A SEARCH FOR LIGHT-INDUCED DWARFISM-GENE (FOR DEVELOPING NEW TRANSGENIC PLANTS)

点击翻译按钮获取中文摘要

The changes in growth and gene expression of gibberellin (GA) 3β-hydroxylase were determined in dark-grown, 6-d-old, tall (cv. Alaska) and dwarf (cv. Progress No. 9) pea (Pisum sativum L.) seedlings after transferred to the condition of red light irradiation. Red light inhibited the shoot elongation of Progress No. 9 much greater than that of Alaska, and the elongation of Progress No. 9 during 48 h was 23% that of Alaska. The transcript level of GA 3β-hydroxylase gene was slightly greater in the shoots of dark-grown Alaska than that of dark-grown Progress No. 9. The red light decreased the transcript levels in both cultivars and the levels at 48 h were about 50% and 60% compared to the initial levels for Alaska and Progress No. 9, respectively. These results indicate that the difference in the transcript levels in both cultivars is not apparent. The only difference in GA 3β-hydroxylase proteins between Alaska and Progress No. 9 was the replacement of alanine with threonine at position 229 in their amino acid residues, which may affect the activity of the enzyme and may, at least partially, contribute to the growth habits of those cultivars. A possibility of additional function to distinguish the growth habits of those cultivars was also discussed.