Increased capacity for sucrose uptake leads to earlier onset of protein accumulation in developing pea seeds.

Pea (Pisum sativum L.) cotyledons, overexpressing a potato sucrose transporter (StSUT1), were used to explore the hypothesis that sucrose stimulates the onset of storage protein biosynthesis. The study focused on the transition between pre-storage and storage phases of seed development.

Temporal and spatial expression of hexose transporters in developing tomato (Lycopersicon esculentum) fruit.

Correlative physiological evidence suggests that membrane transport into storage parenchyma cells is a key step in determining hexose levels accumulated in tomato (Lycopersicon esculentum Mill.) fruit (Ruan et al. 1997).

Seed-specific overexpression of a potato sucrose transporter increases sucrose uptake and growth rates of developing pea cotyledons.

During the storage phase, cotyledons of developing pea seeds are nourished by nutrients released to the seed apoplasm by their maternal seed coats. Sucrose is transported into pea cotyledons by sucrose/H+ symport mediated by PsSUT1 and possibly other sucrose symporters. PsSUT1 is principally localised to plasma membranes of cotyledon epidermal and subepidermal transfer cells abutting the seed coat.

Analysis of promoter activity for the gene encoding pyruvate orthophosphate dikinase in stably transformed C4 flaveria species.

The C4 enzyme pyruvate orthophosphate dikinase is encoded by a single gene, Pdk, in the C4 plant Flaveria trinervia. This gene also encodes enzyme isoforms located in the chloroplast and in the cytosol that do not have a function in C4 photosynthesis. Our goal is to identify cis-acting DNA sequences that regulate the expression of the gene that is active in the C4 cycle.

Genomic structure and expression of the pyruvate, orthophosphate dikinase gene of the dicotyledonous C4 plant Flaveria trinervia (Asteraceae).

Pyruvate orthophosphate dikinase (PPDK) is a key enzyme of C4 photosynthesis providing the acceptor molecule for the primary CO2 fixation in the mesophyll cells. Here we present the isolation and characterisation of the corresponding gene (termed pdk) from the C4 plant Flaveria trinervia (Asteraceae). Southern analysis indicates that in contrast to maize pdk sequences in F.