Tools - Reference - Detail

Reference Detail

Reference
Author Shima S, Matsui H, Tahara S, Imai R.
Title Biochemical characterization of rice trehalose-6-phosphate phosphatases supports distinctive functions of these plant enzymes.
Abstract:
Substantial levels of trehalose accumulate in bacteria, fungi, and invertebrates, where it serves as a storage carbohydrate or as a protectant against environmental stresses. In higher plants, trehalose is detected at fairly low levels; therefore, a regulatory or signaling function has been proposed for this molecule. In many organisms, trehalose-6-phosphate phosphatase is the enzyme governing the final step of trehalose biosynthesis. Here we report that OsTPP1 and OsTPP2 are the two major trehalose-6-phosphate phosphatase genes expressed in vegetative tissues of rice. Similar to results obtained from our previous OsTPP1 study, complementation analysis of a yeast trehalose-6-phosphate phosphatase mutant and activity measurement of the recombinant protein demonstrated that OsTPP2 encodes a functional trehalose-6-phosphate phosphatase enzyme. OsTPP2 expression is transiently induced in response to chilling and other abiotic stresses. Enzymatic characterization of recombinant OsTPP1 and OsTPP2 revealed stringent substrate specificity for trehalose 6-phosphate and about 10 times lower K(m) values for trehalose 6-phosphate as compared with trehalose-6-phosphate phosphatase enzymes from microorganisms. OsTPP1 and OsTPP2 also clearly contrasted with microbial enzymes, in that they are generally unstable, almost completely losing activity when subjected to heat treatment at 50 degrees C for 4 min. These characteristics of rice trehalose-6-phosphate phosphatase enzymes are consistent with very low cellular substrate concentration and tightly regulated gene expression. These data also support a plant-specific function of trehalose biosynthesis in response to environmental stresses.
Journal FEBS J.
Country Japan
Volume 274(5)
Pages 1192-201.
Year 2007
PubMed ID 17257172
PubMed Central ID -
DOI 10.1111/j.1742-4658.2007.05658.x
URL -
Relation
Gene MKK6 SALT TPP1 TPP2 TPP3 TPP4 TPP5 TPP6 TPP7 TPP8 TPP9
INSD -
Strain Wild Core Collection -
Induced Mutation Lines(NIG Collection) -
Sterile Seed Strain -
Lethal Embryo
Mutantion Strain
-
Stages in Each Organ
- Muant Lines (Gene)
-
Cultivated Varieties(NIG Collection) -
Stages in Each Organ -
/rice/oryzabase