Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China.
Sci Rep. 2017 Sep 21;7(1):12102. doi: 10.1038/s41598-017-12387-3.
The adaptation of herbivorous insects to various host plants facilitates the spread and outbreak of many important invasive pests, however, the molecular mechanisms that underneath this process are poorly understood. In the past three decades, two species of the whitefly Bemisia tabaci complex, Middle East-Asia Minor 1 and Mediterranean, have invaded many countries. Their rapid and widespread invasions are partially due to their ability to infest a wide range of host plants. In this study, we determined the transcriptome and phenotypic changes of one Mediterranean whitefly population during its adaptation to tobacco, an unsuitable host plant. After several generations on tobacco, whiteflies showed increased survival and fecundity. High-throughput RNA sequencing showed that genes involved in muscle contraction and carbohydrate metabolism were significantly up-regulated after adaptation. Whiteflies reared on tobacco were further found to have increased body volume and muscle content and be trapped by tobacco trichomes in a lower frequency. On the other hand, gene expression in endosymbionts of whitefly did not change significantly after adaptation, which is consistent with the lack of cis-regulatory element on endosymbiont genomes. Over all, our data suggested that higher body volume and strengthened muscle might help whiteflies overcome physical barriers and survive on tobacco.
植食性昆虫对各种宿主植物的适应性促进了许多重要入侵害虫的传播和爆发，但这一过程背后的分子机制还了解甚少。在过去的三十年中，烟粉虱复合种的两个物种，中东-小亚细亚 1 型和地中海型，已经入侵了许多国家。它们的快速和广泛入侵部分归因于它们能够侵袭广泛的宿主植物。在这项研究中，我们确定了地中海型烟粉虱种群在适应烟草（一种不适宜的宿主植物）过程中的转录组和表型变化。在烟草上经过几代的适应后，粉虱的存活率和繁殖力都有所提高。高通量 RNA 测序表明，适应后与肌肉收缩和碳水化合物代谢相关的基因显著上调。进一步发现，在烟草上饲养的粉虱的体型和肌肉含量增加，并且被烟草表皮毛困住的频率降低。另一方面，适应后粉虱共生体中的基因表达没有明显变化，这与共生体基因组上缺乏顺式调控元件一致。总体而言，我们的数据表明，更大的体型和更强壮的肌肉可能有助于粉虱克服物理障碍并在烟草上生存。
