Metabolismo e express?o g?nica em Crambe abyssinica Hochst. ex. R.E. Fries sob diferentes condi??es de cultivo visando aplica??o industrial

• Autor(a) principal: Brito, Diego de Mello Conde de
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/3521
• topic: Biocombust?veis; Metabolismo do nitrog?nio; Produ??o de ?leo; Biofuels; Nitrogen metabolism; Oil yield; Bioqu?mica

Crambe (Crambe abyssinica Hochst. ex. R.E. Fries) is an oleaginous culture that belongs to the cruciferae family, and is toxic for human feed, which presents a great potential for use in biofuel industry as well as a source of erucic acid. Nowadays, there is only one variety of crambe developed in Brazil and adapted to its conditions, designated FMS Brilhante. The main characteristics that highlight this variety as a promising option of market are precocity, high grain yield, low production cost and high oil percentage in seeds. However, few information about the metabolic aspects of this culture are available. In the context of vegetal nutrition, nitrogen must be mentioned because is generally the element required in major concentrations and is strongly related to the production costs and can cause serious environmental problems. Thus, the major objective of this work was evaluate the influence of variation in N levels, in nitrate form, under different aspects of crambe metabolism (FMS Brilhante variety), including gene expression, aiming primarily its relation with yield parameters. Also was evaluated the pH influence of cultivation medium under some metabolic aspects of this culture. Three experiments were done, with three replicates arranged in a completely randomized experimental design. In the experiments I and II plants were submitted in hydroponic system to different nitrate-N doses (0,2; 2 and 4 mM) and pH variation (5,0; 5,5; 6,0 and 6,5), respectively, and harvested at the end of vegetative period. In the experiment III plants were cultivated in a argisol soil under crescent nitrate-N supply (0,8; 1,6; 2,4 and 3,2 mM) and three harvests were done: One at initiation and the other one at end of flowering and the last at final of seed maturation. The results obtained with experiment I highlight the role of stem in nitrate storage in this specie. On the other hand, in experiment II was observed that variation in pH of nutrient solution do not influence significantly the mass production and that plants cultivated under pH 6,0 showed an increase in the processes related to nitrogen reduction and assimilation. Among the main results obtained with the experiment III is possible to highlight that with 1,6 mM of nitrate-N was obtained a high seed and oil yield and also a satisfactory fatty acid composition of oil, aiming the use of crambe in biodiesel industry. Furthermore, was observed an increase in erucic acid concentration of crambe oil with the reduction of nitrate-N supply. Important information is that the 3-cetoacil-CoA sintase (KCS) gene cannot be one of the main factors involved in erucic acid synthesis. However, the expression of lysophosphatidyl aciltransferase (LPAT) gene seems to be strongly related with the synthesis of erucic acid in this specie. Thereby, crambe cultivation is possible with low nitrate-N supply, for use of culture in biodiesel industry or for erucic acid extraction (Used in plastic, lubricants and other industries), and that contribute for a reduction in production costs and environmental impacts and for an increase in yield parameters.