Abstract
Summary Extracellular polysaccharides (ECPs) were produced in liquid cultures of tuberose (Poliantbes tuberosa L.) callus regardless of the cell growth cycle. The major component of the ECPs was called tuberose polysaccharide (TPS), which has a molecular weight (mol.wt.) of ≧ 106. Using protoplasts labelled with 14C-glucose, no 14C-TPS was found, but two 14C-labelled low molecular weight polysaccharides (L-1: 1 × 105 mol.wt., L-2: 2–3 × 104 mol.wt.) were secreted into the medium. Both L-1 and L-2 polysaccharides were also detected in the intracellular polysaccharide (ICP) fractions extracted from calluses, single cells and protoplasts. Based on the neutral sugar compositions of 14C-labelled L-1, L-2 and TPS, the L-1 polysaccharide was identified as a putative TPS precursor. The addition of brefeldin-A blocked TPS production, whereas the intracellular synthesis of its precursor was not markedly inhibited. Histochemical and electron microscopic observations showed that TPS is deposited in the intercellular spaces among the surface cells of the callus mass.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
