The aim of this study was to investigate carbohydrate metabolism in rice seedlings subjected salt-alkaline stress. Two relatively tolerant (Changbai 9) and sensitive (Jinongda 138) cultivars, grown hydroponically, were stress via 50 mM solution. content the activities metabolism-related enzymes leaves roots investigated. results showed that contents sucrose, fructose, glucose increased under St...

Effects of thermal transitions (glass transition, crystallization), water, and glycerol on invertase activity in freeze-dried carbohydrate systems were investigated. Efficacy of κ-carrageenan to delay sugar crystallization in freeze-dried carbohydrate systems was also studied. Water sorption properties and glass transition temperatures, Tg, were determined for freeze-dried carbohydrate-sucrose ...

A mathematical model representing metabolite interconversions in the central carbohydrate metabolism of Arabidopsis (Arabidopsis thaliana) was developed to simulate the diurnal dynamics of primary carbon metabolism in a photosynthetically active plant leaf. The model groups enzymatic steps of central carbohydrate metabolism into blocks of interconverting reactions that link easily measurable qu...

The SUC2 gene of Saccharomyces cerevisiae encodes two differently regulated mRNAs (1.8 and 1.9 kilobases) that differ at their 5' ends. The larger RNA encodes a secreted, glycosylated form of invertase and the smaller RNA encodes an intracellular, nonglycosylated form. We have determined the nucleotide sequence of the amino-terminal coding region of the SUC2 gene and its upstream flanking regio...

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H(+)) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exert...

Invertases, or P-fructofuranosidases, hydrolyze SUC into Fru and Glc. Immobilized acid invertases in plants have been described as localized in the cell wall (Eschrich, 1980; Gogarten, 1986; Sturm and Chrispeels, 1990). Soluble acid invertases were ascribed to the vacuole (Leigh et al., 1979). At least in dicotyledonous plants these organelle-specific isoforms are encoded by separate genes (Stu...

We have outlined a procedure that allows the large-scale screening of mutagenized Neurospora crassa populations for invertaseless mutants. We have isolated and characterized three mutations, inv(DBL1), inv(DBL9) and inv(DBL14), which have been mapped at or near the invertase structural gene. One of these, inv(DBL1), is particularly interesting. Our experiments indicate that the reduced level of...