Alteration of the embryo transcriptome of hexaploid winter wheat (Triticum aestivum cv. Mercia) during maturation and germination

Grain dormancy and germination are areas of biology that are of considerable interest to the cereal community. We have used a 9,155-feature wheat unigene cDNA microarray resource to investigate changes in the wheat embryo transcriptome during late grain development and maturation and during the first 48 h of postimbibition germination. In the embryo 392 mRNAs accumulated by twofold or greater over the time course from 21 days postanthesis (dpa) to 40 dpa and on through 1 and 2 days postgermination. These included mRNAs encoding proteins involved in amino acid biosynthesis and metabolism, cell division and subsequent cell development, signal transduction, lipid metabolism, energy production, protein turnover, respiration, initiation of transcription, initiation of translation and ribosomal composition. A number of mRNAs encoding proteins of unknown function also accumulated over the time course. Conversely 163 sequences showed decreases of twofold or greater over the time course. A small number of mRNAs also showed rapid accumulation specifically during the first 48 h of germination. We also examined alterations in the accumulation of transcripts encoding proteins involved in abscisic acid signalling. Thus, we describe changes in the level of transcripts encoding wheat Viviparous 1 (Vp1) and other interacting proteins. Interestingly, the transcript encoding wheat Viviparous-interacting protein 1 showed a pattern of accumulation that correlates inversely with germination. Our data suggests that the majority of the transcripts required for germination accumulate in the embryo prior to germination and we discuss the implications of these findings with regard to manipulation of germination in wheat

Corporate social responsibility and corporate performance: evidence from a panel of US listed companies

We investigate whether inclusion and permanence in the domini social index (DSI) affects corporate performance on a sample of around 1000 firms in a 13-year interval by controlling for size, industry, business cycle and time invariant firm idiosyncratic characteristics. Our results find partial support to the hypothesis that corporate social responsibility is a move from the shareholders wealth to a multi-stakeholders welfare target. On the one side, permanence into the domini index (DI) is shown to increase (reduce) significantly total sales per employee (returns on equity but not when large and R&D investing firms are excluded from the sample). On the other side, lower returns on equity for Domini firms seem nonetheless to be accompanied by relatively lower conditional volatility and lower reaction to extreme shocks with respect to the control sample. An explanation for these findings, suggested by the inspection of Domini criteria, is that social responsibility implies, on the one side, decisions leading to higher cost of labour and of intermediate output, but may, on the other side, enhance involvement, motivation and identification of the workforce with company goals with positive effects on productivity.

DNA synthesis and mRNA accumulation during germination of embryos of the orchid Spathoglottis plicata

10.1007/BF01276822Protoplasma1831-4137-147PROT

Metodologia para o teste de envelhecimento acelerado em sementes de ervilha Accelerated aging test on pea seeds

A produção de ervilha no Brasil vem utilizando sementes produzidas no próprio país. O presente trabalho teve como objetivo verificar a eficiência do teste de envelhecimento acelerado para avaliar o vigor de sementes de ervilha. Foram utilizados dez lotes de sementes de ervilha, sendo cinco da cultivar Axé (sementes rugosas, indicada para produção de grãos verdes) e cinco da cultivar Mikado (sementes lisas, indicada para produção de grãos secos). Para avaliar a qualidade fisiológica inicial dos lotes foram utilizados os testes de germinação, primeira contagem e emergência de plântulas em campo. Determinou-se também o teor de água das sementes. O envelhecimento acelerado foi conduzido a 41&deg;C por períodos de 24; 48 e 72 horas, com e sem uso de solução saturada de NaCl. O experimento foi conduzido no delineamento inteiramente casualizado. O teste de envelhecimento acelerado mostrou-se eficiente para avaliar o vigor de sementes de ervilha. Quando conduzido sem o uso de solução saturada com NaCl, verificou-se que o período de envelhecimento que permitiu melhor estratificação dos lotes de sementes foi 72 horas. Porém, a porcentagem de germinação após esse período mesmo nos lotes de maior vigor (35% para a cultivar Axé e 38% para a cultivar Mikado) foi muito baixa em relação às observadas após apenas 24 horas, superior a 80% para ambas as cultivares. Quando conduzido com o uso de solução saturada de NaCl, o período de 48 horas, a 41&deg;C, foi o mais adequado para a classificação dos lotes em diferentes níveis de vigor. Nessas condições, os lotes de maior vigor das cultivares Axé e Mikado apresentaram germinação superior a 68 e 79%, respectivamente. Os testes de germinação, primeira contagem e emergência de plântulas em campo não apresentaram isoladamente bom poder discriminatório da qualidade fisiológica inicial dos lotes de sementes. Quando seus resultados foram tomados em conjunto, porém, foi possível identificar os lotes de melhor qualidade.<br>Pea production in Brazil uses seeds produced in the country. The objective of this study was to examine the efficiency of the accelerated aging test for vigor evaluation of pea seeds. Five seed lots of cultivar Axé (wrinkled seeds) and five seed lots of cultivar Mikado (smooth seeds) were used. The initial quality of each seed lot was evaluated by germination test, first counting, and seedling emergence in the field. Seed moisture content was also assessed. The accelerated aging test was set at 41ºC for periods of 24; 48; and 72 hours, with and without saturated NaCl solution. The experiment was carried out in a completely randomized design. The accelerated aging test was efficient for vigor evaluation of pea seeds, and the period of 48 hours at 41ºC, using saturated NaCl solution was the most adequate procedure to indicate vigor levels of pea seeds. However, the seed germination after this period was very low when compared to 24 hour-period (80%) for both cultivars, even in higher vigor seed lots (35% for Axé and 38% for Mikado). In the saturated NaCl solution, the period of 48 hours at 41ºC was the most adequate for separate seeds through vigor levels. In these conditions, seed lots of highest vigor showed germination of 68% and 79% for Axé and Mikado, respectively. Results of the germination test, first counting, and seedling emergence were not effective in discriminating physiological seed quality when used individually. Nevertheless, when results from these tests were used all together, it was possible to identify the best seed lots