Diurnal changes of Rubisco in response to elevated CO2, temperature and nitrogen in wheat grown under temperature gradient tunnels.

Growth at elevated CO2 and temperature often leads to decreased Rubisco activity. We investigated the effects of increased CO2, temperature and nitrogen on the diurnal changes in the control of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) activity in wheat (Triticum aestivum L.). Spring wheat was grown at ambient and 700 μmol mol-1 CO2, under ambient and 4 ºC warmer temperatures, and with two levels of nitrogen supply in field tunnels in a Mediterranean environment. At ear emergence, elevated CO2 increased Rubisco activation, but decreased Rubisco protein and, with high nitrogen, Rubisco specific activity, and had no effect on the rbcS transcript. Warmer temperatures tended to decrease the rbcS mRNA level and Rubisco protein, although the effect on Rubisco activity was small. High nitrogen decreased Rubisco activation or specific activity, depending on the CO2 concentration. It increased Rubisco protein at the end of the night, but accelerated its diurnal loss. The main changes after anthesis were the disappearance of the decrease in Rubisco specific activity caused by elevated CO2, an increase in this activity with above-ambient temperatures combined with high nitrogen, and that high temperature and nitrogen did not affect Rubisco protein contents. This study suggests that decreased leaf protein and increased levels of a Rubisco inhibitor, rather than gene repression by sugars, are involved in acclimation to elevated CO2. High nitrogen increases this down regulation. Changes during growth in levels of leaf metabolites and protein may alter the relative importance of levels of inhibitors and Rubisco amounts for Rubisco regulation.The technical cooperation of Libia Hernandez and Angel Verdejo is acknowledged. The staff of the IRNASA experimental farm helped with crop sowing and fertilizer application. The Northern blots analyses were made at the laboratory of Prof. M. Stitt (Botanical Institute, University of Heidelberg, Germany) with Marina Bueno CSIC-DFG funds granted to R. Morcuende. This work was funded by the Spanish Plan Nacional de Investigación y Desarrollo (grant no. CLI96-0396). We thank Dr. Christine Raines (Dept. of Biological Sciences, John Tabor Laboratories, University of Essex, UK) for the generous gift of the Rubisco cDNA.Peer reviewe

Spread of a SARS-CoV-2 variant through Europe in the summer of 2020.

Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3–5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes. © 2021, The Author(s), under exclusive licence to Springer Nature Limited

Contenido mineral del fruto de fresa y su relación con el nitrógeno y con el potasio del medio.

9 p.[EN] The contents of nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese and boron of the strawberry fruit are described, as well as their relationships to nitrogen and potassium in the rooting medium. The nitrogen and potassium contents of the fruit increase as their respective contents in the medium increase, and there is an inverse relationship between the fruit content of each of these nutrients and the level ofsupply of the other. Rising the level of nitrogen supply increases the fruit iron content and rising the level of potassium supply increases the fruit phosphorus content. The calcium content does not show any relation to nitrogen and its responsc to potassium varies behveen experiment. The magnesium content does not significantly vary with the levels of nitrogen or potassium.[ES] Se describen los contenidos de nitrógeno, potasio, calcio, magnesio, hierro, manganeso y boro del fruto de fresa y su relación con el nitrógeno y con el potasio medio. El nitrógeno y el potasio del fruto aumentan con sus contenidos respectivas en el medio, y a su vez varían inversamente con las dosis del otro nutriente. Las dosis crecientes de nitrógeno inciden además en un aumento del contenido de hierro en el fruto y las dosis crecientes de potanio en un aumento del fósforo. El calcio no muestra relación con el nitrógeno y la respuesta al potasio varía de unos ensayos a otros. El magnesio no varía significativamente con la dosis de nitrógeno ni con las de potasio.Peer reviewe

Relaciones entre el crecimiento vegetativo y la producción de fruto de la planta de fresa

8 páginas, 3 figuras[EN]The relationships between vegetative growth at various times and fruit yield in the strawberry plant are studied; these relationships correspond to two glasshouse experiments in which several levels of nitrogen and potassium are used. In general, there exists a direct relationships between reproductive and vegetative growth, although conditions of nutrient excess are given which an increase in vegetative growth is not accompanied by an increase in fruit yield: The numbers of inflorescences and flowers are directly related to the number and total weight of leaves while the percentage fruit set is mainly related to the development of the crown and the root. In the smaller sized plants producing high yields, leaf expansion as well as crown and root development experience a reduction during fruiting, which in some cases in still shown after fruit ripering[ES]Se estudian las relaciones entre el crecimiento vegetativo en diferentes épocas del ciclo y la producción de fruto de la planta de fresa: estas relaciones corresponden a dos experimentos de invernadero, en los que se emplean dosis variables de nitrógeno y de potasio. En general, existe relación directa entre el crecimiento vegetativo y el reproductivo, si bien se dan condiciones de nutrición por exceso para las que el aumento del crecimiento vegetativo no coincide con incremento de la producción de fruto. El número de inflorescencias y flores está relacionado directamente con el número de hojas y su peso total, mientras que el porcentaje de fructificación lo está principalmente con el desarrollo de la corona y de la raíz. Para las plantas de menor tamaño que dan producciones elevadas, la expansión de las hojas, así como el desarrollo de la corona y de la raíz experimentan una reducción durante la fructificación, que sigue manifestándose, en algunos caos, en la postmaduración.Peer reviewe

Influencia del nitógeno y del potásio en la calidad del fruto de la fresa.

10 p.[ESP] La calidad del fruto de fresa varia con la nutrición nitrogenada y potásica de la planta. Frente al potasio la acidez valorable es el componente que presenta mayor respuesta, que aumenta con la concentración del nutriente en la hoja Y en el fruto, coincidiendo el contenido más alto, con la concentración más alta de potasio. En el peciolo durante la fructificación su valor es aproximadamente del 5 %. Los azúcares totales y la vitamina C aumentan con el contenido de este nutriente en el limbo y peciolo hasta 1,2 y 2 % respectivamente: contenidos superiores no coinciden, en general, con aumento de estos componentes. Frente al nitrógeno, son los azúcares los que presentan mayor respuesta, disminuyendo con la concentración de este nutriente, lo que sucede también con la vitamina C, pero a partir de valores más altos. En cambio la acidez valarable no muestra relacián con este nutriente, al menos si el contenido de potasio en el peciolo es del orden de 4,4 %. Es posible que el contenido en azúcares dependa en aiguna medida del equilibrio nitr6geno-potasio; es máximo, en general, para los valores más bajos de N/K, alrededor de 4 en el limbo (ambos nutrientes en meq). Independientemente de la nutrición nitrogenada y potásica los azúcares totales y la acidez valorable disminuyen can el número de frutas par planta.[ENG] The quality of the strawberry fruit varies with the nitrogen and potassium nutrition of the plant. The component most affected by potassium is the titrable acidity of the fruit, which increases whenever potassium concentration in the leaf and the fruit increases. Potassium concentrarion in the petiole at fruiting is about 5 %. Total sugars and vitamin C increase with potassium content of the lamina and petiole until nutrient concentrations of 1.2 % and 2 S, respectively: higher contents are generally not associated with increases in these components. Sugan have the greatest response to nitrogen, decreasing as the nutrient concentration increases. A similar trend is shown by vitamin C, but starting at higher nitrogen contents. Titrable acidity, however, is not related to nitrogen, at least when potassium content in the petiole is around 4.4 %. It is possible that sugar content depends to some extent on the nitrogenpotassium equilibrium; sugar content is generally maximum for the lowest Y/K values, which are about 4 in the lamina (both nutrients in meq). Total sugars and titrable acidity decrease with the number of fruits per plant, independently of nitrogen and potassium nutrition

Contenido de varias fracciones de nitrógeno en el fruto de fresa y su relación con el nitrógeno y con el potásio del medio

10 p.[EN] The effect of the nitrogen (1/3 as ammonium and 2/3 as nitrate) and potassium of the medium, in sand culture, on the content of free amide andamine nitroeen and of ammonium in the ripe strawberry ruit is described. Increasine U levels of nitrogen determine an increase of these three fractions, particularly the amides, mainly when the potassium levels are lower. The relation with the potassium level depends upon the nitrogen level; thr frrr amino acids and amides follow a decreasing relationship up to a potassium level which is greater the higher the nitrogen level, and then increases when the levels arc higher. Among the free amino acids and amides the most abundant are asparagine and glutamine, followed by aspartic acid, alanine and glutamic acid.[ES] Se describe la incidencia del nitrógeno (1/3 en forma amoniacal y 2/3 en forma nítrica) y del potasio del medio, en cultivo de arena, en el contenido de nitrógeno amídico y amínico libres y amonio en el fruto de fresa maduro. Las dosis crecientes de nitrógeno determinan un aumento de las tres fracciones, principalmente cuando las dosis de potasio son más bai,as ,v en .a rticular en las amidas. Frente a las dosis de potasio. la relación depende de la dosis de nitrógeno; los aminoácidos y amidas libres siguen una relación decreciente hasta una dosis de potasio tanto mayor cuanto más elevada es la de nitrógeno, aumentando de nuevo para dosis más altas. Entre los aminoácidos y amidas libres los más abundantes son la asparagina y la glutamina. seguidos del ácido aspárúco, alanina y ácido glutámico

Fertilidad de los suelos cultivados de la Cuenca Media del Duero. Producción Vegetal. (Campaña 1983-1984)

13 páginas, 11 tablas. -- Con la colaboración técnica de: Juan Bustos Álvarez, Dionisio González de Dios, María Luz Cosme[EN]Soil fertility has been studied by means of the relationship between its composition and crop yield in 12 field experiments with wheat (cv. Astral R-1), located at the central Duero basin, which were fertilized with several rates of nitrogen, prosphorus and potassium. Biomass production and grain yield increased with the levels of nitrogen, organic matter and calcium, as well as with the soil pH and proportion of silt plus clay. The nitrogen requirements decreased as its level and that of organic matter in the soil increased. The responses to phosphorus and potassium fertilizers decreased with the content of organic matter and with the porportion of silt plus clay in the soil, respectively. Levels of nitrogen and organic matter lower than 0.07% and 1.l%, respectively, were associated with low grain yields[ES]Se estudia en 12 campos de experimentación de trigo (var. Astral), situados en la Cuenca Media del Duero y abonados con varias dosis de nitrógeno, fósforo y potasio, la fertilidad de los suelos, a través de las relaciones entre su composición y la producción vegetal. La producción de biomasa y el rendimiento en grano aumentaron con los niveles de nitrógeno, materia orgánica y calcio, así como con el pH y la proporción de limo más arcilla del suelo. Los requerimientos en nitrógeno disminuyeron al aumentar su nivel y el de la materia orgánica del suelo. Las respuestas a los fertilizantes fosfatado y potásico disminuyeron respectivamente con el contenido de materia orgánica y la proporción de limo más arcilla del suelo. Niveles de nitrógeno y de materia orgánica inferiores a 0.07% y a 1.1% respectivamente se correspondieron con bajos rendimientos en la producción de granoPeer reviewe

Fertilidad de suelos cultivados de la Cuenca Media del Duero. III. Producción Vegetal

15 páginas, 9 tablas. -- Los autores agradecen a D. Juan Bustos el análisis estadístico de los datos y a D. Dionisio González y a Dª María Luz Cosme la realización de la parte experimental[EN]Soil fertility has been studied by means of the relationship between its composition and crop yield in 12 field experiments with Astral wheat, located at the central Duero basin, which were fertilized with varying rates of nitrogen, prosphorus and potasium. The yield of the control is positevely related to the levels of nitrogen and organic matter in the soil. The requirements for nitrogen, phosphorus and potassium decrease as the levels of these nutrients in the soil increase. Also, the responses to phosphorus fertilizer decrease with organic matter content in the soil, and the responses to added potassium decrease with the proportion of silt plus clay. Levels in the soil lower than 0.09% N, 8 mg/100 g P2O5 and 18 mg/100 g K2O could limit growth and yiel of wheat.[ES]Se estudia, en 12 campos de experimentación de trigo (var. Astral R-1) situados en la Cuenca media del Duero y abonados con varias dosis de nitrógeno, fósforo y potasio, la fertilidad de los suelos, a través de las relaciones entre su composición y las producciones conseguidas. La producción del testigo sigue una relación creciente con los niveles de nitrógeno y materia orgánica en el suelo. Los requerimientos en nitrógeno, fósforo y potasio disminuyen al aumentar los niveles de los respectivos nutrientes en el suelo. Además, las respuestas al fertilizante fosfatado disminuyen con el contenido de materia orgánica y las respuestas al potásico con la proporción de limo más arcilla. Niveles en el suelo inferiores a 0.09% de N, a 8 mg/100 de P2O5 y a 18 mg/100 g de K2O podrían restringir el crecimiento y rendimiento del trigoPeer reviewe

Diagnóstico de la nutrición mineral del trigo, cultivado en el campo, al final del ahijamiento y en la antesis

14 páginas, 7 tablas. -- Con la colaboración técnica de: D. Dionisio González y Dña. Mª Luz Cosme y asimismo los autores agradecen al Dr. Fidel Escudero y a D. Francisco Busto el análisis estadístico de los datos.[EN]The relationships of plant growth at the end of tillering and at anthesis and of final grain yield, with the mineral composition of the plant at these growth stages, have been studied in four field trials of winter wheat (var. Astral) with several rates of nitrogen, phosphorus and potassium in the provinces of Salamanca, Zamora and Valladolid. At the end of tillering, the dilution effect seems to alter strongly the relationships between growth and mineral composition of the plant; these relationships occur only with strong deficiency of the nutrient, thus preventing the establishement of optimal levels. At anthesis, nitrogen and phosphorus appear as the nutrients most limiting for the development of the aerial parts of the crop, while calcium, together with nitrogen and magnesium, are the most limiting for grain yield. Based on the regression equations it is estimated that the optimum levels in the leaf at anthesis could be around 4.5% for nitrogen, 0.42 % for phosphorus, 1.5% for calcium and 0.43% for magnesium.[ES]Se estudia en cuatro campos de experimentación de trigo (var. Astral) de las provincias de Salamanca, Zamora y Valladolid, abonados con varias dosis de nitrógeno, fósforo y potasio, las relaciones del crecimiento de la planta al final del ahijamiento y en la antesis, y de la producción de grano con la composición mineral de la planta en las épocas señaladas. Al final del ahijamiento, el efecto de dilución parece alterar fuertemente las relaciones entre el crecimiento de la planta y su composición mineral, teniendo lugar éstas solamente en los casos de fuerte deficiencia en el nutriente, lo que impide establecer niveles óptimos. En la antesis, el nitrógeno y el fósforo apararecen como los principales limitantes del desarrollo de la parte aérea, y el calcio, junto con nitrógeno y magnesio, de la producción de grano. De las ecuaciones de regresión se estima que en la antesis los niveles óptimos en la hoja podrían estar alrededor de 4.5% para nitrógeno, de 0.42% para fósforo, de 1.5% para calcio y de 0.43% para magnesio.Peer reviewe

Varietal differences in amino acid composition of wheat (Triticum aeativum L) grain

The differences in the amino acid composition of the developing grain between the three winter wheat (Triticum aestivum L) varieties Splendeur, Hobbit and Maris Huntsman were analysed in a growth-room experiment. At 15 days after anthesis, Maris Huntsman, the variety with the fastest leaf senescence, had a larger proportion of glutamate and smaller levels of threonine, glycine, alanine, valine, methionine and isoleucine in the total amino acid fraction; at later dates these differences were in general less pronounced, particularly compared with Splendeur. This suggests that, in the variety with the fastest leaf senescence, rapid gliadin synthesis in the grain occurs earlier. At any given percentage of nitrogen in the mature grain, Hobbit had a smaller proportion of glutamate and greater proportions of lysine, arginine and alanine; Splendeur, the only bread-making variety, had smaller levels of aspartate and lysine; and Maris Huntsman had the greatest relative amount of phenylalanine. The possible differences among the varieties in the relative proportion of some protein fractions are discussed. Until 25 days after anthesis Maris Huntsman had smaller relative proportions of free alanine, valine, leucine, isoleocine and threonine, in particular when compared with Splendeur. In Maris Huntsman, the relative amount of aspartate increased from 15 days after anthesis onwards, whereas in Hobbit it only did so in mature grains