Expression and Localization of Phosphoenolpyruvate Carboxylase in Developing and Germinating Wheat Grains1
AUTOR(ES)
González, María-Cruz
FONTE
American Society of Plant Physiologists
RESUMO
Phosphoenolpyruvate carboxylase (PEPC) activity and corresponding mRNA levels were investigated in developing and germinating wheat (Triticum aestivum) grains. During grain development PEPC activity increased to reach a maximum 15 d postanthesis. Western-blot experiments detected two main PEPC polypeptides with apparent molecular masses of 108 and 103 kD. The most abundant 103-kD PEPC subunit remained almost constant throughout the process of grain development and in the scutellum and aleurone layer of germinating grains. The less-abundant 108-kD polypeptide progressively disappeared during the second half of grain development and was newly synthesized in the scutellum and aleurone layer of germinating grains. PEPC mRNA was detected throughout the process of grain development; however, in germinating grains PEPC mRNA accumulated transiently in the scutellum and aleurone layer, showing a sharp maximum 24 h after imbibition. Immunolocalization studies revealed the presence of the enzyme in tissues with a high metabolic activity, as well as in the vascular tissue of the crease area of developing grains. A clear increase in PEPC was observed in the scutellar epithelium of grains 24 h after imbibition. The data suggest that the transiently formed PEPC mRNA in the scutellar epithelium encodes the 108-kD PEPC subunit.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=35031Documentos Relacionados
- Amino Acid and Peptide Uptake in the Scutella of Germinating Grains of Barley, Wheat, Rice, and Maize 1
- Expression of Phosphoenolpyruvate Carboxylase and Phosphoenolpyruvate Carboxylase Kinase Genes. Implications for Genotypic Capacity and Phenotypic Plasticity in the Expression of Crassulacean Acid Metabolism1
- In Vivo Regulation of Wheat-Leaf Phosphoenolpyruvate Carboxylase by Reversible Phosphorylation.
- In Vivo Regulatory Phosphorylation of Novel Phosphoenolpyruvate Carboxylase Isoforms in Endosperm of Developing Castor Oil Seeds1
- In Vivo and in Vitro Phosphorylation of the Phosphoenolpyruvate Carboxylase from Wheat Seeds during Germination.