The mutualistic interaction in arbuscular mycorrhiza (AM) is characterized by an exchange of mineral nutrients and carbon. The major benefit of AM, which is the supply of phosphate to the plant, and the stimulation of mycorrhization by low phosphate fertilization has been well studied. However, less is known about the regulatory function of carbon availability on AM formation. Here the effect o...

Peptide N-glycosidase from Flavobacterium meningosepticum cleaves complex as well as neutral glycoproteins (Plummer, T.H., Jr., Elder, J.H., Alexander, S., Phelan, A.W., and Tarentino, A.L. (1984) J. Biol. Chem. 259, 10700-10704). Examples of neutral glycoprotein substrates include ribonuclease B (one high mannose oligosaccharide chain) and yeast external invertase (nine chains/invertase subuni...

Proper seed development requires coordinated growth among the three genetically distinct components, the embryo, the endosperm, and the seed coat. In Arabidopsis, embryo growth rate accelerates after endosperm cellularization, which requires a chromatin-remodeling complex, the FIS2-Polycomb Repressive Complex 2 (PRC2). After cellularization, the endosperm ceases to grow and is eventually absorb...

Invertases are key enzymes in carbon partitioning in higher plants. They gain additional importance in the distribution of carbohydrates in the event of wounding or pathogen attack. Although many researchers have found an increase in invertase activity upon infection, only a few studies were able to determine whether the source of this activity was host or parasite. This article analyzes the ro...

Yeast invertase contains 14 sequons, all of which are glycosylated to varying degrees except for sequon 5 which is marginally glycosylated, if at all. This sequon overlaps with sequon 4 in a sequence consisting of Asn92-Asn93-Thr94-Ser95(Reddy et al., 1988, J. Biol. Chem., 263, 6978-6985). To determine whether glycosylation at Asn93is sterically hindered by the oligosaccharide on Asn92, the lat...

Cell-wall invertase genes are spatially and temporally regulated in several plant species, including Daucus carota L., Lycopersicon esculentum L. and Solanum tuberosum L. However, few studies of cell-wall invertase genes of trees have been conducted, despite the importance of trees as a source of lignocellulosic biopolymers. We identified three putative cell-wall invertase genes in hybrid popla...

Fructans are the main storage polysaccharides found in Agave species. The synthesis of these complex carbohydrates relies on the activities of specific fructosyltransferase enzymes closely related to the hydrolytic invertases. Analysis of Agave tequilana transcriptome data led to the identification of ESTs encoding putative fructosyltransferases and invertases. Based on sequence alignments and ...

Pectin methylesterase (PME) and invertase are key enzymes in plant carbohydrate metabolism. Inhibitors of both enzymes constitute a sequence family of extracellular proteins. Members of this family are selectively targeted toward either PME or invertase. In a comparative structural approach we have studied how this target specificity is implemented on homologous sequences. By extending crystall...

In some preliminary experiments it was found that certain yeast invertase preparations which had been variously purified by adsorption to kaolin and alumina in accordance with the Willstiitter procedures (1) were soluble in saturated aqueous solutions of ammoniym sulfate. This solubility of the enzyme is interesting for two reasons. In the first place, saturated aqueous solution of ammonium sul...

It is not known why some species accumulate high concentrations of sucrose in leaves during photosynthesis while others do not. To determine the possible basis, we have studied 10 species, known to differ in the accumulation of sucrose, in terms of activities of sucrose hydrolyzing enzymes. In general, acid invertase activity decreased as leaves expanded; however, activities remaining in mature...