PLANT NUCLEOTIDE-SUGAR PYROPHOSPHATASE/PHOSPHODIESTERASE (NPPASE), METHOD OF OBTAINING SAME AND USE OF SAME IN THE PRODUCTION OF ASSAY DEVICES AND IN THE PRODUCTION OF TRANSGENIC PLANTS.

摘要

The invention relates to NPPase which is an enzyme that catalyses the hydrolysis of a wide range of small molecules with phosphosulphate and phosphodiester bonds, notably ADPG (adenosine diphosphate glucose) and APS (adenosine 5'phosphosulphate). The enzyme obtained from plant extracts is used in assay devices in order to (i) determine nucleoside-diphosphate sugar levels which are based on either the sugar-1-phosphate released or on the nucleoside monophosphate products, both formed by the reaction catalysed by the NPPase, and (ii) detect sulphonucleotides such as 3'-phosphoadenosine 5'phosphosulphate (PAPS) and APS. Moreover, the invention relates to the amino acid sequence of the enzyme and to the nucleotide sequence of a complete cDNA and another incomplete cDNA.The invention further relates to the production of transgenic plants which overexpress NPPase and which possess a high sugar content, a low starch content and cell wall polysaccharides and a good resistance to high salt concentrations and high temperatures.