Lotus tenuis x L. corniculatus interspecific hybridization as a means to breed bloat-safe pastures and gain insight into the genetic control of proanthocyanidin biosynthesis in legumes

Background: Proanthocyanidins (PAs) are secondary metabolites that strongly affect plant quality traits. The concentration and the structure of these metabolites influence the palatability and nutritional value of forage legumes. Hence, modulating PAs in the leaves of forage legumes is of paramount relevance for forage breeders worldwide. The lack of genetic variation in the leaf PA trait within the most important forage species and the difficulties in engineering this pathway via the ectopic expression of regulatory genes, prompted us to pursue alternative strategies to enhance this trait in forage legumes of agronomic interest. The Lotus genus includes forage species which accumulate PAs in edible organs and can thus be used as potential donor parents in breeding programs. Results: We recovered a wild, diploid and PA-rich population of L. corniculatus and crossed with L. tenuis. The former grows in an alkaline-salty area in Spain while the latter is a diploid species, grown extensively in South American pastures, which does not accumulate PAs in the herbage. The resulting interspecific hybrids displayed several traits of outstanding agronomic relevance such as rhizome production, PA levels in edible tissues sufficient to prevent ruminal bloating (around 5 mg of PAs/g DW), biomass production similar to the cultivated parent and potential for adaptability to marginal lands. We show that PA levels correlate with expression levels of the R2R3MYB transcription factor TT2 and, in turn, with those of the key structural genes of the epicatechin and catechin biosynthetic pathways leading to PA biosynthesis. Conclusions: The L. tenuis x L. corniculatus hybrids, reported herein, represent the first example of the introgression of the PA trait in forage legumes to levels known to provide nutritional and health benefits to ruminants. Apart from PAs, the hybrids have additional traits which may prove useful to breed forage legumes with increased persistence and adaptability to marginal conditions. Finally, our study suggests the hybrids and their progeny are an invaluable tool to gain a leap forward in our understanding of the genetic control of PA biosynthesis and tolerance to stresses in legumes.Fil: Escaray, Francisco José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Passeri, Valentina. Institute of Biosciences and BioResources; Italia. Consiglio Nazionale delle Ricerche; ItaliaFil: Babuin, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Marco, Francisco. Universidad de Valencia; EspañaFil: Carrasco, Pedro. Universidad de Valencia; EspañaFil: Damiani, Francesco. Consiglio Nazionale delle Ricerche; Italia. Institute of Biosciences and BioResources; ItaliaFil: Pieckenstain, Fernando Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Paolocci, Francesco. Consiglio Nazionale delle Ricerche; Italia. Institute of Biosciences and BioResources; ItaliaFil: Ruiz, Oscar Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

Compartmentalized Phosphodiesterase-2 Activity Blunts β-Adrenergic Cardiac Inotropy via an NO/cGMP-Dependent Pathway

β-Adrenergic signaling via cAMP generation and PKA activation mediates the positive inotropic effect of catecholamines on heart cells. Given the large diversity of protein kinase A targets within cardiac cells, a precisely regulated and confined activity of such signaling pathway is essential for specificity of response. Phosphodiesterases (PDEs) are the only route for degrading cAMP and are thus poised to regulate intracellular cAMP gradients. Their spatial confinement to discrete compartments and functional coupling to individual receptors provides an efficient way to control local [cAMP] i in a stimulus-specific manner. By performing real-time imaging of cyclic nucleotides in living ventriculocytes we identify a prominent role of PDE2 in selectively shaping the cAMP response to catecholamines via a pathway involving β 3 -adrenergic receptors, NO generation and cGMP production. In cardiac myocytes, PDE2, being tightly coupled to the pool of adenylyl cyclases activated by β-adrenergic receptor stimulation, coordinates cGMP and cAMP signaling in a novel feedback control loop of the β-adrenergic pathway. In this, activation of β 3 -adrenergic receptors counteracts cAMP generation obtained via stimulation of β 1 /β 2 -adrenoceptors. Our study illustrates the key role of compartmentalized PDE2 in the control of catecholamine-generated cAMP and furthers our understanding of localized cAMP signaling

Intra-varietal variability of Romanesco variety (Vitis vinifera L.)

Most historical sources that describe the presence of Romanesco variety in vine-growing areas of Lazio Region (Italy) highlighted the variability of morphological traits within the variety. This partly justifies the presence of different synonyms, true or presumed, reported by many authors for this grape variety. With the aim of analysing this variability, eight accessions related to the variety, collected in Lazio Region and grown in the DAFNE grape germplasm collection, have been characterized over five productive seasons. The ampelographic description was carried out using 50 OIV morphological descriptors and ampelometric analyses were carried out on mature leaves by SuperAmpelo software. The DNA of the different accessions, extracted from young leaves, was analyzed using 14 microsatellite loci. Furthermore, at harvest, the grapes of each accession were sampled to assess main compositive characteristics. Results showed differences among accessions on some ampelographic descriptors of the mature leaf, of the bunch, and on phenological stages. Microsatellite profiles allowed for classification of the accessions into three distinct groups. Qualitative analysis of the berry skin showed differences among accessions in the content of the main classes of phenolic compounds

Raccolta, conservazione e valutazione di germoplasma viticolo dell'Alto Lazio: attività in corso in un campo collezione presso l'Università della Tuscia

Nel Lazio il germoplasma viticolo è piuttosto diversificato. Molti sono i biotipi presenti sul territorio non ancora caratterizzati. La ricerca ha preso in considerazione vitigni ritenuti autoctoni del Lazio, ed in particolare del territorio della Tuscia viterbese in cui sono stati reperiti e dove storicamente rappresentano la base ampelografica della vitivinicoltura locale. In particolare, il vitigno Rossetto (Trebbiano giallo) entra in varie d.o.c. sia nella provincia di Roma (Castelli Romani, Trebbiano di Aprilia, etc.) sia in quella di Viterbo ( Est! Est!! Est!!!, Vignanello, etc.); l’Aleatico caratterizza la produzione enologica del comprensorio del comune di Gradoli, mentre Romanesco e Petino sono stati utilizzati in passato nei disciplinari di produzione di vini locali (Est! Est!! Est!!!), per essere sostituiti in tempi più recenti da altre cultivar più diffuse. A questi vitigni, è stato affiancato il Procanico (Trebbiano toscano), che è presente da secoli nel territorio laziale ed entra in diverse produzioni. Il lavoro di caratterizzazione ampelografica e molecolare svolto rappresenta un primo contributo alla caratterizzazione di vitigni autoctoni dell’Alto Lazio ed un supporto alla valorizzazione del germoplasma e delle produzioni locali ad esso connesse