ABSTRACT
A gene encoding NAD+-dependent sorbitol dehydrogenase (SDH) in peach fruit was cloned and expressed in Escherichia coli. Recombinant SDH protein with 6×His-tagged was localized exclusively in the cytoplasmic soluble fraction of E. coli when the strains were grown for 4-5 h at 37 ºC. Highly pure protein was isolated by Ni2+-resin chromatography with 150 mM imidazole in 50 mM Tris, pH 8.0, by elution. In order to ensure that the recombinant SDH could be used for further study, the fluorescence and ultraviolet spectrum of the recombinant SDH were detected. Recombinant SDH was confirmed to be capable of oxidizing sorbitol by enzymatic activity assay. The activity of the recombinant SDH was 2.73 U mg-1min-1, which was similar with that directly extracted from peach fruits. The activities of SDH extracted from the fruits in different periods (30, 60, 90 days after flowing) were 7.75, 5.95, 3.26 U mg-1min-1, respectively.
ABSTRACT
The peach fruit fly, Bactrocera zonata, is a significant pest of fruit and vegetable crops in South East Asia and Pacific region. Ccontrol strategies of fruit flies, relying chiefly on insecticides, have serious environmental consequences, disturbing the agro-ecosystem as well as eliminating natural enemies. This study was oriented at exploring the potential of turmeric, Curcuma longa, extracts to control the peach fruit fly. Freshly emerged female adults of Bactrocera zonata were continuously fed for 16 days on diet containing 1000, 500 and 250 ppm of acetone extract of Curcuma longa separately in laboratory cages. The extract caused 85.00, 66.67 and 56.67 percent mortality at 1000, 500 and 250 ppm respectively. The surviving females were mated and allowed to reproduce on clean guava fruits in separate cages. The inhibition in pupal progeny was 67.90, 60.74 and 51.96 percent in the flies fed on 1000, 500 and 250 ppm, the inhibition observed in adult progeny was 84.68, 79.03 and 67.74 percent, respectively.
A mosca do pêssego, Bactrocera zonata, é uma importante praga das frutas e produtos hortícolas no Sudeste Asiático e Pacífico. As estratégias de controle de moscas-das-frutas, que se baseia principalmente no uso de inseticidas, têm consequências ambientais graves, perturbando o agroecossistema, bem como eliminando os inimigos naturais. Este estudo foi orientado a explorar as potencialidades dos extratos de açafrão Curcuma longa para controle de B. zonata. Após a emergência, adultos de fêmeas de B. zonata foram continuamente alimentados, durante 16 dias, com dieta contendo 1000, 500 e 250 ppm de extrato acetônico de C. longa separadamente em gaiolas no laboratório. O extrato causou 85,00, 66,67 e 56,67 por cento de mortalidade em 1000, 500 e 250 ppm, respectivamente. As fêmeas foram acasaladas e postas para ovipositar separadamente em goiabas dentro das gaiolas. A inibição na progênie pupal foi 67,90, 60,74 e 51,96 por cento nos insetos alimentados em 1000, 500 e 250 ppm, a inibição observada na progênie adulta foi 84,68, 79,03 e 67,74 por cento, respectivamente.