Abstract
Summary Protoplasts were isolated from tomato ( Lycopersicon esculentum L. cv. Dombito ) source leaves. Sucrose uptake into these protoplasts displays both a saturable and a linear component in response to increasing substrate concentrations. Sucrose uptake is inhibited by (1) the nonpermeant sulfhydryl group modifier, p-chloromercuribenzene sulfonic acid (PCMBS) and (2) an uncoupler, (p-trifluoromethoxy) carbonyl cyanide phenylhydrazone (FCCP). It is stimulated by fusicoccin (FC). The uptake of fructose, which proceeded at about half the rate of sucrose, displays kinetics similar to sucrose. However, glucose uptake shows only a linear nonsaturable response to sugar concentration between 1 and 50 mM and is also insensitive to FCCP and PCMBS. The kinetics of sucrose uptake in the presence of fructose indicates that fructose may be a non-competitive inhibitor for the sucrose specific membrane carrier, and that sucrose and fructose may be taken up by different carriers.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.