Increase in the level of arabinoxylan-hydroxycinnamate network in cell walls of wheat coleoptiles grown under continuous hypergravity conditions
Increase in the level of arabinoxylan-hydroxycinnamate network in cell walls of wheat coleoptiles grown under continuous hypergravity conditions
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DOI：
10.1111/j.1399-3054.2005.00544.x
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发表时间：
2005-09-01
影响因子：
6.4
通讯作者：
Hoson, T
中科院分区：
文献类型：
--
作者：
Wakabayashi, K;Soga, K;Hoson, T
研究了小麦（Triticum aestivum L.）细胞壁组分的数量和组成对持续超重力刺激的响应。胚芽鞘在超重力（300 g）条件下生长2-4 d的胚芽鞘长度为1 g对照的60-70%。然而，半纤维素多糖和纤维素在超重力处理的胚芽鞘中的净含量逐渐增加，与对照胚芽鞘中的那些一样多。因此，在超重力条件下，单位长度胚芽鞘中它们的含量大大增加。在半纤维素馏分中，阿拉伯糖和木糖的量，馏分的主要成分，显着增加响应超重力。当半纤维素多糖被分离成中性和酸性聚合物的阴离子交换柱，由（葡萄糖醛酸）阿拉伯糖组成的酸性馏分的量较高，在超重力处理的胚芽鞘比在控制胚芽鞘。细胞壁结合的阿魏酸和二阿魏酸（DFA）的量显着增加，在1克控制和超重力处理的胚芽鞘。特别是，在超重力处理的胚芽鞘中的DFA的量显着高于那些在对照胚芽鞘的孵化期。这些结果表明，持续的超重力增加刚性网络结构，通过阿拉伯聚糖羟基肉桂酸酯交联在小麦胚芽鞘细胞壁结构。这些结构可能具有承重功能，并有助于构建抵抗重力的稳定细胞壁。
Changes in the amount and composition of cell wall constituents in response to continuous hypergravity stimuli were studied in wheat (Triticum aestivum L.) coleoptiles. The lengths of coleoptiles grown under hypergravity (300 g) conditions for 2-4 days from germination stage were 60-70% of those of 1 g control. However, the net amounts of hemicellulosic polysaccharides and cellulose in hypergravity-treated coleoptiles increased progressively as much as those in the control coleoptiles. As a result, their contents per unit length of coleoptile largely increased under hypergravity conditions. In the hemicellulose fraction, the amounts of arabinose and xylose, the major components of the fraction, prominently increased in response to hypergravity. When hemicellulosic polysaccharides were separated into neutral and acidic polymers by an anion-exchange column, the amounts of the acidic fraction consisting of (glucurono)arabinoxylans were higher in hypergravity-treated coleoptiles than in control coleoptiles. The amounts of cell wall-bound ferulic acid and diferulic acid (DFA) increased dramatically in both 1 g control and hypergravity-treated coleoptiles. Particularly, the amounts of DFA in hypergravity-treated coleoptiles were significantly higher than those in control coleoptiles during the incubation period. These results suggest that continuous hypergravity increases the rigid network structures via arabinoxylan-hydroxycinnamate cross-links within cell wall architecture in wheat coleoptiles. These structures may have a load-bearing function and contribute to construct the stable cell wall against the gravitational force.