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Anthocyanin Pigments (anthocyanin + pigment)
Selected AbstractsOptimization of hot water extraction of roselle juice using response surface methodology: a comparative study with other extraction methodsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2003Peng-Kong Wong Abstract Roselle has regained the attention of many fruit juice manufacturers in Malaysia as a product that contains high ascorbic acid and anthocyanins. However, ascorbic acid and anthocyanin pigments can be easily destroyed during processing of fruit juice. Therefore, in the present study, the effects of different processing methods, namely hot water extraction (HWE), hot water blending, cold water blending and screw press, on the changes in anthocyanins and ascorbic acid contents of roselle juice were evaluated. The anthocyanins and ascorbic acid contents of roselle were determined using the pH differential method and high-performance liquid chromatography respectively. The physico-chemical characteristics and sensory properties of roselle juice were also evaluated. The results of the study indicate that the HWE method is the most effective extraction method, resulting in high anthocyanins and ascorbic acid contents of 43 g l,1 (as delphinidin-3-glucoside) and 2.34 g kg,1 respectively. The optimum juice extraction conditions were 3.5 h at 60 °C. Copyright © 2003 Society of Chemical Industry [source] Ustilago maydis, model system for analysis of the molecular basis of fungal pathogenicityMOLECULAR PLANT PATHOLOGY, Issue 2 2004Christoph W. Basse SUMMARY Ustilago maydis, a facultative biotrophic basidiomycete fungus, causes smut disease in maize. A hallmark of this disease is the induction of large plant tumours that are filled with masses of black-pigmented teliospores. During the last 15 years U. maydis has become an important model system to unravel molecular mechanisms of fungal phytopathogenicity. This review highlights recent insights into molecular mechanisms of complex signalling pathways that are involved in the transition from budding to filamentous growth and operate during the pathogenic growth phase. In addition, we describe recent progress in understanding the structural basis of morphogenesis and polar growth in different stages of U. maydis development. Finally, we present an overview of recently identified genes related to pathogenic development and summarize novel molecular and genomic approaches that are powerful tools to explore the genetic base of pathogenicity. Taxonomy: Ustilago maydis (DC) Corda (synonymous with Ustilago zeae Ung.)-Kingdom Eukaryota, Phylum Fungi, Order Basidiomycota, Family Ustilaginomycetes, Genus Ustilago. Host range: Infects aerial parts of corn plants (Zea mays) and its progenitor teosinte (Zea mays ssp. parviglumis). Maize smut is distributed throughout the world. Disease symptoms: U. maydis causes chlorotic lesions in infected areas, the formation of anthocyanin pigments, necrosis, hyperplasia and hypertrophy of infected organs. Infection by U. maydis can inhibit development and lead to stunting of infected plants. A few days after infection plant tumours develop in which massive fungal proliferation and the formation of the black-pigmented, diploid teliospores occurs. Under natural conditions tumours predominantly develop on sexual organs (tassels and ears), stems and nodal shoots. Tumours may vary in size from minute pustules to several centimetres in diameter and contain up to 200 billion spores. Useful web site: http://www-genome.wi.mit.edu/annotation/fungi/ustilago_maydis/ [source] Why are all colour combinations not equally represented as flower-colour polymorphisms?NEW PHYTOLOGIST, Issue 1 2001John Warren Summary ,,Flower-colour polymorphism within the British flora appears more common in species whose flowers typically contain pink, purple or blue anthocyanin pigments rather than other coloured pigments. In this study we test the hypothesis that this variation in anthocyanin pigmentation may be maintained by selection related to environmental heterogeneity and stress tolerance. ,,Observations were made of stem pigmentation, shoot dry mass and seed production in five polymorphic species under different droughted and well watered conditions. ,,The results show that over both treatments the morphs did not differ in their fitness. However, a significant morph times treatment interaction revealed that the pigmented plants performed relatively better in the droughted conditions, while the unpigmented plants performed relatively better in the well watered treatment. ,,The results support the idea that anthocyanin based flower-colour polymorphisms may be better considered as polymorphism for the presence or absence of anthocyanin pigmentation throughout the entire plant. This variation may be maintained by selection related to environmental heterogeneity and stress tolerance. [source] Shade facilitates an invasive stem succulent in a chenopod shrubland in South AustraliaAUSTRAL ECOLOGY, Issue 5 2003TANJA I. LENZ Abstract The invasive stem succulent Orbea variegata (L) Haw. (Asclepiadaceae) tends to be more abundant underneath shrubs than in open areas in chenopod shrublands near Whyalla, South Australia. To assess the role of facilitation in the life cycle of O. variegata, we investigated the effect of chenopod shrubs on different life stages of the species by experimentally manipulating temperature, light, soil moisture and nutrient levels. Experimental results suggest that the reduction in light and temperature under shrubs, but not increased nutrient levels, are the main facilitative mechanisms for O. variegata. Temperatures above 30°C, which are more likely to occur on the soil surface of open areas than under shrubs, inhibited seed germination. Seedling survival at low watering frequency and the growth of established ramets were increased by 75,80% shade cloth. Ramets growing in full light contained a high concentration of anthocyanin pigments. One of the functions of these pigments is to absorb excess radiation, suggesting that O. variegata experiences radiation stress in full light. In the field O. variegata performed considerably better under Atriplex vesicaria Heward ex Benth. (Chenopodiaceae) or under 75,80% shade cloth than in full light. Monthly irrigation of 20 mm did not reduce this positive effect of the A. vesicaria canopy on O. variegata, suggesting that O. variegata is inhibited by high light intensities or temperatures, independent of water availability. In conclusion, whereas shrub canopies do not seem to be required for the establishment or survival of O. variegata, shrubs improve adult growth and can improve establishment. The possibility of exotic plants being facilitated by other plants has to be taken into account when assessing the probability and rate of invasion. [source] | ||||||||||