Location: Corn Insects and Crop Genetics ResearchTitle: Development of reference transcriptomes for the major insect pests of cowpea: a toolbox for insect pest management approaches in West Africa Author
Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2013
Publication Date: 11/22/2013
Citation: Agunbiade, T.A., Sun, W., Coates, B.S., Djouaka, R., Tamo, M., Ba, M.N., Binso-Dabire, C., Baoua, L., Olds, B.P., Pittendrigh, B.R. 2013. Development of reference transcriptomes for the major insect pests of cowpea: a toolbox for insect pest management approaches in West Africa. PLoS One. 8(11):e79929. Interpretive Summary: Insect pests of cultivated crops threaten producer viability, and contribute to human food shortages worldwide. Controlling these pest insects in developing nations is difficult due to technical and technological challenges. Understanding insect pest biology and ecology will help scientist develop ecologically sound and attainable methods for managing insect populations. Next generation sequencing technologies (NGS) can be applied to discover genes involved in insecticide resistance and to identify potential targets for novel control measures. We used NGS to sequence genes expressed in four highly destructive pest insect species from West Africa. We applied these data to identify mutations in genes that will be used for developing molecular genetic markers, and to identify genes potentially involved in the development of insecticide resistance. These results will be useful to all scientists, particularly in developing countries, who are interested in novel and practical methods for controlling insect populations, and supports sustainable food security in efforts to reduce poverty in developing countries.
Technical Abstract: Cowpea crops are widely cultivated and a major nutritional source of protein for indigenous human populations in West Africa. Annual yields and longevity of grain storage is greatly reduced by feeding damage caused by a complex of insect pests that include Anoplocnemis curvipes, Aphis craccivora, Clavigralla tomentosicollis and Megalurothrips sjostedti. Efforts to control these pests remain inconsistent due to the lack of widespread availability of chemical insecticides and difficulties involved in timing the application of biological control agents. We generated expressed sequence tags (ESTs) from A. curvipes, A. craccivora, C. tomentosicollis and M. sjostedti using 454 pyrosequencing which were respectively assembled into 11,855; 7,622; 10,774 and 7,518 transcripts. Functional annotation of the resulting transcripts identified genes putatively involved in insecticide resistance, and pathogen defense and immunity which may be important for enhancing control efforts. Additionally, sequences that matched the primary aphid endosymbiont, Buchnera aphidicola, were identified among A. craccivora transcripts. Furthermore, 444; 139; 278 and 222 single nucleotide polymorphisms (SNPs) were respectively predicted among A. curvipes, A. craccivora, C. tomentosicollis and M. sjostedti transcripts, and will likely be valuable tools for future molecular genetic marker development. These results demonstrate that Roche 454-based transcriptome sequencing is a method for the development of genomic resources for cowpea pest insects in West Africa.