title: Changes in polyamine pattern are involved in floral initiation and development in Polianthes tuberosa.
abstract: In the day-neutral plant Polianthes tuberosa (cv. Double) putrescine and spermine in corms at the early floral initiation stage decreased by 26 and 36%, respectively, compared with that in the vegetative stage. In contrast, a sharp increase in spermidine and cadaverine titers in corms was recorded at the early floral initiation stage. However, cadaverine in corms disappeared at the flower development stage. Polyamines in the roots were generally lower than those in the leaves and corms. In no case was the change in endogenous polyamine titers in the roots and leaves associated with floral initiation and flower development in P. tuberosa. Exogenous application of spermidine at 5, 25 or 150 microg per plant at the vegetative stage did not affect flower primordium counts. However, addition of a spermidine synthase inhibitor, cyclohexylamine, at 150 or 250 microg per plant (each dose was applied two times in total at an interval of 4 days) significantly reduced flower primordium counts, indicating that spermidine is involved in floral initiation and floral development in P. tuberosa. In P. tuberosa corms at the vegetative stage arginine decarboxylase activity rises and decreases at the early floral initiation stage. In contrast, ornithine decarboxylase activity reaches the highest level at the early floral initiation stage and declines significantly at the vegetative stage. Results indicate that an increase in spermidine and a transient increase in cadaverine titers in the corms seem characteristic of early floral initiation in P. tuberosa. It is also suggested that a significant reduction in putrescine and spermine in the corms is involved in the early floral initiation in P. tuberosa.
authors.affiliation: Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung City, Taiwan, ROC.
authors.forename: Chiung-Kuei
authors.initials: CK
authors.lastname: Huang
authors.forename: Bao-Su
authors.initials: BS
authors.lastname: Chang
authors.forename: Kuo-Cheng
authors.initials: KC
authors.lastname: Wang
authors.forename: Sheng-Jou
authors.initials: SJ
authors.lastname: Her
authors.forename: Tian-Wen
authors.initials: TW
authors.lastname: Chen
authors.forename: Yun-An
authors.initials: YA
authors.lastname: Chen
authors.forename: Chung-Lung
authors.initials: CL
authors.lastname: Cho
authors.forename: Li-Jen
authors.initials: LJ
authors.lastname: Liao
authors.forename: Kuang-Liang
authors.initials: KL
authors.lastname: Huang
authors.forename: Wen-Shaw
authors.initials: WS
authors.lastname: Chen
authors.forename: Zin-Huang
authors.initials: ZH
authors.lastname: Liu
mesh_terms: D000070357:Asparagaceae / Q000201:enzymology / Q000254:growth & development*; D002262:Carboxy-Lyases / Q000378:metabolism; D035264:Flowers / Q000502:physiology*; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism*
chemical_list: D011073:Polyamines; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; C019722:arginine decarboxylase