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Control of cell expansion and cortical microtubule arrangement by plant hormones

植物激素对细胞扩张和皮质微管排列的控制

基本信息

批准号：
03640575
负责人：
KATSUMI Masayuki
金额：
$ 1.41万
依托单位：
International Christian University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

1 Relationship between gibberellin (GA)-induced stimulation and ABA-induced inhibition of hypocotyl elongation and changes in the pattern of cortical microtubule (MT) arrangement was examined using light-grown cucumber seedlings. In the tangential surface of epidermal cells, the predominant pattern of MT arrangement was oblique, while in the radial surface of epidermal cells and cortex cells, MT arrangement was mostly transverse. GA increased and ABA decreased cells with transversely arranged MT. GA and ABA counteracted to each other. The frequency of the occurrence of cells with trasversely arranged MT in the tangential surface of the epidermis was found to be highly correlated to the growth rate of the hypocotyl, suggesting that the epidermis is an essential tissue for hypocotyl elongation.2 Relationship between the growth and the pattern of MT arrangement in the tangential surface of epidermal cells of the coleoptile was examined using D_8, a putative GA-receptor dwarf mutant of maize, and its normal sib. The length of the coleoptile as well as the cell length in D_8 seedlings was shorter than those in normal seedlings. In D_8, cells with obliquely and longitudinally arranged MT are dominant, while in normal those with transversely arranged MT are dominant. Treatment with uniconazole, a GA biosynthesis inhibitor, inhibited the growth of the coleoptile and increased cells with obliquely and longitudinally arranged MT in both D_8 and normal. The growth of the coleoptile seems to be controlled by endogenous GA through its control of MT arrangement.3 Brassinolide, a new plant hormone, also had an effect on MT arrangement similar to that of GA in the epidermal cells of light-grown cucumber hypocotyls.4 The in vitro formation of microtubules from tubulins extracted from etiolated pea seedlings was stimulated by GA and brassinolide.

以光生黄瓜幼苗为研究对象，研究了赤霉素（GA）诱导的刺激和aba诱导的下胚轴伸长抑制与皮质微管（MT）排列模式变化的关系。在表皮细胞的切向表面，MT以斜向排列为主，而在表皮细胞和皮层细胞的径向表面，MT以横向排列为主。MT横向排列时，GA增加，ABA减少，GA与ABA相互抵消。在表皮切向表面出现MT横排细胞的频率与下胚轴的生长速度高度相关，表明表皮是下胚轴伸长的重要组织利用推定的玉米ga受体矮突变体D_8及其正常同胞，研究了玉米胚芽鞘表皮细胞切向表面MT排列模式与生长的关系。D_8幼苗的胚芽鞘长度和细胞长度均短于正常幼苗。在D_8中，倾斜和纵向排列的细胞占主导地位，而在正常情况下，横向排列的细胞占主导地位。单康唑（一种GA生物合成抑制剂）抑制了D_8和正常的胚芽鞘的生长，增加了倾斜和纵向排列的MT细胞。内源GA似乎通过控制MT的排列来控制胚芽鞘的生长油菜素内酯（Brassinolide）是一种新的植物激素，它对光生黄瓜下胚轴表皮细胞中MT的排列也有类似于GA的影响赤霉素和油菜素内酯刺激了黄化豌豆幼苗微管的体外形成。