Brassica juncea, a major oilseed crop, suffers substantial yield losses due to infestation by mustard aphids (Lipaphis erysimi). Unavailability of resistance genes within the accessible gene pool underpins significance of the transgenic strategy in developing aphid resistance. In this study, we aimed for the identification of an aphid-responsive promoter from B. juncea, based on the available genomic resources. A monosaccharide transporter gene, STP4 in B. juncea was activated by aphids and sustained increased expression as the aphids colonized the plants. We cloned the upstream intergenic region of STP4 and validated its stand-alone aphid-responsive promoter activity. Further, deletion analysis identified the putative cis-elements important for the aphid responsive promoter activity. The identified STP4 promoter can potentially be used for driving high level aphid-inducible expression of transgenes in plants. Use of aphid-responsive promoter instead of constitutive promoters can potentially reduce the metabolic burden of transgene-expression on the host plant.

中文翻译：

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印度芥菜中 STP4 启动子的表征用作蚜虫响应启动子

芥菜是一种主要的油籽作物，由于受到芥菜蚜虫 (Lipaphis erysimi) 的侵染，产量大幅下降。可访问的基因库中抗性基因的不可用性巩固了转基因策略在发展蚜虫抗性方面的重要性。在这项研究中，我们的目标是根据可用的基因组资源从芥菜中鉴定一个蚜虫响应启动子。芥菜中的单糖转运蛋白基因 STP4 被蚜虫激活，并随着蚜虫在植物中定殖而持续增加表达。我们克隆了 STP4 的上游基因间区域并验证了其独立的蚜虫响应启动子活性。此外，缺失分析确定了对蚜虫响应启动子活性很重要的假定顺式元件。鉴定出的 STP4 启动子可潜在地用于驱动植物中转基因的高水平蚜虫诱导表达。使用蚜虫响应启动子代替组成型启动子可以潜在地减少转基因表达对宿主植物的代谢负担。