Mechanical Stress and Gibberellin: Regulation of Hollowing Induction in the Stem of a Bean Plant, Phaseolus vulgaris L. |
| |
Authors: | Takano Mamoru; Takahashi Hideyuki; Suge Hiroshi |
| |
Institution: | Institute of Genetic Ecology, Tohoku University Katahira, Aoba-ku, Sendai, 980-77 Japan |
| |
Abstract: | In pole bean plants, mechanical stress (MS) inhibited stem elongationand induced radial thickening of the stem. Application of uniconazole,an inhibitor of gibberellin biosynthesis, also reduced stemgrowth but had no effect on stem diameter. Both MS and uniconazolesignificantly reduced hollowing of the first internodes, butonly the former increased ethylene evolution from the firstinternode. Application of GA3 increased the length of the firstinternode and decreased its diameter in bush bean plants; thiswas accompanied by a significant promotion of stem hollowing.Aminooxyacetic acid (AOA) decreased ethylene evolution fromthe GA3-treated internodes, though it did not reduce the GA3-inducedhollowing of the first internodes. Application of GA3 affectedneither ethylene evolution nor cellulase activity in the firstinternodes of bush bean plants. Application of GA3 stimulatedmuch greater cell elongation in the center of pith tissue thanin the outer surrounding tissues, suggesting a possible physicalbreakage of the inner cells, which leads the hollowing of beanstems. These results suggest that gibberellin is a factor responsiblefor stem hollowing in bean plants. Because MS is known to reducegibberellin content in bean plants Suge (1978) Plant Cell Physiol.21: 303] MS may inhibit stem hollowing by reducing the amountof endogenous gibberellin. (Received July 1, 1994; Accepted November 8, 1994) |
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|