High Level Production of Polyhedra in a Scorpion toxin-containing Recombinant Baculovirus for Better Control of Insect Pests

提高多角體產量以增加具蠍神經毒表現能力之桿狀病毒的殺蟲效果

段淑人(Shu-Jen Tuan) ； 侯豐男(Roger F. Hou) ； 李至芬(Chi-Fen Lee) ； 趙裕展(Yu-Chan Chao)

《Botanical Studies》 48卷3期 (2007/07) Pp. 273-281

摘要

含蠍毒桿狀病毒之多角體量產的成功與否，是成為害蟲防治利器的關鍵因素。本研究中兩種由加州苜蓿夜蛾核多角體病毒(Autographa californica (Speyer) nucleopolyhedroviruses, AcMNPVs)改造而成含以色列黃蠍之鎮定神經毒(Leiurus quinquestriatus hebraeus (Ehrenberg), LqhIT2)之重組病毒vAPcmIT2及vAP10IT2 (Tuan et al., 2005)，分別利用早期起動子(p-PCm)及非常晚期起動子(p10)來表現蠍毒基因。試驗目在於探討兩種重組病毒多角體的量產效率，發現無論係在體內或體外系統，早期表現蠍毒之重組病毒均顯著優於晚期表現蠍毒之重組病毒。以Sf21細胞株生產病毒，vAPcmIT2的量產效果較vAP10IT2顯著良好，以擬尺蠖(Trichoplusia ni (Hübner))及甜菜夜蛾(Spodoptera exigua (Fabricius))兩種幼蟲繁殖病毒時，發現雖然vAP10IT2的產量尚不如野生型AcMNPV，但卻是vAP10IT2多角體產量的十倍。含蠍毒重組病毒對兩種具抗藥性的蔬菜害蟲－甜菜夜蛾及小菜蛾(Plutella xylostella (Linnaeus))幼蟲之起始致死時間(LT10)及半致死時間(LT50)均較野生型病毒有顯著提早之效果。在甘藍盆栽試驗，含蠍毒重組病毒導致甜菜夜蛾幼蟲提早死亡，表現90%以上的防治效果，且較野生型病毒處理組顯著減少58.7~67.4%之葉片受害率。以病毒多角體量產的效率及防治效果而言，早期表現蠍毒之重組病毒vAPcmIT2較晚期表現蠍毒之重組病毒 vAP10IT2及野生型病毒更具開發成生物農藥的優勢。

關鍵字

加州苜蓿夜蛾核多角體病毒 ； 重組病毒 ； 以色列黃蠍 ； 鎮定神經毒 ； 甜菜夜蛾 ； 擬尺蠖 ； 小菜蛾 ； 多角體量產 ； 防治效果

並列摘要

A sufficient occlusion body yield by a scorpion toxin-containing baculovirus is important to the success of a pest management program. In this study, recombinant baculoviruses, AcMNPV, vAPcmIT2, by which the scorpion toxin (LqhIT2) is driven by an early phase promoter (p-PCm); and another recombinant baculovirus vAP10IT2, by which LqhIT2 is driven by a very late p10 promoter, were tested for the efficiency of their polyhedral production. In Sf21 cells, the yield of polyhedra by vAPcmIT2 is significantly better than that of vAP10IT2. Although in Trichoplusia ni (Hübner) and Spodoptera exigua (Fabricius) the polyhedra yields by vAPcmIT2-infected larvae were not as good as those of the wild type virus, they were about tenfold higher than those produced by vAP10IT2-infected larvae. To test the insecticidal activity of these recombinant baculoviruses, vAPcmIT2 and vAP10IT2 were applied against two major pesticide-resistant vegetable pests, Plutella xylostella (Linnaeus) and S. exigua. Our results demonstrated a significant shortening of the lethal time (LT10 and LT50) compared to those larvae infected with wild type AcMNPV. In field trials, larvae of S. exigua infected with the toxin-recombinant viruses provided more than 90% control efficacy and resulted in a 58.7~67.4% reduction in leaf area consumed compared to wild type AcMNPV. Based on the efficacy of polyhedral production and crop protection, the superiority of vAPcmIT2 over both vAP10IT2 and wild type AcMNPV renders it a better candidate to serve as a useful biopesticide.

並列關鍵字

Autographa californica nucleopolyhedrovirus ； AcMNPV ； Leiurus quinquestriatus hebraeus ； Insecticidal efficacy ； Neurotoxin ； Plutella xylostella ； Polyhedral production ； Recombinant virus ； Spodoptera exigua ； Trich