Abstract
In the present study we have observed a higher state of coupling in respiring mitochondria isolated from green as compared to red tomatoes (Lycopersicon esculentum, Mill.). Green tomato mitochondria produced a membrane potential (deltapsi) high enough to phosphorylate ADP, whereas in red tomato mitochondria, BSA and ATP were required to restore deltapsi to the level of that obtained with green tomato mitochondria. This supports the notion that such uncoupling in red tomato mitochondria is mediated by a plant uncoupling mitochondrial protein (PUMP; cf. Vercesi et al., 1995). Nevertheless, mitochondria from both green and red tomatoes exhibited an ATP-sensitive linoleic acid (LA)-induced deltapsi decrease providing evidence that PUMP is also present in green tomatoes. Indeed, proteoliposomes containing reconstituted green or red tomato PUMP showed LA uniport and LA-induced H+ transport. It is suggested that the higher concentration of free fatty acids (PUMP substrates) in red tomatoes could explain the lower coupling state in mitochondria isolated from these fruits.
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.
