliothis virescens. Science 293:857-860
  13. Nalini, M., Y. Lee and Y. Kim (2007) Pyriproxyfen inhibits hemocytic phagocytosis of the beet armyworm. Spodoptera exigua. Kor. J. Pesti. Sci. 11:164-170
  14. Park, Y. and Y. Kim (2000) Eicosanoids rescue Spodoptera exigua infected with Xenorhabdus nematophila, the symbiotic bacteria to the entomopathogenic nematode Steinernema carpocapsae. J. Insect Physiol. 46:1469-1476
  15. 고현관, 이상계, 이비파, 최귀문, 김정화 (1991) 인공사료에 의한 파밤나방의 대량사육법. 한응곤지 29:180-183
  16. Jung, S. and Y. Kim (2006) Synergistic effect of Xenorhabdus nematophila K1 and Bacillus thuringiensis subsp. aizawai against Spodoptera exigua (Lepidoptera: Noctuidae). Biol. Control 39:201-209
  17. Kang, S., S. Han and Y. Kim (2004) Identification of an entomopathogenic bacterium, Photorhabdus temperata subsp. temperata, in Korea. J. Asia-Pacific Entomol. 7:331-337
  18. Shrestha, S. and Y. Kim (2007b) Factors affecting the activation of hemolymph prophenoloxidase of Spodoptera exigua (Lepidoptera: Noctuidae). J. Asia-Pacific Entomol. 10:131-135
  19. Boemare, N. (2002) Biology, taxonomy and systematics of Photorhabdus and Xenorhabdus. pp. 35-56, In Entomopathogenic Nematology (ed. R. Gaugler), CABI Publishing, New York
  20. Kim, Y., D. Ji, S. Cho and Y. Park. 2005. Two groups of entomopathogenic bacteria, Photorhabdus and Xenorhabdus, share an inhibitory action against phospholipase A2 to induce host immunodepression. J. Invertebr. Pathol. 89:258-264
  21. Kaya, H.K. and R. Gaugler (1993) Entomopathogenic nematodes. Annu. Rev. Entomol. 38:181-206
  22. Kwon, B. and Y. Kim (2008) Benzylideneacetone, an immunosuppressant, enhances virulence of Bacillus thuringiensis against beet armyworm (Lepidoptera: Noctuidae). J. Econ. Entomol. (In press)
  23. Akhurst, R.J. (1980) Morphological and functional dimorphism in Xenorhabdus spp., bacteria symbiotically associated with the insect pathogenic nematodes Neoaplectana and Heterorhabditis. J. Gen. Microbiol. 121:303-309
  24. Shrestha, S. and Y. Kim (2007a) An entomopathogenic bacterium, Xenorhabdus nematophila, inhibits hemocyte phagocytosis of Spodoptera exigua by inhibiting phospholipase A2. J. Invertebr. Pathol. 96:64-70
  25. Rajagopal, R., S. Sivakumar, N. Agrawal, P. Malhotra and R.K. Bhatnagar (2002) Silencing of midgut aminopeptidase N of Spodoptera litura by double-stranded RNA established its role as Bacillus thuringiensis toxin receptor. J. Biol. Chem. 277:46849-46851
  26. Adams, B.J. and K.B. Nguyen (2002) Taxonomy and systematics. pp. 1-33, In Entomopathogenic Nematology (ed. R. Gaugler), CABI Publishing, New York
  27. Ji, D., Y. Yi, G.H. Kang, Y.H. Choi, P. Kim, N.I. Baek and Y. Kim (2004b) Identification of an antibacterial compound, benzylideneacetone, from Xenorhabdus nematophila against major plant-pathogenic bacteria. FEMS Microbiol. Lett. 239:241-248
  28. Van Rie, J., S. Jansens, H. Hofte, D. Degheele and H. Van Mellaert (1989) Specificity of Bacillus thuringiensis-endotoxins. Importance of specific receptors on the brush border membrane of the midgut of target insects. Eur. J. Biochem. 186:239-247
  29. Gill, M. and D. Ellar (2002) Transgenic Drosophila reveals a functional in vivo receptor for the Bacillus thuringiensis toxin Cry1Ac1. Insect Mol. Biol. 11:619-625
  30. Ji, D. and Y. Kim (2004) An entomopathogenic bacterium, Xenorhabdus nematophila, inhibits the expression of an antibacterial peptide, cecropin, of the beet armyworm, Spodoptera exigua. J. Insect Physiol. 50:489-496
  31. Park, Y. and Y. Kim (2003) Xenorhabdus nematophilus inhibits p-bromophenacyl bromide (BPB)-sensitive PLA2 of Spodoptera exigua. Arch. Insect Biochem. Physiol. 54:134-142
  32. 배수일, 권성진, 김용균 (2007) 유약호르몬 동력제 pyriproxyfen의 파밤나방(Spodoptera exigua) 혈구세포 활착행동에 대한 억제 효과. 자연자원연구 7:48-53
  33. Shrestha, S. and Y. Kim. 2008. Eicosanoids mediate prophenoloxidase release from oenocytoids in the beet armyworm Spodoptera exigua. Insect Biochem. Mol. Physiol. 38:99-112
  34. SAS Institute, Inc. (1989) SAS/STAT user's guide, Release 6.03, Ed. Cary, N.C
  35. Dunphy, G.B. and J.M. Webster (1991) Antihemocytic surface components of Xenorhabdus nematophilus var. dutki and their modification by serum of nonimmune larvae of Galleria mellonella. J. Invertebr. Pathol. 58:40-51
  36. Dennis, E.A. (1994) Diversity of group types, regulation, and function of phospholipase A2. J. Biol. Chem. 269:13057-13060
  37. Hoffmann, C., H. Vanderbruggen, H. Hofte, J. Van Rie, S. Jansens and H. Van Mellaert (1988) Specificity of Bacillus thuringiensis-endotoxins is correlated with the presence of high-affinity binding sites in the brush border membrane of target insect midgets. Proc. Natl. Acad. Sci. USA 85:7844-7848
  38. Stanley, D. (2000) Eicosanoids in invertebrate signal transduction systems. Priceton University Press, New Jersey
  39. Raymond, M. (1985) Presentation d'un programme d'analyse log-probit pour micro-ordinateur. Cah. ORS-TOM. Ser. Ent. Med. et Parasitol. 22:117-121
  40. Garcia, E.S., E.M.M. Machado and P. Azambuja (2004) Effects of eicosanoid biosynthesis inhibitors on the prophenoloxidase- activating system and microaggregation reactions in the hemolymph of Rhodnius prolixus infected with Trypanosoma rangeli. J. Insect Physiol. 50:157-165
  41. Gillespie, J.P., M.R. Kanost and T. Trenczek (1997) Biological mediators of insect immunity. Annu. Rev. Entomol. 42:611-643