Evaluation of the primary metabolism of Eucalyptus grandis cambial region and bark

Eucalyptus genus is the most widely planted hardwood crop in the world because of its superior growth, broad adaptability and multipurpose wood properties. In today\'s \"new carbon economy\", eucalypts are receiving attention as fast-growing, short-rotation, renewable biomass crop for energy production. In spite of its economical importance, little information is available about the molecular changes that occur in primary metabolism in the wood and bark forming tissues. Furthermore, there is less information about molecular changes that occur during wood and bark formation in response to seasonal variation. It\'s known that Eucalyptus cambial region presents higher metabolic activity in summer than in winter. Thus, in order to observe the dynamic changes in transcript, protein and metabolite levels, mainly related to primary metabolism, we compared cambial tissue and bark collected in two different seasons (summer high temp + high rainfall) and winter (lower temp and little rainfall). Transcript expression patterns were analyzed by Real-Time PCR, normalization chosen by NormFinder and statistical analysis carried out using REST. The protein profile was obtained by bidimensional electrophoresis (2D-PAGE) followed by liquid chromatography associated with mass spectrometry (LC-MS/MS) and analyzed by Mascot Daemon. Metabolite profile was obtained by GC-TOF/MS, peaks were analyzed in MatLab and statistical analyses were done using SIMCA and \"R\". The results obtained with transcripts indicate differential gene expression in the cambial region and bark during summer and winter. A total of 77 and 75 proteins in cambium and bark, respectively, presented statistically significant alterations and were identified and classified into functional categories. We identified many proteins from primary metabolism. Metabolites from carbohydrate metabolism were also identified. (AU)