Asokan R, Rebijith K B, Roopa H K, Kumar N K Krishna
Division of Biotechnology, Indian Institute of Horticultural Research (IIHR), Hessaraghatta Lake (PO), Bangalore, 560 089, India,
Appl Biochem Biotechnol. 2015 Feb;175(4):2288-99. doi: 10.1007/s12010-014-1437-6. Epub 2014 Dec 6.
The sweet potato whitefly, Bemisia tabaci (G.) biotype B (Hemiptera: Aleyrodidae), is one of the most economically important pest, by being a dreaded vector of Geminiviruses, and also causes direct damage to the crops by sucking phloem sap. Glutathione S-transferase (GST) is a large family of multifunctional enzymes that play pivotal roles in the detoxification of secondary allelochemical produced by the host plants and in insecticide resistance, thus regulates insect growth and development. The objective of this study is to show the potential of RNA interference (RNAi) in the management of B. tabaci. RNAi is a sequence-specific gene silencing mechanism induced by double-stranded RNA (dsRNA) which holds tremendous potential in pest management. In this regard, we sequenced the GST from B. tabaci and synthesized approximately 500-bp dsRNA from the above and delivered through diet to B. tabaci. Real-time quantitative PCR (RT-qPCR) showed that continuous application of dsGST at 1.0, 0.5, and 0.25 μg/μl reduced mRNA expression levels for BtGST by 77.43, 64.86, and 52.95 % which resulted in mortality by 77, 59, and 40 %, respectively, after 72 h of application. Disruption of BtGST expression will enable the development of novel strategies in pest management and functional analysis of vital genes in B. tabaci.
烟粉虱，即烟粉虱（G.）生物型B（半翅目：粉虱科），是经济上最重要的害虫之一，它是双生病毒可怕的传播媒介，还通过吸食韧皮部汁液对作物造成直接损害。谷胱甘肽S-转移酶（GST）是一个多功能酶的大家族，在宿主植物产生的次生化感物质的解毒以及抗药性方面发挥着关键作用，从而调节昆虫的生长和发育。本研究的目的是展示RNA干扰（RNAi）在烟粉虱防治中的潜力。RNAi是一种由双链RNA（dsRNA）诱导的序列特异性基因沉默机制，在害虫防治中具有巨大潜力。在这方面，我们对烟粉虱的GST进行了测序，并从上述序列合成了约500bp的dsRNA，通过饲料投喂给烟粉虱。实时定量PCR（RT-qPCR）显示，以1.0、0.5和0.25μg/μl的浓度持续施用dsGST可使烟粉虱BtGST的mRNA表达水平分别降低77.43%、64.86%和52.95%，施用72小时后导致的死亡率分别为77%、59%和40%。破坏BtGST的表达将有助于开发害虫防治的新策略以及对烟粉虱重要基因进行功能分析。
