Growth and phenotype of potato plants expressing an antisense gene of P-protein of glycine decarboxylase under control of a promoter with preference for the mesophyll

A cDNA encoding P-protein of glycine decarboxylase was expressed in antisense orientation in leaves of potato (Solanum tuberosum cv. Solara) under control of the promoter of a P-protein gene of glycine decarboxylase from Flaveria pringlei. This promoter targets gene expression preferentially to the leaf mesophyll cells. In two of the transgenic lines, mitochondria oxidise glycine only with extremely low rates. Phenotypically, these transgenic lines were only marginally different from wild type plants under ambient carbon dioxide concentrations and indistinguishable from wild type plants when grown under 800 ppm carbon dioxide. When grown in ambient carbon dioxide, transgenic plants accumulated high amounts of glycine during the light period followed by nearly complete degradation in the following night.