CONTENIDO DE POLIAMINAS LIBRES EN PALMAS AFECTADAS POR PUDRICION DEL COGOLLO EN LAS ZONAS CENTRAL Y OCCIDENTAL DE COLOMBIA

La pudrición del cogollo (PC) es la principal enfermedad de la palma en Colombia. En las zonas palmeras Central (ZC) y Oriental (ZE), las palmas enfermas pueden recuperarse naturalmente. En la Zona Occidental (ZW) el proceso de recuperación no es evidente. La recuperación de palmas está ligada a gran actividad meristemática que podría involucrar la acción inductora de metabolitos como las poliaminas (PA). Este trabajo muestra la relación entre poliaminas del meristemo y la capacidad de recuperación de palmas con PC, en dos zonas agroclimáticas diferentes. Poliaminas extraídas del meristemo de palmas sembradas en ZC y ZW, fueron analizadas por HPLC. En ZC, donde existe recuperación espontánea, los niveles más altos de PA se presentan en palmas sanas y en recuperación y a medida que avanza la enfermedad la concentración desciende hasta un mínimo en el estado de PC inicial (PCI). Luego la concentración de PA aumenta hasta el estado de Buena Recuperación (BR) donde los valores de poliaminas son más altos que los de palmas sanas. En la ZW, con la enfermedad el contenido de PA aumenta llegando al máximo en plantas sin recuperación y el mínimo se presenta en plantas sanas. Las diferencias entre zonas pueden explicarse por diferentes roles de las poliaminas en plantas. En la ZC la cantidad elevada de PA en palmas sanas o en recuperación funcionaría en la inducción de actividad meristemática, para la recuperación espontánea. En la ZW el aumento en el contenido de PA con la enfermedad induciría la generación de especies reactivas de oxígeno para defensa secundaria de la planta ante la imposibilidad de, a través de incrementos en la actividad meristemática producir rápidamente estructuras sanas que no sean reinfectadas

Design of a monitoring system for cattle using LPWAN technology

El monitoreo de bovinos es una actividad indispensable para el sector ganadero, porque permite conocer el estado de salud y entorno del bovino para tomar medidas correctivas y/o preventivas en caso de alguna eventualidad y velar por el bienestar del ganado. En las principales regiones ganaderas de Colombia, esta actividad se ha abordado, con herramientas convencionales y poco efectivas, lo cual se evidencia en las elevadas cifras de abigeato y detección tardía de potenciales situaciones de riesgo para el bovino. A pesar del bajo nivel de herramientas tecnológicas usadas en este sector, el aumento de las cifras de conectividad a internet impulsado por la coyuntura del Covid-19, contribuye a la implementación de nuevas tecnologías enfocadas en el desarrollo de la industria ganadera. A partir de lo anterior, se diseñó un sistema de monitoreo para ganado bovino, basado en tecnología de comunicación LPWAN (Low Power Wide Area Network) utilizando el protocolo LoRaWAN, para el monitoreo a las variables del estado del bovino: ubicación geográfica mediante mediada por coordenadas de latitud y longitud y temperatura corporal superficial en grados centígrados. El sistema diseñado genera alarmas ante anomalías en las variables monitoreadas, proporcionando una herramienta de control mediante la interfaz del sistema y beneficios económicos e intrínsecos al ganadero tras su implementación. De acuerdo con la estructura el Internet de las Cosas (IoT), se establecieron cuatro capas que componen el sistema: la capa física, la capa de acceso, la capa de integración de la información y la capa de la interfaz, que se desarrollaron e integraron cada una respectivamente. Inicialmente, se identificaron y seleccionaron las herramientas de captura de datos, para el posterior diseño y elaboración del dispositivo adherido al bovino, el cual fue el actor en la capa física del sistema. Para esto se tuvieron en cuenta metodologías de priorización como el método AHP y de diseño de ingeniería de producto, en el que los criterios fueron planteados con respecto a los variables requeridas del sistema y la salubridad del bovino. Posteriormente, se realizó una selección de alternativas de herramientas de recepción de datos que permitieran la conexión entre el dispositivo seleccionado y el software de almacenamiento, mediante la programación y ejecución de los protocolos de comunicación de acuerdo con la selección de la plataforma de servicio en la nube, utilizada para la configuración y estructuración de la base de datos. Teniendo en cuenta los requerimientos mencionados, se seleccionó Azure SQL Database para la creación de la base de datos con tablas estructuradas que permitieron un adecuado flujo de información. En cuanto al proceso de generación de alarmas, servicio del sistema de monitoreo que interactúa transversalmente con los actores de las capas hasta llegar al ganadero, quien recibe alarmas generadas a través de mensajes de texto. Se realizó la investigación de las condiciones de los riesgos potenciales en el ganado bovino, obteniendo cuatro casos de alarmas que requieren intervención inmediata, moderada, prolongada o nula según sea el caso. Los casos de activación dependieron de: ubicación fuera del límite del predio, temperatura inferior a los límites mínimos, temperatura superior a los límites, tiempo del estado de alerta y variables dentro de los límites establecidos, estos casos fueron necesarios para el diseño y programación del código que generó las alarmas a través de la plataforma y permitió su envío al usuario. Además, se desarrolló la capa de interfaz, con base en la investigación de las preferencias y necesidades del ganadero. De acuerdo con los resultados, se planteó y se diseñó el flujo de información e interacción con el usuario en el software de visualización. A partir de esto y de las características de las demás capas del sistema, se procedió a realizar la respectiva selección del software para la interfaz y su desarrollo, teniendo en cuenta características como la usabilidad, funcionalidad y facilidad en la comprensión. Una vez lograda la integración completa del sistema, se diseñaron los procesos de evaluación del mismo, a partir de los requerimientos que abarcaron desde la precisión de los datos transferidos en cada capa, siendo aceptable de acuerdo a los rangos establecidos por los intervalos de incertidumbre, hasta la efectividad de las alarmas, obteniendo como resultado un 95%. Las pruebas de campo fueron implementadas en un predio ubicado en Tibasosa, Boyacá con un ejemplar bovino. Finalmente, el precio de venta del sistema, comprendido por una inversión inicial por dispositivo y cobro fijo mensual referentes a las licencias de los softwares, se determinó estableciendo los costos fijos y variables junto con el porcentaje de ganancia esperado del 20%. Como resultado el precio de venta del sistema por dispositivo fue de $217.953 COP, con un costo mensual de$122.600 COP. Ligado a lo anterior, se usó la metodología QFD para la determinación del posicionamiento del sistema diseñado frente a los principales competidores, obteniendo como criterio diferenciador el precio de venta al ser superior en promedio 3,5 puntos en una escala de calificación de 1 a 5. Por último, para el análisis costo-beneficio se evaluaron los factores que representaban riesgos en el cuidado del ganado bovino, que junto al porcentaje de mitigación del riesgo ofrecido por el sistema de monitoreo del 71,75% se obtuvo un Retorno sobre la Inversión (ROI) anual del 25,4%.Cattle monitoring is an indispensable activity for the livestock sector, because it allows to know the health status and location of cattle in order to take corrective and/or preventive measures in case of any eventuality and to ensure the welfare of livestock. In the main cattle-raising regions of Colombia, this activity has been approached with conventional and ineffective tools, which is evidenced by the high numbers of cattle rustling and late detection of potentials risk situations for cattle. Despite the low level of technological tools used in this sector, the increase in Internet connectivity figures driven by the Covid-19 situation, contributes to the implementation of new technologies focused on the development of the livestock industry. Given the above, a prototype monitoring system for cattle was designed, based on LPWAN (Low Power Wide Area Network) communication technology using the LoRaWAN protocol, to monitor the variables of the cattle's condition: geographic location measured by latitude and longitude coordinates and surface body temperature in degrees Celsius. The designed system generates alarms in case of anomalies in the monitored variables, providing a control tool through the system interface and economic benefits to the farmer after its implementation. According to the structure of the Internet of Things (IoT), four layers that make up the system were established: the physical layer, the access layer, the information integration layer and the interface layer, each of which was respectively developed and integrated. Initially, the data capture tools were identified and selected for the subsequent design and development of the device attached to the bovine, which acted as the physical layer of the system. For this purpose, prioritization methodologies such as the AHP method and product engineering design were considered, in which the criteria were established with respect to the required variables of the system and the healthiness of the bovine. Subsequently, a selection of alternatives of data reception tools was made to allow the connection between the selected device and the storage software, through the programming and execution of the communication protocols according to the selection of the cloud service platform, used for the configuration and structuring of the database. Considering the aforementioned requirements, Azure SQL Database was selected for the creation of the database with structured tables that allowed an adequate flow of information. Regarding the alarm generation process, a service of the monitoring system that interacts transversally with the actors of the layers until it reaches the farmer, who receives alarms generated through text messages. Research was carried out on the conditions of potential risks in cattle, obtaining four cases of alarms that require immediate, moderate, prolonged or no intervention, depending on the case. The activation cases were built upon the following: location outside the property boundary, temperature below the minimum limits, temperature above the limits, time of alert status and variables within the established limits; these cases were necessary for the design and programming of the code that generated the alarms through the platform and allowed them to be sent to the user. In addition, the interface layer was developed, based on the research of the farmer's preferences and needs. Based on the results, the flow of information and interaction with the user in the visualization software was planned and designed. On the basis of this and the characteristics of the other layers of the system, the respective selection of the software for the interface and its development was made, considering characteristics such as usability, functionality and ease of understanding. Once the complete integration of the system was achieved, the evaluation processes were designed, based on the requirements that ranged from the accuracy of the data transferred in each layer, being acceptable according to the ranges established by the uncertainty intervals, to the effectiveness of the alarms, obtaining 95% as a result. The field tests were implemented in a farm located in Tibasosa, Boyacá with a bovine specimen. Finally, the selling price of the system, comprising an initial investment per device and a fixed monthly charge for the software licenses, was determined by establishing the fixed and variable costs together with the expected profit percentage of 20%. As a result, the selling price of the system per device was $217,953 COP, with a monthly cost of$122,600 COP. Linked to the above, the QFD methodology was used to determine the positioning of the designed system compared to the main competitors, obtaining as a differentiating criterion the sales price, which was on average 3.5 points higher on a rating scale of 1 to 5. Finally, for the cost-benefit analysis, the factors that represented risks in the care of cattle were evaluated, which together with the percentage of risk mitigation offered by the monitoring system of 71.75%, resulted in an annual Return on Investment (ROI) of 25,4%.Ingeniero (a) IndustrialPregrad

Photosynthesis in Arabidopsis Is Unaffected by the Function of the Vacuolar K + Channel TPK3

Photosynthesis is limited by the slow relaxation of nonphotochemical quenching, which primarily dissipates excess absorbed light energy as heat. Because the heat dissipation process is proportional to light-driven thylakoid lumen acidification, manipulating thylakoid ion and proton flux via transport proteins could improve photosynthesis. However, an important aspect of the current understanding of the thylakoid ion transportome is inaccurate. Using fluorescent protein fusions, we show that the Arabidopsis ( ) two-pore K channel TPK3, which had been reported to mediate thylakoid K flux, localizes to the tonoplast, not the thylakoid. The localization of TPK3 outside of the thylakoids is further supported by the absence of TPK3 in isolated thylakoids as well as the inability of isolated chloroplasts to import TPK3 protein. In line with the subcellular localization of TPK3 in the vacuole, we observed that photosynthesis in the Arabidopsis null mutant , which carries a transfer DNA insertion in the first exon, remains unaffected. To gain a comprehensive understanding of how thylakoid ion flux impacts photosynthetic efficiency under dynamic growth light regimes, we performed long-term photosynthesis imaging of established and newly isolated transthylakoid K - and Cl -flux mutants. Our results underpin the importance of the thylakoid ion transport proteins potassium cation efflux antiporter KEA3 and voltage-dependent chloride channel VCCN1 and suggest that the activity of yet unknown K channel(s), but not TPK3, is critical for optimal photosynthesis in dynamic light environments

Stromal NADH supplied by PHOSPHOGLYCERATE DEHYDROGENASE3 is crucial for photosynthetic performance

During photosynthesis, electrons travel from light-excited chlorophyll molecules along the electron transport chain to the final electron acceptor nicotinamide adenine dinucleotide phosphate (NADP) to form NADPH, which fuels the Calvin-Benson-Bassham cycle (CBBC). To allow photosynthetic reactions to occur flawlessly, a constant resupply of the acceptor NADP is mandatory. Several known stromal mechanisms aid in balancing the redox poise, but none of them utilizes the structurally highly similar coenzyme NAD(H). Using Arabidopsis (Arabidopsis thaliana) as a C-3-model, we describe a pathway that employs the stromal enzyme PHOSPHOGLYCERATE DEHYDROGENASE 3 (PGDH3). We showed that PGDH3 exerts high NAD(H)-specificity and is active in photosynthesizing chloroplasts. PGDH3 withdrew its substrate 3-PGA directly from the CBBC. As a result, electrons become diverted from NADPH via the CBBC into the separate NADH redox pool. pgdh3 loss-of-function mutants revealed an overreduced NADP(H) redox pool but a more oxidized plastid NAD(H) pool compared to wild-type plants. As a result, photosystem I acceptor side limitation increased in pgdh3. Furthermore, pgdh3 plants displayed delayed CBBC activation, changes in nonphotochemical quenching, and altered proton motive force partitioning. Our fluctuating light-stress phenotyping data showed progressing photosystem II damage in pgdh3 mutants, emphasizing the significance of PGDH3 for plant performance under natural light environments. In summary, this study reveals an NAD(H)-specific mechanism in the stroma that aids in balancing the chloroplast redox poise. Consequently, the stromal NAD(H) pool may provide a promising target to manipulate plant photosynthesis

The Arabidopsis T‐DNA mutant SALK_008491 carries a 14‐kb deletion on chromosome 3 that provides rare insights into the plant response to dynamic light stress

Abstract In nature, plants experience rapid changes in light intensity and quality throughout the day. To maximize growth, they have established molecular mechanisms to optimize photosynthetic output while protecting components of the light‐dependent reaction and CO2 fixation pathways. Plant phenotyping of mutant collections has become a powerful tool to unveil the genetic loci involved in environmental acclimation. Here, we describe the phenotyping of the transfer‐DNA (T‐DNA) insertion mutant line SALK_008491, previously known as nhd1‐1. Growth in a fluctuating light regime caused a loss in growth rate accompanied by a spike in photosystem (PS) II damage and increased non‐photochemical quenching (NPQ). Interestingly, an independent nhd1 null allele did not recapitulate the NPQ phenotype. Through bulk sequencing of a backcrossed segregating F2 pool, we identified an ~14‐kb large deletion on chromosome 3 (Chr3) in SALK_008491 affecting five genes upstream of NHD1. Besides NHD1, which encodes for a putative plastid Na+/H+ antiporter, the stromal NAD‐dependent D‐3‐phosphoglycerate dehydrogenase 3 (PGDH3) locus was eradicated. Although some changes in the SALK_008491 mutant's photosynthesis can be assigned to the loss of PGDH3, our follow‐up studies employing respective single mutants and complementation with overlapping transformation‐competent artificial chromosome (TAC) vectors reveal that the exacerbated fluctuating light sensitivity in SALK_008491 mutants result from the simultaneous loss of PGDH3 and NHD1. Altogether, the data obtained from this large deletion‐carrying mutant provide new and unintuitive insights into the molecular mechanisms that function to protect the photosynthetic machinery. Moreover, our study renews calls for caution when setting up reverse genetic studies using T‐DNA lines. Although second‐site insertions, indels, and SNPs have been reported before, large deletion surrounding the insertion site causes yet another problem. Nevertheless, as shown through this research, such unpredictable genetic events following T‐DNA mutagenesis can provide unintuitive insights that allow for understanding complex phenomena such as the plant acclimation to dynamic high light stress

H+ Transport by K+ EXCHANGE ANTIPORTER3 Promotes Photosynthesis and Growth in Chloroplast ATP Synthase Mutants

The composition of the thylakoid proton motive force (pmf) is regulated by thylakoid ion transport. Passive ion channels in the thylakoid membrane dissipate the membrane potential (Ɗψ) component to allow for a higher fraction of pmf stored as a proton concentration gradient (ƊpH). K+/H+ antiport across the thylakoid membrane via K+ EXCHANGE ANTIPORTER3 (KEA3) instead reduces the ƊpH fraction of the pmf. Thereby, KEA3 decreases nonphotochemical quenching (NPQ), thus allowing for higher light use efficiency, which is particularly important during transitions from high to low light. Here, we show that in the background of the Arabidopsis (Arabidopsis thaliana) chloroplast (cp)ATP synthase assembly mutant cgl160, with decreased cpATP synthase activity and increased pmf amplitude, KEA3 plays an important role for photosynthesis and plant growth under steady-state conditions. By comparing cgl160 single with cgl160 kea3 double mutants, we demonstrate that in the cgl160 background loss of KEA3 causes a strong growth penalty. This is due to a reduced photosynthetic capacity of cgl160 kea3 mutants, as these plants have a lower lumenal pH than cgl160 mutants, and thus show substantially increased pH-dependent NPQ and decreased electron transport through the cytochrome b6f complex. Overexpression of KEA3 in the cgl160 background reduces pH-dependent NPQ and increases photosystem II efficiency. Taken together, our data provide evidence that under conditions where cpATP synthase activity is low, a KEA3-dependent reduction of ƊpH benefits photosynthesis and growth