Compositional Analysis by Infrared Spectroscopy of the Lignin of Eucalyptus urophylla S. T. Blake Treated with Growth Regula

Abstract

This work comes to contribute with relevant aspect of the lignification, the possibility of change compositional of the lignin for the several uses of the wood in the forest section.The synthesis of the lignin can be affected by several factors abiotic and biotic, being one of those factors the growth regulators, that act as indicator molecules in the plant. Being the growth regulators an interference factor in the lignification, give relevance, in that work, to two important classes of plant hormones: auxins and jasmonates. To verify the performance of those in the relationship compositional of the units of ligninin Eucalyptus urophylla , the jasmonic acid (AJ) and the 2, 4-dichlorophenoxyaceticacid (2,4-D) were used, both with role in the physiology, growth and development of the plant. The applications of those isolated and combined regulators were initiate 90 days after sowing, being nine treatments with five repetitions each one. The obtained results were analyzed by infrared spectroscopy. The spectra showed that there were not changes relevant compositional. However, there was a small alteration, in all of the treatments (J2, A1, A2, J1A1, J1A2, J2A1 and J2A2) where it was shown that the relationship guaiacyl/siringyl (G/S) it was lightly above the control (H2O), except for J1 that showed inferior relationship to the control. This takes us inside to propose that any one of these treatments didn’t affect the phase of the first stage of formation of the lignin of the citoplasmatic compartment. The jasmonic acid and the 2, 4-dichlorophenoxyaceticacid can activate or to inhibit the phase of polymerization of the lignin depending on the used concentration.