48 research outputs found
Accumulation of Mutated Maize Zeins in Transgenic Forage Legumes
Accumulation of zeins, the endosperm storage proteins of maize, in a heterologous plant expression system was attempted. Plants of birdsfoot trefoil (Lotus corniculatus) and alfalfa (Medicago sativa) were transformed by Agrobacterium with binary vectors harboring genes that code for Îł-zein and ÎČ-zein, two proteins rich in sulphur amino acids. Adding the ER retention signal KDEL to the C-terminal domain modified zein polypeptides. Our long-term goal was to improve birdsfoot trefoil and alfalfa forage quality. Significant levels of Îł- zein:KDEL and ÎČ-zein:KDEL were detected in primary transformants of birdsfoot trefoil. Moreover, alfalfa plants expressing Îł-zein:KDEL in the leaves were obtained. Îł-zein:KDEL accumulated in spherical or elliptical electron-dense bodies of birdsfoot trefoil leaves. The protein bodies were present in the cytoplasm of either mesophyll cells or epidermis cells
Light Intensity Is Positively Correlated with the Synthesis of Condensed Tannins in \u3ci\u3eLotus corniculatus\u3c/i\u3e
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
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
Role of the BANYULS(BAN) Gene from Arabidopsis Thaliana in Transgenic Alfalfa Expression of Anthocyanins and Proanthocyanidins
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
Diagnostic du cancer du poumon: dĂ©veloppement dâune mĂ©thode pour la dĂ©tection de la mutation EGFR T790M
Le but de ce travail est de comparer le rendement de 4 kits dâextraction de ctDNA dans le plasma dans le cadre du cancer du poumon NSCLC-EGFR positif. Une bonne qualitĂ© dâADN permettrait de rechercher la mutation de rĂ©sistance EGFR p.T790M
An Italian functional genomic resource for Medicago truncatula
Background: Medicago truncatula is a model species for legumes. Its functional genomics have been considerably boosted in recent years due to initiatives based both in Europe and US. Collections of mutants are becoming increasingly available and this will help unravel the genetic control of important traits for many species of legumes.
Findings: Our report is on the production of three complementary mutant collections of the model species Medicago truncatula produced in Italy in the frame of a national genomic initiative. Well established strategies were used: Tnt1 mutagenesis, TILLING and activation tagging. Both forward and reverse genetics screenings proved the efficiency of the mutagenesis approaches adopted, enabling the isolation of interesting mutants which are in course of characterization. We anticipate that the reported collections will be complementary to the recently established functional genomics tools developed for Medicago truncatula both in Europe and in the United States
PĂ©rigord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis
LetterInternational audienceThe PĂ©rigord black truffle ( Vittad.) and the Piedmont white truffle dominate today's truffle market. The hypogeous fruiting body of is a gastronomic delicacy produced by an ectomycorrhizal symbiont endemic to calcareous soils in southern Europe. The worldwide demand for this truffle has fuelled intense efforts at cultivation. Identification of processes that condition and trigger fruit body and symbiosis formation, ultimately leading to efficient crop production, will be facilitated by a thorough analysis of truffle genomic traits. In the ectomycorrhizal , the expansion of gene families may have acted as a 'symbiosis toolbox'. This feature may however reflect evolution of this particular taxon and not a general trait shared by all ectomycorrhizal species. To get a better understanding of the biology and evolution of the ectomycorrhizal symbiosis, we report here the sequence of the haploid genome of , which at 125âmegabases is the largest and most complex fungal genome sequenced so far. This expansion results from a proliferation of transposable elements accounting for 58% of the genome. In contrast, this genome only contains 7,500 protein-coding genes with very rare multigene families. It lacks large sets of carbohydrate cleaving enzymes, but a few of them involved in degradation of plant cell walls are induced in symbiotic tissues. The latter feature and the upregulation of genes encoding for lipases and multicopper oxidases suggest that degrades its host cell walls during colonization. Symbiosis induces an increased expression of carbohydrate and amino acid transporters in both and , but the comparison of genomic traits in the two ectomycorrhizal fungi showed that genetic predispositions for symbiosis 'the symbiosis toolbox' evolved along different ways in ascomycetes and basidiomycete
Optimal population size for RFLP-assisted cultivar identification in alfalfa (Medicago sativa L.)
The ability of RFLP markers to distinguish between 2 heterogeneous alfalfa ecotypes, "Vogherese" and
"Maremmana", was correlated with the number of plants sampled in either single-plant or bulk analyses.
Independent subsample populations of 20 and 50 plants were compared for variance component partitioning
and band frequencies in 20-, 50- and 100-plant subpopulations of Maremmana. Homogeneity within 3
independent bulks of the same size as given above was taken as a measure of bulk optimal size. A minimum
of 50 plants is required for both single-plant and bulk analyses; however, for a large majority of bands
analysed, no significant differences were detected for their frequency among populations of 20, 50 and 100
plants, with the exception of 6 bands out of 48. One ecotype-specific marker was found through bulk
analysis. Results are discussed in relation to the improvement of RFLP methodology for cultivar
identification in alfalfa.Taille de population optimale pour l'identification des cultivars par RFLP chez la luzerne
(Medicago sativa L.). La capacité des marqueurs RFLP de distinguer entre deux écotypes hétérogÚnes
de luzerne, "Vogherese " et "Maremmana ", a été comparée avec le nombre de plantes composant un
échantillon utilisé aussi bien pour l'analyse sur des plantes individuelles que sur des plantes en mélange
("bulk "). La partition des composantes de la variance a été comparée dans des sous-échantillons de
populations indépendantes de 20 et 50 plantes, et les fréquences de bandes ont été aussi comparées dans
des sous-populations de Maremmana constituĂ©es par 20, 50 et 100 plantes. Le degrĂ© d'homogĂ©nĂ©itĂ© rĂ©velĂ© Ă
l'intĂ©rieur de 3 "bulks " indĂ©pendants, de tailles identiques Ă celles qui viennent d'ĂȘtre mentionnĂ©es,
a été pris comme mesure de la taille optimale du "bulk ". Un minimum de 50 plantes est nécessaire aussi
bien pour l'analyse sur plantes individuelles qu'en "bulk ", alors que pour la grande majorité des
bandes analysée, aucune différence significative de leur fréquence n'a été relevée entre les populations
de 20, 50 et 100 plantes, à l'exception de 6 bandes sur 48. Un marqueur spécifique d'un écotype a été
trouvé au moyen de l'analyse "bulk ". Les résultats sont discutés dans l'optique d'une amélioration de
la méthodologie RFLP servant à l'identification des cultivars chez la luzerne