The positive response observed in growth for oil palm
in elevated CO2 could also be attributed to an increase
cell production or cell elongation (Pritchard et al. 1999).
This hypothesis was supported by the findings of
Amanda et al. (2008) that cell wall-related genes, viz.,
alpha-L-arabinofuranosidase (EC 3.2.1.55), xyloglucan
endotransglycosylase/hydoxase (EC 2.4.1.207), caffeoyl-
CoA-3-O-methyltransferase (EC 2.1.1.68) and cell wall
invertase (EC 3.2.1.26) were induced under elevated
CO2. Higher sucrose content of seedlings under elevated
CO2 has also been suggested by Ranasinghe and Taylor
(1996) to contribute in the increased growth due to
improved activities of growth enzyme known as cyclindependent
protein kinases (EC 2.7.11.22) that enhances
cell division.