Soto-Cerda BJ, Urbina H, Navarro C, Mora P. (2011). Characterization of novel genic SSR markers in Linum usitatissimum (L.) and their transferability across elevenLinum species. Electronic Journal of Biotechnology. 14; 2.
Little is known about the evolutionary relationships among Linum species, basically because of the lack of transferable molecular markers. Currently, expressed sequence tags available in public databases provide an opportunity for the rapid and inexpensive development of simple sequence repeat (SSR) markers in wild flax species. In this regard, fifty expressed sequence tag-derived microsatellite markers (EST-SSRs) were evaluated for polymorphism and transferability in 50 Linum usitatissimumcultivars/accessions and 11 Linum species. Among them 23 EST-SSRs were polymorphic in L. usitatissimum, while 2-4 alleles were detected (average 2.26 per locus). The polymorphism information content value ranged from 0.08 to 0.55 (average 0.38). Forty one genic markers (95.3%) produced strong amplicons in at least two of the 11 Linum species. The percentage of cross amplification ranged from 34.1% to 92.7% in L. tauricum and L. bienne, respectively. Moreover, the rate of transferability was associated positively with the botanical section. Our results suggest that the high degree of EST-SSRs transferability to Linum species can be a useful enhancement of the current database of SSR markers for future genetic and evolutionary studies.
Soto-Cerda BJ, Carrasco RA, Aravena GA, Urbina HA, Navarro CS. (2011). Identifying novel polymorphic microsatellites from cultivated flax (Linum ussitatisimum L.) following data mining. Plant Molecular Biology Reporter. 29; 3; 753-759.
One of the major concerns in genetic characterization and breeding of cultivated flax is the lack of informative microsatellite markers (SSRs). In this regard, the development of SSRs using molecular methods might be time-consuming, laborious, and expensive. On the other hand, using bioinformatics to mine sequences in public databases enables a cost-effective discovery of SSRs. A total of 3,242 Linum usitatissimum genomic sequences were surveyed for the identification of SSRs. Among them, 118 non-redundant sequences containing repeats were selected for designing primers. The most abundant motifs were tri- (72.4%) and dinudeotide (16.6%), within which AGG/CCT and AG/CT were predominant. Primers were tested for polymorphism in 60 L.usitatissimum cultivars/accessions including 57 linseed and three fiber flax. Eighty-eight pairs gave amplifications within the expected size range while 60 pairs were found to be polymorphic. The mean number of alleles amplified per primer was 3.0 (range, 2–8; 180 total alleles). The mean polymorphism information content (PIC) value was 0.39 (range, 0.06–0.87), and the highest average PIC was observed in dinucleotide SSRs (0.41). The SSR data mining presented here demonstrates the usefulness of in silico development of microsatellites. These novel genomic SSR markers could be used in genetic diversity studies, the development of genetic linkage maps, quantitative trait loci mapping, association mapping, and marker-assisted selection.
Rubilar, M., Jara, C., Poo, Y., Acevedo, F., Gutiérrez, C., Sineiro, J., Shene, C. (2011). Extracts of Maqui (Aristotelia chilensis) and Murta (Ugni molinae Turcz.): A Source of Antioxidant Compounds and α-Glucosidase/α-Amylase Inhibitors. Journal of Agricultural and Food Chemistry. 59; 5; 1630-1637.
The objective of this work was to evaluate the antioxidant and antihemolytic activities of crude, aqueous, and organic-aqueous extracts of maqui (Aristotelia chilensis) and murta (Ugni molinae Turcz.), together with their inhibiting effect on enzymes involved in the metabolism of carbohydrates. Radical scavenging activity, inhibition of linoleic acid oxidation in a micellar system, antihemolytic activity, and inhibition of α-amylases and α-glucosidases were analyzed. Crude extracts of maqui leaves and fruits were found to be important sources of polyphenolic compounds, showing 69.0 ± 0.9 and 45.7 ± 1.1 mg GAE/g dm, respectively. Polyphenols from maqui leaves were active as antioxidants and antihemolytic compounds (p< 0.05), showing a noncompetitive inhibiting effect on α-glucosidase. Flavan-3-ol polymers and glycosylated flavonols, such as quercetin glucoside and kaempferol glucoside, were tentatively identified in extracts. This preliminary observation provides the basis for further examination of the suitability of polyphenol-enriched extracts from maqui and murta as nutritional or medicinal supplements with potential human health benefits.
Esparza, Y., Huaiquil, A., Neira, L., Leyton, A., Rubilar, M., Salazar, L., Shene, C. (2011). Optimization of process conditions for the production of a prolyl-endopeptidase by Aspergillus niger ATCC 11414 in solid state fermentation. Food Science and Biotechnology. 20; 5; 1323-1330.
The effect of 8 factors [(with/without) daily mixing and moisture control, incubation time (t), temperature, ratio between dry substrate mass and bed’s cross section area (MA), inoculum size (spores/g), wheat germ content (WG), initial pH, and moisture content (M)] in the production of a prolyl endopeptidase (PEP) by Aspergillus niger ATCC 11414 in solid state fermentation (SSF) was tested. Contribution of all the factors was significant (p<0.05); main effects were those of MA, t, and M. The 4 interactions that presented high interaction severity indexes involved the WG. Under optimized conditions PEP and protease activity were 9.76±0.06 and 3.6×106±1.5×105 U/kg, respectively. The enzyme was partially purified (ammonium sulfate precipitation, dialysis, DEAE-Sepharose ionexchange); it has a molecular weight of 66 kDa (SDS-PAGE), and maximum activity was exhibited at pH 4 and 50°C. The enzyme is stable in a wide pH range (2.2–10) and at temperatures lower than 70°C.