Physiological and morphological characteristics during development of pedunculate oak (Quercus robur L.) zygotic embryos
Physiological and morphological characteristics during development of pedunculate oak (Quercus robur L.) zygotic embryos
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DOI：
10.1007/s00468-005-0012-8
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发表时间：
2006-01-01
影响因子：
2.3
通讯作者：
Wilhelm, E
中科院分区：
文献类型：
--
作者：
Prewein, C;Endemann, M;Wilhelm, E
根据形态学和生理学特征，对橡树合子胚的发育阶段进行了研究。从6月到9月，每隔1周收获一次种子。利用生长参数将离体胚胎分为4个发育阶段。在生理特性方面，测定了内源脱落酸（阿坝）、吲哚-3-乙酸（IAA）、L-脯氨酸、淀粉含量和水分状况。在阿坝处理之前和之后，在未成熟的子叶ZEs中测试橡树豆球蛋白贮藏蛋白基因的表达。阿坝水平的胚胎表现出一个显着的高峰期的中期成熟阶段（阶段III），然后再次下降，在后期成熟阶段（阶段IV）结束。伴随着阿坝，水分含量下降，最大胚大小。高IAA水平被发现在开始的胚胎扩大指数增长发生（第二阶段），但在进一步发展下降。淀粉积累逐渐成熟的过程中，而显着的值被发现在第四阶段ZEs附近脱落。脯氨酸，鲜重的基础上，是高的阶段I和II。渗透势增加时，快速干物质积累，第二阶段ZES达到其最大尺寸在早期中期发展。早熟萌发的表达在无淀粉培养基上更高，特别是在第II阶段和第III阶段ZEs之间。植物激素水平的变化与组织水分状况的变化相结合，似乎是橡树ZE发展的重要因素。
The developmental stages of oak zygotic embryos ( ZEs) are characterized here according to morphological and physiological features. Seeds were harvested from June to September in 1-week intervals. Excised embryos were classified into four stages of development by using growth parameters. For physiological characterization, endogenous levels of abscisic acid ( ABA), indole-3-acetic acid ( IAA), L-proline, starch content and water status were determined. The expression of the oak legumin storage protein gene was tested in immature cotyledonary ZEs before and after ABA treatment. The ABA levels of the embryos showed a significant peak during the intermediate stage of maturation ( stage III) and then decreased again at the end of the late maturation phase ( stage IV). Concomitant with ABA, the moisture content declined with the maximum embryo size. High IAA levels were found at the beginning of embryo enlargement as exponential growth occurred ( stage II) but decreased during further development. Starch accumulated gradually in the course of maturation, whereas significant values were found in stage IV ZEs near shedding. Proline, on fresh weight basis, was high during stages I and II. Osmotic potential increased when, by rapid dry matter accumulation, stage II ZEs reached their maximum size during early intermediate development. Expression of precocious germination was higher on hormone-free medium, in particular, among stage II and stage III ZEs. Variations in phytohormone levels in combination with changes in tissue water status seem to be important factors for oak ZE development.