International audienceThe use of phosphate-solubilizing bacteria (PSB) as inoculants simultaneously increases P uptake by the plant and crop yield. A method to isolate efficient strains, an overview of some updated molecular techniques useful in their characterization (16S rRNA sequencing, LMW RNA profiles, TP-RADP and rep-PCR fingerprinting) and a method for obtaining strain-specific DNA probes will be briefly explained. These methodologies are not time-consuming and, in general, do not require sophisticated equipment.Les bactéries qui solubilisent les phosphates comme inoculants en agriculture : utilisation de techniques moléculaires récentes pour leur étude. L'utilisation de bactéries qui solubilisent les phosphates comme inoculants augmente en même temps l'absorption de cet élément par la plante ainsi que le rendement des cultures. Cet article contient une brève revue des techniques récentes de biologie moléculaire utilisées pour caractériser ces bactéries (séquençage du 16S RNA, profils de LMW RNA, et empreintes par TP-RAPD et rep-PCR). On présente aussi une méthode d'isolation de souches efficientes pour la solubilisation du phosphate et une méthode pour obtenir des sondes d'ADN spécifiques des souches. Il s'agit de méthodes rapides qui, en général, n'ont pas besoin d'un équipement sophistiqué

The species Phaseolus vulgaris is a promiscuous legume nodulated by several species of the family Rhizobiaceae. During a study of rhizobia nodulating this legume in Portugal, we isolated several strains that nodulate P. vulgaris effectively and also Macroptilium atropurpureum and Leucaena leucocephala, but they form ineffective nodules in Medicago sativa. According to phylogenetic analysis of the 16S rRNA gene sequence, the strains from this study belong to the genus Rhizobium, with Rhizobium rhizogenes and Rhizobium tropici as the closest related species, with 99?9 and 99?2 % similarity, respectively, between the type strains of these species and strain P1-7 The strains isolated in this study can be also differentiated from R. rhizogenes and R. tropici by several phenotypic characteristics. The results of DNA-DNA hybridization showed means of 28 and 25 % similarity between strain P1-7 T and R.rhizogenes ATCC 11235 T and R. tropici CIAT 899 T , respectively. All these data showed that the strains isolated in this study belong to a novel species of the genus Rhizobium, for which we propose the name Rhizobium lusitanum sp. nov.; the type strain is P1-7 T (=LMG 22705 T =CECT 7016 T ).

Morphological variation in seed characters includes differences in seed size and shape. Seed shape is an important trait in plant identification and classification. In addition it has agronomic importance because it reflects genetic, physiological, and ecological components and affects yield, quality, and market price. The use of digital technologies, together with development of quantification and modeling methods, allows a better description of seed shape. Image processing systems are used in the automatic determination of seed size and shape, becoming a basic tool in the study of diversity. Seed shape is determined by a variety of indexes (circularity, roundness, and J index). The comparison of the seed images to a geometrical figure (circle, cardioid, ellipse, ellipsoid, etc.) provides a precise quantification of shape. The methods of shape quantification based on these models are useful for an accurate description allowing to compare between genotypes or along developmental phases as well as to establish the level of variation in different sets of seeds.

Several bacterial strains were isolated from root nodules of Phaseolus vulgaris plants grown in a soil from Portugal. The strains were Gram-negative, aerobic, curved rod-shaped and motile. The isolates were catalase-and oxidase-positive. The TP-RAPD (two-primer randomly amplified polymorphic DNA) patterns of all strains were identical, suggesting that they belong to the same species. The complete 16S rDNA sequence of a representative strain was obtained and phylogenetic analysis based on the neighbour-joining method indicated that this bacterium belongs to the b-Proteobacteria and that the closest related genus is Herbaspirillum. The DNA G+C content ranged from 57?9 to 61?9 mol%. Growth was observed with many different carbohydrates and organic acids including caprate, malate, citrate and phenylacetate. No growth was observed with maltose, meso-inositol, meso-erythritol or adipate as sole carbon source. According to the phenotypic and genotypic data obtained in this work, the bacterium represents a novel species of the genus Herbaspirillum, and the name Herbaspirillum lusitanum sp. nov. is proposed. The type strain is P6-12 T (=LMG 21710 T =CECT 5661 T ).

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Title page 1 INTRODUCTIONThe description of plant form and shape is useful to understand evolutionary relationships and quantify differences between species, as well as to define the processes of plant development over space and time. The scientific discipline of Plant Morphology (Kaplan, 2001), however, needs to be mathematically and not solely descriptively based. Seed spacing in a sunflower head, or rings swirls on a pineapple fruit, whose distribution follows Fibonacci series, are good examples, while others remain awaiting discovery. Computational modeling of plant development has been applied to legume lateral root development (Han et al, 2011) as well as nodule pattern (Han et al, 2010b). Such mathematical and computational basis permits the in silico testing of thousands of experimental conditions to achieve outcomes which then need to be verified in "real world" experiments.Recently we described a mathematical-geometrical model to quantify the shape of Arabidopsis seeds. It consisted in the comparison of the outline of the longitudinal equatorial section of the seed with a transformed cardioid (Cervantes et al., 2010). The cardioid is the trajectory described by a point of a circle that rolls around another fixed circle with the same radius, and transforming it by multiplying the x-axis by the scaling factor  (  1.61803399), the so-called "Golden Ratio", the figure obtained resembled the image of an Arabidopsis dry seed. The similarity was evaluated by a factor, the G index, allowing the precise morphological description of genotypes and opening new ways for the association between genetic changes and alterations in the morphology, i.e., a classical genome-phenome analysis. (Cervantes et al., 2010). The functional connection between ethylene perception and seed shape is unclear but may involve diverse aspects of seed development as well as drying rates.Legume seeds offer an excellent material to expand this type of analysis in search of accurate morphological descriptions. Legumes are a large family containing members of great agronomic interest (e.g., soybean, pea, common bean, medics, clovers as well as trees such as Acacias, Robinia and Pongamia; Biswas et al., 2011). In the context of seed morphology, legume species are characterized by remarkable variation, ranging from small seeds such as Lotus japonicus to large-sized seeds of Phaseolus or Vicia and gigantic ones (7-8 cm long) in Black Bean Tree (Castanospermum australe) in Australia.Interestingly, Lotus japonicus and Medicago truncatula, two model species intensively used in genomic analysis (Jiang and Gresshoff, 1997;Sato et al., 2008; Cannon et al., 2006; Young et al., 2005), are amenable to morphological analysis based on a simple model resembling the one described for Arabidopsis, i.e., the comparison with a cardioid. Whereas the seed dimensions of Lotus japonicus match well to a cardioid, in Medicago truncatula accurate adjustment is obtained by the simple transformation of scaling the vertical axis by a factor equal to the Golden Rati...

Synthetic oligonucleotides corresponding to conserved regions of cysteine proteinases were used as primers in the RT-PCR amplification of a fragment of cDNA corresponding to a region of a cysteine proteinase gene expressed during germination of chickpea (cac for Cicer arietinum cysteine proteinase). The identity of the PCR-amplified fragment was confirmed by sequencing and the fragment used as a probe to investigate the pattern of cac gene expression during germination and its hormonal regulation. The corresponding transcript is undetected in the seed during embryogenesis and before imbibition, being detected 24 h after imbibition. Ablation of the embryonic axis before imbibition results in a dramatic decrease in the amount of transcript detected. Expression of the cac transcript in excised cotyledons is restored in the presence of aqueous extracts from embryonic axes and also by incubating the excised cotyledons in 1 mM ethephon. Experiments with various known inhibitors of ethylene action indicate that ethylene activates the expression of cac gene in the cotyledons of chickpea during normal germination.