Over-expression of sucrose phosphate synthase in Ababidopsis thaliana results in increased foliar sucrose/starch ratios and favours decreased foliar carbohydrate accumulation in plants after prolonged growth with CO2 enrichment |
| |
Authors: | Signora L; Galtier N; Skot L; Lucas H; Foyer C |
| |
Institution: | Department of Environmental Biology, Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB, UK; Laboratoire du Metabolisme, INRA, Route de Saint-Cyr, F-78026 Versailles Cedex, France; Laboratoire de Biologie Cellulaire, INRA, Route de Saint-Cyr, F-78026 Versailles Cedex, France; Corresponding author; e-mail: christine.foyer@bbsrc.ac.uk |
| |
Abstract: | Arabidopsis thaliana ecotype Columbia was transformed
with a maize sucrose phosphate synthase (SPS) cDNA under the control of the
promoter for the small subunit of ribulose-1,5-bisphosphate carboxylase
from tobacco (rbcS). The effects of SPS over-expression were compared in
plants of the T2 and T3 generations grown either in air or with CO2
enrichment (700 l 1-1)
for either 4 or 10 weeks. Maximal extractable foliar SPS activities were
three times those of the untransformed controls in the highest rbcS-SPS
expressing line. In untransformed Arabidopsis leaves
SPS activity was not subject to light/dark regulation, but was modified by
incubation with either the inhibitor, orthophosphate, or the activator,
mannose. Photosynthesis (Amax) values were similar in
all lines grown in air. After 10 weeks of CO2 enrichment a decrease in
Amax in the untransformed controls, but not in the
high SPS expressors, was observed. There was a strong correlation between
the sucrose-to-starch ratio of the leaves and their SPS activity in both
growth conditions. The total foliar carbohydrate contents of 4-week-old
plants was similar in all lines whether plants were grown in air or with
CO2 enrichment. After 10 weeks growth the leaves of the high rbcS-SPS
expressors accumulated much less total carbohydrate than untransformed
control leaves in both growth conditions. It was concluded that SPS
over-expression causes increased foliar sucrose/starch ratios in
Arabidopsis leaves and favours decreased foliar
carbohydrate contents when plants are grown for long periods with CO2
enrichment. |
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|