Sample records for lyases
from WorldWideScience.org

Sample records 1 - 2 shown.



1

Pectinases: aplicações industriais e perspectivas/ Pectinolytic enzymes: industrial applications and future perspectives

Uenojo, Mariana; Pastore, Glaucia Maria
2007-04-01

Resumo em inglês Pectic substances are structural heteropolysaccharides that occur in the middle lamellae and primary cell walls of higher plants. They are composed of partially methyl-esterified galacturonic acid residues linked by alpha-1, 4-glycosidic bonds. Pectinolytic enzymes are complex enzymes that degrade pectic polymers and there are several classes of enzymes, which include pectin esterases, pectin and pectate lyases and polygalacturonases. Plants, filamentous fungi, bacteria a (mais) nd yeasts are able to produce pectinases. In the industrial world, pectinases are used in fruit juice clarification, in the production of wine, in the extraction of olive oil, fiber degumming and fermentation of tea, coffee and cocoa.

Scientific Electronic Library Online (Portuguese)

2

Aplicação foliar de silício na resistência da soja à ferrugem e na atividade de enzimas de defesa/ Effect of foliar application of silicon on soybean resistance against soybean rust and on the activity of defense enzymes

Pereira, Sandra C.; Rodrigues, Fabrício A.; Carré-Missio, Vivian; Oliveira, Maria Goreti A.; Zambolim, Laércio
2009-06-01

Resumo em português A ferrugem da soja, causada por Phakopsora pachyrhizi, tem sido controlada pela aplicação de fungicidas devido a indisponibilidade de cultivares resistentes. O silício (Si) tem aumentado a resistência de várias espécies de plantas a patógenos. Assim, este trabalho avaliou o efeito da aplicação foliar desse elemento na severidade da ferrugem e na potencialização da atividade de quitinases, β-1,3-glucanases, peroxidases, polifenoloxidases, lipoxigenases e fe (mais) nilalanina amônia-liases. Plantas de soja (cultivar MG/BR-46 Conquista) foram pulverizadas com água (controle), silicato de potássio (KSi) (pH 10,5), KSi (pH 5,5) e acibenzolar-S-metílico (ASM) 24 horas antes da inoculação. Não houve diferença significativa entre os tratamentos para os teores foliares de Si e potássio. A severidade foi significativamente menor em plantas pulverizadas com KSi, independente do pH, e ASM em relação ao controle. O ASM reduziu significativamente a severidade em 65,5% em relação ao controle sem diferença significativa do ASM para a aplicação de KSi pH 5,5. Aplicação de KSi, independente do pH, também reduziu a severidade. Não houve potencialização da atividade das enzimas estudadas pela aplicação de KSi, independente do pH, e do ASM, embora houve redução da severidade em relação ao controle, o que poderia ser explicado pelo possível efeito desses produtos sobre o fungo. Resumo em inglês Soybean rust, caused by Phakopsora pachyrhizi, has been controlled by fungicide application due to the absence of resistant cultivars. Silicon (Si) has increased the resistance of many plant species to pathogens. Therefore, this study evaluated the effect of foliar application of this element on rust severity and if it can potentiate the activity of chitinases, β-1,3-glucanases, peroxidases, polyphenoloxidases, lipoxygenases, and phenylalanine ammonia-lyases. Soybean (mais) plants (cultivar "MG/BR-46 Conquista") were sprayed with water (control), potassium silicate (KSi) (pH 10.5), KSi (pH 5.5), and acibenzolar-S-methyl (ASM) 24 hours before inoculation. There was no significant difference among the treatments for content of Si and potassium in leaf tissue. Rust severity was significantly lower on plants sprayed with KSi, regardless of pH, and ASM compared to plants from control treatment. The ASM significantly decreased severity by 65.5% in comparison to control; however, there was no significant difference from ASM to KSi pH 5.5 treatment. Application of KSi, regardless of the pH, also reduced severity. There was no potentiation of the enzymes studied with KSi, regardless of pH and of ASM, even though there was severity reduction compared to the control treatment. This could be explained by the possible effect of these products on the fungus.

Scientific Electronic Library Online (Portuguese)