Dark-induced hormone changes coincide with the resumption of light-inhibited shoot growth in Catasetum fimbriatum (Orchidaceae)

被引：6

作者：

Suzuki, Rogerio M. ^{[1
]}

Kerbauy, Gilberto B. ^{[2
]}

Pescador, Rosete ^{[3
]}

Purgatto, Eduardo ^{[4
]}

Ceccantini, Gregorio C. T. ^{[2
]}

Ferreira, Wagner de M. ^{[5
]}

机构：

[1] Inst Bot, Secao Orquidario, BR-04301902 Sao Paulo, Brazil

[2] Univ Sao Paulo, Dept Bot, Inst Biociencias, BR-05422970 Sao Paulo, Brazil

[3] Fundacao Univ Reg Blumenau, Dept Ciencias Nat, BR-89010971 Blumenau, SC, Brazil

[4] Univ Sao Paulo, Fac Ciencias Farmaceut, Dept Alimentos & Nutr Expt, BR-05508000 Sao Paulo, Brazil

[5] Univ Fed Tocantins, NEAMB, BR-77500000 Porto Nacl, Tocantins, Brazil

来源：

JOURNAL OF PLANT PHYSIOLOGY | 2010年 / 167卷 / 05期

基金：

巴西圣保罗研究基金会;

关键词：

Development resumption; Endogenous hormones; In vitro culture; Orchid; Shoot apical meristem; CYTOKININS; TOBACCO;

D O I：

10.1016/j.jplph.2009.10.002

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Catasetum fimbriatum plants cultivated in the absence of light exhibit continuous shoot growth leading to the formation of nodes and internodes. On the other hand, when these plants are incubated in the presence of light, shoot longitudinal growth is inhibited and pseudobulbs develop just below the shoot apical meristem. These facts provide evidence of a possible influence of light on mitotic cell division in the shoot apex as well as on pseudobulb initiation. The effects of light and dark on the interruption and/or maintenance of shoot apex mitotic activity and the subsequent formation of pseudobulbs in the sub-meristematic regions were investigated by means of histological and hormonal studies. The interruption of shoot apex development occurred around the 150th d of light incubation and seems to have resulted from the establishment of a strong storage sink in the region of the future pseudobulb, in detriment to the continuous activity of the shoot apical meristem. The reduced total cytokinins/IAA ratio in the apex, mainly due to high levels of IAA, could be a key factor in the interruption of cell divisions. Transfer to the dark brings about the resumption of shoot apex development of plants through the re-entrance of cells in the cell cycle which coincides with a significant increase in the total cytokinins/IAA ratio. (C) 2009 Elsevier GmbH. All rights reserved.

引用

页码：375 / 381

页数：7