Physical appearance antioxidant effect alpha-amylase inhibition and alpha-glucosidase of Carissa carandas products

This research aimed to examine tea production from the leaves and fruit of the Karanda (Carissa carandas) at different stages of development. The antioxidant activity of Carissa carandas leaves was determined by their total phenolic content, antioxidant capacity DPPH (2,2-diphenyl-1-picrylhydrazyl), and ferric-reducing capacity (FRAP). The experiment results were freeze-dried and ground into a powder. Young tea leaves had more antioxidants than older ones. Antioxidant capacity DPPH and ferric reduction ability were greater in Carissa carandas juice powder than in Carissa carandas powder. The amount of water extracted is greater. Using Carissa carandas powder, the leftover portion was substituted for tea leaves at weights of 0, 5, 10, 15, and 20 %. Color, total acid content, and total anthocyanin content were measured. The tea was a deeper shade of crimson. Substituting 20% of the fruit pulp for the Carissa carandas resulted in the greatest increase in redness and total acid content, including the total amount of anthocyanin. Superior to all other formulations to increase the total phenolic content, Carissa carandas development should be blended amongst the leaf portions. In sensory characteristics testing, it was determined that the highest acceptable substitution level on the 9-point Hedonic scale test was the 10% substitution level, with scores on appearance, color, odor, taste, texture, and preference that were distinct from those of other samples: 8.56, 8.89, 8.43, 8.21, 8.76, and 8.38.Monruthai Srithongkerd (Tropical Agriculture Program, Faculty of Agriculture), Amorn Owatworakit (Microbial Product and Innovation Research Group, Mae Fah Luang University), Nongnuch Siriwong (Department of Home Economics, Faculty of Agriculture, Kasetsart University)Includes bibliographical references

Push-pull farming systems

Farming systems for pest control, based on the stimulo-deterrent diversionary strategy or push–pull system, have become an important target for sustainable intensification of food production. A prominent example is push–pull developed in sub-Saharan Africa using a combination of companion plants delivering semiochemicals, as plant secondary metabolites, for smallholder farming cereal production, initially against lepidopterous stem borers. Opportunities are being developed for other regions and farming ecosystems. New semiochemical tools and delivery systems, including GM, are being incorporated to exploit further opportunities for mainstream arable farming systems. By delivering the push and pull effects as secondary metabolites, for example, (E)-4,8-dimethyl-1,3,7-nonatriene repelling pests and attracting beneficial insects, problems of high volatility and instability are overcome and compounds are produced when and where required

The Role of Glucosylation in Plant Defence in Oats

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Sad3 and Sad4 are required for saponin biosynthesis and root development in oat

Avenacins are antimicrobial triterpene glycosides that are produced by oat (Avena) roots. These compounds confer broad-spectrum resistance to soil pathogens. Avenacin A-1, the major avenacin produced by oats, is strongly UV fluorescent and accumulates in root epidermal cells. We previously defined nine loci required for avenacin synthesis, eight of which are clustered. Mutants affected at seven of these (including Saponin-deficient1 [Sad1], the gene for the first committed enzyme in the pathway) have normal root morphology but reduced root fluorescence. In this study, we focus on mutations at the other two loci, Sad3 (also within the gene cluster) and Sad4 (unlinked), which result in stunted root growth, membrane trafficking defects in the root epidermis, and root hair deficiency. While sad3 and sad4 mutants both accumulate the same intermediate, monodeglucosyl avenacin A-1, the effect on avenacin A-1 glucosylation in sad4 mutants is only partial. sad1/sad1 sad3/sad3 and sad1/sad1 sad4/sad4 double mutants have normal root morphology, implying that the accumulation of incompletely glucosylated avenacin A-1 disrupts membrane trafficking and causes degeneration of the epidermis, with consequential effects on root hair formation. Various lines of evidence indicate that these effects are dosage-dependent. The significance of these data for the evolution and maintenance of the avenacin gene cluster is discussed. © 2008 American Society of Plant Biologists

Erratum: Glycosyltransferases from oat (Avena) implicated in the acylation of avenacins (Journal of Biological Chemistry (2013) 288 (3696-3704) DOI: 10.1074/jbc.A112.426155)

Plants produce a huge array of specialized metabolites that have important functions in defense against biotic and abiotic stresses. Many of these compounds are glycosylated by family 1 glycosyltransferases (GTs). Oats (Avena spp.) make root-derived antimicrobial triterpenes (avenacins) that provide protection against soil-borne diseases. The ability to synthesize avenacins has evolved since the divergence of oats from other cereals and grasses. The major avenacin, A-1, is acylated with N-methylanthranilic acid. Previously, we have cloned and characterized three genes for avenacin synthesis (for the triterpene synthase SAD1, a triterpene-modifying cytochrome P450 SAD2, and the serine carboxypeptidase-like acyl transferase SAD7), which form part of a biosynthetic gene cluster. Here, we identify a fourth member of this gene cluster encoding a GT belonging to clade L of family 1 (UGT74H5), and show that this enzyme is an N-methylanthranilic acid O-glucosyltransferase implicated in the synthesis of avenacin A-1. Two other closely related family 1 GTs (UGT74H6 and UGT74H7) are also expressed in oat roots. One of these (UGT74H6) is able to glucosylate both N-methylanthranilic acid and benzoic acid, whereas the function of the other (UGT74H7) remains unknown. Our investigations indicate that UGT74H5 is likely to be key for the generation of the activated acyl donor used by SAD7 in the synthesis of the major avenacin, A-1, whereas UGT74H6 may contribute to the synthesis of other forms of avenacin that are acylated with benzoic acid