Journal Article

Antisense repression of both ADP-glucose pyrophosphorylase and triose phosphate translocator modifies carbohydrate partitioning in potato leaves

Hattenbach, A, Muller-Rober, B, Nast, G, Heineke, D

1997

Overview

Previous experiments have shown that carbohydrate partitioning in leaves of potato (Solanum tuberosum L.) plants can be modified by antisense repression of the triose phosphate translocator (TPT), favoring starch accumulation during the light period, or by leaf-specific antisense repression of ADP-glucose pyrophosphorylase (AGPase), reducing leaf starch content. These experiments showed that starch and sucrose synthesis can partially replace each other. To determine how leaf metabolism acclimates to an inhibition of both pathways, transgenic potato (S. tuberosum L. cv Desiree) plants, with a 30% reduction of the TPT achieved by antisense repression, were transformed with an antisense cDNA of the small subunit of AGPase, driven by the leaf-specific ST-LS1 promoter. These double-transformed plants were analyzed with respect to their carbohydrate metabolism, and starch accumulation was reduced in all lines of these plants. In one line with a 50% reduction of AGPase activity, the rate of CO2 assimilation was unaltered. In these plants the stromal level of triose phosphate was increased, enabling a high rate of triose phosphate export in spite of the reduction of the TPT protein by antisense repression. In a second line with a 95% reduction of AGPase activity, the amount of chlorophyll was significantly reduced as a consequence of the lowered triose phosphate utilization capacity

• Publisher: American Society of Plant Physiologists
• Subject: ACTIVIDAD ENZIMATICA / ACTIVITE ENZYMATIQUE / adenosine diphosphate / ADN / ADP / ALMIDON / AMIDON / ANTISENSE DNA / BIOCHEMICAL PATHWAYS / Biological and medical sciences / BIOSINTESIS / BIOSYNTHESE / BIOSYNTHESIS / CARBOHYDRATE METABOLISM / CHEMICAL COMPOSITION / chemical constituents of plants / chlorophyll / CHLOROPHYLLE / CHLOROPHYLLS / Chloroplasts / CLOROFILAS / COMPOSICION QUIMICA / COMPOSITION CHIMIQUE / DNA / enzyme activity / ENZYMIC ACTIVITY / EXPRESION GENICA / EXPRESSION DES GENES / FEUILLE / FOSFOPIROLASA / FOTOSINTESIS / Fundamental and applied biological sciences. Psychology / GENE EXPRESSION / GENETIC REGULATION / GENETIC VARIATION / GENETICA / GENETICS / GENETIQUE / GENOTIPOS / GENOTYPE / GENOTYPES / GLUCOSA / GLUCOSE / HOJAS / INHIBICION / INHIBITION / LEAVES / Metabolism / METABOLISME DES GLUCIDES / METABOLISMO DE CARBOHIDRATOS / METABOLITE / METABOLITES / METABOLITOS / MONOSACARIDOS / MONOSACCHARIDE / MONOSACCHARIDES / NET ASSIMILATION RATE / NUTRIENT TRANSPORT / Phosphates / PHOSPHORYLASE / Photophase / PHOTOSYNTHESE / PHOTOSYNTHESIS / Photosynthesis, respiration. Anabolism, catabolism / Plant physiology and development / PLANTAS TRANSGENICAS / PLANTE TRANSGENIQUE / Plants / promoter regions / PROMOTERS / Repression / SACCHAROSE / SOLANUM TUBEROSUM / STARCH / Starches / SUCROSA / SUCROSE / TRANSFORMATION / TRANSGENIC PLANTS / TRANSPORT DES SUBSTANCES NUTRITIVES / TRANSPORTE DE NUTRIENTES / trioses / VARIACION GENETICA / VARIATION GENETIQUE / VIA BIOQUIMICA DEL METABOLISMO / VOIE BIOCHIMIQUE DU METABOLISME / Whole Plant, Environmental, and Stress Physiology