Comparative genomic analysis of light-regulated transcripts in the Solanaceae

<p>Abstract</p> <p>Background</p> <p>Plants use different light signals to adjust their growth and development to the prevailing environmental conditions. Studies in the model species <it>Arabidopsis thaliana </it>and rice indicate that these adjustments are mediated by large changes in the transcriptome. Here we compared transcriptional responses to light in different species of the Solanaceae to investigate common as well as species-specific changes in gene expression.</p> <p>Results</p> <p>cDNA microarrays were used to identify genes regulated by a transition from long days (LD) to short days (SD) in the leaves of potato and tobacco plants, and by phytochrome B (phyB), the photoreceptor that represses tuberization under LD in potato. We also compared transcriptional responses to photoperiod in <it>Nicotiana tabacum </it>Maryland Mammoth (MM), which flowers only under SD, with those of <it>Nicotiana sylvestris</it>, which flowers only under LD conditions. Finally, we identified genes regulated by red compared to far-red light treatments that promote germination in tomato.</p> <p>Conclusion</p> <p>Most of the genes up-regulated in LD were associated with photosynthesis, the synthesis of protective pigments and the maintenance of redox homeostasis, probably contributing to the acclimatization to seasonal changes in irradiance. Some of the photoperiodically regulated genes were the same in potato and tobacco. Others were different but belonged to similar functional categories, suggesting that conserved as well as convergent evolutionary processes are responsible for physiological adjustments to seasonal changes in the Solanaceae. A β-ZIP transcription factor whose expression correlated with the floral transition in <it>Nicotiana </it>species with contrasting photoperiodic responses was also regulated by photoperiod and phyB in potato, and is a candidate gene to act as a general regulator of photoperiodic responses. Finally, <it>GIGANTEA</it>, a gene that controls flowering time in <it>Arabidopsis thaliana </it>and rice, was regulated by photoperiod in the leaves of potato and tobacco and by red compared to far-light treatments that promote germination in tomato seeds, suggesting that a conserved light signaling cascade acts across developmental contexts and species.</p

Inoculation with Azospirillum sp. and Herbaspirillum sp. Bacteria Increases the Tolerance of Maize to Drought Stress

Stress drought is an important abiotic factor that leads to immense losses in crop yields around the world. Strategies are urgently needed to help plants adapt to drought in order to mitigate crop losses. Here we investigated the bioprotective effects of inoculating corn grown under drought conditions with two types of plant growth-promoting rhizobacteria (PGPR), A. brasilense, strain SP-7, and H. seropedicae, strain Z-152. Plants inoculated with the bacteria were grown in a greenhouse with perlite as a substrate. Two hydric conditions were tested: normal well-watered conditions and drought conditions. Compared to control non-inoculated plants, those that were inoculated with PGPR bacteria showed a higher tolerance to the negative effects of water stress in drought conditions, with higher biomass production; higher carbon, nitrogen, and chlorophyll levels; and lower levels of abscisic acid and ethylene, which are plant hormones that affect the stress response. The oxidative stress levels of these plants were similar to those of non-inoculated plants grown in well-watered conditions, showing fewer injuries to the cell membrane. We also noted higher relative water content in the vegetal tissue and better osmoregulation in drought conditions in inoculated plants, as reflected by significantly lower proline content. Finally, we observed lower gene expression of ZmVP14 in the inoculated plants; notably, ZmVP14 is involved in the biosynthesis of abscisic acid. Taken together, these results demonstrate that these bacteria could be used to help plants cope with the negative effects of drought stress conditions

La enseñanza del Derecho Asociativo en las escuelas de derecho y ciencias económicas

A university that to deliver the diploma degree enables the graduate to the exercise of the profession, recognizes not only have formed in the subjects own of the curriculum but also trained for their performance in the field of their chosen discipline. Such is the case of graduates of law schools and economics sciences. Compared to the discipline in particular here occupies, it is inevitable considering the level of success that today contain the teaching programs of Corporate Law to conclude up to where the graduate is trained to use and application of knowledge in the hange of action which constitutes the company. These thoughts are an invitation to rethink the teaching methods, merely repeating of a legal text, to configure from the university classroom a scope of thought where are constructed, from the right, the content that is applied to that center producer of goods and services are used for their development and growth.Fil: Curá, José María. Universidad de Buenos Aires. Facultad de Ciencias Económicas. Buenos Aires, ArgentinaUna Universidad que al entregar el diploma de grado habilita al egresado para el ejercicio de la profesión, reconoce no solo haberlo formado en las materias propias del plan de estudios sino que, además, lo capacitó para su desempeño en el ámbito propio de la disciplina elegida. Tal el caso de los egresados de las escuelas de Derecho y de Ciencias Económicas. Frente a la disciplina que en particular aquí ocupa, resulta inevitable examinar el nivel de acierto que hoy contienen los programas de enseñanza de Derecho Societario para concluir hasta dónde el graduado se encuentra capacitado para hacer uso y aplicación del conocimiento en el ámbito propio de actuación que constituye la empresa. Son estos pensamientos una invitación para repensar los métodos de enseñanza, meramente repetitivos de un texto legal, para configurar desde el aula universitaria un ámbito de pensamiento donde se construyan, a partir del Derecho, los contenidos que, aplicados a ese centro productor de bienes y servicios, sirvan para su desarrollo y crecimiento

Role of Beneficial Microorganisms and Salicylic Acid in Improving Rainfed Agriculture and Future Food Safety

Moisture stress in rainfed areas has significant adverse impacts on plant growth and yield. Plant growth promoting rhizobacteria (PGPR) plays an important role in the revegetation and rehabilitation of rainfed areas by modulating plant growth and metabolism and improving the fertility status of the rhizosphere soils. The current study explored the positive role of PGPR and salicylic acid (SA) on the health of the rhizosphere soil and plants grown under rainfed conditions. Maize seeds of two different varieties, i.e., SWL-2002 (drought tolerant) and CZP-2001 (drought sensitive), were soaked for 4 h prior to sowing in 24-h old culture of Planomicrobium chinense strain P1 (accession no. MF616408) and Bacillus cereus strain P2 (accession no. MF616406). The foliar spray of SA (150 mg/L) was applied on 28-days old seedlings. The combined treatment of the consortium of PGPR and SA not only alleviated the adverse effects of low moisture stress of soil in rainfed area but also resulted in significant accumulation of leaf chlorophyll content (40% and 24%), chlorophyll fluorescence (52% and 34%) and carotenoids (57% and 36%) in the shoot of both the varieties. The PGPR inoculation significantly reduced lipid peroxidation (33% and 23%) and decreased the proline content and antioxidant enzymes activities (32% and 38%) as compared to plants grown in rainfed soil. Significant increases (&gt;52%) were noted in the contents of Ca, Mg, K Cu, Co, Fe and Zn in the shoots of plants and rhizosphere of maize inoculated with the PGPR consortium. The soil organic matter, total nitrogen and C/N ratio were increased (42%), concomitant with the decrease in the bulk density of the rhizosphere. The PGPR consortium, SA and their combined treatment significantly enhanced the IAA (73%) and GA (70%) contents but decreased (55%) the ABA content of shoot. The rhizosphere of plants treated with PGPR, SA and consortium showed a maximum accumulation (&gt;50%) of IAA, GA and ABA contents, the sensitive variety had much higher ABA content than the tolerant variety. It is inferred from the results that rhizosphere soil of treated plants enriched with nutrients content, organic matter and greater concentration of growth promoting phytohormones, as well as stress hormone ABA, which has better potential for seed germination and establishment of seedlings for succeeding crops

Principal Component Analysis for Characterization of Fretting wear Experiments on Spline Couplings

Spline couplings are often used in aerospace industry for the purpose of power and torque transfer. A spline coupling typically consists of a hub and shaft with internal and external teeth respectively. As the teeth are engaged and the spline coupling is put into operation, repeated relative surface movement of teeth begins and results in fretting wear. Principal component analysis (PCA) is a statistical technique to identify the important parameters and their relationships with each other. This work deals with the characterization of fretting wear by the help of principal component analysis. PCA has been applied to the experimental data obtained from fretting wear tests in the lab and important variables with respect to fretting wear identified. This serves as a new tool to interpret the experimental results and hypothesis generation in the field of fretting wea

Derecho privado: sociedades y otras formas de organización jurídica de la empresa

- Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 347(82) D431

Derecho privado: sociedades y otras formas de organización jurídica de la empresa

- Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 347(82) D431