An extremely low stomatal density mutant overcomes cooling limitations at supra-optimal temperature by adjusting stomatal size and leaf thickness

The impact of global warming on transpiration and photosynthesis would compromise plant fitness, impacting on crop yields and ecosystem functioning. In this frame, we explored the performance of a set of Arabidopsis mutants carrying partial or total loss-of-function alleles of stomatal development genes and displaying distinct stomatal abundances. Using microscopy and non-invasive imaging techniques on this genotype collection, we examined anatomical leaf and stomatal traits, plant growth and development, and physiological performance at optimal (22 C) and supraoptimal (30 C) temperatures. All genotypes showed thermomorphogenetic responses but no signs of heat stress. Data analysis singled out an extremely low stomatal abundance mutant, spch-5. At 22 C, spch-5 had lower transpiration and warmer leaves than the wild type. However, at 30 C, this mutant developed larger stomata and thinner leaves, paralleled by a notable cooling capacity, similar to that of the wild type. Despite their low stomatal density (SD), spch-5 plants grown at 30 C showed no photosynthesis or growth penalties. The behavior of spch-5 at supra-optimal temperature exemplifies how the effect of very low stomatal numbers can be counteracted by a combination of larger stomata and thinner leaves. Furthermore, it provides a novel strategy for coping with high growth temperatures.AGL2015- 65053-R and PID2019-105362RB-I00 RTI2018-094652-B-I00 Spanish Government RTI2018-094652-B-I00 MCIN/AEI/10.13039/501100011033 “ERDF A way of making EuropePPII10- 0194-4164 and SBPLY/17/180501/000394 Junta de Comunidades de Castilla-La ManchaUCLM intramural fundsEU FEDER fund

Novel Vegetation Indices to Identify Broccoli Plants Infected With Xanthomonas campestris pv. campestris

A rapid diagnosis of black rot in brassicas, a devastating disease caused by Xanthomonas campestris pv. campestris (Xcc), would be desirable to avoid significant crop yield losses. The main aim of this work was to develop a method of detection of Xcc infection on broccoli leaves. Such method is based on the use of imaging sensors that capture information about the optical properties of leaves and provide data that can be implemented on machine learning algorithms capable of learning patterns. Based on this knowledge, the algorithms are able to classify plants into categories (healthy and infected). To ensure the robustness of the detection method upon future alterations in climate conditions, the response of broccoli plants to Xcc infection was analyzed under a range of growing environments, taking current climate conditions as reference. Two projections for years 2081–2100 were selected, according to the Assessment Report of Intergovernmental Panel on Climate Change. Thus, the response of broccoli plants to Xcc infection and climate conditions has been monitored using leaf temperature and five conventional vegetation indices (VIs) derived from hyperspectral reflectance. In addition, three novel VIs, named diseased broccoli indices (DBI1-DBI3), were defined based on the spectral reflectance signature of broccoli leaves upon Xcc infection. Finally, the nine parameters were implemented on several classifying algorithms. The detection method offering the best performance of classification was a multilayer perceptron-based artificial neural network. This model identified infected plants with accuracies of 88.1, 76.9, and 83.3%, depending on the growing conditions. In this model, the three Vis described in this work proved to be very informative parameters for the disease detection. To our best knowledge, this is the first time that future climate conditions have been taken into account to develop a robust detection model using classifying algorithms.MCIN/AEI RTI2018-094652-B-I00ERDF: A way of making EuropeConsejo Superior de Investigaciones Cientificas (CSIC) through the Unidad de Recursos de Informacion Cientifica para la Investigacion (URICI

Diagnosis of the infection of sunflower by Orobanche cumana using multicolour fluorescence imaging

Orobanche cumana is an holoparasite and thus totally dependent on sunflower for fixed carbon. Initial stages of the infection occur in the first weeks after sowing and are critical for the establishment of a continuum between the host and the parasite vascular system. From that moment the parasite obtains its supply of water, mineral nutrients, and assimilates from the host plant. Alterations of plant metabolism can be detected using remote sensing techniques for detection of fluorescence emitted by plants. One of these indirect techniques is multicolour fluorescence imaging. In this work, we assessed the early infection of sunflower by O. cumana using multicolour fluorescence imaging and we inferred physiological processes affected in sunflower plants infected by the parasite. Ten germinated seeds of the inbred line NR5 were inoculated with population LP2013 of O. cumana. The same number of not inoculated seeds was used as control. Sunflower was planted in pots with soil mixture and grown in greenhouse at 12–22°C for 6 weeks. Multicolour fluorescence imaging was conducted 3, 4, and 5 weeks after inoculation. The two first pairs of fully expanded leaves of each sunflower plant were imaged, and, for each measure date, five fluorescence variables in inoculated plants were compared to those in the control. Three weeks after inoculation, when symptoms of infection were still not observed, decreased levels of blue and green fluorescence and increased far-red fluorescence were observed in leaves of the inoculated plants. At 4 and 5 weeks after inoculation, when inoculated plants displayed symptoms of infection by O. cumana, differences in fluorescence between inoculated plants and the controls were the same and statistically supported. These results are consistent with an increase in total chlorophyll content of sunflower plants infected by O. cumana, and a decrease in the accumulation of secondary metabolites, both related to the need of higher photosynthetic activity to supply the parasite with photosynthate. Biochemical mechanisms underlying alterations in photosynthesis must be further investigated. The results obtained showed that multicolour fluorescence imaging can be used to detect fluorescence differences in inoculated sunflower as early as 3 weeks after inoculation. Therefore, this technique can be used as a diagnostic tool for early detection of genotypes of sunflower which are susceptible or resistant to O. cumana.Financial support from the Spanish Ministry of Education and Science (AGL2010-17909), Junta de Andalucía (P12-AGR370 and P12-AGR1281) and Spanish National Research Council (20134R060).Peer Reviewe

El análisis mediante RNA-seq y técnicas de captura de imagen de la interacción melón-Podosphaera xanthii revela modulación de la fotosíntesis y del metabolismo secundario de la planta por el patógeno

La familia de las cucurbitáceas incluye especies con gran relevancia económica entre las que destacan melón, sandía, calabacín, pepino y calabaza. Estos cultivos se ven afectados, entre otros, por el hongo biotrofo obligado Podosphaera xanthii, principal agente causal del oídio de las cucurbitáceas. El conocimiento sobre las bases moleculares de las interacciones entre P. xanthii y las diferentes especies de cucurbitáceas es, aún, muy limitado. Por ello, en este trabajo se ha realizado un análisis RNA-seq con el fin de conocer los cambios de expresión génica ocurridos en melón durante los primeros estadios de la enfermedad (24, 48 y 72 hpi). Además, estas fases tempranas de la enfermedad también fueron estudiadas usando técnicas de captura de imágenes como fluorescencia multiespectral y termografía. El análisis bioinformático permitió detectar 1.114 genes de la planta diferencialmente expresados a 24 h, 3.785 a 48 h y 4.226 a 72 h. El posterior enriquecimiento funcional reveló que los principales procesos que se estaban viendo modulados durante la infección eran la fotosíntesis y varias rutas metabólicas relacionadas con la defensa vegetal, resultados que fueron corroborados mediante las técnicas de captura de imagen. La combinación de ambas técnicas nos ha permitido comprender mejor el desarrollo de esta enfermedad desde dos enfoques diferentes pero complementarios e integradores.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Este trabajo ha sido financiado por el Ministerio de Economía y Competitividad (AGL2013-41939-R; AGL2016-76216-C2-1-R) cofinanciado con fondos FEDER (UE). Álvaro Polonio es beneficiario de un contrato predoctoral para la formación de doctores del Ministerio de Economía y Competitividad. Los autores también agradecen ayudas de la Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech, para la asistencia a este congreso

Contribution of the non-effector members of the HrpL regulon, iaaL and matE, to the virulence of Pseudomonas syringae pv. tomato DC3000 in tomato plants

Incluye 4 ficheros de datosBackground: The phytohormone indole-3-acetic acid (IAA) is widely distributed among plant-associated bacteria. Certain strains of the Pseudomonas syringae complex can further metabolize IAA into a less biologically active amino acid conjugate, 3-indole-acetyl-ε-L-lysine, through the action of the iaaL gene. In P. syringae and Pseudomonas savastanoi strains, the iaaL gene is found in synteny with an upstream gene, here called matE, encoding a putative MATE family transporter. In P. syringae pv. tomato (Pto) DC3000, a pathogen of tomato and Arabidopsis plants, the HrpL sigma factor controls the expression of a suite of virulence-associated genes via binding to hrp box promoters, including that of the iaaL gene. However, the significance of HrpL activation of the iaaL gene in the virulence of Pto DC3000 is still unclear. Results: A conserved hrp box motif is found upstream of the iaaL gene in the genomes of P. syringae strains. However, although the promoter region of matE is only conserved in genomospecies 3 of this bacterial group, we showed that this gene also belongs to the Pto DC3000 HrpL regulon. We also demonstrated that the iaaL gene is transcribed both independently and as part of an operon with matE in this pathogen. Deletion of either the iaaL or the matE gene resulted in reduced fitness and virulence of Pto DC3000 in tomato plants. In addition, we used multicolor fluorescence imaging to visualize the responses of tomato plants to wild-type Pto DC3000 and to its ΔmatE and ΔiaaL mutants. Activation of secondary metabolism prior to the development of visual symptoms was observed in tomato leaves after bacterial challenges with all strains. However, the observed changes were strongest in plants challenged by the wild-type strain, indicating lower activation of secondary metabolism in plants infected with the ΔmatE or ΔiaaL mutants. Conclusions: Our results provide new evidence for the roles of non-type III effector genes belonging to the Pto DC3000 HrpL regulon in virulence.This research was supported by the Spanish Plan Nacional I+D+i grants AGL2011-30343-CO2-01, AGL2014-53242-C2-1-R and BIO2007-67874-C02-02 as well as by grants ref. P08-CVI-03475 and P12-AGR-0370 from the Junta de Andalucía (Spain)

Antivascular and antitumor properties of the tubulin-binding chalcone TUB091

We investigated the microtubule-destabilizing, vascular-targeting, anti-tumor and anti-metastatic activities of a new series of chalcones, whose prototype compound is (E)-3-(3’’-amino-4’’-methoxyphenyl)-1-(5’-methoxy-3’,4’-methylendioxyphenyl)- 2-methylprop-2-en-1-one (TUB091). X-ray crystallography showed that these chalcones bind to the colchicine site of tubulin and therefore prevent the curved-tostraight structural transition of tubulin, which is required for microtubule formation. Accordingly, TUB091 inhibited cancer and endothelial cell growth, induced G2/M phase arrest and apoptosis at 1-10 nM. In addition, TUB091 displayed vascular disrupting effects in vitro and in the chicken chorioallantoic membrane (CAM) assay at low nanomolar concentrations. A water-soluble L-Lys-L-Pro derivative of TUB091 (i.e. TUB099) showed potent antitumor activity in melanoma and breast cancer xenograft models by causing rapid intratumoral vascular shutdown and massive tumor necrosis. TUB099 also displayed anti-metastatic activity similar to that of combretastatin A4-phosphate. Our data indicate that this novel class of chalcones represents interesting lead molecules for the design of vascular disrupting agents (VDAs). Moreover, we provide evidence that our prodrug approach may be valuable for the development of anti-cancer drugs.M-DC thanks the Fondo Social Europeo (FSE) and the JAE Predoc Programme for a predoctoral fellowship. This work has received the Ramón Madroñero award for young researchers (to M-DC and OB) in the XVII call www.impactjournals.com/oncotarget 17 Oncotarget sponsored by the Spanish Society of Medicinal Chemistry (SEQT). This project has been supported by the Spanish Ministerio de Economia y Competitividad (SAF2012- 39760-C02-01 to M-JC, M-JP-P, SV and E-MP; and BIO2013-42984-R to JFD), Comunidad de Madrid (BIPEDD2; ref. P2010/BMD-2457 to M-JC and J-FD), the Swiss National Science Foundation (310030B_138659 and 31003A_166608; to MOS). The authors acknowledge networking contribution by the COST Action CM1407 “Challenging organic syntheses inspired by nature - from natural products chemistry to drug discovery” and COST action CM1470.Peer reviewe

Agreement Between 18F-FDG PET/CT and Whole-Body Magnetic Resonance Compared With Skeletal Survey for Initial Staging and Response at End-of-Treatment Evaluation of Patients With Multiple Myeloma

PURPOSE: To compare the agreement between whole-body (WB) magnetic resonance (MR) imaging, 18F-FDG PET/CT, and skeletal survey (SS) in patients with multiple myeloma (MM) for diagnosis, initial staging, response evaluation, and early detection of complications. METHODS: This is a retrospective cohort study including MM patients who were diagnosed, treated, and followed in 2 institutions. These patients were studied with SS, WB-MR, and/or 18F-FDG PET/CT. We studied bone lesions by anatomical locations and analyzed the concordance between SS and a tomographic technique (WB-MR or 18F-FDG PET/CT) and between both tomographic techniques (WB-MR and PET/CT). RESULTS: Forty-four MM patients with a mean age of 62.6 years (range, 38-85 years) were included from January 2012 to February 2016. Whole-body MR and 18F-FDG PET/CT found more lesions than SS in every location except in the skull. Concordance between WB-MR and 18F-FDG PET/CT was either good or excellent in most of the locations and in plasmacytoma studies. However, WB-MR was better than 18F-FDG PET/CT in the study of complications (medullar compression and vascular necrosis). CONCLUSIONS: Our results suggest the study of MM patients should include WB-MR and/or 18F-FDG PET/CT, whereas SS is only useful for the skull. Whole-body MR and 18F-FDG PET/CT are complementary techniques, because both of them show good concordance in almost every location. It is still necessary to individualize the indication of each technique according to patient characteristics.None declare

SARS-CoV-2 Infection and C-Section: A Prospective Observational Study

Pregnant women are particularly vulnerable to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In addition to unfavorable perinatal outcomes, there has been an increase in obstetric interventions. With this study, we aimed to clarify the reasons, using Robson's classification model, and risk factors for cesarean section (C-section) in SARS-CoV-2-infected mothers and their perinatal results. This was a prospective observational study that was carried out in 79 hospitals (Spanish Obstetric Emergency Group) with a cohort of 1704 SARS-CoV-2 PCR-positive pregnant women that were registered consecutively between 26 February and 5 November 2020. The data from 1248 pregnant women who delivered vaginally (vaginal + operative vaginal) was compared with those from 456 (26.8%) who underwent a C-section. C-section patients were older with higher rates of comorbidities, in vitro fertilization and multiple pregnancies (p < 0.05) compared with women who delivered vaginally. Moreover, C-section risk was associated with the presence of pneumonia (p < 0.001) and 41.1% of C-sections in patients with pneumonia were preterm (Robson's 10th category). However, delivery care was similar between asymptomatic and mild-moderate symptomatic patients (p = 0.228) and their predisposing factors to C-section were the presence of uterine scarring (due to a previous C-section) and the induction of labor or programmed C-section for unspecified obstetric reasons. On the other hand, higher rates of hemorrhagic events, hypertensive disorders and thrombotic events were observed in the C-section group (p < 0.001 for all three outcomes), as well as for ICU admission. These findings suggest that this type of delivery was associated with the mother's clinical conditions that required a rapid and early termination of pregnancy.This project was supported by public funds that were obtained in competitive calls: Grant COV20/00021 (EUR 43,000 from the Instituto de Salud Carlos III-Spanish Ministry of Health) and co-financed with Fondo Europeo de Desarrollo Regional (FEDER) funds

Factors related to the development of high antibody titres against SARS-CoV-2 in convalescent plasma donors from the ConPlas-19 trial

Background and objectives: The efficacy of COVID-19 convalescent plasma (CP) associates with high titres of antibodies. ConPlas-19 clinical trial showed that CP reduces the risk of progression to severe COVID-19 at 28 days. Here, we aim to study ConPlas-19 donors and characteristics that associate with high anti-SARS-CoV-2 antibody levels. Materials and methods: Four-hundred donors were enrolled in ConPlas-19. The presence and titres of anti-SARS-CoV-2 antibodies were evaluated by EUROIMMUN anti-SARS-CoV-2 S1 IgG ELISA. Results: A majority of 80.3% of ConPlas-19 donor candidates had positive EUROIMMUN test results (ratio ≥1.1), and of these, 51.4% had high antibody titres (ratio ≥3.5). Antibody levels decline over time, but nevertheless, out of 37 donors tested for an intended second CP donation, over 90% were still EUROIMMUN positive, and nearly 75% of those with high titres maintained high titres in the second sample. Donors with a greater probability of developing high titres of anti-SARS-CoV-2 antibodies include those older than 40 years of age (RR 2.06; 95% CI 1.24-3.42), with more than 7 days of COVID-19 symptoms (RR 1.89; 95% CI 1.05-3.43) and collected within 4 months from infection (RR 2.61; 95% CI 1.16-5.90). Male donors had a trend towards higher titres compared with women (RR 1.67; 95% CI 0.91-3.06). Conclusion: SARS-CoV-2 CP candidate donors' age, duration of COVID-19 symptoms and time from infection to donation associate with the collection of CP with high antibody levels. Beyond COVID-19, these data are relevant to inform decisions to optimize the CP donor selection process in potential future outbreaks.European Regional Development Fund (FEDER); Government of Spain, Ministry of Science and Innovation, Instituto de Salud Carlos III, Grant/Award Number: COV20/00072; SCReN (Spanish Clinical Research Network), Instituto de Salud Carlos III, Grant/Award Number: PT17/0017/0009S

COVID-19 outbreaks in a transmission control scenario: challenges posed by social and leisure activities, and for workers in vulnerable conditions, Spain, early summer 2020

Severe acute respiratory syndrome coronavirus 2 community-wide transmission declined in Spain by early May 2020, being replaced by outbreaks and sporadic cases. From mid-June to 2 August, excluding single household outbreaks, 673 outbreaks were notified nationally, 551 active (>6,200 cases) at the time. More than half of these outbreaks and cases coincided with: (i) social (family/friends’ gatherings or leisure venues) and (ii) occupational (mainly involving workers in vulnerable conditions) settings. Control measures were accordingly applied