Anthocyanins are antioxidants and are among the natural products synthesized via the flavonoid biosynthesis pathway. Anthocyanins have been recommended for dietary intake in the prevention of ...cardiovascular diseases, cancer, and age-related conditions such as Alzheimer's disease or dementia. With an increasingly aging population in many parts of the world, strategies for the commercial production of in vitro synchronized red cell cultures as natural antioxidants will be a significant contribution to human medicine. Red pigmented fruits such as grapes (Vitis sp.) are a major source of bioavailable anthocyanins and other polyphenols. Since the level of antioxidants varies among cultivars, this study is the first one that phytochemically and genetically characterizes native grape cultivars of North America to determine the optimal cultivar and berry cells for the production of anthocyanins as antioxidants. Using real-time PCR and bioinformatics approaches, we tested for the transcript expression of the chalcone synthase (CHS) gene, an enzyme involved in the flavonoid and anthocyanin biosynthesis pathway, in different parts of physiologically mature grape berries and in vitro synchronized red cells. A low level of expression was recorded in berry flesh, compared with an elevated expression in berry skins and in vitro synchronized red cells, suggesting increased production of flavonoids in skin and cell cultures. This preliminary study demonstrates the potential of functional genomics in natural products research as well as in systematic studies of North American native grapes, specifically in muscadine (Vitis rotundifolia).
The genus Brassica comprises economically important oilseed and vegetable crops. Their susceptibility to fungal diseases such as blackleg causes yield loss. In this study, thirty accessions from USDA ...germplasm collection representing two diploid Brassica species (Brassica rapa and Brassica oleracea var. virids) and fifteen tetraploid cultivars (Brassica napus) from the national winter canola variety trials (NWCVT) were evaluated using 13 sets of random amplified polymorphic DNA (RAPD) associated with blackleg resistance in Brassica nigra. 126 highly polymorphic bands with an average of 10 per primer were detected. A UPGMA dendrogram showed B. rapa as highly diverse and was supported from three different basal branches, while B. napus accessions were generally monophyletic. Similarly, all of B. oleraceae accessions were supported from the same basal node. Generally, the three species were reciprocally paraphyletic, suggesting that the RAPD markers showed both functional relationships as well as homology, possibly due to selection at the RAPD loci associated with blackleg resistance. Consequently, two potentially susceptible B. napus accessions were identified. The high polymorphic information content (PIC) and number of phylogenetically informative bands established RAPD as a useful tool for phylogenetic reconstruction, quantification of genetic diversity for conservation, cultivar classification and molecular breeding in Brassica.
Grapes (Vitis spp.) are consumed as fresh table fruits, raisins, and processed into wine, juice, jelly and other value-added products. Grapes contain bioactive secondary metabolites (polyphenols), ...such as proanthocyanins (oliogemeric flavonoids), flavonoids (catechin, epicatechin, and quercetin), and anthocyanins. They have non-flavonoids such as hydroxycinnamic acids (p-coumaric, cinnamic, caffeic, gentisic, ferulic, and vanillic acids), and hydroxybenzoic acids: trihydroxy stilbenes (resveratrol and polydatin). These phytochemicals are of economic importance to pharmaceutical, food and cosmetic industries. Nutraceuticals from grape seeds have potential cardioprotective, anti-cancer, antioxidant, anti-inflammatory, antiviral, neuroprotective, hepatoprotective and antimicrobial properties. Grape seed nutraceuticals have been re-invented in the past few years as a new paradigm in human medicine. In particular, nutraceuticals from grape seeds have been used in stopping wound bleeding, anti-inflammatory agents, pain relief, and anti-diarrhea. In addition, they can be used for the treatment of various human health conditions such as cancer, cholera, smallpox, and nausea as well as eye infections, skin, kidney, liver diseases, etc. Nowadays, consumers are demanding for healthy supplements and personal care products with natural ingredients. Therefore, the present review highlights recent developments and future opportunities of grape seed nutraceuticals for the prevention of human diseases.
Blackleg, caused by Leptosphaeria maculans, is a serious disease of Brassica species. Genetic analysis of resistance to L. maculans was carried out with 15 accessions from the USDA Brassica germplasm ...collections, representing diploids (A, C), and tetraploid (AC) genomes, respectively; and 9 cultivars from the National Winter Canola Variety Trials (NWCVT) all carrying AC genomes. All genotypes were screened for blackleg disease at the cotyledonary stage. The results indicated that 46% of the 24 genotypes were resistant, while 54% were susceptible. On the other hand, adult plant screening revealed that all the public genotypes were resistant. In an effort to identify molecular markers associated with resistance to blackleg disease, all genotypes were screened with 13 RAPD and 8 SSR markers producing 169 amplified products. Six RAPD markers (OPB01, OPE03, OPE16, OPF10, OPE12, and OPI01) were polymorphic, while the SSR markers were monomorphic. Chi-square analysis indicated that 5 amplified fragments (OPE03-4000, OPE16-1100, OPE16-1300, OPE16-1900, and OPI01-280) from RAPD primers were significantly associated with blackleg resistance. Thus this study demonstrated that RAPD primers could be effectively used to identify DNA markers that are associated with blackleg disease resistance, and that resistance to L. maculans might also exist in the A and C genomes.
Sterol demethylation inhibitors (DMIs) are considered among the most effective fungicides used to control Cercospora leaf spot (CLS), caused by Cercospora beticola Sacc., in sugar beet. Resistance to ...DMI fungicides has been reported in the C. beticola population from the United States, but the molecular mechanism is not known. It is considered that genetic changes in the C. beticola 14α-demethylase (CbCyp51) gene may be contributing to DMI resistance. The study investigated a silent mutation (GAG to GAA) at codon 170 as a potential mechanism for C. beticola DMI resistance. The CbCyp51 gene was obtained from DMI-sensitive and -resistant isolates, cloned into a plasmid vector, transformed in an isogenic yeast R-1, and tested for DMI sensitivity. Transformed yeast showed low ED50 values (0.02 - 0.09 μg ml–1) as compared to high ED50 values from C. beticola DMI-resistant isolates (21 - 65 μg ml–1). The finding did not support our hypothesis that a silent mutation in the CbCyp51 gene may be associated with C. beticola DMI resistance. Furthermore, genetic analysis of the CbCyp51 gene found no mutation in 2 C. beticola DMI-resistant isolates from the Central High Plains. Further studies will be required to investigate additional mechanisms which have been associated with DMI resistance in fungi. Thus, we could not develop a molecularbased assay for the rapid detection of C. beticola DMI resistance, because no mutation was found in the CbCyp51 gene. Currently, fungicide sensitivity assay could be the best method screen for C. beticola DMI resistance
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