Esglésies del Baix Vallès d'origen romànic

Deu imatges d'esglésies vallesanes de l'entorn de Mollet, els orígens de les quals es remunten a l'Alta Edat Mitjana. Els originals d'aquestes imatges, obra de Jordi Mas, s'han realitzat amb la tècnica pictòrica de l'aquarel·la. Cada imatge s'acompanya d'una síntesi de trajectòria històrica d'aquests edificis de culte. I precedint-les hem sintetitzat alguns trets significatius del context històric en el qual s'emmarquen els orígens d'aquests temples : en uns territoris recuperats als sarraïns, pagesos i senyors malden per fer realitat el projecte d'una Catalunya en construcció, on l'església tindrà un paper molt destaca

Editorial: Translational research for cucurbit molecular breeding: Traits, markers, and genes

Cucurbits (family Cucurbitaceae) are economically important vegetable crops. Major cucurbits growing globally include cucumber, melon, watermelon, and squash/pumpkin. Other cucurbits like bitter melon, bottle gourd, winter melon, and luffa are popular in many Asian and African countries. The last decade has witnessed a rapid development of genetic and genomics resources including draft genome assemblies, and high-density genetic maps in a dozen cucurbit crops, making it possible to accelerate translational research for cucurbit breeding. This Research Topic is a collection of 21 Original Research articles or Reviews highlighting the achievements and future directions in cucurbit translational research. These articles cover a variety of topics ranging from improvement of the cucurbit genome assemblies to identification and molecular mapping of horticulturally important genes or QTL for horticultural traits, and the use of such knowledge in marker-assisted selection for cucurbit improvement. Major findings from these investigations are summarized below.info:eu-repo/semantics/publishedVersio

Generation of a BAC-based physical map of the melon genome

13 páginas, 4 figuras, 3 tablas.[Background]: Cucumis melo (melon) belongs to the Cucurbitaceae family, whose economic importance among horticulture crops is second only to Solanaceae. Melon has high intra-specific genetic variation, morphologic diversity and a small genome size (450 Mb), which make this species suitable for a great variety of molecular and genetic studies that can lead to the development of tools for breeding varieties of the species. A number of genetic and genomic resources have already been developed, such as several genetic maps and BAC genomic libraries. These tools are essential for the construction of a physical map, a valuable resource for map-based cloning, comparative genomics and assembly of whole genome sequencing data. However, no physical map of any Cucurbitaceae has yet been developed. A project has recently been started to sequence the complete melon genome following a whole-genome shotgun strategy, which makes use of massive sequencing data. A BAC-based melon physical map will be a useful tool to help assemble and refine the draft genome data that is being produced. [Results]: A melon physical map was constructed using a 5.7 × BAC library and a genetic map previously developed in our laboratories. High-information-content fingerprinting (HICF) was carried out on 23,040 BAC clones, digesting with five restriction enzymes and SNaPshot labeling, followed by contig assembly with FPC software. The physical map has 1,355 contigs and 441 singletons, with an estimated physical length of 407 Mb (0.9 × coverage of the genome) and the longest contig being 3.2 Mb. The anchoring of 845 BAC clones to 178 genetic markers (100 RFLPs, 76 SNPs and 2 SSRs) also allowed the genetic positioning of 183 physical map contigs/singletons, representing 55 Mb (12%) of the melon genome, to individual chromosomal loci. The melon FPC database is available for download at http://melonomics.upv.es/static/files/public/physical_map/ webcite. [Conclusions]: Here we report the construction of the first physical map of a Cucurbitaceae species described so far. The physical map was integrated with the genetic map so that a number of physical contigs, representing 12% of the melon genome, could be anchored to known genetic positions. The data presented is already helping to improve the quality of the melon genomic sequence available as a result of a project currently being carried out in Spain, adopting a whole genome shotgun approach based on 454 sequencing data.This project was funded by the Plan Nacional de Investigación Científica of the Spanish Ministerio de Educación y Ciencia (Project BIO2007-61789) and by the Consolider-Ingenio 2010 Programme of the Spanish Ministerio de Ciencia e Innovación (CSD2007-00036 "Center for Research in Agrigenomics").Peer reviewe

An improved melon reference genome with single-molecule sequencing uncovers a recent burst of transposable elements with potential impact on genes

The published melon (Cucumis melo L.) reference genome assembly (v3.6.1) has still 41.6 Mb (Megabases) of sequences unassigned to pseudo-chromosomes and about 57 Mb of gaps. Although different approaches have been undertaken to improve the melon genome assembly in recent years, the high percentage of repeats (~40%) and limitations due to read length have made it difficult to resolve gaps and scaffold's misassignments to pseudomolecules, especially in the heterochromatic regions. Taking advantage of the PacBio single- molecule real-time (SMRT) sequencing technology, an improvement of the melon genome was achieved. About 90% of the gaps were filled and the unassigned sequences were drastically reduced. A lift-over of the latest annotation v4.0 allowed to re-collocate protein-coding genes belonging to the unassigned sequences to the pseudomolecules. A direct proof of the improvement reached in the new melon assembly was highlighted looking at the improved annotation of the transposable element fraction. By screening the new assembly, we discovered many young (inserted less than 2Mya), polymorphic LTR-retrotransposons that were not captured in the previous reference genome. These elements sit mostly in the pericentromeric regions, but some of them are inserted in the upstream region of genes suggesting that they can have regulatory potential. This improved reference genome will provide an invaluable tool for identifying new gene or transposon variants associated with important phenotypes.info:eu-repo/semantics/publishedVersio

The 2-C-methylerythritol 4-phosphate pathway in melon is regulated by specialized isoforms for the first and last steps

The 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway provides the precursors for the biosynthesis of plastidial isoprenoids, which include the carotenoid pigments of many fruits. We have analysed the genes encoding the seven enzymes of the MEP pathway in melon (Cucumis melo L.) and determined that the first one, 1-deoxyxylulose 5-phosphate synthase (DXS), and the last one, 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (HDR), are represented in the genome as a small gene family and paralogous pair, respectively. In the case of DXS, three genes encode functional DXS activities which fall into previously established type I (CmDXS1) and II (CmDXS2a and CmDXS2b) categories, while a fourth DXS-like gene belonging to the type III group did not encode a protein with DXS activity. Their expression patterns and phylogenies suggest that CmDXS1 is functionally specialized for developmental and photosynthetic processes, while CmDXS2a and CmDXS2b are induced in flowers and ripening fruit of orange- (but not white-) fleshed varieties, coinciding with β-carotene accumulation. This is the first instance connecting type II DXS genes to specialized isoprenoid biosynthesis in the fruit of an agronomically important species. Two HDR paralogues were shown to encode functional enzymes, although only CmHDR1 was highly expressed in the tissues and developmental stages tested. Phylogenetic analysis showed that in cucurbits such as melon, these HDR paralogues probably arose through individual gene duplications in a common angiosperm ancestor, mimicking a prior division in gymnosperms, while other flowering plants, including apple, soy, canola, and poplar, acquired HDR duplicates recently as homoeologues through large-scale genome duplications. We report the influence of gene duplication history on the regulation of the MEP pathway in melon and the role of specialized MEP-pathway isoforms in providing precursors for β-carotene production in orange-fleshed melon varieties

Drought-resistant fungi control soil organic matter decomposition and its response to temperature

Microbial-mediated decomposition of soil organic matter (SOM) ultimately makes a considerable contribution to soil respiration, which is typically the main source of CO2 arising from terrestrial ecosystems. Despite this central role in the decomposition of SOM, few studies have been conducted on how climate change may affect the soil microbial community and, furthermore, on how possible climate-change induced alterations in the ecology of microbial communities may affect soil CO2 emissions. Here we present the results of a seasonal study on soil microbial community structure, SOM decomposition and its temperature sensitivity in two representative Mediterranean ecosystems where precipitation/throughfall exclusion has taken place during the last 10 years. Bacterial and fungal diversity was estimated using the terminal restriction fragment length polymorphism technique. Our results show that fungal diversity was less sensitive to seasonal changes in moisture, temperature and plant activity than bacterial diversity. On the other hand, fungal communities showed the ability to dynamically adapt throughout the seasons. Fungi also coped better with the 10 years of precipitation/throughfall exclusion compared with bacteria. The high resistance of fungal diversity to changes with respect to bacteria may open the controversy as to whether future 'drier conditions' for Mediterranean regions might favor fungal dominated microbial communities. Finally, our results indicate that the fungal community exerted a strong influence over the temporal and spatial variability of SOM decomposition and its sensitivity to temperature. The results, therefore, highlight the important role of fungi in the decomposition of terrestrial SOM, especially under the harsh environmental conditions of Mediterranean ecosystems, for which models predict even drier conditions in the future

The haplotype-resolved T2T reference genome highlights structural variation underlying agronomic traits of melon

Melon (Cucumis melo L.) is an important vegetable crop that has an extensive history of cultivation. However, the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet available. Here we report a chromosome-level T2T genome assembly for 821 (C. melo ssp. agrestis var. acidulus), a semi-wild melon with two haplotypes of ~373 Mb and ~364 Mb, respectively. Comparative genome analysis discovered a significant number of structural variants (SVs) between melo (C. melo ssp. melo) and agrestis (C. melo ssp. agrestis) genomes, including a copy number variation located in the ToLCNDV resistance locus on chromosome 11. Genome-wide association studies detected a significant signal associated with climacteric ripening and identified one candidate gene CM_ac12g14720.1 (CmABA2), encoding a cytoplasmic short chain dehydrogenase/reductase, which controls the biosynthesis of abscisic acid. This study provides valuable genetic resources for future research on melon breeding.This work was supported by funding from the Agricultural Science and Technology Innovation Program (CAAS-ASTIP-2016-ZFRI-06), the China Agriculture Research System (CARS-25-2023-G6), the Key Research and Development Program of Hainan (ZDYF2021XDNY164), the European Research Council (ERC-NectarGland, 101095736), the 111 Project (B17043) and Henan Province Science and Technology Research Project (232102110185).info:eu-repo/semantics/acceptedVersio

Sequencing of 6.7 Mb of the melon genome using a BAC pooling strategy

<p>Abstract</p> <p>Background</p> <p><it>Cucumis melo </it>(melon) belongs to the Cucurbitaceae family, whose economic importance among horticulture crops is second only to Solanaceae. Melon has a high intra-specific genetic variation, morphologic diversity and a small genome size (454 Mb), which make it suitable for a great variety of molecular and genetic studies. A number of genetic and genomic resources have already been developed, such as several genetic maps, BAC genomic libraries, a BAC-based physical map and EST collections. Sequence information would be invaluable to complete the picture of the melon genomic landscape, furthering our understanding of this species' evolution from its relatives and providing an important genetic tool. However, to this day there is little sequence data available, only a few melon genes and genomic regions are deposited in public databases. The development of massively parallel sequencing methods allows envisaging new strategies to obtain long fragments of genomic sequence at higher speed and lower cost than previous Sanger-based methods.</p> <p>Results</p> <p>In order to gain insight into the structure of a significant portion of the melon genome we set out to perform massive sequencing of pools of BAC clones. For this, a set of 57 BAC clones from a double haploid line was sequenced in two pools with the 454 system using both shotgun and paired-end approaches. The final assembly consists of an estimated 95% of the actual size of the melon BAC clones, with most likely complete sequences for 50 of the BACs, and a total sequence coverage of 39x. The accuracy of the assembly was assessed by comparing the previously available Sanger sequence of one of the BACs against its 454 sequence, and the polymorphisms found involved only 1.7 differences every 10,000 bp that were localized in 15 homopolymeric regions and two dinucleotide tandem repeats. Overall, the study provides approximately 6.7 Mb or 1.5% of the melon genome. The analysis of this new data has allowed us to gain further insight into characteristics of the melon genome such as gene density, average protein length, or microsatellite and transposon content. The annotation of the BAC sequences revealed a high degree of collinearity and protein sequence identity between melon and its close relative <it>Cucumis sativus </it>(cucumber). Transposon content analysis of the syntenic regions suggests that transposition activity after the split of both cucurbit species has been low in cucumber but very high in melon.</p> <p>Conclusions</p> <p>The results presented here show that the strategy followed, which combines shotgun and BAC-end sequencing together with anchored marker information, is an excellent method for sequencing specific genomic regions, especially from relatively compact genomes such as that of melon. However, in agreement with other results, this map-based, BAC approach is confirmed to be an expensive way of sequencing a whole plant genome. Our results also provide a partial description of the melon genome's structure. Namely, our analysis shows that the melon genome is highly collinear with the smaller one of cucumber, the size difference being mainly due to the expansion of intergenic regions and proliferation of transposable elements.</p

Modulating climacteric intensity in melon through QTL stacking

Fruit ripening is one of the main processes affecting fruit quality and shelf life. In melon there are both climacteric and non-climacteric genotypes, making it a suitable species to study fruit ripening. In the current study, in order to fine tune ripening, we have pyramided three climacteric QTLs in the non-climacteric genotype “Piel de Sapo”: ETHQB3.5, ETHQV6.3 and ETHQV8.1. The results showed that the three QTLs interact epistatically, affecting ethylene production and ripening-related traits such as aroma profile. Each individual QTL has a specific role in the ethylene production profile. ETHQB3.5 accelerates the ethylene peak, ETHQV6.3 advances the ethylene production and ETHQV8.1 enhances the effect of the other two QTLs. Regarding aroma, the three QTLs independently activated the production of esters changing the aroma profile of the fruits, with no significant effects in fruit firmness, soluble solid content and fruit size. Understanding the interaction and the effect of different ripening QTLs offers a powerful knowledge for candidate gene identification as well as for melon breeding programs, where fruit ripening is one of the main objectives.info:eu-repo/semantics/publishedVersio

Modern sedimentation patterns and human impacts on the Barcelona continental shelf (NE Spain)

Seafloor sediments were collected from the Barcelona continental shelf, NE Spain, to determine the textural characteristics and sedimentary processes related to different depositional systems and human pressures. The Barcelona continental shelf is principally influenced by the discharge of the Llobregat and Besòs rivers, and also by anthropogenic modifications Duch as the diversion of the Llobregat River or the enlargement of the Port of Barcelona. Sedimentological, physical and biogeochemical properties of 14 sediment cores and grabs indicate the presence of three distinct depositional environments linked to river-influenced, marine-influenced and mixed sedimentation. Sedimentological results have been used to groundtruth available backscatter data. The river-influenced environment, mainly associated to the Llobregat River input, does not reach the shelf edge as the prevailing oceanographic currents deflect sediments south-westward. Riverine sediments are fine-grained, with abundant plant debris, micas and relatively high organic carbon content. The associated sedimentary features are the Holocene prodelta and two modern mud patches. The marine-influenced environment extends north-easterly over the middle and outer shelf and on the upper continental slope. The sediments are coarser grained with abundant bioclasts and lower organic carbon content. Mixed sedimentation is present between the river- and marine-influenced areas. In addition, 210Pb, 226Ra and 137Cs radiometric analyses were used to estimate accumulation rates as well as to identify sites with disturbed sedimentation. Relatively high sediment accumulation rates (up to 0.70-1.03 g•cm-2•yr-1 equivalent to 6.4-10 mm•yr-1) are estimated on the Llobregat prodelta while moderate rates 0.21-0.46 g•cm-2•yr-1 or 1.6-3.6 mm•yr-1) are found between the Besòs and the Llobregat outlets. Two sediment cores show a sharp change from river-influenced to marine-dominated conditions that occurred in the mid- 1960s. This is interpreted as a significant regression (~2.5 km in 40 years) of the river-influenced domain that may be associated to the extension of the Port of Barcelona and the canalization of the Besòs River, amongst other reasons. Other important human impacts observed in the Barcelona continental shelf are (i) sediment mixing by dredging, ship anchoring and trawling; and (ii) possible organic pollution associated to river and sewage discharges