Molecular mechanism of the osmoregulation during phtomorphogenesis in plant seedlings

植物幼苗光形态发生过程中渗透调节的分子机制

• 批准号: 09640778
• 负责人: KAMISAKA Seiichiro
• 金额: $ 1.92万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640778/
• 关键词: Zea mays; coleoptile; mesocotyl; growth; osmotic potential; invertase; white light; growth inhibition; 第一葉

The growth rate of the stem cells is mainly determined by two parameters, the osmotic potential and the mechanical properties of cell walls. Much evidence indicates that white light inhibits shoot elongation in etiolated seedlings by decreasing the mechanical extensibility of cell walls. On the other hand, there is a report suggesting that white light increases osmotic potential, resulting in inhibited stem elongation in etiolated maize seedlings (Parvez et al. 1996). In this report, the mechanism by which white light regulates osmotic properties was studied, in relation to stem growth in maize seedlings.White light strongly inhibited growth of the coleoptils, while it stimulated growth of the first leaf. Osmotic potential in the coleoptile was increased, in response to the irradiation of white light. On the other hand, white light decreased osmotic potential in the first leaf. Changes in the growth rate in the coleoptile and the first leaf were correlated with changes in osmotic poten … More tial. The total amount of osmotica in the coleoptile and first leaf was correlated with that a soluble sugars. White light inhibited the activity of acid invertase bound to cell walls, while it promoted the enzyme activity in the first leaf. The activity of the acid invertase was correlated with the content of soluble sugars in the coleoptile and the first leaf.In addition to the coleoptile and first leaf, white light also increased osmotic potential in the mesocotyl. In response to the irradiation of white light, the activity of acid invertase decreased in the mesocotyl. Sugar exudation from the cut of the segments excised from the coleoptile and the mesocotyl in the presence of EDTA was stimulated by white light irradiation. The mesocotyl was cut 10 mm above the caryopsis, to examine the effect of light on sugar transport from the caryopsis to the mesocotyl. Sugar exudation from the cut of the mesocotyl was not influenced by light irradiation. Vanadate a potent inhibitor of plasma membrane-proton ATPase nullified the effect of white light on sugar exudation from the cut of the coleoptile and the mesocotyl.From these experimental results, it was concluded that white light controls shoot growth in maize seedling by controlling sugar distribution among organs in maize seedlings via controlling the activity of acid invertase bound to cell walls. At present, the cloning of acid invertase gene is in progress, to study the regulatory mechanism of the gene expression on acid invertase in organs in maize seedlings during photomorphogenesis. Less

干细胞的生长速率主要由两个参数决定，渗透势和细胞壁的机械性质。许多证据表明，白色光通过降低细胞壁的机械伸展性来抑制黄化幼苗的芽伸长。另一方面，有报道表明，白色光增加渗透势，导致黄化玉米幼苗的茎伸长受到抑制（Parvez等，1996）。本文研究了白色光对玉米幼苗渗透特性的调节机制，发现白色光强烈抑制胚芽鞘的生长，而促进第一叶的生长。胚芽鞘中的渗透势增加，响应于白色光的照射。另一方面，白色光降低了第一叶的渗透势。胚芽鞘和第一片叶的生长速率的变化与渗透势的变化相关。 ...更多信息 tial。胚芽鞘和第1叶中的可溶性糖总量与可溶性糖总量呈显著正相关。白色光抑制了细胞壁酸性转化酶的活性，但促进了第一叶酸性转化酶的活性。酸性转化酶活性与胚芽鞘和第一叶中可溶性糖含量相关，除胚芽鞘和第一叶外，白色光还能提高中胚轴的渗透势。在白色光照射下，中胚轴酸性转化酶活性降低。在EDTA存在下，通过白色光照射刺激从胚芽鞘和中胚轴切下的片段的切口的糖渗出。在颖果上方10 mm处切割中胚轴，以检查光对糖从颖果运输到中胚轴的影响。光照射不影响中胚轴切段的糖分泌。钒酸盐（Vanadate）是质膜质子ATP酶的有效抑制剂，它能抑制白色光对胚芽鞘和中胚轴切段糖分泌的影响，因此，白色光通过控制细胞壁酸性转化酶的活性来控制玉米幼苗各器官间糖的分配，从而控制玉米幼苗的生长。目前，酸性转化酶基因的克隆正在进行中，以研究酸性转化酶基因在玉米幼苗光形态建成过程中的表达调控机制。少

项目成果

Parvez,M.M.et al.: "White light-induced sugar distribution controls growth and osmotic properties in the coleoptile and the first leaf in Zea mays seedlings" Physiologia Plantarum. 102・1. 1-8 (1998)

Parvez, M.M. 等人：“白光诱导的糖分布控制玉米幼苗的胚芽鞘和第一片叶子的生长和渗透特性”Physiologia Plantarum 102·1 (1998)。

Soga, K. et al.: "Inhibition of reproductive growth of Arabidopsis in airtight vessels"Adv. Space Res.. 23・5. 2037-2040 (1999)

Soga, K. 等：“密闭容器中拟南芥繁殖生长的抑制”Adv. Space Res. 2037-2040 (1999)

Miyamoto, K. et al.: "Auxin polar transport in Arabidopsis under simulated microgravity condition - Relevevance to growth and development"Adv. Space Res.. 23・5. 2033-2036 (1999)

Miyamoto, K. 等：“模拟微重力条件下拟南芥中的生长素极地运输 - 与生长和发育的相关性”Adv. Space Res. 23・5 (1999)。

Chen, L. et al.: "Suppression of (1→3),(1→4)-β-D-glucan turnover during light-induced inhibition of rice coleoptile growth"J. Plant Res.. 112・1. 7-13 (1999)

Chen, L. 等：“光诱导抑制水稻胚芽鞘生长过程中 (1→3),(1→4)-β-D-葡聚糖转换的抑制”J. Plant Res.. 112・1。 -13 (1999)

Soga, K. et al.: "Increased molecular mass of hemicellulosic polysaccharides is involved in growth inhibition of maize coleoptile and mesocotyls under hypergravity conditions"Journal of Plant Research. 112・2. 273-278 (1999)

Soga, K. 等人：“半纤维素多糖的分子量增加参与超重力条件下玉米胚芽鞘和中胚轴的生长抑制”《植物研究杂志》112・2 (1999)。