In the halophytic species Mesembryanthemum crystallinum, the induction of crassulacean acid metabolism (CAM) by salinity requires a substantial investment of resources in storage carbohydrates to provide substrate for nocturnal CO(2) uptake. Acclimation to salinity also requires the synthesis and accumulation of cyclitols as compatible solutes, maintenance of root respiration, and nitrate assim...

Our knowledge of starch has been gained largely from a study of the properties and composition of this substance as found in the storage organs of plants, such as seeds, tubers, and roots. Although its presence in leaves as a product of photosynthesis, that is autochthonic starch, has been known for a long time, and its formation, dissolution, and some of its properties in situ have been studie...

Perennial, temperate, C4 grasses, such as switchgrass and miscanthus have been tabbed as sources of herbaceous biomass for the production of green fuels and chemicals based on a number of positive agronomic traits. Although there is important literature on the management of these species for biomass production on marginal lands, numerous aspects of their biology are as yet unexplored at the mol...

We report that protein phosphorylation is involved in the control of starch metabolism in Arabidopsis leaves at night. sex4 (starch excess 4) mutants, which have strongly reduced rates of starch metabolism, lack a protein predicted to be a dual specificity protein phosphatase. We have shown that this protein is chloroplastic and can bind to glucans and have presented evidence that it acts to re...

Resistant starch (RS) escapes digestion in the small intestine and may ferment in the large intestine. The purpose of this study was to determine the resistant starch content in typical starchy foods and to estimate the daily resistant starch intake and identify key sources of dietary resistant starch in the Chinese diets. The resistant starch contents of 121 foods were determined using a metho...

The early stages of tuber development are characterized by cell division, high metabolic activity, and the predominance of invertase as the sucrose (Suc) cleaving activity. However, during the subsequent phase of starch accumulation the cleavage of Suc occurs primarily by the action of Suc synthase. The mechanism that is responsible for this switch in Suc cleaving activities is currently unknow...

The me-chanism by which the reversible conversion of starch ito sucrose takes place in potato tubers exposed t,o cold is as yet essentilally unknown. Early 'studies on the subjectt tried to correllate this conversion with va,riations in the activity of related enzymes (10). Those responsible for the synthesis of sucrose and sticrose-6--phosphiate (1) are undoubtedly highly relevant. In add'itio...

Starch the main storage carbohydrate in higher plants Ta& 1. Characterjstjcs of the SBE c-NA from p a t o and is composed of the two polysaccharides, amylopectin (approximately 75%) and amylose (approximately 25%). Amylopectin is a highly branched a-1,4 glucan containing a1,6 branch points, whereas amylose is composed of long, linear a-1,4 glucans, some of which have very few a-1,6 branch point...

After wheat and rice, potato is the third most important staple food worldwide. A collection of ten tetraploid (Solanum tuberosum) and diploid (S. phureja and S. chacoense) genotypes with contrasting carotenoid content was subjected to molecular characterization with respect to candidate carotenoid loci and metabolic profiling using LC-HRMS. Irrespective of ploidy and taxonomy, tubers of these ...

Starch and sugar content of potato tubers are quantitative traits, which are models for the candidate gene approach for identifying the molecular basis of quantitative trait loci (QTL) in noninbred plants. Starch and sugar content are also important for the quality of processed products such as potato chips and French fries. A high content of the reducing sugars glucose and fructose results in ...