General up regulation of Spodoptera frugiperda trypsins and chymotrypsins allows its adaptation to soybean proteinase inhibitor

Autor(es)

Brioschi, Daniela ; Nadalini, Larissa D. ; Bengtson, Mario H. ; Sogayar, Mari Cleide ; Moura, Daniel S. ; Silva Filho, Marcio C. ^[6]

• Tipo de documento: Artigo Científico
• Fonte: Insect Biochemistry and Molecular Biology; v. 37, n. 12, p. 1283-1290, Dec. 2007.
• Área do conhecimento: Ciências Biológicas - Bioquímica
• Assunto(s): Lepidópteros Mariposas Spodoptera Biblioteca gênica Enzimas Quimotripsina Tripsina

Resumo

The existence of a diverse serine proteinase gene family in lepidopteran insects suggests they play a significant role in the insect adaptation to plant proteinase inhibitors. These proteinases have been shown to be involved in the process of proteolytic digestion in insect larvae. We carried out a selective transcriptome study of midguts from Spodoptera frugiperda larvae fed on a diet supplemented with soybean proteinase inhibitor (SPI). Using subtracted cDNA libraries made of gut-expressed transcripts, a total of 2100 partial sequences were obtained, of those 38% were related to digestive process. Two large and diverse groups of chymotrypsins and trypsins were obtained, and some of these proteinase-encoding genes were further characterized by quantitative RT-PCR. The transcription analyses revealed two groups: one group of genes constitutively expressed in the control larvae that is up regulated by introducing SPI to the diet, and a second group that is absent in the control but is induced by the SPI-rich diet. This observation suggests that adaptation of S. frugiperda to SPI involves de novo synthesis and also up regulation of existing enzymes. Proteases from intestines of larvae reared on a diet with SPI showed insensitivity to the inhibitor. The proteases were also insensitive to a broad-spectrum potato proteinase inhibitor preparation. We propose that adaptation of S. frugiperda to SPI follows a "shotgun" approach, based on a general up regulation of a large set of endoproteinases. (AU)

• Processo FAPESP: 02/08661-1 - Isolamento e caracterização de polipeptpídeos hormonais em cana-de-açúcar
• Beneficiário: Daniel Scherer de Moura
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 02/11462-0 - Interação planta-inseto: um processo co-evolutivo envolvendo maquinarias adaptativas distintas
• Beneficiário: Márcio de Castro Silva Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular