Functional classification of esterases from leaves of Aspidosperma polyneuron M. Arg. (Apocynaceae)

Polyacrylamide gel electrophoresis system (PAGE) and inhibition tests for biochemical characterization of alpha- and beta-esterases were used to obtain a functional classification of esterases fromAspidosperma polyneuron. The characterization of alpha- and beta-esterases from young leaves of A. polyneuron by the PAGE system showed fourteen esterase isozymes. The differential staining pattern showed that Est-2 isozyme hydrolyzes beta-naphthyl acetate; Est-6, Est-7 and Est-8 isozymes hydrolyze alpha-naphthyl acetate, and Est-1, Est-3, Est-4, Est-5, Est-9, Est-10, Est-11, Est-12, Est-13, and Est-14 isozymes hydrolyze both alpha- and b-naphthyl acetate. Inhibition pattern of a- and beta-esterases showed that Folidol is a more potent inhibitor that Malathion, while Thiamethoxan (an insecticide with organophosphorus-like action) acts as an Est-4 and Est-6 inhibitor and induces the appearance of Est-5 and Est-7 isozymes as more intensely stained bands. Inhibition tests showed that OPC insecticides inhibit or activate plant esterases. Thus, plant esterases may be used as bioindicators to detect the presence and toxicity of residues of topically applied insecticides in agriculture and may be valuable for monitoring pollutants in the environment

Functional classification of esterases from leaves of Aspidosperma polyneuron M. Arg. (Apocynaceae)

Polyacrylamide gel electrophoresis system (PAGE) and inhibition tests for biochemical characterization of alpha- and beta-esterases were used to obtain a functional classification of esterases fromAspidosperma polyneuron. The characterization of alpha- and beta-esterases from young leaves of A. polyneuron by the PAGE system showed fourteen esterase isozymes. The differential staining pattern showed that Est-2 isozyme hydrolyzes beta-naphthyl acetate; Est-6, Est-7 and Est-8 isozymes hydrolyze alpha-naphthyl acetate, and Est-1, Est-3, Est-4, Est-5, Est-9, Est-10, Est-11, Est-12, Est-13, and Est-14 isozymes hydrolyze both alpha- and b-naphthyl acetate. Inhibition pattern of a- and beta-esterases showed that Folidol is a more potent inhibitor that Malathion, while Thiamethoxan (an insecticide with organophosphorus-like action) acts as an Est-4 and Est-6 inhibitor and induces the appearance of Est-5 and Est-7 isozymes as more intensely stained bands. Inhibition tests showed that OPC insecticides inhibit or activate plant esterases. Thus, plant esterases may be used as bioindicators to detect the presence and toxicity of residues of topically applied insecticides in agriculture and may be valuable for monitoring pollutants in the environment

Differential genetic stability in vineyards of the cultivar ‘Italy’ (

During more than 50 years the vegetative propagation has been the form of maintaining and multiplication of the cv. ’Italy’ vineyards, a ’Bicane’ x ’Muscat Hamburg’ hybrid. In the current study, polymorphism in 17 microsatellite loci was used to evaluate the genetic stability at DNA level in vineyards of cv. ’Italy’ planted in different regions of the states of Paraná and São Paulo, Brazil. Unchanged and equal allele frequency indicating genetic stability was reported in 47% of the microsatellite loci in vineyards of six localities, while allele frequency variation has been observed in Scu15vv, Udv44, Udv74, Udv96, Udv107, Udv108, Vvmd5, Vvmd6 and Vvs3 microsatellite loci. Alleles Udv96140 and Vvs3448, detected in vines in only one of the vineyards, evidenced somatic mutations at molecular level in cv. ’Italy’. Genetic diversity, as result of changes in the allele frequencies in 53% of microsatellite loci, was detected more frequently than somatic mutations due to new alleles. Polymorphism in microsatellite loci revealed different genetic stability in vineyards of cv. ’Italy’ cultivated in six different Brazilian regions and indicated vineyards with less genetic stability as a possible source of somatic mutants, showing traits of agronomic interest with a potential to generate new cultivars

retrotransposon and

Somatic mutations in grapes are relatively frequent and associated with diversity in grape skin color and berry morphology. Mutations that occur on a side branch of the ‘Benitaka’ cultivar with rosy-red berry skin color generated the ‘Brasil’ cultivar, and mutations that occurred on a side branch of ‘Brasil’ generated the ‘Black Star’ cultivar, both showing a black color in the berry skin. Therefore, genetic characterization of the Gret1 retrotransposon and the VvmybA1 gene in ‘Italia’, ‘Rubi’, ‘Benitaka’, ‘Brasil’, and ‘Black Star’ was started to find whether the altered coloration of berries in ‘Brasil’ and ‘Black Star’ is a product of different mutation patterns in the investigated sequences. Six primer combinations were used for the amplification of different sequences of the Gret1 retrotransposon and VvmybA1 gene of the five cultivars. Polymerase chain reaction (PCR) of the Gret1 retrotransposon and the VvmybA1 gene and sequencing of the amplified products using six primer combinations showed no different alleles or different nucleotide sequences in ‘Brasil’ and ‘Black Star’. The sequencing of the VvmybA1 gene in the present study showed that the mutations that occurred in the cultivar ‘Italia’ for generating the ‘Benitaka’ cultivar persisted in the ‘Brasil’ and ‘Black Star’ cultivars

Esterase-3 polymorphism in the sugarcane borer Diatraea saccharalis (Lepidoptera, Pyralidae)

The migration rate of esterases and their substrate specificity for 4-methylumbelliferyl esters (acetate, propionate, and butyrate) and alpha- and beta-naphthyl esters were analyzed in Diatraea saccharalis by starch gel electrophoresis. Substrate preference of esterases was observed with Est-2 and Est-8 isozymes showing substrate specificity for 4-methylumbelliferyl esters and Est-4 isozyme showing specificity for 4-methylumbelliferyl butyrate and alpha-naphthyl butyrate. Allele variation was detected at the Est-3 locus. Two alleles, Est-3F and Est-3S, were identified in pupae with fluorogenic and ester-naphthyl substrates. Chi-square analysis showed no differences between the observed genotypic frequencies and those expected on the basis of Hardy-Weinberg frequencies for the Est-3 locus (chi² = 2.4; p < 0.01). The negative value for the Wright's fixation index (F = -0.2096) calculated for the D. saccharalis population maintained under laboratory conditions indicates an excess of heterozygotes, however, the observed Hardy-Weinberg equilibrium indicates that in the laboratory the population of D. saccharalis behaved as if the moth were randomly mating in nature. The high level of heterozygosity at the Est-3 locus indicates also that this esterase may be a good genetic marker for studies of natural D. saccharalis populations