Transcriptional responses of invasive and indigenous whiteflies to different host plants reveal their disparate capacity of adaptation.

Hong-Xing Xu,Yue Hong,Yong-Liang Wang,Min-Zhu Zhang,Xiao-Wei Wang,Shu-Sheng Liu

doi:10.1038/srep10774

Abstract

The whitefly Bemisia tabaci contains more than 35 cryptic species. The higher adaptability of Middle East-Asia Minor 1 (MEAM1) cryptic species has been recognized as one important factor for its invasion and displacement of other indigenous species worldwide. Here we compared the performance of the invasive MEAM1 and the indigenous Asia II 3 whitefly species following host plant transfer from a suitable host (cotton) to an unsuitable host (tobacco) and analyzed their transcriptional responses. After transfer to tobacco for 24 h, MEAM1 performed much better than Asia II 3. Transcriptional analysis showed that the patterns of gene regulation were very different with most of the genes up-regulated in MEAM1 but down-regulated in Asia II 3. Whereas carbohydrate and energy metabolisms were repressed in Asia II 3, the gene expression and protein metabolisms were activated in MEAM1. Compared to the constitutive high expression of detoxification genes in MEAM1, most of the detoxification genes were down-regulated in Asia II 3. Enzymatic activities of P450, GST and esterase further verified that the detoxification of MEAM1 was much higher than that of Asia II 3. These results reveal obvious differences in responses of MEAM1 and Asia II 3 to host transfer.

Highlights

Adaptability than many indigenous species of the B. tabaci complex, which may play an important role in the process of whitefly invasion as well[12,14,17,18]
As the nutritional quality of phloem sap varies in different plants, it’s interesting to investigate the mechanisms for B. tabaci to adapt to different host plant diets
After they were transferred to cotton plants for 24 h, the mortalities of MEAM1 and Asia II 3 whiteflies were comparable, suggesting that cotton is suitable to both species

Summary

Introduction

Adaptability than many indigenous species of the B. tabaci complex, which may play an important role in the process of whitefly invasion as well[12,14,17,18]. We compared the transcriptional responses of MEAM1, one of the most important invasive pest in China[16], and Asia II 3 which is a native whitefly species and had almost been replaced by MEAM1 in China[17], to host plant transfer (from cotton to tobacco). While MEAM1 can survive poorly on tobacco, all Asia II 3 whiteflies end up dead after several days on tobacco It is an adaptation process for MEAM1 and a non-host process for Asia II 3, when they were transferred from cotton to tobacco. Through this comparison, we hope to reveal the adaptation or tolerance mechanism of the invasive MEAM1 to an unsuitable host plant. We measured the detoxification enzyme activities of MEAM1 and Asia II 3 transferred from cotton to tobacco separately to illustrate the function of different detoxification systems during host plant transfer

Methods

Results

Discussion

Conclusion