Detection of DNA polymerase λ activity during seed germination and enhancement after salinity stress and dehydration in the plumules of indica rice (Oryza sativa L.).

DNA polymerase λ (DNA pol λ) is the only reported X-family DNA polymerases in plants and has been shown to play a significant role in dry quiescent seeds, growth, development and nuclear DNA repair. cDNA for DNA pol λ has been reported in Arabidopsis and japonica rice cultivar and has been characterized from E. coli expressed protein, but very little is known about its activity at protein level in plants. The enzymatic activity of DNA pol λ was studied in dry, imbibed and during different germination stages of indica rice IR-8 (salt sensitive) by in-gel activity assay to determine its physiological role in important stages of growth and development. The upstream sequence was also analyzed using plantCARE database and was found to contain several cis-acting elements, including light responsive elements, dehydration responsive elements, Myb binding sites, etc. Hence, 4-day-old germinating seedlings of IR29, a salt-sensitive, but high yielding indica rice cultivar and Nonabokra, a salt-tolerant, but low yielding cultivar were treated with water (control) or 250 mM NaCl or 20% polyethyleneglycol-6000 for 4 and 8 h. The protein was analyzed by in vitro DNA pol λ activity assay, in-gel activity assay and Western blot analysis. DNA pol λ was not detected in dry seeds, but enhanced after imbibition and detectable from low level to high level during subsequent germination steps. Both salinity and dehydration stress led to the enhancement of the activity and protein level of DNA pol λ, as compared to control tissues. This is the first evidence of the salinity or dehydration stress induced enhancement of DNA pol λ activity in the plumules of rice (Oryza sativa L.) cultivars.

effects of salinity on growth and germination of wheat embryos

Selected genotype of wheat [Triticum aestivum L] progeny line W4909 [salt tolerance] was used In this study. Wheat embryos were grown and subjected to different concentrations of NaCl [0,50,100,150 and 200 mM] in Gzapek Agar [GZ] solid media. The results shown that total length, fresh weight and water content of wheat seedling decreased as the NaCl concentrations increased. Dry weight and total protein content also increased in wheat seedling that exposed to moderate [100 mM] and severe [150 mM] NaCl stress respectively. Furthermore, protoplasm desiccation appeared in the cells of wheat seedling that grown up to 150 mM Nad It can be concluded that embryos of progeny lines W4909 was tolerant to NaCl stress and were grown successfully in salty media up to 150 mM NaCl even thought the seedlings show a decrease in growth parameters

Germination of three wheat varieties under equipotential levels of matric [vm] and osmotic [vs] stress

Choice of a crop plant to be suitable for cultivation in desert areas must be within some considerations. Desert areas are generally characterized by: [I] lack of water, [2] climatic extremes, [3] several wide deficiencies in nutrient elements, [4] salinity and ion toxicity problems and [5] interaction between one or more of such previous factors. In this work, the response of three wheat varieties [Sids 1, Sakha 93 and Glza 168] to major environmental hazards existing in desert habitats is accounted for. Besides, the combined effects of temperature, matric or osmotic water potentials under different temperatures on different germination characteristics are studied. The study is concerned with both the germination stage and the early seedling stage to ensure success of the vegetative growth later. In most cases, temperature as a single factor had the dominant effect on germination characteristics

Using of polyacrylamide as growth media in germination of cucumber seeds and barley grains

This study was conducted on cucumber seeds variety of [[DAMEX, Fl line -105] and barley seeds variety of [Aruge, lineS-R]. Effort was made to compare germination and growth of cucumber and barley seeds under in vitro condition by using of both polyacryiamide [PCA] and Czapek dox ager media. Both media were supplied with growth regulators Gibberellic acid [Gas] at concentrations 4ppm, IGppm and Indol-3-buteric acid [3-IBA] at concentrations 4ppm and 16 ppm respectively. After weeks of growth and germination, seeds were transferred to soil pots for adaption. Important seedling characters like total seedling length, root length and shoot length were recorded also DNA amount estimated. The result shown that, no significant difference was observed in total seedling length between both polyacrylmide and Czapek dox ager media also estimation of DNA amount does not reveal to any significant differences, barley seedling that grown in Czapek dox ager media shown an increase in their shoot lenght compared with barley seedling grown in polyacryiamide media. Root length increased significantly in barley seeds grown in polyacryiamide media only. It can be noticed that, cucumber seedlings grown on polyacriyamide media showed an increase in their shoot length while cucumber seedling that grown on czapek dox ager media showed an increase in their root length. Growth regulators [GAs and 3-IBA] increased root length of both cucumber and barley seedling. Also they increased root length of barley seedling that grown in czapek dox ager media

Kinetic analysis of gene expression during mycelium to yeast transition and yeast to mycelium germination in Paracoccidioides brasiliensis / Análisis de la cinética de expresión de genes durante la transición de micelio a levadura y la germinación levadura a micelio en Paracoccidioides brasiliensis

Introduction: Paracoccidioidomycosis is an endemic systemic mycosis caused by Paracoccidioides brasiliensis, a thermally dimorphic fungus that in tissues and cultures at 37°C grows as a yeast while at lower temperatures (less than 24°C) it becomes a mold; however the genes that rule these processes and their expression are poorly understood. Objective: This research focused on the kinetic expression of certain genes in P. brasiliensis throughout the dimorphic process, one that involves the transition from the mycelium to yeast forms and the germination from the yeast to mycelium form. Materials and methods: A real-time quantitative polymerase chain reaction (RT-qPCR) was optimized to measure the expression of ten genes connected with diverse cellular functions including cell synthesis and wall structure, oxidative stress response, heat shock response, metabolism, proteins’ processing, solute transport across the cell membrane and signal transduction pathways at different time points during the mycelia to yeast transition, as well as in the yeast to mycelia germination processes. Results: Genes involved in cell synthesis and wall structure, metabolism and signal transduction were differentially expressed and highly up-regulated during the yeast to mycelia germination process; on the other hand, genes involved in heat shock response, cell synthesis and wall structure were highly up-regulated during the mycelia to yeast transition process. The remaining genes were differentially regulated during both processes. Conclusion: In this work the up-regulation of certain genes involved in the morphological changes occurring in P. brasiliensis yeast and mycelia forms were confirmed, indicating that these biological processes play an important role during the host-pathogen interactions, as well as in the fungus adaptation to environmental conditions.

Introducción. La paracoccidioidomicosis es una micosis sistémica causada por el hongo termodimorfo Paracoccidioides brasiliensis. En tejidos y cultivos a 37°C crece como levadura, mientras que a temperaturas menores de 24°C crece como un moho. Sin embargo, se conoce poco sobre los genes que regulan estos procesos. Objetivo. Se evaluó la cinética de expresión de algunos genes en P. brasiliensis mediante el proceso de dimorfismo incluida la transición del micelio a levadura y de la germinación de levadura a micelio. Materiales y métodos. Se optimizó una PCR cuantitativa en tiempo real (RT-qPCR) para medir la expresión de diez genes relacionados con diversas funciones celulares que incluyeron: síntesis de pared, respuesta al estrés oxidativo, respuesta al choque térmico, metabolismo, procesamiento de proteínas, trasporte de solutos a través de membranas y transducción de señales, todo ello a diferentes tiempos durante la transición de micelio a levadura, así como de la germinación de levadura a micelio. Resultados. Se encontró que los genes relacionados con síntesis de pared, metabolismo y transducción de señales, se expresaban de manera diferencial y con regulación positiva durante la germinaciónlevadura a micelio, mientras que algunos genes relacionados con respuesta a choque térmico y a síntesis de pared estaban sobreexpresados en la transición de micelio a levadura. Los genes restantes se regularon de manera diferencial en ambos procesos. Conclusiones. En este trabajo se confirma la regulación positiva de algunos genes relacionados con los cambios morfológicos de las fases levadura y micelio en P. brasiliensis, procesos biológicos que juegan un papel de importancia durante la interacción huésped-parásito y durante la adaptación del hongo al ambiente, respectivamente.

Evaluación de la germinación y crecimiento de Plántula de Chiltepín -Capsicum annuum L variedad glabriusculum- en invernadero / Evaluation of germination and seedling Growth of Chiltepín -Capsicum annuum L variedad glabriusculum- greenhouse

The chiltepin is one of the natural resources of the sinaloense saw, which reaches a commercial value of $100.00 mexican pesos for 250 g approximately, due to the fact that its crop implies penetrating in the low caducifolia jungle and crossing kilometeres to be able to obtain it, in addition the persons of the region who collect it obtain the resource of an irrational way extracting the plant in its entirety from the root, which causes a minor production in the following season of crop. Due to the fact that it is a native plant of the highland region and that the conditions of germination of the seed are achieved when the fruit is consumed by birds and passes for its digestive tract, it is a plant difficult to cultivate. By what preliminary studies were realized to evaluate the germinative percentage of the plant of chiltepín. There was placed to the shade for one month a whole of 2 000 seeds distributed in 4 charolas by 500 seeds each one. To stimulate the germination the hormone of growth was used giberelina. The beginning of the germination was observed to 8 days, reaching a month an average height of 6.5 cm. The percentage of germination that was reached under these conditions is 97 % (in other studies it has been achieved to obtain in the laboratory up to 57 % of germination), which indicates that in the laboratory it is feasible to cultivate it in a favorable way. It is necessary to realize researches related to the growth, development and establishment of the culture of chiltepín to generate in the region economic resources that derive from this activity.

El chiltepín es uno de los recursos naturales de la sierra sinaloense, el cual alcanza un valor comercial de $100.00 pesos mexicanos por 250 g aproximadamente, ya que su cosecha implica internarse en la selva baja caducifolia y recorrer kilómetros para poder obtenerlo, además las personas de la región que lo colectan lo obtienen sin ninguna técnica, pues extraen la planta en su totalidad desde la raíz, lo que ocasiona una menor producción en la siguiente temporada de cosecha. El chiltepín es difícil de cultivar, debido a que es una planta nativa de la región serrana y a que las condiciones de germinación de la semilla se logran cuando el fruto es ingerido por aves y pasa por su tracto digestivo. Por ello se realizaron estudios preliminares para evaluar el porcentaje germinativo de esta planta. Se colocaron a la sombra, por un mes, un total de 2 000 semillas, distribuidas en 4 charolas con 500 semillas cada una. Para estimular la germinación se empleó la hormona de crecimiento giberalina. El inicio de la germinación se observó a los 8 días, alcanzando al mes una talla promedio de 6,5 cm de altura. El porcentaje de germinación que se alcanzó bajo estas condiciones fue de 97% (en otros estudios se ha logrado obtener en el laboratorio hasta un 57% de germinación), lo cual indica que en el laboratorio es factible cultivarlo de manera favorable. Es necesario realizar investigaciones relacionadas con el crecimiento, desarrollo y establecimiento del cultivo de chiltepín para generar en la región recursos económicos que deriven de esta actividad.

Germinación in vitro de híbridos de Vanilla planifolia y V. pompona / In vitro germination of Vanilla planifolia and V. pompona hybrids

El cultivo de la vainilla se lleva a cabo ampliamente por medio de propagación clonal, de manera asexual por cortes de tallos y la producción de frutos se realiza por autopolinización. Esta práctica inhibe la variación genética y la emergencia de nuevos individuos por recombinación sexual. Por lo anterior, se considera necesario realizar cruzas por propagación sexual entre especies para obtener nuevos individuos con características deseables para el cultivo. En el presente trabajo se obtuvieron híbridos de dos especies de vainilla como parte de un programa de mejoramiento genético. En general, las semillas híbridas obtenidas que presentaron mayor porcentaje de germinación fueron las cruzas interespecíficas interespecíficos de V. planifolia y V. pompona (85%), seguido de la cruza inversa V. planifolia y V. pompona (57,9%). Las semillas producto de V. pompona autopolinizada obtuvieron valores muy bajos de germinación (10,8%), mientras que las obtenidas de V. planifolia autopolinizada no presentaron germinación. El medio de cultivo más eficiente en todos los tratamientos fue el Murashige & Skoog (MS) adicionado con 400 mg/L-1 de glutamina y 80 mg/L-1 de sulfato de adenina.

The cultivation of vanilla is extensive clonal asexual propagation by cuttings and fruit production by artificial self-pollination. This feature tends to inhibit the genetic variation and the emergence of new individuals by sexual recombination. Therefore, sexual propagation between species it is considered necessary to obtain new individuals with desirable characteristics for cultivation. In this paper we were able to obtain hybrids of two species of vanilla. In general, the hybrids seeds obtained whit the higher germination percentage were interspecific crosses of V. planifolia and V. pompona (85%), followed by reverse cross V. planifolia and V. pompona (57.9%). Seeds obtained of V. pompona self-pollination were very low germination (10.8%) while those obtained from V. planifolia self-pollination showed no germination in any media culture. The most efficient medium for all treatments was the Murashige & Skoog (MS) supplemented whit 400 mg/L-1glutamine and 80 mg/L-1 of adenine sulfate.

Obtención de suspensiones celulares y embriones somáticos de cafeto (Coffea canephora P) con el empleo de metabolitos bacterianos / Obtaining of cell suspensions and somatic embryos of coffee (Coffea canephora P) using of bacterial metabolites

La embriogénesis somática es importante como sistema modelo para estudiar el desarrollo de eventos fisiológicos, citológicos y moleculares que sustentan la embriogénesis en plantas, por ser un sistema adecuado para la propagación masiva de especies vegetales y servir de herramienta para el mejoramiento genético, la conservación de germoplasma y la validación de nuevos productos biológicos, y facilitar la producción a gran escala a través del cultivo en medio líquido y su aplicación en biorreactores, proporcionando alta frecuencia de multiplicación, rápido crecimiento del embrión, facilidad de absorción de nutrientes y reducción de la labor de subcultivo. En este trabajo se empleó la embriogénesis somática como vía de multiplicación para evaluar el efecto de metabolitos bacterianos en la inducción de suspensiones celulares y embriones somáticos en tres genotipos de cafeto pertenecientes a Coffea canephora P. variedad Robusta. Para ello se estudiaron densidades de inóculo entre 0,2, 0,5, 1,0 y 3,0 gMF/L-1, y se evaluó el efecto de diferentes medios de cultivo en el desarrollo del proceso. Los resultados mostraron un comportamiento diferenciado en el genotipo M-28, en medios de cultivo suplementados con reguladores de crecimiento convencionales y en los alternativos. Se evidenció una fuerte relación entre la viabilidad celular y el número de células, ante las diferentes condiciones de cultivo y según la densidad de inóculo, se observó un amplio rango de tamaño y forma en las poblaciones de embriones somáticos. Los porcentajes de conversión de ES con el medio MDE-2 evidenciaron mejoras de este indicador para el cultivo del cafeto.

The somatic embryogenesis is important as model system to study the development of physiologic and molecular events that sustain the embryogenesis in plants, is an appropriate system for the massive propagation of vegetable species and as tool for the genetic improvement, the germplasm conservation and the validation of new biological products and to facilitate the multiplication to great scale through the culture in liquid medium, as well as application in bioreactores, providing high multiplication frequency, quick growth of the embryo, easiness of absorption of nutritious and reduction of the subculturing. In this paper the somatic embryogenesis was used to evaluate the effect of bacterial compounds in the induction of cellular suspensions and somatic embryos in three coffee genotypes of Coffea canephora P. var. Robusta. Were studied inoculo densities among 0.2, 0.5, 1.0 and 3.0 gMF/L-1 and the effect of different culture medium in the development of the process. The results showed a behavior differed in the genotype M-28, in medium culture with conventional regulators of growth and the alternatives. Strong relationship was evidenced between the cellular viability and the number of cells, in the different cultivation conditions and according to the inoculo density, a wide range of size and forms as observed in the populations of somatic embryos. The conversion percentages with the medium MDE-2, evidenced improvements of this indicator for the coffee.

Conservación del ombusillo, planta amenazada de la provincia de Buenos Aires, Argentina / Conserving ombusillo, an endangered plant from the province of Buenos Aires, Argentina

Phytolacca tetramera Hauman "ombusillo", es una especie vegetal endémica del SE de la Provincia de Buenos Aires, Argentina, que se halla en peligro crítico de extinción. Su principal factor de amenaza es la reducción del hábitat por acción antrópica. Esta especie presenta principios activos fungicidas y, posiblemente, dada su afinidad con otras especies del mismo género, presente compuestos antivirales, antitumorales, bactericidas e insecticidas. Se realizaron ensayos de macropropagación con distintas concentraciones de reguladores de crecimiento de tipo auxínicos que muestran claramente un enraizamiento óptimo correspondiente a segmentos de ejes aéreos vegetales “estacas” sometidas a 300 ppm de ácido indol butírico y a segmentos de tallos subterráneos sin aplicación de hormonas. Así mismo, se realizaron ensayos de germinación, en condiciones de luz y de oscuridad, comprobándose que las semillas presentan fotoblastismo positivo con un porcentaje de germinación del 65%, el cual disminuye enormemente luego del año de cosecha.

Phytolacca tetramera Hauman "ombusillo" is an endemic plant species which is in critical danger of becoming extinct; it comes from the south-east of the province of Buenos Aires. The main factor threatening this species is the reduction of its natural environment by antropic action.This species has antifungal properties and, due to its relationship with other species from the same genus, it could also have antiviral, antitumour, antibacterial and insecticidal compounds. Macropropagation experiments were carried out using different concentrations of auxinic growth regulators. Segements of aerial axis “stakes” treated with 300 ppm of indol-butiric acid and segments of underground stems without hormonal treatment provided optimum rooting. Germination experiments in dark and light conditions were also carried out, finding that seeds showed positive photoblastisme with a 65% germination rate which declined considerably after the crop had been harvested.

Germination and mycelial growth of Bipolaris euphorbiae Muchovej & Carvalho as influenced by herbicides and surfactants

Bipolaris euphorbiae Muchovej & Carvalho can be combined with herbicide in order to control a large spectrum of weed species, being a strong candidate for the biocontrol of Euphorbia heterophylla L. (milk weed). The fungus release can be combined with herbicide in order to control a broader spectrum of weed species. Thus. Laboratory experiments were set up to study the feasibility of using tank mixes of B. euphorbiae spores with herbicides or surfactants recommended for soybean. Mycelial growth and conidia germination were evaluated in PDA medium enriched with the herbicides oxasulfuron (80 g/ha), glyphosate (4 L/ha), bentazon (1.5 L/ha), fomesafen (1 L/ha), chlorimuron-ethyl (80 g/ha), lactofen (1 L/ha) and imazetaphyr (1 L/ha), and the surfactants Energic (2 ml/L), Aterbane (2.5 ml/L), Silwet L-77 Ag (1 ml/L), Herbitensil (2 ml/L) and Natur LÆóleo (10 ml/L). Dilution of the herbicides at 50 percent and 25 percent were evaluated based on solution consumption of 300 L/ha. The surfactants were evaluated only in the recommended concentrations. Mycelial growth was not affected by bentazon and fomesafen and slightly by oxasulfuron. However, glyphosate and the surfactants Energic, Herbitensil and Aterbane strongly reduced its growth. The reduction observed on imazetaphyr enriched medium was intermediate and the NaturÆóleo promoted mycelial growth. All of the surfactants allowed B. euphorbiae conidia germination equivalent to that reached in the presence of water. Energic and Herbitensil caused an expressive retardation on spore germination. The germinative process only began after 120 minutes in the presence of Herbitensil. In relation to the herbicides, it was observed that only in the presence of glyphosate and imazetaphyr the conidia germination did not follow the trend of the treatment with water.

Variability of strains of Metarhizium anisopliae var. anisopliae (metsch.) sorokin in terms of protein content and spore germination

A variaçäo de proteínas totais e a germinaçäo de esporos das linhagens E9, Pegro e BSA de M. anisopliae var. anisopliae foram analisadas neste trabalho. Verificou-se que o tempo de germinaçäo mínimo (TGM, no presente estudo empregado para expressar o período no qual 85 p/cento dos esporos estäo germinados) para as três linhagens estudadas em MM foi de 12h. O conteúdo de proteína total foi analisado e mostrou que há variaçöes quantitativas mas näo qualitativas relacionadas com o tempo de germinaçäo e início da síntese destas proteínas para as três linhagens. A linhagem E9 iniciou a síntese de proteínas emtre os tempos de germinaçäo de 0 e 7h e as linhagens Pegro e BSA entre 7 e 13h

Sobre la germinacion de Stephania rotunda Lour / About germination of Stephania rotunda Lour

Se evalua la germinacion de semillas de Stephania rotunda con uno o dos meses de cosechadas en diferentes tratamientos pregerminativos. El comportamiento de la germinacion en Stephania rotunda constituye un proceso muy variable. Aplicaciones exogenas de acido giberelico entre 750 y 1 000 ppm favorecen el porcentaje final y la homogeneidad del proceso de germinacion. Estas aplicaciones se ven mas favorecidas con semillas de menor tiempo de cosechadas

La germinacion del culantro (Eryngium foetidum L.) / Germination of coriander (Eryngium foetidum L.)

Se evaluo la germinacion de semillas de Eryngium foetidum L. (Apiaceae) las cuales permanecienron almacenadas durante un periodo de 0 a 12 mese. Las evaluaciones se realizaron cada dos dias a partir de las fechas de simebra. En todos los tratamientos se calcularon el porcentaje final de germinacion (porciento F), dias para el inicio de la germinacion, dias para el final de la germinacion, duracion de la germinacion, y coeficiente de velocidad de germinacion. Los datos obtenidos fueron transformados y evaluados. Las semillas requieren un proceso de posmaduracion mayor de seis mese, antes de comenzar la germinacion, y son capaces de mantener una germinacion apreciable (mayor de 80 porciento) hasta los ocho meses de cosechadas. A partir de ese tiempo, decrece rapidamente, hasta llegar a cero. Con semillas de siete y ocho meses de cosechadas es posible obtener buena germinacion en un periodo brreve, lo que posibilitaria el establecimiento de plantaciones de culantro