224 research outputs found

    Light Intensity Is Positively Correlated with the Synthesis of Condensed Tannins in \u3ci\u3eLotus corniculatus\u3c/i\u3e

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    The importance of Condensed Tannins (CT) in forage legumes has been well documented in several studies. The role of plant genetics in this field is the acquisition of competences in order to be able to modulate CT synthesis in leaves of these species. The role of light has been investigated in this work on the increase of condensed tannin levels in leaves of two contrasting genotypes of birdsfoot trefoil (Lotus corniculatus)

    High Polymorphism for Forage Production of \u3ci\u3eLotus corniculatus Sn\u3c/i\u3e Transformants

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    Transgenic plants obtained from transformation of one individual of Lotus corniculatus with the maize gene Sn, a transactivator of anthocyanin pathway, were analysed for the expression of the transgene and for the accumulation of condensed tannins. A great variability was observed for these two traits. Some extreme individuals were clonally propagated and analysed for rooting ability and plant growth. Unexpectedly, a strong correlation between condensed tannin level, rooting ability and plant growth was observed. These results are discussed in order to explore new strategies to increase plant productivity in forage legumes

    Alteration of Condensed Tannin Sythesis in Transgenic Forage Legumes

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    The transformation of Lotus corniculatus plants with the maize gene Sn, reorganizes the tissue specificity of condensed tannins accumulation. In particular the transformed plants show an increase of tannin content in roots and a decrease in leaves. Molecular and enzymatic analyses suggest that the transgene can functionally substitute an endogenous unknown gene not expressed in roots and induces its silencing when it is expressed. These findings could have applications for reducing tannin content in unpalatable plants and for cloning genes involved in tannin synthesis

    Role of the BANYULS(BAN) Gene from Arabidopsis Thaliana in Transgenic Alfalfa Expression of Anthocyanins and Proanthocyanidins

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    Condensed tannins (CTs) are flavonoid oligomers, many of which have beneficial effects on animal (bloat safe) and human health. The BAN gene encodes anthocyanidin reductase (ANR), an enzyme proposed to convert anthocyanidins to their corresponding 2,3-cis-flavan-3-ols (Xie et al., 2003). Ectopic expression of BAN in Alfalfa transgenic foliage results in accumulation of CTs. Thus, it has been assumed that the BAN gene also acts in starter units for the condensation of tannins in Alfalfa

    Gene Flow in Medicago Through Somatic Hybridization

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    The objective of this research was the characterization at both molecular and phenotypic level of three somatic hybrid plants obtained by electrofusion of protoplasts of Medicago sativa with those of M.coerulea, M.falcata and M.arborea, three Medicago species in a different relation with alfalfa. Different kinds of rearrangements including the amplification of new spacer-length variants were detected at rDNA loci in the somatic hybrids. Analysis of field performances confirmed the suitability of these plants for breeding purposes

    Feasibility study to realize an anaerobc digester fed with vegetables matrices in central Italy

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    In the present paper we have analysed the possibility to realize an anaerobic digester in a bio-Energy Park located in CittĂ  della Pieve, a small town in Central Italy. The use of anaerobic digesters is quite common in Europe for reducing the environmental impact of manure in a co-digestion procedure with vegetables materials. In addition, for several areas of Central Italy there is the need to find alternative productions to improve farmer's incomes, as traditional cropping systems are loosing convenience. An interesting alternative seems to be cultivation of energy crops because of the favourable conditions of the electric energy market. We are suggesting a low input cropping system to be implemented in areas where low input food/feed crops are no more profitable. In particular our case-study is an example based on the use of a forage legume, alfalfa (Medicago sativa L.), together with other crops, like sorghum, to realize small-size bio-digesters plants. Alfalfa: is a highly sustainable crop as it is able to fix nitrogen and therefore it does not require this fertilization with the consequence of avoiding underground water pollution. Moreover alfalfa residual products are nitrogen rich thus improving soil structure and fertility more than popular graminaceous energy crops such as corn. Beside, alfalfa mostly does not need irrigation in the typical Central Italy environment, all these traits make it one of the species with the lowest energy needs for growing. The aims of this feasibility study are: i) optimization of plant materials feeding the bio-digester, ii) typology of bio-digester, iii) size of bio-digester in relation with land availability for growing energetic cultures, iv) the utilization of bio-gas produced by bio-digester plant to produce electric and thermal energy using cogeneration engines, vi) disposal of waste-water produced according to regional and national laws. The final aim of this study is to verify the possibility to develop an alternative economical use of marginal soils in relatively dry areas of Central Italy that would be replicable in other European areas with a similar climatic situation

    On the Anomalies and Schwinger Terms in Noncommutative Gauge Theories

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    Invariant (nonplanar) anomaly of noncommutative QED is reexamined. It is found that just as in ordinary gauge theory UV regularization is needed to discover anomalies, in noncommutative case, in addition, an IR regularization is also required to exhibit existence of invariant anomaly. Thus resolving the controversy in the value of invariant anomaly, an expression for the unintergrated anomaly is found. Schwinger terms of the current algebra of the theory are derived.Comment: LaTeX, axodraw.sty, 1 figure; v2: Typos corrected, References added, Version to appear in Int. J. Mod. Phys. A (2006

    On the stringy nature of winding modes in noncommutative thermal field theories

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    We show that thermal noncommutative field theories admit a version of `channel duality' reminiscent of open/closed string duality, where non-planar thermal loops can be replaced by an infinite tower of tree-level exchanges of effective fields. These effective fields resemble closed strings in three aspects: their mass spectrum is that of closed-string winding modes, their interaction vertices contain extra moduli, and they can be regarded as propagating in a higher-dimensional `bulk' space-time. In noncommutative models that can be embedded in a D-brane, we show the precise relation between the effective `winding fields' and closed strings propagating off the D-brane. The winding fields represent the coherent coupling of the infinite tower of closed-string oscillator states. We derive a sum rule that expresses this effective coupling in terms of the elementary couplings of closed strings to the D-brane. We furthermore clarify the relation between the effective propagating dimension of the winding fields and the true codimension of the D-brane
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