| Project/Area Number |
06453162
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Plant nutrition/Soil science
|
|---|
| Research Institution | Faculty of Agriculture, Niigata University |
|---|
Principal Investigator |
IKARASHI Taro Facul.Agr.Niigata Univ., Professor, 農学部, 教授 (50018537)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OHYAMA Takuji Facul.Agr.Niigata Univ., Assoc.Professor, 農学部, 助教授 (30152268)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Project Status |
Completed (Fiscal Year 1995)
|
| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥6,800,000 (Direct Cost: ¥6,800,000)
|
|---|
| Keywords | tulip / bulb scale / low temperature / starch / storage protein / amylase / chapillary electrophores / forcing / 球根植物 / 低温貯蔵 / α-アミラーゼ / タンパク質 |
|---|
| Research Abstract |
To investigate the mechanism of degradation of starch and storage protein in tulip (Tulipa gesneriana) bulb scales, one group of bulbs were treated with cold temperature and another control bulbs were kept in room temperature .
Cold temperature promoted the degradation of starch during and after low temperature treatment, although the starch content was constant in control bulbs. The alpha-amylase activity was increased during cold storage period from August till October both in cold-treated and control bulbs. However, the acitivity in the central tissue of bulbscales was only detected in cold storagebulbs . Control bulbs exhibited the activity only near epidermal cells where no starch was observed. It can be concluded that low temperature induce amylase acitivity in the central tissue of scales where starch is accumulated. alpha-amylase was purified and characterized from tulip bulb scales. The optimum temperture and pH were 75ﾟC and 5.0-5.6 respectively. alpha-amylase requires Ca^<2+> for the stability of the enzyme. Cu^<2+> and Hg^<2+> inhibited the activity. These characteristics are similar to those of the otherplant amylases reported. There are at least 4 or 5 isozymes of amylase.
At lifting tulip bulb scales contain 33,21,22, and 32kDa storage peptides, and during cold treatment, the 22 and 32kDa peptides were initially degraded and 17kDa peptide and soluble amino acids were increased . Cold temperature enhanced the endopeptidase and aminopeptidase activities in scales, but no carboxypeptidase activity was detected. The 21kDa peptide was purified as a single band in SDS-PAGE.The separation of storage proteins by capillary electrophoresis was investigated, and the peptide patterns were very variable by pH of electrolyte solutions .
|
