58º Congresso Brasileiro de Genética
Resumos do 58o Congresso Brasileiro de Genética • 11 a 14 de setembro de 2012
Rafain Palace Hotel e Convention Center • Foz do Iguaçu • PR • Brasil
www.sbg.org.br - ISBN 978-85-89109-06-2
42
Isolation of a gene with insecticidal activity
Figueiredo, CS1; Marucci, SC1; Silva, CC1; Tezza, RID2; Desidério, JA1
1
Laboratório de genética de bactérias e biotecnologia aplicada; 2Laboratório de Bioinformática do CREBIO (Centro de
Recursos Biológicos e Biologia Genômica) Faculdade de Ciências Agrarias e Veterinárias, Unesp, Jaboticabal SP.
[email protected]
Keywords: insecticidal protein, Bacillus thuringiensis, biological control, lepidopteran, resistance.
The integrated pest management (IPM) has a fundamental role on the control of the main pest since it takes into account
ecological, economical and social parameters, aiming at interfering the minimum possible with the ecosystems. The
biological control is used as selective tool. The bacterium Bacillus thuringiensis is seen as one of the best options due to its
entomopathogenic action and specificity. The Vegetative Insecticidal Proteins (Vip) are secreted during the vegetative
growth of B. thuringiensis. Four classes of Vip toxins have been described. Vip 1 and Vip 2 are toxic to coleopteran
species, Vip3 act on the control of the most important lepidopteran pests, and Vip4 activity has not been described
yet. The researches about Vip3 toxins are important for the resistance management of this class of proteins and other
proteins of B. thuringiensis. The objective of this study was to isolate vip3A gene from B. thuringiensis. Thus, one isolate
was selected by bioassays of toxicity against lepidopteran pests. The supernatant culture of this isolate promoted high
insecticidal activity against Anticarsia gemmatalis and Spodoptera frugiperda. The vip3A gene was amplified from this
Brazilian isolate. The amplification product was cloned into a vector. The full sequence of nucleotides was obtained by
primer walking. Results from the sequence aligningment obtained in this study compared to the sequences deposited
in the databases using the BlastX algorithm tool indicate 99% similarity. The gene was deposited in the GenBank
(JQ946639) and was named Vip3Aa50 toxin. This result is important, because small differences in amino acid sequence
of these Vip3A proteins may lead to an increased insecticidal activity. The Vip3A proteins are active against a wide
spectrum of lepidopteran insects. The species S. frugiperda is a model insect to study the action of these insecticides
proteins. However, in the literature there are no reports of the Vip3 action in control of A. gemmatalis. The gene
isolated in this work may be used to control these caterpillars by biological means or to develop transgenics plants.
Financial Support: FAPESP.