Tomato floral induction and flower development are orchestrated by the interplay between gibberellin and two unrelated microRNA-controlled modules

[EN] Age-regulated microRNA156 (miR156) and targets similarly control the competence to flower in diverse species. By contrast, the diterpene hormone gibberellin (GA) and the microRNA319-regulated TEOSINTE BRANCHED/CYCLOIDEA/PCF (TCP) transcription factors promote flowering in the facultative long-day Arabidopsis thaliana, but suppress it in the day-neutral tomato (Solanum lycopersicum). We combined genetic and molecular studies and described a new interplay between GA and two unrelated miRNA-associated pathways that modulates tomato transition to flowering. Tomato PROCERA/DELLA activity is required to promote flowering along with the miR156-targeted SQUAMOSA PROMOTER BINDING-LIKE (SPL/SBP) transcription factors by activating SINGLE FLOWER TRUSS (SFT) in the leaves and the MADS-Boxgene APETALA1(AP1)/MC at the shoot apex. Conversely, miR319-targeted LANCEOLATE represses floral transition by increasing GA concentrations and inactivating SFT in the leaves and AP1/MC at the shoot apex. Importantly, the combination of high GA concentrations/responses with the loss of SPL/SPB function impaired canonical meristem maturation and flower initiation in tomato. Our results reveal a cooperative regulation of tomato floral induction and flower development, integrating age cues (miR156 module) with GA responses and miR319-controlled pathways. Importantly, this study contributes to elucidate the mechanisms underlying the effects of GA in controlling flowering time in a day-neutral species.We thank Dr C. Schommer for kindly providing tcp4-soj8/+ seeds, and Carlos Rojas for Arabidopsis flowering time analyses. This work was supported by FAPESP (grant no. 15/17892-7 and fellowships nos 15/23826-7 and 13/16949-0). The authors declare no conflict of interest.Silva, G.; Silva, E.; Correa, J.; Vicente, M.; Jiang, N.; Notini, M.; Junior, A.... (2018). 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De novo domestication of wild tomato using genome editing

Breeding of crops over millennia for yield and productivity1 has led to reduced genetic diversity. As a result, beneficial traits of wild species, such as disease resistance and stress tolerance, have been lost2. We devised a CRISPR–Cas9 genome engineering strategy to combine agronomically desirable traits with useful traits present in wild lines. We report that editing of six loci that are important for yield and productivity in present-day tomato crop lines enabled de novo domestication of wild Solanum pimpinellifolium. Engineered S. pimpinellifolium morphology was altered, together with the size, number and nutritional value of the fruits. Compared with the wild parent, our engineered lines have a threefold increase in fruit size and a tenfold increase in fruit number. Notably, fruit lycopene accumulation is improved by 500% compared with the widely cultivated S. lycopersicum. Our results pave the way for molecular breeding programs to exploit the genetic diversity present in wild plants

Reticulate evolution: frequent introgressive hybridization among chinese hares (genus lepus) revealed by analyses of multiple mitochondrial and nuclear DNA loci

<p>Abstract</p> <p>Background</p> <p>Interspecific hybridization may lead to the introgression of genes and genomes across species barriers and contribute to a reticulate evolutionary pattern and thus taxonomic uncertainties. Since several previous studies have demonstrated that introgressive hybridization has occurred among some species within <it>Lepus</it>, therefore it is possible that introgressive hybridization events also occur among Chinese <it>Lepus </it>species and contribute to the current taxonomic confusion.</p> <p>Results</p> <p>Data from four mtDNA genes, from 116 individuals, and one nuclear gene, from 119 individuals, provides the first evidence of frequent introgression events via historical and recent interspecific hybridizations among six Chinese <it>Lepus </it>species. Remarkably, the mtDNA of <it>L. mandshuricus </it>was completely replaced by mtDNA from <it>L. timidus </it>and <it>L. sinensis</it>. Analysis of the nuclear DNA sequence revealed a high proportion of heterozygous genotypes containing alleles from two divergent clades and that several haplotypes were shared among species, suggesting repeated and recent introgression. Furthermore, results from the present analyses suggest that Chinese hares belong to eight species.</p> <p>Conclusion</p> <p>This study provides a framework for understanding the patterns of speciation and the taxonomy of this clade. The existence of morphological intermediates and atypical mitochondrial gene genealogies resulting from frequent hybridization events likely contribute to the current taxonomic confusion of Chinese hares. The present study also demonstrated that nuclear gene sequence could offer a powerful complementary data set with mtDNA in tracing a complete evolutionary history of recently diverged species.</p

Geometric Analysis to Determine Kinking and Shortening of Bridging Stents After Branched Endovascular Aortic Repair

Purpose: To evaluate bridging stent geometry in patients who underwent branched endovascular aortic repair (B-EVAR) and to correlate the outcomes with intrinsic bridging stent characteristics aiming to identify the stent(s) that guarantees the best performance. Methods: Pre-operative and post-operative computed tomography images of all patients undergoing B-EVAR between September 2016 and April 2019 were retrospectively analyzed. Following geometrical features were measured: target vessel take-off angle (TOA); longitudinal stent shortening; shape index (SI), intended as ratio between minimum and maximum diameter of the lumen cross sections, averaged on three segments: zone 1 (proximal stented zone), zone 2 (intermediate), and zone 3 (distal). Results: Thirty-eight branches (8 right (RRA) and 8 left renal arteries (LRA), 11 superior mesenteric arteries (SMA), 11 celiac trunks (CTR)) were treated. Fluency (Bard Peripheral Vascular), COVERA (Bard Peripheral Vascular), and VBX (WLGore&Assoc) stent-grafts were implanted in 10, 12, and 16 branches, respectively. Pre-operative TOA was more acute in RRA and LRA when compared to CTR and SMA, and straightened in post-operative configuration (109.86 ± 28.65° to 150.27 ± 21.0°; P < 0.001). Comparable values of SI among the stent types were found in zone 1 (P = 0.08), whereas higher SI in VBX group was detected in zones 2 (P < 0.001) and 3 (P < 0.001). The VBX group was also the most affected by stent shortening (11.12 ± 5.65%; P = 0.001). Conclusion: Our early experience showed that the VBX stent offers greater stent circularity than the other devices even if a greater shortening has been observed drawing attention with regards to the decision of the nominal stent length

Record of intermediate-depth subduction seismicity in a dry slab from an exhumed ophiolite

The ophiolitic peridotite and gabbro of Moncuni (Southern Lanzo Massif, Western Alps) retain pre-subduction mantle-to-oceanic, high-temperature (>700C∘) ductile fabrics. These fabrics are overprinted by seismic fracturing and faulting associated with pseudotachylytes. Within the gabbro, the pseudotachylytes preserve dry glass and pristine microlites. The occurrence of rare, minute garnet and the static development of eclogite-facies assemblages in local hydrated domains indicate that pseudotachylytes experienced subduction conditions of 600C∘ and 2.1 GPa. The exceptional survival of glass and the absence of post-oceanic ductile deformation demonstrate prevailing dry conditions during the entire Alpine subduction and exhumation path. Dry conditions inhibited reaction kinetics and viscous flow. In contrast, the majority of the Alpine ophiolites, derived from the upper hydrated portions of the oceanic lithosphere, show pervasive fluid-assisted metamorphism and ductile deformation. The Moncuni body can, therefore, be regarded as representative for the rheological behaviour during subduction of seismic, dry, deeper oceanic lithosphere that is rarely exhumed to the Earth's surface. In Moncuni, the brittle-ductile transition of dry oceanic rocks is constrained to be between 600 and 750C∘. This temperature range corresponds to the observed cut-off of intermediate-depth seismicity within subducting slabs. We infer that the base of the seismic layer corresponds to the brittle-ductile transition of a dry slab rather than the locus of antigorite breakdown triggering earthquakes by dehydration embrittlement