Fenotipado de plantas: del laboratorio al campo, de la cámara al dron

Esta línea de investigación se centra en el estudio de los procesos vegetales implicados en la señalización redox y en la asimilación eficiente de carbono, así como en los mecanismos de tolerancia de la planta a estreses bióticos y abióticos. Estos estudios combinan enfoques fisiológicos, bioquímicos, biofísicos y moleculares mediante el uso de plantas de interés agronómico como el guisante y la fresa, además de otras plantas modelo como el tabaco o Arabidopsis. El uso de técnicas moleculares, proteómicas, cristalográficas, inmunológicas y de imagen (fluorescencia, termografía, etc.) nos permite descifrar los mecanismos de regulación molecular de procesos vegetales complejos tales como el metabolismo del carbono, sistemas antioxidantes clave y la respuesta de la planta huésped a la infección por patógenos.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

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

The donor side of Photosystem II as the copper-inhibitory binding site

We have measured, under Cu (II) toxicity conditions, the oxygen-evolving capacity of spinach PS II particles in the Hill reactions H2O -> SiMo (in the presence and absence of DCMU) and H2O -> PPBQ, as well as the fluorescence induction curve of Tris-washed spinach PS II particles. Cu (II) inhibits both Hill reactions and, in the first case, the DCMU-insensitive H2O -> SiMo activity. In addition, the variable fluorescence is lowered by Cu (II). We have interpreted our results in terms of a donor side inhibition close to the reaction center. The same polarographic and fluorescence measurements carried out at different pHs indicate that Cu (II) could bind to amino acid residues that can be protonated and deprotonated. In order to reverse the Cu (II) inhibition by a posterior EDTA treatment, in experiments of preincubation of PS II particles with Cu (II) in light we have demonstrated that light is essential for the damage due to Cu (II) and that this furthermore is irreversible.This work was supported by a grant from the Spanish DGICYT (PB94-0116). J.B. Arellano was the recipient of a fellowship from the Spanish Science and Education Ministry.Peer reviewe

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

Opportunities and limitations of crop phenotyping in southern european countries

ReviewThe Mediterranean climate is characterized by hot dry summers and frequent droughts. Mediterranean crops are frequently subjected to high evapotranspiration demands, soil water deficits, high temperatures, and photo-oxidative stress. These conditions will become more severe due to global warming which poses major challenges to the sustainability of the agricultural sector in Mediterranean countries. Selection of crop varieties adapted to future climatic conditions and more tolerant to extreme climatic events is urgently required. Plant phenotyping is a crucial approach to address these challenges. High-throughput plant phenotyping (HTPP) helps to monitor the performance of improved genotypes and is one of the most effective strategies to improve the sustainability of agricultural production. In spite of the remarkable progress in basic knowledge and technology of plant phenotyping, there are still several practical, financial, and political constraints to implement HTPP approaches in field and controlled conditions across the Mediterranean. The European panorama of phenotyping is heterogeneous and integration of phenotyping data across different scales and translation of “phytotron research” to the field, and from model species to crops, remain major challenges. Moreover, solutions specifically tailored to Mediterranean agriculture (e.g., crops and environmental stresses) are in high demand, as the region is vulnerable to climate change and to desertification processes. The specific phenotyping requirements of Mediterranean crops have not yet been fully identified. The high cost of HTPP infrastructures is a major limiting factor, though the limited availability of skilled personnel may also impair its implementation in Mediterranean countries. We propose that the lack of suitable phenotyping infrastructures is hindering the development of new Mediterranean agricultural varieties and will negatively affect future competitiveness of the agricultural sector. We provide an overview of the heterogeneous panorama of phenotyping within Mediterranean countries, describing the state of the art of agricultural production, breeding initiatives, and phenotyping capabilities in five countries: Italy, Greece, Portugal, Spain, and Turkey. We characterize some of the main impediments for development of plant phenotyping in those countries and identify strategies to overcome barriers and maximize the benefits of phenotyping and modeling approaches to Mediterranean agriculture and related sustainabilityinfo:eu-repo/semantics/publishedVersio

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

Seed treatments with Bacillus species induce a beneficial metabolic reprogramming in melon plants

Plant-beneficial microbes are known to provide multifaceted traits to the plant health. Among them, Bacillus species are commonly detected members of the plant holobiont which have been described as stimulators of seed germination, plant growth and the defense against phytopathogens. In this work we describe, with the utilization of untargeted metabolomics and bioinformatic tools as GNPS, MolNetEnhancer and MZmine, the different metabolomic patterns found according to the elderly of the leaves. In addition, we compare the metabolomic profile of plants emerged from seeds bacterized with B. subtilis and B. velezensis identifying tryptophan, a chlorophyll A analog and flavonoids as key metabolites in the specific response of each bacterium against abiotic stresses.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

IAA : Información y actualidad astronómica (22)

Sumario : Estrellas binarias: un matrimonio muy ventajoso.-- Mujeres y ciencia: rompiendo techos.-- La estrella más masiva.-- DECONSTRUCCIÓN Y otros ENSAYOS : Criterios termodinámicos en la evolución de agujeros negros.-- ACTUALIDAD.-- ENTRE BASTIDORES.-- CIENCIA: PILARES E INCERTIDUMBRES. Núcleos de galaxias activas .-- HISTORIAS DE ASTRONOMÍA: “Serendipia” cósmica.-- El increíble y asombroso viaje de Fotón. II Parte.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda de la Acción Complementaria CCT005-06-00178 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica.N

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)