A CYTOCHEMICAL STUDY OF EMBRYO SAC DEVELOPMENT IN STELLARIA MEDIA
A CYTOCHEMICAL STUDY OF EMBRYO SAC DEVELOPMENT IN STELLARIA MEDIA
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繁星培养基中胚囊发育的细胞化学研究
DOI：
10.1002/j.1537-2197.1964.tb06646.x
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发表时间：
1964
影响因子：
3
通讯作者：
H. N. Pritchard
中科院分区：
文献类型：
--
作者：
H. N. Pritchard
应用拓扑细胞化学方法研究了繁缕胚胎发生的心皮型，并对核酸、蛋白质和多糖进行了表征。初级胚柄细胞最初含有高水平的细胞质RNA，但这些下降后，第一次几个细胞分裂迅速。细胞质蛋白质水平高，在整个存在的初级胚柄细胞，成为集中成蛋白质体在子叶开始在胚胎中的时间。这些质体的RNA和DNA均为阴性，而多糖和脂类的检测仅呈轻微阳性。细胞质和核仁的RNA和蛋白质水平高，在整个胚胎的发展。子叶和胚乳也表现出较高的RNA和蛋白质水平。细胞质DNA存在于胚胎顶端分生组织细胞的形式Feulgen阳性，脱氧核糖核酸酶可去除的颗粒。细胞质组蛋白存在于胚和胚乳中。多糖在子叶、皮层、胚乳和珠心中均有表达。尽管大量植物的胚胎学已在形态学上作了相当详细的描述，但目前有关植物生长和分化的生理和生化方面的资料还很少。由于高等植物的胚胎被包裹在种子中，因此除了少数例外，它们在技术上比许多低等动物形式更不容易进行实验操作。由于这个原因，相对较少的实验胚胎学工作已经做了植物。实验生物学中的两个主要技术发展使植物胚胎的功能研究成为可能：细胞化学和体外胚胎培养方法。尽管植物细胞学家很早就利用了细胞化学技术，但这项技术在植物生理学和生物化学问题上的应用却远远落后于它在动物学上的应用。Gifford和Tepper（1962 a，B）对顶端分生组织的研究和詹森（1963）对棉花胚的研究是两个主要的例外。我于1963年9月12日接受出版。这项研究是博士学位的一部分。论文提交给利哈伊大学，伯利恒，宾夕法尼亚州。这项工作在佛罗里达大学J. Hillis米勒健康中心病理学系完成，得到了佛罗里达大学资助#6294 H 03、癌症培训资助# CT 5068（C-6）和NIH研究资助#RG-10003-02（授予R博士）的支持。R.考登作者感谢R博士。R.感谢考登在实验和手稿准备过程中提供的宝贵帮助、鼓励和建议，并感谢J。爱德华兹，病理学系主任，使用该部门的设施。本研究的前一部分（Pritchard，1964）涉及3大类大分子化合物的分布，即，大孢子发育过程中的核酸、蛋白质和多糖的变化。西里尔本研究代表了本研究的扩展，包括胚胎发生发育。繁缕是石竹科繁缕中常见的一种，由于其世界性分布和花期长达一年，子房容易在任何时候获得，因此被选作本研究的对象。根据M\Jaheshwari（1950）的分类，S.媒体经历了一个caryophyllad型胚胎发育。Crete（1947）在S. uliginosa穆尔。和S.媒体此外，白色（1954）已在试管中培育了后者的胚胎，这为对其发育进行实验研究提供了进一步的途径。材料和方法-S.培养基在温室中生长。在植物已经建立并盛开之后，所有的花都被剪掉，这样第二天就会产生所有新的“第一天”开花。这些花是用骆驼毛刷授粉的，并用彩色线做了标记。以这种方式，获得了从1-10日龄不等的几个系列的卵巢。将卵巢杀死并固定在3种不同的固定剂中：FAA、Carnoy和10%中性福尔马林用于组蛋白染色。固定在FAA中的组织在脱水之前保持在该流体中3天至3周
The caryophyllad type of embryogenesis in Stellaria media was investigated using topological cytochemical methods for the demonstration of nucleic acids, proteins and polysaccharides. The primary suspensor cell initially contained high levels of cytoplasmic RNA, but these declined rapidly after the first few cell divisions. Cytoplasmic protein levels were high throughout the existence of the primary suspensor cell, becoming concentrated into proteinoplasts at the time of cotyledon initiation in the embryo. These plastids were RNAand DNA-negative, and only slightly positive with methods for polysaccharides and lipids. Cytoplasmic and nucleolar RNA and protein levels were high in the embryo throughout its development. The cotyledons and endosperm also showed high RNA and protein levels. Cytoplasmic DNA was present in the embryonic apical meristematic cells in the form of Feulgen-positive, deoxyribonuclease-removable granules. Cytoplasmic histones were present in the embryo and endosperm. Polysaccharides were demonstrable in the cotyledons, cortex, endosperm, and nucellus. ALTHOUGH the embryology of a great number of plants has been described in considerable morphological detail, very little information is currently available concerning the physiological and biochemical aspects of plant growth and differentiation. Since higher plant embryos are enclosed in seeds, they have been, with few exceptions, technically less amenable to experimental manipulation than many of the lower animal forms. For this reason, comparatively little experimental embryological work has been done with plants. Two main technological developments in experimental biology have made functional investigations of plant embryos feasible: cytochemistry and in vitro embryo culture methods. In spite of the fact that botanical cytologists made early use of cytochemical techniques, the application of this technology to problems of plant physiology and biochemistry has lagged considerably behind its use in zoology. Gifford and Tepper's (1962a,b) study of the apical meristem, and Jensen's (1963) study of the cotton embryo represent 2 principal exceptions to this. I Received for publication September 12, 1963. This investigation formed a part of a Ph.D. dissertation submitted to Lehigh University, Bethlehem, Pennsylvania. The work was completed at the Department of Pathology, J. Hillis Miller Health Center, University of Florida, under support from University of Florida Grant # 6294H03, Cancer Training Grant # CT 5068 (C-6) and NIH research grant #RG-10003-02 to Dr. R. R. Cowden. The author is indebted to Dr. R. R. Cowden for his invaluable assistance, encouragement and advice in the experimentation and preparation of the manuscript, and to Dr. J. L. Edwards, Head of the Department of Pathology, for use of the facilities of that department. The previous portion of this study (Pritchard, 1964) was concerned with the distribution of 3 major classes of macromolecular compounds, i.e., nucleic acids, proteins, and polysaccharides during the development of the megaspore of Stellaria media (L.) Cyrill. The present study represents an extension of this investigation to include embryogenic development. Stellaria media, the common chickweed of the family Caryophyllaceae, was selected for this study because of its cosmopolitan distribution and year-long blooming period which made ovaries easily available at any time. According to the M\Jaheshwari (1950) classification, S. media undergoes a caryophyllad type of embryonic development. Development in this genus has previously been described by Crete (1947) for S. uliginosa Murr. and by Pal (1953) for S. media. Embryos of the latter, moreover, have been grown in vitro by White (1954), this offering further avenues for experimental studies of its development. MATERIALS AND METHODS-Specimens of S. media were grown in the greenhouse. After the plants had become established and in full bloom, all the blossoms were clipped off so that the following day would yield all new "first-day" blooms. These blossoms were pollinated using a camel's hair brush, and marked with colored threads. In this manner, several series of ovaries were obtained varying from 1-10 days old. Ovaries were killed and fixed in 3 different fixatives: FAA, Carnoy's, and 10%o neutral formalin for histone staining. Tissues fixed in FAA remained in that fluid for 3 days to 3 weeks before they were dehydrated