Exploring the Midgut Transcriptome and Brush Border Membrane Vesicle Proteome of the Rice Stem Borer, Chilo suppressalis (Walker)

Weihua Ma,Fei Li,Xiaoping Wang,Chuanhua Peng,Zan Zhang,Yongjun Lin,Alfredo Herrera-Estrella

doi:10.1371/journal.pone.0038151

Abstract

The rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is one of the most detrimental pests affecting rice crops. The use of Bacillus thuringiensis (Bt) toxins has been explored as a means to control this pest, but the potential for C. suppressalis to develop resistance to Bt toxins makes this approach problematic. Few C. suppressalis gene sequences are known, which makes in-depth study of gene function difficult. Herein, we sequenced the midgut transcriptome of the rice stem borer. In total, 37,040 contigs were obtained, with a mean size of 497 bp. As expected, the transcripts of C. suppressalis shared high similarity with arthropod genes. Gene ontology and KEGG analysis were used to classify the gene functions in C. suppressalis. Using the midgut transcriptome data, we conducted a proteome analysis to identify proteins expressed abundantly in the brush border membrane vesicles (BBMV). Of the 100 top abundant proteins that were excised and subjected to mass spectrometry analysis, 74 share high similarity with known proteins. Among these proteins, Western blot analysis showed that Aminopeptidase N and EH domain-containing protein have the binding activities with Bt-toxin Cry1Ac. These data provide invaluable information about the gene sequences of C. suppressalis and the proteins that bind with Cry1Ac.

Highlights

The rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is one of the most important rice pests
One promising possibility is use of the toxic protein produced by the bacterium Bacillus thuringiensis (Bt)
Bt toxins are considered to be safe and have been widely used in transgenic plants to control lepidopteran pests such as Helicoverpa armigera [2,3,4,5]. This tactic is successful in controlling rice stem borer at present, the ability of target pests to develop resistance poses a challenge

Summary

Introduction

The rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is one of the most important rice pests. Exploring the midgut transcriptome and proteome of C. suppressalis will provide invaluable information about its gene sequences and promote investigations of plant-insect interactions. Annotation of predicted proteins Among the midgut transcripts, 15,446 (41%) showed significant similarity (E-value ,1e25) to known proteins in the NCBI database (Table 2). Comparative analysis Comparison of the derived C. suppressalis midgut transcripts with protein sequences in the draft genomes of Drosophila melanogaster, Anopheles gambiae, and Tribolium casteneum conducted using the BLASTX algorithm program revealed high sequence similarity (38%, 13,968 out of 37,040) to the T. casteneum genome (Figure 1).

Results

Conclusion