Plantes transgèniques en recerca

El conjunt d'aproximacions presentades en aquest article il·lustra alguns dels usos més habituals de les plantes transgèniques en la recerca, que han permès, i encara permeten, respondre moltes preguntes genuïnes de gran interès biològic difícilment resolubles per altres aproximacions. Per això es pot afirmar que les plantes transgèniques han revolucionat la recerca bàsica i aplicada en el camp de la biologia vegetal. La seua utilització ens està ajudant a entendre millor com uns organismes tan fascinants i plàstics com les plantes es formen i, en interaccionar amb el medi, responen alterant la seua forma o fisiologia. Encara ens queda molt per conèixer, i l'ús de plantes transgèniques en la nostra recerca encara té molt a dir. Esbrinar més o menys depèn, en gran mesura, de la imaginació dels investigadors.The different strategies summarized in the manuscript illustrate some of the most common uses of transgenic plants in research. They have allowed answering several questions of great biological importance that cannot be easily addressed by other approaches. For that reason it is probably correct to state that transgenic plants have revolutionized basic and applied research in plant biology. Its utilization is helping us to better understand how these fascinating and plastic organisms are formed and, when interacting with the environment, responding by changing their form and/or physiology. We still have a lot to learn, and usage of transgenic plants in our research still has a lot to give. To discover more or less depends, partially, on the imagination of researchers

Light signaling: back to space

Recent work has increased our understanding of the molecular and cellular mechanisms of the phytochrome family of photoreceptors in controlling plant photomorphogenesis. However, the importance of long-distance communication in controlling light responses has received relatively little attention and is poorly understoodPostprint (author's final draft

Plant proximity perception dynamically modulates hormone levels and sensitivity in Arabidopsis

Shade perception involves altered hormone synthesis and sensitivity. Here, we showed that several shade regulators act as positive and negative modulators of the hypocotyl auxin and/or brassinosteroid-induced elongation. The s hade a voidance s yndrome (SAS) refers to a set of plant responses initiated after perception by the phytochromes of light enriched in far-red colour reflected from or filtered by neighbouring plants. These varied responses are aimed at anticipating eventual shading from potential competitor vegetation. In Arabidopsis thaliana, the most obvious SAS response at the seedling stage is the increase in hypocotyl elongation. Here, we describe how plant proximity perception rapidly and temporally alters the levels of not only auxins but also active brassinosteroids and gibberellins. At the same time, shade alters the seedling sensitivity to hormones. Plant proximity perception also involves dramatic changes in gene expression that rapidly result in a new balance between positive and negative factors in a network of interacting basic helix-loop-helix proteins, such as HFR1, PAR1, and BIM and BEE factors. Here, it was shown that several of these factors act as auxin- and BR-responsiveness modulators, which ultimately control the intensity or degree of hypocotyl elongation. It was deduced that, as a consequence of the plant proximity-dependent new, dynamic, and local balance between hormone synthesis and sensitivity (mechanistically resulting from a restructured network of SAS regulators), SAS responses are unleashed and hypocotyls elongate

Kawasaki disease is more prevalent in rural areas of Catalonia (Spain)

INTRODUCTION: Kawasaki disease (KD) is an acute self-limited systemic vasculitis relatively common in childhood. The etiology of KD is still unknown, although clinical, laboratory and epidemiological features suggest an infectious origin or trigger. Differences on incidence between countries have been related to specific genetic factors, ethnicity, country of birth and some other sociocultural and environmental factors. We present a population-based study on incidence of KD in Catalonia (Spain), focusing on differences between patients in rural and non-rural areas of the region. METHODS: Observational population-based study including all Pediatric Units in Catalan hospitals, between 2004 and 2014. A 12-month (March 2013-March 2014) prospective collection of new cases of KD was carried out to determine the incidence of KD. The rest of the data was retrieved retrospectively. RESULTS: Data from 399 patients over the 10-year study period was analyzed. Among the total KD patients, 353 (88.5%) lived in non-rural areas and 46 (11.5%) in rural areas. It was found that there is a significant difference (P<.001) between the percentage of rural population observed in patients with KD (11.5%), and the expected 5% of the Catalan population. CONCLUSION: This is the first population-based study showing significant differences on KD incidence rates between rural and non-rural areas

Proposal for a definition for response to treatment, inactive disease and damage for JIA associated uveitis based on the validation of a uveitis related JIA outcome measures from the Multinational Interdisciplinary Working Group for Uveitis in Childhood (MIWGUC)

Correction: PEDIATRIC RHEUMATOLOGY Volume: 18 Issue: 1 Article Number: 14 DOI: 10.1186/s12969-019-0396-4Background JIA-associated uveitis (JIAU) is a serious, sight-threatening disease with significant long-term complications and risk of blindness, even with improved contemporary treatments. The MIWGUC was set up in order to propose specific JIAU activity and response items and to validate their applicability for clinical outcome studies. Methods The group consists of 8 paediatric rheumatologists and 7 ophthalmologists. A consensus meeting took place on November 2015 in Barcelona (Spain) with the objective of validating the previously proposed measures. The validation process was based on the results of a prospective open, international, multi-centre, cohort study designed to validate the outcome measures proposed by the initial MIWGUC group meeting in 2012. The meeting used the same Delphi and nominal group technique as previously described in the first paper from the MIWGUC group (Arthritis Care Res 64:1365-72, 2012). Patients were included with a diagnosis of JIA, aged less than 18 years, and with active uveitis or an uveitis flare which required treatment with a disease-modifying anti-rheumatic drug. The proposed outcome measures for uveitis were collected by an ophthalmologist and for arthritis by a paediatric rheumatologist. Patient reported outcome measures were also measured. Results A total of 82 patients were enrolled into the validation cohort. Fifty four percent (n = 44) had persistent oligoarthritis followed by rheumatoid factor negative polyarthritis (n = 15, 18%). The mean uveitis disease duration was 3.3 years (SD 3.0). Bilateral eye involvement was reported in 65 (79.3%) patients. The main findings are that the most significant changes, from baseline to 6 months, are found in the AC activity measures of cells and flare. These measures correlate with the presence of pre-existing structural complications and this has implications for the reporting of trials using a single measure as a primary outcome. We also found that visual analogue scales of disease activity showed significant change when reported by the ophthalmologist, rheumatologist and families. The measures formed three relatively distinct groups. The first group of measures comprised uveitis activity, ocular damage and the ophthalmologists' VAS. The second comprised patient reported outcomes including disruption to school attendance. The third group consisted of the rheumatologists' VAS and the joint score. Conclusions We propose distinctive and clinically significant measures of disease activity, severity and damage for JIAU. This effort is the initial step for developing a comprehensive outcome measures for JIAU, which incorporates the perspectives of rheumatologists, ophthalmologists, patients and families.Peer reviewe

The HY5-PIF regulatory module coordinates light and temperature control of photosynthetic gene transcription

The ability to interpret daily and seasonal alterations in light and temperature signals is essential for plant survival. This is particularly important during seedling establishment when the phytochrome photoreceptors activate photosynthetic pigment production for photoautotrophic growth. Phytochromes accomplish this partly through the suppression of phytochrome interacting factors (PIFs), negative regulators of chlorophyll and carotenoid biosynthesis. While the bZIP transcription factor long hypocotyl 5 (HY5), a potent PIF antagonist, promotes photosynthetic pigment accumulation in response to light. Here we demonstrate that by directly targeting a common promoter cis-element (G-box), HY5 and PIFs form a dynamic activation-suppression transcriptional module responsive to light and temperature cues. This antagonistic regulatory module provides a simple, direct mechanism through which environmental change can redirect transcriptional control of genes required for photosynthesis and photoprotection. In the regulation of photopigment biosynthesis genes, HY5 and PIFs do not operate alone, but with the circadian clock. However, sudden changes in light or temperature conditions can trigger changes in HY5 and PIFs abundance that adjust the expression of common target genes to optimise photosynthetic performance and growth

Tuberculosis in pediatric patients treated with anti-TNFα drugs: a cohort study

Background: Adult patients receiving anti-TNFα drugs are at increased risk of tuberculosis (TB), but studies in pediatric populations are limited, and the best strategy for latent tuberculosis infection (LTBI) screening in this population remains controversial. We describe the prevalence of LTBI prior to anti-TNFα therapy and the long-term follow-up after biological treatment initiation in a cohort of children and adolescents. Methods: Cohort observational study in children and adolescents receiving anti-TNFα agents in a tertiary-care pediatric hospital. LTBI was ruled out prior to the implementation of anti-TNFα drugs by tuberculin skin test (TST), and, from March 2012 on, QuantiFERON Gold-In Tube® test (QTF-G). During anti-TNFα treatment, patients were evaluated every 6 months for TB with history and physical examination. TST/QTF-G were not repeated unless signs or symptoms consistent with TB arose or there was proven TB contact. Results: The final cohort consisted of 221 patients (56.1 % female; 261 treatments), of whom 51.7 %/30.0 %/17.3 % were treated with etanercept/adalimumab/infliximab, respectively, for a variety of rheumatic diseases (75.6 %), inflammatory bowel disease (20.8 %), and inflammatory eye diseases (3.6 %). The median (IQR) age at diagnosis of the primary condition was 6.8 years (2.7-11.0) and the duration of the disease before implementing the anti-TNFα agent was 1.8 years (0.6-4.2). LTBI was diagnosed in 3 adolescent girls (prevalence rate: 1.4 %; 95 % CI: 0.4-4.2) affected with juvenile idiopathic arthritis: TST tested positive in only 1, while QTF-G was positive in all cases (including 2 patients already on etanercept). They all received antiTB chemoprophylaxis and were later (re)treated with etanercept for 24-29 months, without incidences. No incident cases of TB disease were observed during the follow-up period under anti-TNFα treatment of 641 patients-year, with a median (IQR) time per patient of 2.3 years (1.4-4.3). Conclusions: In our study, the prevalence of LTBI (1.4 %) was similar to that reported in population screening studies in Spain; no incident cases of TB disease were observed. In low-burden TB settings, initial screening for TB in children prior to anti-TNFα treatment should include both TST and an IGRA test, but systematic repetition of LTBI immunodiagnostic tests seems unnecessary in the absence of symptoms or known TB contact

Gibberellin A1 Metabolism Contributes to the Control of Photoperiod-Mediated Tuberization in Potato

Some potato species require a short-day (SD) photoperiod for tuberization, a process that is negatively affected by gibberellins (GAs). Here we report the isolation of StGA3ox2, a gene encoding a GA 3-oxidase, whose expression is increased in the aerial parts and is repressed in the stolons after transfer of photoperiod-dependent potato plants to SD conditions. Over-expression of StGA3ox2 under control of constitutive or leaf-specific promoters results in taller plants which, in contrast to StGA20ox1 over-expressers previously reported, tuberize earlier under SD conditions than the controls. By contrast, StGA3ox2 tuber-specific over-expression results in non-elongated plants with slightly delayed tuber induction. Together, our experiments support that StGA3ox2 expression and gibberellin metabolism significantly contribute to the tuberization time in strictly photoperiod-dependent potato plants

Plantes transgèniques en recerca

The different strategies summarized in the manuscript illustrate some of the most common uses of transgenic plants in research. They have allowed answering several questions of great biological importance that cannot be easily addressed by other approaches. For that reason it is probably correct to state that transgenic plants have revolutionized basic and applied research in plant biology. Its utilization is helping us to better understand how these fascinating and plastic organisms are formed and, when interacting with the environment, responding by changing their form and/or physiology. We still have a lot to learn, and usage of transgenic plants in our research still has a lot to give. To discover more or less depends, partially, on the imagination of researchers.El conjunt d'aproximacions presentades en aquest article il·lustra alguns dels usos més habituals de les plantes transgèniques en la recerca, que han permès, i encara permeten, respondre moltes preguntes genuïnes de gran interès biològic difícilment resolubles per altres aproximacions. Per això es pot afirmar que les plantes transgèniques han revolucionat la recerca bàsica i aplicada en el camp de la biologia vegetal. La seua utilització ens està ajudant a entendre millor com uns organismes tan fascinants i plàstics com les plantes es formen i, en interaccionar amb el medi, responen alterant la seua forma o fisiologia. Encara ens queda molt per conèixer, i l'ús de plantes transgèniques en la nostra recerca encara té molt a dir. Esbrinar més o menys depèn, en gran mesura, de la imaginació dels investigadors