Incorporation of D-[U-14C]glucose and 14CO2 into the Cell-Wall Polymers of Flax Hypocotyl, in the Course of the Fibre Differentiation

Cellulose deposits in the fibres of flax hypocotyl were observedon transverse sections of the distal part, after several daysof plant growth under continuous light. The secondary celluloseof the fibres was not labelled preferentially when a pulse of¹⁴CO₂ was given. Conversely, the D-[U-¹⁴C]glucose was well incorporatedinto the fibre secondary cellulose, whatever the day of thepulse. The glucose was, first incorporated into storage polysaccharides(probably starch) and used when needed, for secondary cellulosedeposits. (Received September 16, 1992; Accepted June 2, 1993)