Is Adventitious Bud Differentiation in Dioecious Melandrium album Controlled by Endogenous Levels of Auxin?
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Accession number;00A0222167
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| Title;Is Adventitious Bud Differentiation in Dioecious Melandrium album Controlled by Endogenous Levels of Auxin? |
| Author;
TANIMOTO SHIZUFUMI
(Saga Univ., Fac. of Agric.)
KAWAHARA KENJI
(Saga Univ., Fac. of Agric.)
DOI YOSHIE
(Saga Univ., Fac. of Agric.)
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Journal Title;Bulletin of the Faculty of Agriculture, Saga University
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Journal Code:F0981A
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ISSN:0581-2801
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VOL.;NO.84;PAGE.119-127(1999)
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| Figure&Table&Reference;FIG.5, REF.25 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;In the dioecious plant Melandrium album, it has been reported that all plants regenerated from tissue cultures were of female sex phenotypes. To elucidate female plant regeneration, we examined adventitious bud differentiation from leaf explants of male and female plants. Adventitious buds can be induced from both of female and male plants, when the explants were cultured on the medium contained cytokinin together with auxin transport inhibitor, 2, 3, 5-triiodobenzoic acid (TIBA) or auxin antagonist, 2, 4, 6-trichloro-phenoxyacetic acid. The adventitious bud induction from female explants was inhibited by indoleacetic acid (IAA) even when cytokinin and TIBA were added to the medium. The results suggested that adventitious bud differentiation in M. album was suppressed by high levels of endogenous IAA, and that IAA levels in male plants was higher than female plants. High levels of IAA content was due to either a high production of IAA or because the degradation of IAA was low. We have previously demonstrated that isozyme patterns of peroxidase in male plant proteins was different from female plant proteins, with male plants displaying 2-times more peroxidase isozymes than female plants. IAA oxidase, IAA degrading enzyme, was thought to be one of peroxidases. So, we predicted the possibility that the activity of IAA oxidase in female leaves might be higher than male leaves. Indeed, the endogenous contents of IAA was about 50 ng per g fresh weight in male, and less than 20 ng per g fresh weight in female. When IAA samples from male plants was incubated with protein preparation, the IAA content was gradually decreased. However, the IAA content was decreased to half when the same IAA samples was incubated with a female protein preparation. In conclusion, female plants of M. album expressed larger amounts of IAA oxidase which degrad the endogenous IAA so that adventitious buds can be induced readily.... (author abst.) |
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