ACID PHOSPHATASE LOCALIZATION IN RABBIT EOSINOPHILS

Eosinophil (and heterophil) leukocytes of glycogen-induced rabbit peritoneal exudates were fixed for 1½ min in 2% glutaraldehyde and examined for acid phosphatase activity both biochemically and cytochemically. Biochemical assays showed that enzymatic activity had been inhibited by only ~10% under these conditions. The cytochemical reaction in the eosinophil was confined to the granules in which the reaction product appeared in the matrix, not in the crystalline core (or in the core region after the latter's extraction). Granules wherein the matrix was disrupted and the crystalline core degraded or extracted showed the most intense deposition of reaction product, whereas well preserved granules with morphologically intact matrix and crystals were unreactive. Yet, not all disrupted granules gave a positive reaction, indicating that disruption was a necessary but not sufficient condition for reactivity. In many eosinophil leukocytes, most if not all granules were acid phosphatase-positive, provided they had become disrupted to a certain degree. Factors possibly involved in converting the granules from an unreactive to a reactive state are discussed.     

ENZYME ACTIVITY AND CELL DIFFERENTIATION IN NEUROSPORA

Zalokar , Marko . (Yale U., New Haven, Conn.) Enzyme activity and cell differentiation in Neurospora. Amer. Jour. Bot, 46(7): 555–559. Illus. 1959.—Morphological differences were observed in vegetative cells of Neurospora of different ages and in different parts of the mycelium. The surface layer of mycelium grown in standing cultures could be separated from the deep layer. The first contained most of the growing hyphae rich in protoplasm, while the second contained heavily vacuolated hyphae laden with fat droplets. Specific activities of several enzymes were studied in conidia, young hyphae, and the surface and deep layers of mature mycelium. Succinic dehydrogenase was low in conidia and about 10 times more active in mature mycelium. The surface layer had twice the activity of the deep layer. Aldolase increased about 3 times after the germination of conidia; it was slightly lower in the surface than in the deep layer of mycelium. Tryptophan synthetase exhibited only small differences between conidia and mycelium and was slightly lower in the surface than in the deep layer. β-galactosidase was formed in appreciable amounts only after prolonged growth and had a much higher specific activity in the deep layer. The results were discussed in connection with cell differentiation and aging.     

PHOSPHATASE ACTIVITY AND CELLULAR DIFFERENTIATION IN PHLEUM ROOT MERISTEM

Using 9 different organic phosphate substrates as alternatives in a standardized 5′-nucleotidase histochemical test system, enzyme activity patterns were recorded for timothy grass root epidermis. At least 4 different phosphatases were distinguished on the bases of substrate specificity, reaction rate, tissue distribution, and response to inhibitors. Except with adenosine-3′-monophosphate, all activities were restricted to the 300-mμ-long root tip meristem. These enzyme activities were associated with the earliest phases of differentiation of the epidermal hair and hairless cell initials. The distribution of activities was not associated with the same cell type in each part of the meristem. Little activity was found with most substrates in the undifferentiated cells of the 0-100μ zone; alternating active hairless and inactive hair cell initials predominated in the 100-200μ segment; and active hair–inactive hairless sister cells formed the principal pattern in the 200-300μ segment of the meristem. The data showed that a particular enzyme activity was associated with a specific cell type only in relation to that cell's position along the differentiation gradient of the entire tissue. But, within a meristem segment, a specific cell type might act differently from its neighbors, depending on its mitotic capacity. This complex of physiological dependence and independence of a cell type on tissue ontogeny was cited as a characteristic of the phenomenon of cellular differentiation superimposed on tissue differentiation gradients.     

SOME ASPECTS OF VASCULAR DIFFERENTIATION IN ROOTS OF CASSIA

Hayat, Mohammed Arif (North Dakota State U., Fargo), and Charles Heimsch. Some aspects of vascular differentiation in roots of Cassia. Amer. Jour. Bot. 50(10): 965–971. Illus. 1963.—Vascular development, with emphasis on the differentiation of the protophloem, was studied in tips of primary roots of 18 species of Cassia. Variations in levels of protophloem sieve tube maturation were observed among roots of different species as well as among those of different length in the same species. In general, protophloem matured at greater distances from the apex in roots with the larger diameters. Compared with woody species, herbaceous species exhibited greater uniformity in levels of protophloem maturation, and this was correlated with greater uniformity in root diameter. Roots were either triarch or tetrarch. In some species with tetrarch roots, a change to a triarch pattern occurred during early growth. Structural changes in the differentiating root tip which involve the loss of a xylem arm and subsequent fusion of phloem strands are described.     

鸡胚巨噬细胞AcP酶变化及AcP酶与凋亡细胞的关系

本研究采用电镜及酶细胞化学的方法观察了鸡胚脾脏不同胚龄组巨噬细胞溶酶体酸性磷酸酶（AcP酶）的变化、凋亡实验组巨噬细胞及其AcP酶与凋亡细胞的关系。取10天、13天和17天鸡胚脾脏,按Gomori法显示AcP酶,各胚龄脾脏巨噬细胞AcP酶细胞化学反应阳性,按AcP酶染色阳性做溶酶体计数,结果显示随着胚龄的增加溶酶体数随之增加,尤以第17天组溶酶体数增加最为明显,所得数据经统计分析表明各胚龄组间溶酶体数的差异有统计学意义。凋亡实验组采用放线菌酮诱导15天鸡胚脾脏细胞凋亡,结果显示凋亡细胞为各类幼稚血细胞,以幼稚淋巴细胞为主。巨噬细胞未见凋亡,而是吞噬了大量的凋亡细胞和凋亡小体,AcP酶反应颗粒不仅出现在巨噬细胞的溶酶体、吞噬体,还见于高尔基复合体、内质网等。细胞AcP酶反应强度数字化结果表明：凋亡组酶活性显著高于对照组,差别有统计学意义,提示胚胎巨噬细胞在凋亡细胞出现时AcP酶活性增强,说明巨噬细胞吞噬和消化凋亡细胞或凋亡小体是通过AcP酶等活性物质来实现的。     

DIFFERENTIAL ENZYME ACTIVITY DURING TRICHOBLAST DIFFERENTIATION IN ELODEA CANADENSIS

Enzymes active in the developing root epidermis of Elodea canadensis Michx. were demonstrated by histochemical techniques. The future root-hair-forming cells (trichoblasts) showed a period of elevated activity more extensive than the one previously reported in trichoblasts of another species for dehydrogenases (glucose-6-phosphate, pyruvate, lactate, succinic, isocitrate, glutamate), phosphatases (acid, ATPase, 5-nucleotidase), cytochrome oxidase, and peroxidase. This elevated activity extended from the time of trichoblast formation up to the point of root hair outgrowth, even for enzymes not previously demonstrated in trichoblasts: alkaline phosphatase, NADH diaphorase, NADPH diaphorase, esterase, and leucine aminopeptidase. Glucose-6-phosphatase and aryl sulfatase were not detected. The single exception to this pattern was phosphorylase activity, which intensified only just prior to and during root hair outgrowth. The more generalized activity pattern is considered to indicate the so-called meristematic character of these cells in terms of both macromolecular synthesis and lack of specialization. It is suggested that specific root hair development begins just prior to initiation, at the point marked by elevated phosphorylase activity.     

DIGESTION AND THE DISTRIBUTION OF ACID PHOSPHATASE IN BLEPHARISMA

Suspensions of Blepharisma intermedium were fed latex particles for 5 min and then were separated from the particles by filtration. Samples were fixed at intervals after separation and incubated to demonstrate acid phosphatase activity. They were subsequently embedded and sectioned for electron microscopy. During formation of the food vacuole, the vacuolar membrane is acid phosphatase-negative. Within 5 min, dumbbell-shaped acid phosphatase-positive bodies, possibly derived from the the acid phosphatase-positive Golgi apparatus, apparently fuse with the food vacuole and render it acid phosphatase-positive. A larger type of acid phosphatase-positive, vacuolated body may also fuse with the food vacuole at later stages. At about 20 min after formation, acid phosphatase-positive secondary pinocytotic vesicles pinch off from the food vacuoles and approach a separate system of membrane-bounded spaces. By 1 hr after formation, the food vacuole becomes acid phosphatase-negative, and the undigested latex particles are voided into the membrane-bounded spaces. The membrane-bounded spaces are closely associated with the food vacuole at all stages of digestion and are generally acid phosphatase-negative. Within the membrane-bounded spaces, dense, pleomorphic, granular bodies are found, in which are embedded mitochondria, paraglycogen granules, membrane-limited acid phosphatase-containing structures, and Golgi apparatuses. The granular bodies may serve as vehicles for the transport of organelles through the extensive, ramifying membrane-bounded spaces.     

CORTICAL ONTOGENY IN ROOTS. I. ZEA MAYS

Serial growth stages of young Zea mays primary roots were analyzed for patterns of ground meristem ontogeny. The number of cell layers in the cortex decreases from approximately 15 to 11 during early root growth. The cortex arises mostly by periclinal divisions in the outer portions of the ground meristem at levels 50–150 μm from the meristem tip, although some layers of outer cortex arise beyond 150 μm. The proendodermis contributes 3–5 cell layers to the cortex, but this contribution diminishes during early seedling growth as anticlinal divisions occur in the proendodermis. The relationship between the ground meristem and protoderm changes at the tip of the meristem during root elongation.     

ULTRASTRUCTURE AND ACID PHOSPHATASE IN PEDICEL ABSCISSION OF HIBISCUS

Pedicel abscission in Hibiscus rosa-sinensis was investigated by light and electron microscopy. During the pre-abscission period endoplasmic reticulum declined somewhat, dictyosomes increased in number and apparent activity, and mitochondria maintained their numbers. The observations suggested that dictyosomal vesicles were migrating to and fusing with the plasma membrane. The enzyme acid phosphatase was associated with dictyosomes and dictyosomal saccules, with small vacuoles and invaginations of the plasma membrane, and in the paramural region between the plasma membrane and the cell wall. Our interpretation is that acid phosphatase, (and probably also the enzymes involved in cell wall dissolution) are transported via an endoplasmic reticulum-dictyosome-vesicle carrier system to the paramural regions of the cell. In more general terms, our observations support the view that the enzymes involved in the cell wall hydrolysis of abscission are synthesized within a compartmentalized, lysosomal system prior to their release and action.     

水稻叶片酸性磷酸酯酶活性及其部分特性

从水稻叶片部分纯化了水解磷酸烯醇式丙酮酸的磷酸酯酶,其Ｋｍ（ＰＥＰ）为０．１ｍｍｏｌ／Ｌ,最适ＰＨ５．３．在偏酸性ＰＨ条件下（ＰＨ４．０～７．２）稳定,对热亦较稳定．酶活性受Ｐｉ强烈抑制．它对其底物要求不专一,能水解多种含磷酯键的化合物．表明它是一种非专一性的酸性磷酸酯酶。各种含磷酯键的代谢物对酶活性起竞争性抑制作用,且表现出叠加性．Ｃｕ（２＋）、Ｚｎ（２＋）和Ｆｅ（２＋）抑制酶活性,Ｍｇ（２＋）、Ｍｎ（２＋）、Ｃａ（２＋）、Ｃｏ（２＋）和ＥＤＴＡ无影响．     

大豆子叶内酸性磷酸酶活性的超微结构定位

开花后３５～５０ ｄ 期间和萌发早期（播种后４～８ ｄ）的大豆（Ｇｌｙｃｉｎｅｍ ａｘ Ｌ．）种子中,酸性磷酸酶主要分布在子叶细胞中的蛋白体内;在内质网内也检测到酸性磷酸酶活性。此外,在萌发早期的部分子叶细胞的质膜外侧及其细胞壁基质中可见密集的酸性磷酸酶活性;而且在近质膜的胞质中常见到一些富含磷酸铅沉淀的胞质小泡,似与质膜融合     

HISTOCHEMICAL LOCALIZATION OF ENZYMES IN TAPINANTHUS BANGWENSIS: ACID PHOSPHATASE

The distribution of acid phosphatase in the tissues of Tapinanthus bangwensis, a semiparasitic member of the Loranthaceae, and some of its hosts was studied. It has beer possible to work out convenient routine methods of pretreating tissues for histochemical enzyme localization, to modify, where necessary, conventional histochemical techniques for the localization of acid phosphatase, and to evaluate the azo-dye and metal-salt techniques at the optical level. Histochemical localization showed generally widespread activity and similarity in distribution for this enzyme in the parasite and host tissues. Although there is no direct correlation between these localizations and host-parasite relationships, the bearing that the localizations may have on such relationships is discussed in the light of the distributional evidence and the role usually ascribed to this enzyme.