FUJINO Kaien Faculty of Agriculture, Crop Physiology, Assistant, 農学部, 助手 (80229020)
KODA Yasunori Faculty of Agriculture, Crop Physiology, Assistant Professor, 農学部, 助教授 (20002355)
|Budget Amount *help
¥6,200,000 (Direct Cost : ¥6,200,000)
Fiscal Year 1991 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Fiscal Year 1990 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1989 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Studies on developmental physiology of cell differentiation in crop tissues and cells cultured, in vitro.
By employing plant tissue and cell culture techniques, the process of growth and differentiation of plant cells can be controlled and modified. An investigation was undertaken with the hope that some clue might be found as to the relationship between the formation of tubers in potato, somatic embryos and of adventitious shootbuds in rice cells cultured, in vitro, and the effects of certain hormonal and enviromental conditions on the induction and expression of genes for the growth and differentiation of the crop cells.
The material used was potato plant (Solanus tuberosum L. cv Irish Cobbler and cv May Queen) and rice plant (OryLa sativa L. cv Ishikari) and Barnyardgrass (Echinochloa oryzicola Vasing).
In order to study the process of tuberization in potato, the major turber proteins, such as patatin, 22 k Da protein family, and proteinase inhibitors have been used as biochemi
cal markers. We established a cDNA library from 'in vitro' tubers (cv Irish Cobbler), and a tuber specific cDNA clone, cPTI, was isolated by differential screening with the mRNA from leaves. The nucleotide sequence and the corresponding amino acid sequence were deduced.
Transcripts of a potato Kunitz-type proteinase inhibitor (PKTI) gene were present in discs excised from tubers stored for 14 months as well as in those from 2 months after harvested, and the PKTI gene expression was induced in potato discs by the addition of jasmonic acid (JA) [3-oxo-2-(2'-cis-pentenyl)-cyclopentane-l-acetic acid], the most actively at 10 muM after 24 h treatment. While, the patatin transcripts were also present in discsfrom stored tubers but less than those of the PKPI transcripts.
Callus was initiated from mature seed of Barnyardgrass on a modified Murashige and Skoog medium containing 2.0-20.0mg/1 2, 4-D, 30g/1 sucrose. The rate of callus initiation was increased with the addition of 4mg/1 Tryptophan. Calluses were subcultured in medium containing 6.0mg/1 2.4-D, 30g/1 sucrose. The plantlets were regenerated under the light on MS medium involving various hormonecombination (0.05- 0.5mg/1 2, 4-D ; 0.05mg/1 2, 4-D plus 3.0mg/1 BA ; 0.05mg/1 2, 4-D plus 5.0mg/1 kinetin or 0.05mg/1 2, 4-D plus 2.0mg/1 zeatin). In the regenerated plantlets, there were normal plant 55% and abnormal plant 45% (albino etc.).
The processes of plantlet regeneration of rice were also observed through the supplementation of ABA and proline in medium with the relation this to the activity of nitrate reductase of cells. The proportion of embryogenesis and organgenesis could not be successfully controlled by medium ingredients using 2, 4-D, BA, kinetin and zeatin. Less