Abstract
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.
Highlights
Rather than acting as passive victims, plants have developed a variety of mechanisms to promote resistance against herbivorous insects
Tobacco plant caused severe decrease in survival rate, fecundity, and female ratio of C-MED; it had less impact on T-MED (Fig. 1c–e). These results suggested that MED whitefly could adapt to tobacco plant in several generations and the adaptation to tobacco would not influence their performances on cotton plant
The fast and widespread invasions of invasive whiteflies have been referred to be related to their wide range of host plants[13,14,15]
Summary
Rather than acting as passive victims, plants have developed a variety of mechanisms to promote resistance against herbivorous insects. The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a genetically diverse species complex including many morphologically indistinguishable cryptic species[6] In this species complex, the Mediterranean (MED, previously referred as the ‘Q biotype’) and the Middle East-Asia Minor 1 (MEAM1, previously referred as the ‘B biotype’) whiteflies are well known due to their worldwide invasions and displacements of indigenous whiteflies[6]. On the unsuitable tobacco plant, the activity of oxidative phosphorylation, citrate cycle, glycolysis and detoxification were repressed in the indigenous Asia II 3 whitefly; these pathways were not repressed in the invasive MEAM116. Wang et al.[17] further showed that invasive whiteflies could perform better than indigenous whiteflies on tobacco due to their high activity of detoxification These studies only reported the short-term response of whitefly to unsuitable host plants. We speculated that there might be some changes that cannot be observed in short-term experiment and make invasive whiteflies adapt to tobacco plant
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
