Up-regulation of expression of tubulin genes and roles of microtubules in hypergravity-induced growth modification in Arabidopsis hypocotyls
Up-regulation of expression of tubulin genes and roles of microtubules in hypergravity-induced growth modification in Arabidopsis hypocotyls
复制标题
DOI：
10.1016/j.asr.2007.03.074
复制
发表时间：
2007-01-01
影响因子：
2.6
通讯作者：
Hoson, Takayuki
中科院分区：
文献类型：
--
作者：
Matsumoto, Shouhei;Saito, Yuka;Hoson, Takayuki
我们研究了微管在重力诱导的植物生长和发育的修饰中的作用，通过分析α-和β-微管蛋白基因家族的表达水平以及用微管破坏试剂秋水仙碱、安磺灵和丙苯酰肼处理的拟南芥下胚轴的生长行为。大多数的α-和β-微管蛋白基因的表达上调超重力在300克，虽然基因之间的程度是可变的，表明微管蛋白基因的表达上调是拟南芥下胚轴超重力的普遍反应。超重力通过降低细胞壁的伸展性来抑制伸长生长，而刺激下胚轴的侧向增厚。秋水仙碱，安磺灵，和propyzamide处理，伸长生长受到抑制，横向加厚刺激，下胚轴细胞壁的可伸展性下降剂量依赖性，即使在1克条件下。超重力引起的变化程度随微管破坏剂浓度的增加而降低。因此，超重既不影响长度，厚度，也不是细胞壁的延伸性下胚轴在高浓度的微管破坏试剂的存在下。此外，秋水仙素处理的幼苗，即使在1克的条件下，螺旋生长，这种表型在超重力条件下得到加强。这些结果表明，微管蛋白基因表达的上调参与了重力诱导微管动力学的改变，这可能在植物器官抵抗重力和维持正常生长表型中起重要作用。(C)2007年空间研委会。由爱思唯尔有限公司出版。保留所有权利。
We examined the roles of microtubules in gravity-induced modification of growth and development in plants by analyzing the expression levels of the alpha- and beta-tubulin gene family and growth behavior of Arabidopsis hypocotyls treated with the microtubule-disrupting reagents colchicine, oryzalin, and propyzamide. Expression of the majority of the examined alpha- and beta-tubulin genes was up-regulated by hypergravity at 300 g, although the extent was variable among genes, indicating that up-regulation of the expression of tubulin genes is the universal response of Arabidopsis hypocotyls to hypergravity. Hypergravity suppressed elongation growth by decreasing the cell-wall extensibility, whereas it stimulated lateral thickening of hypocotyls. By treatment with colchicine, oryzalin, and propyzamide, the elongation growth was suppressed, lateral thickening was stimulated, and the cell-wall extensibility of hypocotyls decreased dose-dependently even under 1 g conditions. The degree of hypergravity-induced changes decreased with increasing concentration of microtubule-disrupting reagents. As a result, hypergravity affected neither the length, the thickness, nor the cell-wall extensibility of hypocotyls in the presence of high concentrations of microtubule-disrupting reagents. Moreover, colchicine-treated seedlings showed helical growth even under 1 g conditions, and this phenotype was intensified under hypergravity conditions. These results suggest that the up-regulation of the expression of tubulin genes is involved in gravity-induced modification of microtubule dynamics, which may play an important role in the resistance of plant organs to the gravitational force and maintenance of normal growth phenotype. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.