Brassinosteroids, microtubules and cell elongation in Arabidopsis thaliana.: II.: Effects of brassinosteroids on microtubules and cell elongation in the bul1 mutant
Brassinosteroids, microtubules and cell elongation in Arabidopsis thaliana.: II.: Effects of brassinosteroids on microtubules and cell elongation in the bul1 mutant
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DOI：
10.1007/s004250000467
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发表时间：
2001-04-01
期刊：
影响因子：
4.3
通讯作者：
Sangwan, RS
中科院分区：
文献类型：
--
作者：
Catterou, M;Dubois, F;Sangwan, RS
为了阐明油菜素甾醇类化合物在细胞伸长过程中的作用，利用间接免疫荧光和分子生物学技术研究了拟南芥（Arabidopsis thaliana（L.））矮化突变体bul 1 -1中微管蛋白基因的表达。Heynh..其特征在本期中报道（M. Catterou等人，2001年）。在伸长区被抑制的突变体植物区域（下胚轴和叶柄）中专门研究了微管，使细胞伸长明显减少。α-微管蛋白的间接免疫荧光显示，突变细胞中存在非常少的微管，导致完全缺乏野生型中伸长细胞的典型平行微管组织。油菜素类固醇处理后，微管重组，并成为正确的方向，表明在微管组织的油菜素类固醇的参与。分子分析表明，在油菜素内酯处理的bul 1 -1植物中观察到的微管重组并没有导致微管蛋白基因表达的激活，或从微管蛋白含量的增加，这表明油菜素内酯响应途径的存在，允许微管成核/组织和细胞伸长而不激活微管蛋白基因表达。
In order to elucidate the involvement of brassinosteroids in the cell elongation process leading to normal plant morphology, indirect immunofluorescence and molecular techniques were use to study the expression of tubulin genes in the bul1-1 dwarf mutant of Arabidopsis thaliana (L.) Heynh.. the characteristics of which are reported in this issue (M. Catterou ct al., 2001). Microtubules were studied specifically in the regions of the mutant plant where the elongation zone is suppressed (hypocotyls and petioles), making the reduction in cell elongation evident. Indirect immunofluorescence of alpha -tubulin revealed that very few microtubules were present in mutant cells, resulting in the total lack of the parallel microtubule organization that is typical of elongating cells in the wild type. After brassinosteroid treatment, microtubules reorganized and became correctly oriented, suggesting the involvement of brassinosteroids in microtubule organization. Molecular analyses showed that the microtubule reorganization observed in brassinosteroid-treated bul1-1 plants did not result either from an activation of tubulin gene expression, or from an increase in tubulin content, suggesting that a brassinosteroid-responsive pathway exists which allows microtubule nucleation/organization and cell elongation without activation of tubulin gene expression.