| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
It is important to establish very sensitive and reliable analysis methods for the investigation of plant hormones in vascular tissue of higher plants. For this purpose, several deuterium-labeled gibberellins, which are used as internal standards of GC/SIM analysis, were prepared by chemical or partly biological conversion. The simple method to introduce tritium into gibberellins was also establised. The translocation of plant hormones through vascular tissue was investigated by using phloem sap of rice obtained by laser-insect method as well as using honeydew excreted by brown planthopper. Gibberellin A_1(GA_1), GA_4, GA_<19>, GA_<20>, and GA_<29> were identified in honeydew by GC/SIM and the changes of their levels in honeydew at several growth stages of rice were observed. GA_<19> was the major gibberellin and its level increased at the stage of maximum tillering stage and then decreased at panicle initiation-heading stages. The levels of other gibberellins were low and there was no significant change of level.
Abscisic scid(ABA) in honeydew was determined by gas-liquid chromatography using a electron capture detector. The level of ABA increased from 3rd leaf leaf stage, reached the maximum at maximum tillering stage and decreased at panicle initiation stage. ABA was identified by gas-liquid chromatography in the phloem sap obtained by laser-insect method. Hawever, gibberellins could not be identified in phloem sap due to their very low levels. To clarify the relationship between plant hormones in phloem sap and those in honeydew, the solution containing sucrose and gibberellins or ABA was fed to brown planthopper, and excreted honeydew was analyzed. Although there was not so large difference between gibberellins in sample solution and honeydew, clear conclusion on this problem has not been obtained.
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