Nitrate Reductase and Glutamine Synthetase Activity In Young Plants Of Jatropha Curcas L. Under Levels Of Shade and Nitrate Concentrations.

Jatropha curcas L. is considered an excellent option for many agricultural regions of Brazil, mainly because it is a demanding species with strong sunlight and drought resistance. Currently, this species is being studied more diligently to their commercial use in Brazil, because it is an oleaginous plant viable for obtaining biodiesel. The objective of this study was to assess the influence of different nitrate concentrations and levels of shading on the activities of the enzymes nitrate reductase and glutamine synthetase in young plants of J. curcas. The treatments consisted of four concentrations of nitrate, applied via the nutrient solution Hoagland and Arnon (1938), and four levels of shading (0, 30, 50 and 70% shading). The results showed that the activities of the enzymes nitrate reductase and glutamine synthetase, and the total soluble protein content decreased linearly with increased shading. Nitrogen is a nutrient essential for the metabolism of the species and the initial nitrate concentrations exceeding 30mm are detrimental to the activity of two enzymes analyzed, in the leaves and roots tissues. The leaves are the main sites of nitrate reduction and production of glutamine in J. curcas.