Efeitos da microgravidade em plantas de cana-de-açúcar

Sugarcane (Saccharum spp.) is a plant from Poaceae family that has an impressive ability to accumulate sucrose in the stalk, making it a significant component of the economy of many countries. About 100 countries produce sugarcane in an area of 22 million hectares worldwide. For this reason, many studies have been done using sugarcane as a plant model in order to improve production. A change in gravity may be one kind of abiotic stress, since it generates rapid responses after stimulation. In this work we decided to investigate the possible morphophysiological, biochemical and molecular changes resulting from microgravity. Here, we present the contributions of an experiment where sugarcane plants were submitted to microgravity flight using a vehicle VSB-30, a sounding rocket developed by Aeronautics and Space Institute teams, in cooperation with the German Space Agency. Sugarcane plants with 10 days older were submitted to a period of six minutes of microgravity using the VSB-30 rocket. The morphophysiological analyses of roots and leaves showed that plants submitted to the flight showed changes in the conduction tissues, irregular pattern of arrangement of vascular bundles and thickening of the cell walls, among other anatomical changes that indicate that the morphology of the plants was substantially influenced by gravitational stimulation, besides the accumulation of hydrogen peroxide, an important signaling molecule in stress conditions. We carried out RNA extraction and sequencing using Illumina platform. Plants subjected to microgravity also showed changes in enzyme activity. It was observed an increased in superoxide dismutase activity in leaves and a decreased in its activity in roots as well as for ascorbate peroxidase activity. Thus, it was concluded that the changes in gravity were perceived by plants, and that microgravity environment triggered changes associated with a reactive oxygen specie signaling process. This work has helped the understanding of how the gravity affects the structural organization of the plants, by comparing the anatomy of plants subjected to microgravity and plants grown in 1g gravity

Dimensões didática, afetiva e formativa de docência que tecem as representações sociais entre licenciandos da UFPI

This study intends to analyze the social representation of teaching for students of first years of undergraduate courses in Education, Letters and Biology. The field of this research was the Federal University of Piaui - Campus of Picos in 2009. To reach the objective proposed above, was used the theory of social representations to the seizure of the elements which constitute such representations according to Moscovici and colleagues, considering the contribution of Abric with his Theory of Central Nucleus and Wagner with the Theory of Sociogenesis. Data were collected in two phases: first, through the Technique of Free Association of Words (TFAW) of which 100 subjects evoked representations of their teaching through the inductor terms 'to teach', 'student' and 'teacher'. For those data we used the EVOC software that promoted to detect the elements of the core and to conclude that the social representation of teaching is one of the work performed by a master / teacher who transmits, directed to an apprentice who learns, confined to the school involving the student with all his virtues to be smart, interested and dedicated, and teacher to be friend, wise bearer of knowledge and also intelligent. Then, using the Multiple Classification Procedure (MCP) only 10 subjects made ratings of 25 more evoked words in the first phase, for the analysis of data from the MPC with the use of the SPSS software we used Multidimensional Statistical Analysis (MSA) for the Free Classification we found three dimensions of Social Representation of Teaching: The Didactic, that focuses on teacher and student being superimposed, meaning the inseparability of these elements, the Affective, which presents the elements inherent in teachers with love as the strong point of this dimension, and the Formative, that is as ambiguous as ambivalent because it sees the teacher as a professional directed to help students get an education; for Directed Classification with Similarity Structure Analysis (SSA), we learn that teaching is a profession that materializes in the classroom, which is extremely true because the action happens in this teaching space, supposing a caring, loving, cheerful, capable, apt, patient, partner, responsible, dedicated, committed educator, who has wisdom and knows how to teach and help students through dialogue to there study and learning. All of it s necessary to occur the result of teaching, which is education in a disciplinary manner. The results point to a very traditional social representation of what is the role of teachers, the role of students and the role of the relationship itself between teaching and learning through the act of teaching. With this statement, we can confirm that the structure of Social Representation of Teaching for the investigated subjects reflects the sociogenetic conditions that engendered them, and that these conditions permeate their structural organization, in particular time-context in which social representation was captured

Efeitos da microgravidade em plantas de cana-de-açúcar

Sugarcane (Saccharum spp.) is a plant from Poaceae family that has an impressive ability to accumulate sucrose in the stalk, making it a significant component of the economy of many countries. About 100 countries produce sugarcane in an area of 22 million hectares worldwide. For this reason, many studies have been done using sugarcane as a plant model in order to improve production. A change in gravity may be one kind of abiotic stress, since it generates rapid responses after stimulation. In this work we decided to investigate the possible morphophysiological, biochemical and molecular changes resulting from microgravity. Here, we present the contributions of an experiment where sugarcane plants were submitted to microgravity flight using a vehicle VSB-30, a sounding rocket developed by Aeronautics and Space Institute teams, in cooperation with the German Space Agency. Sugarcane plants with 10 days older were submitted to a period of six minutes of microgravity using the VSB-30 rocket. The morphophysiological analyses of roots and leaves showed that plants submitted to the flight showed changes in the conduction tissues, irregular pattern of arrangement of vascular bundles and thickening of the cell walls, among other anatomical changes that indicate that the morphology of the plants was substantially influenced by gravitational stimulation, besides the accumulation of hydrogen peroxide, an important signaling molecule in stress conditions. We carried out RNA extraction and sequencing using Illumina platform. Plants subjected to microgravity also showed changes in enzyme activity. It was observed an increased in superoxide dismutase activity in leaves and a decreased in its activity in roots as well as for ascorbate peroxidase activity. Thus, it was concluded that the changes in gravity were perceived by plants, and that microgravity environment triggered changes associated with a reactive oxygen specie signaling process. This work has helped the understanding of how the gravity affects the structural organization of the plants, by comparing the anatomy of plants subjected to microgravity and plants grown in 1g gravity