Pesquisa Agropecuária Brasileira
On-line version ISSN 1678-3921
DONATO, Virgínia Maria Tenório Sabino et al. Enzymatic activity in sugar cane varieties cultivated in vitro under nitrogen levels. Pesq. agropec. bras. [online]. 2004, vol.39, n.11, pp. 1087-1093. ISSN 1678-3921. http://dx.doi.org/10.1590/S0100-204X2004001100006.
Nitrogen is considered the most abundant mineral element in the plants and an essential component to biomolecules and several enzymes. The objective of this work was to estimate nitrogen assimilation efficiency process and to identify biological fixation potential parameters on sugar cane varieties cultivated in vitro. The sugar cane varieties used were RB 842021, RB 83102, RB 75126, RB 882980, CO 997, besides Brachiaria arrecta (witness), cultivated in vitro in different nitrogen levels [M1 (9.83 mM), M2 (2.46 mM), M3 (0.49 mM), M4 (0.0 mM)]. All the varieties and plant witness (Brachiaria arrecta) exhibited redutase nitrate activity and glutamina sintetase, even in the ammonium and nitrate absence culture media. The RB 842021 variety showed the highest activity of nitrate reductase and the higher chlorophyll a and b contents, whereas RB 882980 variety showed the highest glutamine sintetase activity when cultivated without nitrogen, representing a higher potential assimilation of nitrogen.
Keywords : Saccharum; glutamina sintetase; nitrate reductase; chlorophyll.