Linked Life Data

8000424

Source:http://linkedlifedata.com/resource/pubmed/id/8000424

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1995-1-25
pubmed:abstractText
A rice suspension cell culture system has been established to study how sugar depletion regulates alpha-amylase expression, carbohydrate metabolism, and other physiological and cellular changes. It is shown here that a group of 44 kDa alpha-amylases are constitutively expressed whether or not the cells are starved of sucrose. However, expression of a new group of alpha-amylases of 46 kDa is dramatically induced when cells are starved of sucrose. Cellular sugar and starch were rapidly consumed and metabolic activity was decreased in the starved cells. Extensive autophagy also occurred in the starved cells, which caused an increase in vacuolar volume and degradation of cytoplasmic constituents including amyloplasts. Immunocytochemical studies revealed that alpha-amylases are localized in starch granules within amyloplasts, in cell walls, and in some of the vacuoles. The presence of putative signal sequences in the N-termini of nine rice alpha-amylases suggests hitherto unidentified pathways for import of alpha-amylases into amyloplasts. The studies show that differential alpha-amylase expression, carbohydrate metabolism, metabolic activity, and vacuolar autophagy are coordinately regulated by the sugar level in the medium. As the starved suspension cells exhibit some sugar-regulated characteristics of alpha-amylase expression in germinating rice embryos as well as physiological changes similar to those in senescing cells, this system represents an ideal tool for studying cellular, biochemical, and molecular biological aspects of alpha-amylase gene regulation, carbohydrate metabolism, senescence, and protein targeting in plants.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
625-36
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Expression of alpha-amylases, carbohydrate metabolism, and autophagy in cultured rice cells is coordinately regulated by sugar nutrient.
pubmed:affiliation
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't