ICAR-National Institute for Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi, 110012, India.
Division of Entomology, Indian Agricultural Research Institute, New Delhi, 110012, India.
Sci Rep. 2020 Jun 29;10(1):10583. doi: 10.1038/s41598-020-66217-0.
Productivity of Indian mustard (B. juncea), a major oil yielding crop in rapeseed-mustard group is heavily inflicted by mustard aphid, L. erysimi. Mustard aphid, a specialist aphid species on rapeseed-mustard crops, rapidly multiplies and colonizes the plants leading to successful infestation. In contrary, legume specific cowpea aphid, A. craccivora when released on B. juncea plants fails to build up population and thus remains unsuccessful in infestation. In the present study, differential host response of B. juncea to the two aphid species, one being successful insect-pest and the other being unsuccessful on it has been studied based on transcriptome analysis. Differential feeding efficiency of the two aphid species on mustard plants was evident from the amount of secreted honeydews. Leaf-transcriptomes of healthy and infested plants, treated with the two aphid species, were generated by RNA sequencing on Illumina platform and de novo assembly of the quality reads. A comparative assessment of the differentially expressed genes due to treatments revealed a large extent of overlaps as well as distinctness with respect to the set of genes and their direction of regulation. With respect to host-genes related to transcription factors, oxidative homeostasis, defense hormones and secondary metabolites, L. erysimi led to either suppression or limited activation of the transcript levels compared to A. craccivora. Further, a comprehensive view of the DEGs suggested more potential of successful insect-pests towards transcriptional reprogramming of the host. qRT-PCR based validation of randomly selected up- and down-regulated transcripts authenticated the transcriptome data.
芥菜（B. juncea）是油菜-芥菜组中的主要产油作物，其生产力受到芥菜蚜（L. erysimi）的严重影响。芥菜蚜是油菜-芥菜作物上的一种专性蚜虫物种，它会迅速繁殖并在植物上定殖，导致成功的侵染。相比之下，豆类专食性的豇豆蚜（A. craccivora）在芥菜植株上释放时，无法建立种群，因此在侵染中不成功。在本研究中，基于转录组分析，研究了芥菜对两种蚜虫的不同宿主反应，一种是成功的昆虫害虫，另一种是不成功的昆虫害虫。两种蚜虫在芥菜植物上的不同取食效率从分泌的蜜露量上可以明显看出。用两种蚜虫处理健康和受侵染的植物后，通过 Illumina 平台上的 RNA 测序生成了叶片转录组，并对高质量的读取进行了从头组装。对因处理而差异表达的基因进行比较评估，发现与处理相关的基因及其调控方向的重叠程度和独特程度都很大。就与转录因子、氧化稳态、防御激素和次生代谢物相关的宿主基因而言，与 A. craccivora 相比，L. erysimi 导致转录水平的抑制或有限激活。此外，对差异表达基因的综合分析表明，成功的昆虫害虫更有可能对宿主进行转录重编程。随机选择的上调和下调转录本的 qRT-PCR 验证验证了转录组数据。
