BioProject

Several reports have investigated the effects of future climate conditions on photosynthesis and biomass production in woody plants but none combining temperature and atmospheric CO2 concentration. More...

Several reports have investigated the effects of future climate conditions on photosynthesis and biomass production in woody plants but none combining temperature and atmospheric CO2 concentration. We used grow chambers to expose Eucalyptus grandis and E. globulus seedlings to three temperature regimes (10-12°C - low temperature, 20-22°C - control temperature and 33-35°C - high temperature) combined with two CO2 concentration (390 ppm – normal and 700 ppm - high). After 35 days the stems were used for transcriptome (RNAseq) analysis aiming to understand  changes in the expression of genes related with biosynthesis and remodeling of the cell wall, as well as genes related with carbon partitioning and hormonal regulation. E. globulus, a species adapted to low temperature, was more responsive to the treatments compared to E. grandis. The most relevant biological processes affected by the treatments were related to stress, secondary metabolism, hormonal response, and signaling. We also analyzed in depth all cell wall biopolymer synthetic genes and their regulation by innumerous transcriptional factors. There was an upregulation of ethylene and auxin biosynthetic genes in both species, but it was stronger under high and low temperature in E.globulus. Temperature was more effective to change cell wall biosynthetic genes than CO2 and CO2 stimulated lignin biosynthetic pathway. We also analyzed lignin composition and structure. There was an increase in F5H and COMT expression and the S/G ratio also increased under high CO2 in E.globulus. Thus, the species responded differently to treatments and stem composition and development was highly affected by temperature and CO2 concentration. Overall design: Total stem mRNA of 35-day-old eucalyptus plants exposed to three temperatures (10°C - low, 20°C - controle and 30°C - high) and two concentrations of carbon dioxide (400 ppm - low and 700 ppm - high) Less...