Efecto del peróxido de hidrógeno en la expresión de proteínas durante la germinación

Comunicaciones a congreso

Cambios inducidos por Plum pox virus en el proteoma de plantas de melocotonero

Comunicaciones a congreso

Nitrate- and nitric oxide-induced plant growth in pea seedlings is linked to antioxidative metabolism and the ABA/GA balance

This study looks at the effects of potassium nitrate (KNO3) and sodium nitroprusside (SNP), a nitric oxide (NO)-donor, on the development, antioxidant defences and on the abscisic acid (ABA) and gibberellin (GA) levels inpea seedlings. Results show that 10 mM KNO3and 50μM SNP stimulate seedling fresh weight (FW), althoughthis effect is not reverted by the action of 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide(cPTIO), a NO-scavenger.The KNO3treatment increased peroxidase (POX) and ascorbate oxidase (AOX) activities. SNP, on the otherhand, reduced monodehydroascorbate reductase (MDHAR) activity and produced a significant increase in su-peroxide dismutase (SOD), POX and AOX activities. The“KNO3plus cPTIO”treatment increased ascorbateperoxidase (APX), MDHAR, glutathione reductase (GR) and SOD activities, but POX activity decreased in re-lation to the KNO3treatment. The“SNP plus cPTIO”treatment increased APX and MDHAR activities, whereas ahuge decrease in POX activity occurred. Both the KNO3and the SNP treatments increased reduced ascorbate(ASC) concentrations, which reached control values in the presence of cPTIO. All treatments increased thedehydroascorbate (DHA) level in pea seedlings, leading to a decrease in the redox state of ascorbate. In the“KNO3plus cPTIO”treatment, an increase in the redox state of ascorbate was observed. Glutathione contents,however, were higher in the presence of SNP than in the presence of KNO3. In addition, KNO3produced anaccumulation of oxidised glutathione (GSSG), especially in the presence of cPTIO, leading to a decrease in theredox state of glutathione. The effect of SNP on reduced glutathione (GSH) levels was reverted by cPTIO, sug-gesting that NO has a direct effect on GSH biosynthesis or turnover.Both the KNO3and SNP treatments produced an increase in GA4 and a decrease in ABA concentrations, andthis effect was reverted in the presence of the NO-scavenger. Globally, the results suggest a relationship betweenantioxidant metabolism and the ABA/GA balance during early seedling growth in pea. The results also suggest arole for KNO3and NO in the modulation of GA4 and ABA levels and antioxidant metabolism in pea seedlings.Furthermore, this effect correlated with an increase in the biomass of the pea seedlingsinfo:eu-repo/semantics/acceptedVersio

Metabolomics and biochemical approaches link salicylic acid biosynthesis to cyanogenesis in peach plants

Despite the long-established importance of salicylic acid (SA) in plant stress responses and other biological processes, its biosynthetic pathways have not been fully characterized. The proposed synthesis of SA originates from chorismate by two distinct pathways: the isochorismate and phenylalanine (Phe) ammonia-lyase (PAL) pathways. Cyanogenesis is the process related to the release of hydrogen cyanide from endogenous cyanogenic glycosides (CNglcs), and it has been linked to plant plasticity improvement. To date, however, no relationship has been suggested between the two pathways. In this work, by metabolomics and biochemical approaches (including the use of [C-13]-labeled compounds), we provide strong evidences showing that CNglcs turnover is involved, at least in part, in SA biosynthesis in peach plants under control and stress conditions. The main CNglcs in peach are prunasin and amygdalin, with mandelonitrile (MD), synthesized from phenylalanine, controlling their turnover. In peach plants MD is the intermediary molecule of the suggested new SA biosynthetic pathway and CNglcs turnover, regulating the biosynthesis of both amygdalin and SA. MD-treated peach plants displayed increased SA levels via benzoic acid (one of the SA precursors within the PAL pathway). MD also provided partial protection against Plum pox virus infection in peach seedlings. Thus, we propose a third pathway, an alternative to the PAL pathway, for SA synthesis in peach plantsThis work was supported by the Spanish Ministry of Economy and Competitiveness (Project AGL2014-52563-R). PDV and CP thank CSIC and UPCT, respectively, as well as the Spanish Ministry of Economy and Competitiveness for their ‘Ramon & Cajal’ research contract, co-financed by FEDER funds. We also acknowledge Prof. Manuel Acosta Echeverría for his very useful commentaries and discussion

Cytosolic ascorbate peroxidase and Cu, Zn-superoxide dismutase improve seed germination, plant growth, nutrient uptake and drought tolerance in tobacco

The effects of over-expression of two cytosolic antioxidant enzymes (Cu, Zn-SOD and/or APX) on plant nutrition, gas exchange, chlorophyll fluorescence, seed viability and germination in transgenic tobacco (Nicotiana tabacum cv. Xanthi) under deficit irrigation or salinity conditions were investigated. Three transgenic lines of tobacco were used in this study: line 17, harboring 2 copies of the cytosolic CuZn-SOD (cytsod) gene; line 51, with 2 copies of the cytosolic APX (cytapx) gene and line 39, harboring one copy of each gene. Over-expression of cytosolic antioxidants enzymes in tobacco plants resulted in a better growth performance that correlated with an improved photosynthetic capacity and nutrient uptake. Moreover, cytsod or cytapx genes promoted seed germination, and enhanced tolerance to mild water stress. In addition, this enhanced antioxidant capacity protected seeds from ageing during prolonged storage, and stimulated germination under salt stress conditions. These results suggest that cytosolic antioxidant transgenes are useful tools to improve drought tolerance, nutrient uptake and seed germination under stressful conditions.PDV acknowledges the CSIC and the Spanish Ministry of Economy and Competitiveness for his ‘Ramon y Cajal’ research contract, co-financed by FEDER funds. This work was supported by the Spanish Ministry of Economy and Competitiveness (Project CICYT BFU2009-07443) co-financed by FEDER funds, and the Spanish Ministry of Economy and Competitiveness (Project INIA, RTA2013-00026-C03-00).Peer reviewe

NaCl-induced physiological and biochemical adaptative mechanisms in the ornamental Myrtus communis L. plants

Physiological and biochemical changes in Myrtus communis L. plants after being subjected to different solutions of NaCl (44, and 88mM) for up to 30 days (Phase I) and after recovery from the salinity period (Phase II) were studied. Myrtle plants showed salinity tolerance by displaying a series of adaptative mechanisms to cope with salt-stress, including controlled ion homeostasis, the increase in root/shoot ratio, the reduction of water potentials and stomatal conductance to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including limiting toxic ion accumulation in leaves, increase in chlorophyll content, and changes in chlorophyll fluorescence parameters, leaf anatomy and increases in catalase activity. Anatomical modifications in leaves, including a decrease in spongy parenchyma and increased intercellular spaces, allow CO2 diffusion in a situation of reduced stomatal aperture. In spite of all these changes, salinity produced oxidative stress in myrtle plants as monitored by increases in oxidative stress parameter values. The post-recovery period is perceived as a new stress situation, as observed through effects on plant growth and alterations in non-photochemical quenching parameters and lipid peroxidation values. © 2015 Elsevier GmbH.This work was supported by the Spanish Ministry of Economy and Competitiveness co-financed by FEDER funds (Project CICYT AGL 2011-30022-C02-01-02) and by The Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (11883/PI/09 and 15356/PI/10). PDV acknowledges the CSIC and the Spanish Ministry of Economy and Competitiveness for his ‘Ramon y Cajal’ research contract, co-financed by FEDER funds.Peer Reviewe

Physiological and biochemical mechanisms of the ornamental Eugenia myrtifolia L. plants for coping with NaCl stress and recovery

Main Conclusion: We studied the response ofEugenia myrtifoliaL. plants, an ornamental shrub native to tropical and subtropical areas, to salt stress in order to facilitate the use of these plants in Mediterranean areas for landscaping.E. myrtifoliaplants implement a series of adaptations to acclimate to salinity, including morphological, physiological and biochemical changes. Furthermore, the post-recovery period seems to be detected by Eugenia plants as a new stress situation. Different physiological and biochemical changes in Eugenia myrtifolia L. plants after being subjected to NaCl stress for up to 30 days (Phase I) and after recovery from salinity (Phase II) were studied. Eugenia plants proved to be tolerant to NaCl concentrations between 44 and 88 mM, displaying a series of adaptative mechanisms to cope with salt-stress, including the accumulation of toxic ions in roots. Plants increased their root/shoot ratio and decreased their leaf area, leaf water potential and stomatal conductance in order to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including the limited accumulation of toxic ions in leaves, increase in chlorophyll content, changes in chlorophyll fluorescence parameters, leaf anatomy and antioxidant defence mechanisms. Anatomical modifications in leaves, including an increase in palisade parenchyma and intercellular spaces and decrease in spongy parenchyma, served to facilitate CO2 diffusion in a situation of reduced stomatal aperture. Salinity produced oxidative stress in Eugenia plants as evidenced by oxidative stress parameters values and a reduction in APX and ASC levels. Nevertheless, SOD and GSH contents increased. The post-recovery period is detected as a new stress situation, as observed through effects on plant growth and alterations in chlorophyll fluorescence and oxidative stress parameters. © 2015, Springer-Verlag Berlin Heidelberg.This work was supported by the Spanish Ministry of Economy and Competitiveness co-financed by FEDER funds (Project CICYT AGL 2011-30022-C02-01-02) and by The Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (11883/PI/09 and 15356/PI/10). Authors thank Mrs Ansley Evans for correction of the English.Peer Reviewe

Biomarkers of tumor-reactive CD4+ and CD8+ TILs associate with improved prognosis in endometrial cancer

Neoplasias genitales; Inmunoterapia; Linfocitos TNeoplàsies genitals; Immunoteràpia; Limfòcits TGenital neoplasms; Immunotherapy; T-LymphocytesBackground Despite the growing interest in immunotherapeutic interventions for endometrial cancer (EC), the prevalence, phenotype, specificity and prognostic value of tumor infiltrating lymphocytes (TILs) in this tumor type remains unclear. Methods To better understand the role of TILs in EC, we analyzed the phenotypic traits of CD8+ and CD4+ EC-resident T cells from 47 primary tumors by high-dimensional flow cytometry. In addition, CD8+ and CD4+ TIL subpopulations were isolated based on the differential expression of programmed cell death protein-1 (PD-1) (negative, dim and high) and CD39 (positive or negative) by fluorescence activated cell sorting (FACS), expanded in vitro, and screened for autologous tumor recognition. We further investigated whether phenotypic markers preferentially expressed on CD8+ and CD4+ tumor-reactive TIL subsets were associated with the four distinct molecular subtypes of EC, tumor mutational burden and patient survival. Results We found that CD8+TILs expressing high levels of PD-1 (PD-1hi) co-expressed CD39, TIM-3, HLA-DR and CXCL13, as compared with TILs lacking or displaying intermediate levels of PD-1 expression (PD-1− and PD-1dim, respectively). Autologous tumor reactivity of sorted and in vitro expanded CD8+ TILs demonstrated that the CD8+PD-1dimCD39+ and PD-1hiCD39+ T cell subsets both contained tumor-reactive TILs and that a higher level of PD-1 expression was associated with increased CD39 and a superior frequency of tumor reactivity. With respect to CD4+ T conventional (Tconv) TILs, co-expression of inhibitory and activation markers was more apparent on PD-1hi compared with PD-1− or PD-1dim T cells, and in fact, it was the CD4+PD-1hi subpopulation that accumulated the antitumor T cells irrespective of CD39 expression. Most importantly, detection of CD8+PD-1hiCD39+ and CD4+PD-1hi tumor-reactive T-cell subsets, but also markers specifically expressed by these subpopulations of TILs, that is, PD-1hi, CD39, CXCL13 and CD103 by CD8+ TILs and PD-1hi and CXCL13 by CD4+ Tconv TILs, correlated with prolonged survival of patients with EC. Conclusions Our results demonstrate that EC are frequently infiltrated by tumor-reactive TILs, and that expression of PD-1hi and CD39 or PD-1hi can be used to select and expand CD8+ and CD4+ tumor-reactive TILs, respectively. In addition, biomarkers preferentially expressed on tumor-reactive TILs, rather than the frequency of CD3+, CD8+ and CD4+ lymphocytes, hold prognostic value suggesting their protective role in antitumor immunity.AG was funded by the Comprehensive Program of Cancer Immunotherapy and Immunology II (CAIMI-II) supported by the BBVA Foundation (grant 53/2021), the La Fundació La Marató de TV3 (201919-30; identification number 488/C/2019), the Spanish Ministry of Science and Innovation (PID2020-118529RB-100) and Instituto de Salud Carlos III (CP15/00058). We thank the CERCA Programme/Generalitat de Catalunya for institutional support. JP was supported by the Beatriu de Pinós programme (BP 2018), cofounded by the Agency for Management of University and Research Grants (AGAUR) and European Union's Horizon 2020. HUB-ICO-IDIBELL Biobank received support from Instituto de Salud Carlos III (PT20/00171) and by Xarxa de Bancs de Tumors de Catalunya sponsored by Pla Director d’Oncologia de Catalunya (XBTC)

Incorporating BEAMing technology as a liquid biopsy into clinical practice for the management of colorectal cancer patients : an expert taskforce review

The importance of mutation identification for advanced colorectal cancer treatment with anti-epidermal growth factor receptor agents is well established. However, due to delays in turnaround time, low-quality tissue samples, and/or lack of standardization of testing methods a significant proportion of patients are being treated without the information that Kirsten rat sarcoma and neuroblastoma rat sarcoma (RAS) testing can provide. The detection of mutated circulating tumor DNA by BEAMing technology addresses this gap in care and allows these patients to receive international guideline-recommended expanded RAS testing with rapid turnaround times. Furthermore, the overall concordance between OncoBEAM RAS colorectal cancer testing and standard of care tissue testing is very high (93.3%). This article presents an overview of the clinical utility and potential applications of this minimally invasive method, such as early detection of emergent resistance to anti-epidermal growth factor receptor therapy. If appropriately implemented, BEAMing technology holds considerable promise to enhance the quality of patient care and improve clinical outcomes

Oxidative stress and antioxidative responses in plant-virus interactions

During plant–virus interactions, defence responses are linked to the accumulation of reactive oxygen species (ROS). Importantly, ROS play a dual role by (1) eliciting pathogen restriction and often localized death of host plant cells at infection sites and (2) as a diffusible signal that induces antioxidant and pathogenesis-related defence responses in adjacent plant cells. The outcome of these defences largely depends on the speed of host responses including early ROS accumulation at virus infection sites. Rapid host reactions may result in early virus elimination without any oxidative stress (i.e. a symptomless, extreme resistance). A slower host response allows a certain degree of virus replication and movement resulting in oxidative stress and programmed death of affected plant cells before conferring pathogen arrest (hypersensitive response, HR). On the other hand, delayed host attempts to elicit virus resistance result in an imbalance of antioxidative metabolism and massively stressed systemic plant tissues (e.g. systemic chlorotic or necrotic symptoms). The final consequence of these processes is a partial or almost complete loss of control over virus invasion (compatible infections).Research in the author's laboratories is supported by grants of the Hungarian Scientific Research Fund (K111995 and PD108455) and the Spanish Ministry of Economy and Competitiveness (Project INIA, RTA2013-00026-C03-00). PDV acknowledges the CSIC and the Spanish Ministry of Economy and Competitiveness for his ‘Ramon y Cajal’ research contract, cofinanced by FEDER funds. MJCM acknowledges the Spanish Ministry of Economy and Competitivenes for her ‘Juan de la Cierva’ research contract.Peer reviewe