We are interested in rice a-amylase genes regulatory system. Expression of
a-amylase genes in rice suspension cells is known to be induced by
carbohydrate depletion. The increase of a-amylase synthesis is assumed to
accelerate by hyrolysis of cellular starch as an energy source when exogenous
carbon source is depleted. Prolonged carbohydrate starvation reduces growth
activities of the starved cells and finally lead to cell death. The
physiological changes during starvation are similar in plant,animal,
and yeast cells. We aim to study the early response of cells to detrimental
environment and the mechanistic of growth arrest using carbohydrate-starved
cells as a model system. We will isolate cDNA clones which are expressed
during early stages of carbohydrate starvation. Some of these clones may be
involved in signal transduction pathway and gene regulation. We would also
study the expression pattern of several genes isolated from normal and starved
cells. We have observed an increase of RNase synthesis in cells during the
course of sucrose starvation. Genes encoding the RNase will also be isolated.
Studied of the regulation and expression of these genes would lead to a better
understanding of the mechanism of growth arrest and cell death in eukaryotes.
Recently, we add okadaic acid (OA) (cytotoxic polyether compound of a
C-38 fatty acid first isolated from marine black sponges. It has been
demonstrated that OA is a potent inhibitor of protein phosphatases 1 and 2A.)
into rice cell culture. After 30 degree, 60 minutes, the mRNA is
performed the Nothern blotting. A intensify hybridization spot is resulted.