Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

In vivo 31 P-nuclear magnetic resonance (NMR) spectroscopy was used to monitor the metabolism of d-galactose in excised root tissues from maize (Zea mays) seedlings. The accumulation of galactose 1-phosphate and uridinediphosphogalactose (UDP-gal) in the tissue was correlated with changes in the glucose 6-phosphate, cytoplasmic P i , vacuolar P i and NTP levels. NMR revealed a complicated time dependence for these metabolites with the galactose 1-phosphate signal going through a maximum after the NTP level had gone through a minimum. Many of the spectroscopic changes could be understood by viewing galactose as a sink for P i and by supplying external P i it was possible to modify the tissue response to galactose. Increasing the external galactose concentration increased the ratio of galactose 1-phosphate to UDP-gal in the loaded tissue whereas the protein synthesis inhibitor cycloheximide, which caused a marked increase in the NTP signals, reduced the ratio. The results suggest that the assimilation of galactose is limited by the slow metabolism of UDP-gal. © 1989.

Original publication

DOI

10.1016/0168-9452(89)90003-4

Type

Journal article

Journal

Plant Science

Publication Date

01/01/1989

Volume

59

Pages

11 - 23