Seed coat lignification level is crucial in Capsicum spp seed longevity.

Capsicum (pepper) is known for its poor seed germination, particularly seed longevity is usually much shorter than other Solanaceae. However, the molecular mechanisms involved are mostly unknown in these species. The present study examines the differences in seed longevity among Capsicum species and varietal types. Feral or less domesticated species, such as Capsicum chinense and particularly Capsicum frutescens, showed higher germination rates than the more domesticated Capsicum annuum after accelerated seed aging treatments. In addition, variability was detected in the expression of genes involved in the response to seed deterioration. The differences observed in ASPG1 expression led us to study the seed protein profile in dry and germinating seeds. Seed storage protein mobilization during germination was faster in seed aging-resistant genotypes. Similarly, the transcriptional change observed for the orthologous gene of the trans-species regulator AtHB25 prompted us to study the structure and molecular components of the seed coat in peppers. All the Capsicum pepper accessions analyzed presented very lignified testa and we observed a positive correlation between the amount of lignin and seed viability. Our results provide essential information to explain the poor germination observed in pepper seeds and provide an experimental framework for future improvements in this important character.

Cytological and molecular characterization of three gametoclones of Citrus clementina.

BACKGROUND: Three gametoclonal plants of Citrus clementina Hort. ex Tan., cv. Nules, designated ESP, FRA, and ITA (derived from three labs in Spain, France, and Italy, respectively), were selected for cytological and molecular characterization in order to elucidate genomic rearrangements provoked by haploidization. The study included comparisons of their ploidy, homozygosity, genome integrity, and gene dosage, using chromosome counting, flow cytometry, SSR marker genotyping, and array-Comparative Genomic Hybridization (array-CGH). RESULTS: Chromosome counting and flow cytometry revealed that ESP and FRA were haploid, but ITA was tri-haploid. Homozygous patterns, represented by a single peak (allele), were observed among the three plants at almost all SSR loci distributed across the entire diploid donor genome. Those few loci with extra peaks visualized as output from automated sequencing runs, generally low or ambiguous, might result from amplicons of paralogous members at the locus, non-specific sites, or unexpected recombinant alleles. No new alleles were found, suggesting the genomes remained stable and intact during gametogenesis and regeneration. The integrity of the haploid genome also was supported by array-CGH studies, in which genomic profiles were comparable to the diploid control. CONCLUSIONS: The presence of few gene hybridization abnormalities, corroborated by gene dosage measurements, were hypothetically due to the segregation of hemizygous alleles and minor genomic rearrangements occurring during the haploidization procedure. In conclusion, these plants that are valuable genetic and breeding materials contain completely homozygous and essentially intact genomes.

Endosperm Persistence in Arabidopsis Results in Seed Coat Fractures and Loss of Seed Longevity.

Seeds are specialized plant organs that carry, nurture, and protect plant offspring. Developmental coordination between the three genetically distinct seed tissues (the embryo, endosperm, and seed coat) is crucial for seed viability. In this study, we explore the relationship between the TFs AtHB25 and ICE1. Previous results identified ICE1 as a target gene of AtHB25. In seeds, a lack of ICE1 (ice1-2) suppresses the enhanced seed longevity and impermeability of the overexpressing mutant athb25-1D, but surprisingly, seed coat lipid polyester deposition is not affected, as shown by the double-mutant athb25-1D ice1-2 seeds. zou-4, another mutant lacking the transcriptional program for proper endosperm maturation and for which the endosperm persists, also presents a high sensitivity to seed aging. Analysis of gso1, gso2, and tws1-4 mutants revealed that a loss of embryo cuticle integrity does not underlie the seed-aging sensitivity of ice1-2 and zou-4. However, scanning electron microscopy revealed the presence of multiple fractures in the seed coats of the ice1 and zou mutants. Thus, this study highlights the importance of both seed coat composition and integrity in ensuring longevity and demonstrates that these parameters depend on multiple factors.

Deep Learning Applied to Intracranial Hemorrhage Detection.

Intracranial hemorrhage is a serious medical problem that requires rapid and often intensive medical care. Identifying the location and type of any hemorrhage present is a critical step in the treatment of the patient. Detection of, and diagnosis of, a hemorrhage that requires an urgent procedure is a difficult and time-consuming process for human experts. In this paper, we propose methods based on EfficientDet's deep-learning technology that can be applied to the diagnosis of hemorrhages at a patient level and which could, thus, become a decision-support system. Our proposal is two-fold. On the one hand, the proposed technique classifies slices of computed tomography scans for the presence of hemorrhage or its lack of, and evaluates whether the patient is positive in terms of hemorrhage, and achieving, in this regard, 92.7% accuracy and 0.978 ROC AUC. On the other hand, our methodology provides visual explanations of the chosen classification using the Grad-CAM methodology.

Agronomic Assessment of a Controlled-Release Polymer-Coated Urea-Based Fertilizer in Maize.

Increasing nutrient use efficiency of fertilizers is one of the major challenges to improve crop yields and minimize environmental impacts. This work compared the efficacy of a new ecological polymer-coated urea fertilizer and a slow release urea-based traditional fertilizer. Reductions in the N doses of the polymer-coated fertilizer were tested. A comparative study was first carried out by measuring the different physiological and yield parameters at the micro-scale level, and later-on field experiments were performed. Grain yield in the field was significantly higher (20%) when applying the new controlled-release fertilizer than when using the traditional one at the same dose. A 20% reduction in N content in the new fertilizer gave similar physiological and yield responses compared to the traditional fertilizer. We conclude that this new fertilizer can be used in extensive cropping of maize, guaranteeing at least the same yields than traditional fertilizers, with a reduction on the impact on soil properties and nitrogen losses.

Enhanced Agronomic Efficiency Using a New Controlled-Released, Polymeric-Coated Nitrogen Fertilizer in Rice.

Fertilizer-use efficiency is one of the most critical concerns in rice cultivation to reduce N losses, increase yields, and improve crop management. The effects of a new polymeric-coated controlled-release fertilizer (CRF) were compared to those of other slow-release and traditional fertilizers in a microscale experiment, which was carried out in cuvettes under partly controlled ambient conditions, and a large-scale field experiment. To evaluate the fertilizer's efficiency, nitrogen and water-use efficiency were calculated using the measurement of different photosynthetic and crop yield parameters. Improved responses regarding some of the analyzed physiological and growth parameters were observed for those plants fertilized with the new CRF. In the microscale experiment, significantly increased yields (ca. 35%) were produced in the plants treated with CRF as compared to traditional fertilizer. These results were in accordance with ca. 24% significant increased levels of N in leaves of CRF-treated plants, besides increased P, Fe, Mn, and cytokinin contents. At the field scale, similar yields were obtained with the slow-release or traditional fertilizers and CRF at a 20% reduced N dose. The new controlled-release fertilizer is a urea-based fertilizer coated with lignosulfonates, which is cheaply produced from the waste of pulp and wood industries, containing humic acids as biostimulants. In conclusion, CRF is recommended to facilitate rice crop management and to reduce contamination, as it can be formulated with lower N doses and because it is ecological manufacturing.

Overexpression of Arabidopsis thaliana LTL1, a salt-induced gene encoding a GDSL-motif lipase, increases salt tolerance in yeast and transgenic plants.

Genes involved in the mechanisms of plant responses to salt stress may be used as biotechnological tools for the genetic improvement of salt tolerance in crop plants. This would help alleviate the increasing problem of salinization of lands cultivated under irrigation in arid and semi-arid regions. We have isolated a novel halotolerance gene from Arabidopsis thaliana, A. thaliana Li-tolerant lipase 1 (AtLTL1), on the basis of the phenotype of tolerance to LiCl conferred by its expression in yeast. AtLTL1 encodes a putative lipase of the GDSL-motif family, which includes bacterial and a very large number of plant proteins. In Arabidopsis, AtLTL1 expression is rapidly induced by LiCl or NaCl, but not by other abiotic stresses. Overexpression of AtLTL1 increases salt tolerance in transgenic Arabidopsis plants, compared to non-transformed controls, allowing germination of seeds in the presence of toxic concentrations of LiCl and NaCl, and stimulating vegetative growth, flowering and seed set in the presence of NaCl. These results clearly point to a role of AtLTL1 in the mechanisms of salt tolerance. In addition, we show that AtLTL1 expression is also activated, although only transiently, by salicylic acid (SA), suggesting that the lipase could also be involved in defence reactions against pathogens.

Expression of Arabidopsis SR-like splicing proteins confers salt tolerance to yeast and transgenic plants.

Searching for novel targets of salt toxicity in eukaryotic cells, we have screened an Arabidopsis thaliana cDNA library to isolate genes conferring increased tolerance to salt stress when expressed in the yeast Saccharomyces cerevisiae. Here we show that expression of the 'alternating arginine-rich' (or RS) domains of two different SR-like, putative splicing proteins from Arabidopsis allows yeast cells to tolerate higher lithium and sodium concentrations. Protection against salt stress appears to require the in vivo phosphorylation of these plant polypeptides, since the yeast SR protein kinase Sky1p, which was able to phosphorylate in vitro at least one of them, also proved to be essential for the observed salt tolerance phenotype. In addition, a clone encoding the U1A protein, a previously characterised Arabidopsis splicing factor, was also isolated in the screening. No significant decrease in the intracellular concentration of lithium was observed in yeast cells incubated in the presence of LiCl upon expression of any of the Arabidopsis proteins, suggesting that their effects are not mediated by the stimulation of ion transport. In support of the general significance of these data, we also show that the expression of the RS domain of one of the SR-like proteins in transgenic Arabidopsis plants increases their tolerance to LiCl and NaCl. These results point to an important role of pre-mRNA splicing and SR-like proteins in the salt tolerance of eukaryotic cells, offering a novel route to improve this important trait in crop plants.

Regresión de un linfoma asociado al virus de Epstein-Barr tras la retirada de metotrexato y ciclosporina A en una paciente con artritis reumatoide / Regression of Epstein-Barr virus associated lymphoma after methotrexate and cyclosporine A with drawal in a patient with rheumathoid arthritis

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