果胶酶的细胞化学定位:马尾松树脂道发生的细胞化学证据

运用薄切片和电镜细胞化学方法观察了马尾松(Pinus massoniana Lamb.)茎皮层树脂道的发育及发育过程中果胶酶的变化.树脂道的发育过程一般可分为4个阶段,即原始细胞阶段、胞间隙形成阶段、腔道扩大阶段和树脂道成熟阶段.在原始细胞阶段,果胶酶的反应产物首先出现在原始细胞膨胀的细胞壁角隅处,然后沿细胞壁中层分布.胞间隙形成后,果胶酶的反应产物分布在细胞壁和胞间隙的交界面.随着胞间隙的扩大,反应产物的密度逐渐降低.当树脂道成熟后,上皮细胞壁上则没有果胶酶的反应产物出现.细胞化学证据表明:在树脂道的发育过程中,果胶酶降解树脂道原始细胞细胞壁中层,支持树脂道以裂生方式形成.果胶酶的细胞化学定位技术还可用于其他植物中与果胶水解有关的发育过程.     

烟草花粉母细胞中果胶酶细胞化学定位及其在次生胞间连丝和胞质通道形成中的作用

对果胶酶在烟草(Nicotiana　tabacum　L.)花粉母细胞减数分裂前期Ⅰ的活性进行了电镜细胞化学定位,以研究其在次生胞间连丝和胞质通道形成中的作用。结果表明:在细线期,酶反应产物主要存在于光面内质网及其衍生小泡内;偶线期,当次生胞间连丝和胞质通道开始形成时,反应产物明显增强。同时果胶酶活性也出现在细胞壁上,尤其是出现在简单或者复杂分枝状的胞间连丝和胞质通道内部或沿着它们附近细胞壁的中胶层分布。胞吐小泡中的酶活性表明果胶酶和纤维素酶一样,也是通过内质网及其衍生小泡由胞吐作用分泌到细胞壁的,并在那里通过特异性降解果胶质而和纤维素酶协同作用导致次生胞间连丝和胞质通道的形成。     

烟草花粉母细胞中果胶酶细胞化学定位及其在次生胞间连丝和胞质通道形成中的作用

对果胶酶在烟草(Nicotiana tabacum L.)花粉母细胞减数分裂前期Ⅰ的活性进行了电镜细胞化学定位,以研究其在次生胞间连丝和胞质通道形成中的作用.结果表明:在细线期,酶反应产物主要存在于光面内质网及其衍生小泡内;偶线期,当次生胞间连丝和胞质通道开始形成时,反应产物明显增强.同时果胶酶活性也出现在细胞壁上,尤其是出现在简单或者复杂分枝状的胞间连丝和胞质通道内部或沿着它们附近细胞壁的中胶层分布.胞吐小泡中的酶活性表明果胶酶和纤维素酶一样,也是通过内质网及其衍生小泡由胞吐作用分泌到细胞壁的,并在那里通过特异性降解果胶质而和纤维素酶协同作用导致次生胞间连丝和胞质通道的形成.     

臭椿茎中分泌道的发育及其组织化学研究

利用植物解剖学方法研究臭椿茎和叶柄中分泌道的结构、分布和发育过程.结果表明:臭椿茎和叶柄中的分泌道分布于髓的周缘,次生木质部中无分泌道.分泌道是由一层分泌细胞围绕分泌腔而构成,分泌细胞外有1～2层鞘细胞.分泌道以裂生方式形成,其发育过程可分为3个阶段:原始细胞阶段、形成阶段和成熟阶段.在原始细胞阶段,一群原始细胞具浓厚细胞质,细胞核清晰可见;形成阶段,原始细胞的中央细胞间细胞壁中层降解,细胞壁分离,形成腔隙,随着分泌细胞数量的增加,分泌腔体积扩大;成熟阶段的分泌道具有12～16个分泌细胞,1～2层鞘细胞,分泌腔直径为30～50μm.组织化学研究表明,分泌细胞及分泌道内含物中含大量的萜类、多糖和脂类物质.机械创伤能够诱导次生木质部中产生创伤分泌道.臭椿茎中的分泌道和创伤性分泌道在抵御生物和非生物胁迫中起重要作用.     

杂交鹅掌楸体胚发生过程中ATP酶活性的超微细胞化学定位

利用透射式电镜,通过胚性细胞的超微切片观察,对杂交鹅掌楸体细胞胚胎发生和发育过程中ATP酶活性进行了超微细胞化学定位.结果表明,非胚性细胞的质膜、液泡膜等膜系统当中存在ATP酶活性,质体、核膜、细胞壁以及细胞间隙上有少许沉积;早期胚性细胞ATP酶反应产物主要沉积于质膜、液泡膜上、淀粉粒、细胞壁加厚处;胚性细胞后期ATP酶活性从质膜逐渐转移入细胞内,细胞质、壁旁体、胞间连丝、细胞膜与细胞间隙、细胞核等处均有ATP酶活性反应.随着胚性细胞的发育及分裂,包裹细胞的厚壁、细胞核、核仁与染色质等处也出现ATP酶活性反应沉淀物.说明杂交鹅掌楸体细胞胚胎发生及发育过程中存在丰富的能量代谢.     

枸杞胚性细胞分化的超微结构和ATP酶的细胞化学定位研究

枸杞的胚性细胞多由愈伤组织表层的薄壁细胞分化而来,与愈伤组织中未分化的细胞相比,胚性细胞呈卵圆形,细胞核大,核仁明显,细胞质浓厚并含有丰富的细胞器,细胞壁较薄,细胞间有胞间连丝相通;胚性细胞发育到晚期细胞壁加厚,胞间连丝逐渐消失,细胞核向一端偏移,有大液泡形成;胚性细胞的第一次分裂多为均等分裂,形成二细胞原胚,继续分裂形成多细胞原胚;组成多细胞原胚胚体的细胞核大,核形状不规则,细胞质浓厚,细胞器丰富,在质体中出现淀粉的积累。在胚性细胞发育的早期,ATP酶活性主要位于质膜上,随后在液泡内和细胞核中都出现ATP酶活性的分布;随着胚性细胞壁的加厚,细胞壁加厚处和细胞间隙中也出现ATP酶活性反应;当多细胞原胚形成后,ATP酶活性反应主要定位于液泡膜上。由此分析了结构特征、ATP酶活性定位变化与胚性细胞分化的关系。     

灵武长枣正常果及裂果中Ca2+的细胞化学定位研究

采用焦锑酸钾沉淀法,对灵武长枣正常果发育过程中的Ca2+及不同开裂度果实中的Ca2+进行细胞化学定位,在透射电镜下观察并比较Ca2+的分布特征和积累规律.结果表明:(1)正常长枣青果期的外果皮细胞及胞间隙中检测到大量的钙沉淀颗粒,而果肉细胞以及叶绿体中很少有钙沉淀颗粒.红果期很多外果皮细胞中钙沉淀颗粒特异性地沿细胞壁呈一圈分布,且越靠近内方的细胞中钙沉淀颗粒越少、越小.果肉细胞中仍无钙沉淀颗粒分布.(2)具轻微开裂的长枣很多外果皮细胞中无钙沉淀颗粒,只有少数细胞中有且集中分布于大液泡中;细胞质沿细胞壁分布,也无钙沉淀颗粒;在果肉细胞中几乎看不到钙沉淀颗粒分布.(3)完全开裂的长枣中钙沉淀颗粒只分布在少数体积较小的外果皮细胞中,而果肉细胞的细胞壁边缘或细胞壁以及胞间隙中分布有大量的钙沉淀颗粒.     

小麦条锈菌胞间菌丝的超微结构和细胞化学研究

本文应用电镜技术和细胞化学方法,对小麦条锈菌寄主胞间菌丝的超微结构进行了研究。观察发现:小麦条锈菌胞间菌丝有两种类型,即具隔膜菌丝和无隔膜菌丝。在胞间菌丝中,多核现象极为普遍。常规染色和细胞化学染色结果表明:胞间菌丝的细胞壁由四层组成,隔膜由三层构成,细胞壁的内层与隔膜的外层相连,细胞壁和隔膜中含有蛋白质和多糖物质。隔膜的发育可分三个阶段,即隔膜突的形成,隔膜壁的延伸和隔膜孔结构的形成。本研究中还观察到胞间菌丝间的融合现象。本文的研究结果表明:小麦条锈菌胞间菌丝的一些特征显然不同于其它锈菌。     

油松茎初生结构中树脂道发育的研究

油松茎初生结构中的树脂道是裂生的胞间道,分布在皮层和初生木质部内。皮层树脂道原始细胞团起始于茎端下约140微米处原形成层束两侧的基本分生组织中。在原生韧皮部最早的筛胞分化形成时出现裂生腔隙。其裂隙直径的进一步扩大主要依靠鞘细胞插入到上皮细胞之间和上皮细胞本身的切向伸长。成熟的树脂道近园形,四周由9～16个上皮细胞包被,其外为1～2层鞘细胞。茎的初生结构内树脂道位于皮层内侧的薄壁组织中,通常为8个,排列成一圈。叶迹进入叶子时,其两侧的每一个树脂道也二叉分枝,其一与叶迹一起进入叶子。初生木质部树脂道起源于原形成层细胞,在初生维管组织分化后期才开始发育。每个维管束的初生木质部一般只有一个树脂道。季节的变化对皮层树脂道的形成过程有一定的影响。在一年的不同季节中,从春季到秋季所形成的树脂道出现孔径逐渐变大,上皮细胞的数目和鞘细胞的层数逐渐增多,茎内树脂道的数目增加等变化。     

西瓜胚乳吸器的发育及ATP酶的超微细胞化学定位

报道了西瓜（Citrullus lanatus)胚乳吸器发育过程,并对胚乳吸器细胞中的ATP酶进行了超微细胞化学定位,球形胚早期,胚囊合点端的壁伸长发育成一管状胚乳吸器,进而吸器靠近乳本体端膨大为囊状,球形胚晚期吸器自珠孔端向合点端逐渐细胞化,胚分化出子叶时,胚乳吸器自合点端向珠孔端退化,在刚形成的胚乳吸器细胞中,ATP酶活性反应主要分布在细胞的核膜,内质网上,胞间连丝和吸器细胞壁内的小球状物上也有较强的ATP酶活性反应;在开始退化的吸器细胞中,核膜上的ATP酶性的反应减弱较早,内质网稍晚,进一步退化的胚乳吸器细胞中,ATP酶主要集中分布在细胞壁,细胞间隙内,核上几乎没有ATP酶性反应,内质网上仅有微弱的ATP酶反应。     

Cytochemical studies of pectin digestion in epidermis with specific cell separation

Summary This investigation concerns a unique type of epidermal cells in the anther ofStrelitzia reginae. At dehiscence these cells are released and form multicellular threads. The radial and tangential middle lamella regions of their cell walls disintegrate by the formation of numerous growing and fusing cavities. The possibility that this process could be due to digestion by pectinase was elucidated by use of cytochemical methods. In immature ordinary and thread-forming cells staining for pectin with hydroxylamine-ferric chloride yielded reaction products mainly in the middle lamella region and the subcuticular layer. After the appearance of cavities reaction took place around but not inside these formations. Treatment with fungal pectinase caused degradation of cell walls in ordinary epidermal tissue. Mature cell walls appeared more resistant to the lytic action than immature ones. In thread-forming tissue, independent of the stage of maturation, digestion of the pectin rich regions was induced. However, the fungal enzyme was not able to produce cavities. No pectin reaction with hydroxylamine-ferric chloride was obtained after pectinase treatment.     

Development and Structure of Primary Secretory Ducts in the Stem of Commiphora wightii (Burseraceae)

Development of gum-resin ducts, sites of resin synthesis inthe epithelial cells and elimination of resin from the protoplasthave been studied in the stem of Commiphora wightii. Formationof an intercellular space amongst a group of densely stainedprocambial cells signals the initiation of a duct. It widensby anticlinal divisions of the epithelial cells and also bytheir further separation along the radial walls. The numerousplastids with varying morphological shapes have an electrondense matrix. Starch granules present in the amyloplasts showevidences of exocorrosion. Mitochondria in the epithelial cellsof developing and mature ducts have well developed, swollencristae. Osmiophilic material originates in association withthe golgi-derived vesicles at its maturing face. It is alsoobserved in close association with plastids, mitochondria andvacuoles, thereby plausibly involving them in the process ofresin formation. The resinous material is eliminated from thecytoplasm by vesicles enveloped by plasmalemma prior to theirdischarge into the apoplast. Myelin-like multilamellate structuresobserved along the inner tangential wall may aid in the secretionof resin across the wall. Commiphora wightii, primary secretory ducts, epithelial cells, ultrastructure, gum-resin secretion     

Ultrastructure of the Resin Ducts of Mangifera indica L. (Anacardiaceae). 1. Differentiation and Senescence of the Shoot Ducts

A detailed electron microscope study has led to the conclusionthat the resin ducts of the shoot of Mangifera indica L. developlysigenously. This study has also established several characteristicswhich can serve as criteria for a clear distinction betweenschizogenous and lysigenous cavities. The main characteristicsof lysigenous cavities are: (1) The presence of disorganized cytoplasm in the duct cavity. (2) The presence of wall remains attached to the wall of livingepithelial cells facing the cavity. (3) The presence of specific intercellular spaces at the cellcorners facing the duct lumen. Duct development starts with the disintegration of a file ofcells forming an initial cavity. Later the cells lining thiscavity differentiate into cells secreting lipophilic compounds.As a result of growth and differentiation of the tissues aroundthe duct, its lumen becomes compressed and comes to resemblea branched narrow slit. Such a slit may wrongly be regardedas an initial stage of a schizogenous duct. Disintegration ofepithelial cells occurs throughout all stages of development.Neighbouring cells partly fill the space which is released bydisintegrating cells. At the end of the stage of secretion thecytoplasm of all epithelial cells darkens, preceding their disintegration.This darkening is a gradual process which begins in the vicinityof ribosomes. When all dark epithelial cells disintegrate thecavity widens and the neighbouring parenchyma cells substitutefor the secretory epithelium without undergoing any significantchange in their cytoplasm. Mangifera indica L., mango, resin ducts, ultrastructure     

毛竹竹秆基本组织发育过程中过氧化物酶的超微定位

利用电镜细胞化学技术对毛竹竹秆基本组织发育过程中过氧化物酶进行了细胞化学定位。基本组织细胞过氧化物酶活性由胞间隙处的胞间层开始逐渐向中间推进,同期过氧化物酶体、内质网等细胞器也具有酶活性,随后质膜和液泡膜出现酶反应物。次生壁形成期长细胞壁上过氧化物酶高活性主要集中在次生壁窄层中,以休眠期酶活性最高。随着年龄的增加,长细胞的过氧化物酶活性逐渐降低,九年生长、短细胞的过氧化物酶活性已很弱。短细胞的酶活性始终高于长细胞,细胞壁、质膜、运输小泡膜和纹孔也都具有较高的酶活性。短细胞伸长停止与高过氧化物酶活性有关。过氧化物酶分布和活性并不完全对应于木质素的沉积部位,短细胞的过氧化物酶可能参与了长细胞壁中木质素的合成。     

Structural and Cytochemical Characteristics of the Stigma and Style in Vitis vinifera L. var. Sangiovese (Vitaceae)

Studies were carried out on structural and cytochemical aspectsof the stigma and style ofVitis vinifera . The stigma is ofthe wet papillate type with a continuous cuticle and pellicle.During the development of the papillae, the cell walls increasein thickness and produce a secretion product constituted oflipids that pass through the wall forming the exudate. The styleis solid with a central core of transmitting tissue which hasconspicuous intercellular spaces that increase remarkably fromthe periphery to the centre where the cuticle is present. Theintercellular spaces, where the pollen tubes grow, contain amatrix that includes polysaccharides, pectic substances andscattered areas of lipidic nature. Cytochemistry; stigma; style; ultrastructure; Vitis vinifera     

Sequential actions of pectinases and cellulases during secretory cavity formation in Citrus fruits

Pectinase and cellulase activities are involved in a number of intercellular space-forming processes in plants. In this study, we combined cytochemistry with ultrastructural analysis to investigate the ontogeny of secretory cavity in fruits of Citrus medica L. var. sarcodactylis (Noot.) Swingle, Citrus reticulata Blanco and Citrus limon (L.) Burm. f. Pectinase activity was first detectable at the initial stage of cavity formation, peaked at the intercellular space-forming stage, and diminished at the following stages. In comparison, no cellulase activity was detected until the early lumen-expanding stage. The cellulase activity increased at the late lumen-expanding stage and culminated at the near-mature stage. In the fruit of C. medica var. sarcodactylis, the distribution of pectinase and cellulase reaction products was restricted to the endoplasmic reticulum (ER), the vesicles derived from ER and the cell wall. We also observed that multivesicular structure containing the pectinase reaction product at the initial stage of cavity formation. Our results suggest that pectinase and cellulase are synthesized on ER and secreted directly into the cell wall through exocytosis of ER-derived vesicles. Our observations are consistent with the notion that the secretory cavity in Citrus fruits is formed through a schizolysigenous process in which pectinase activity is involved in the degradation of the middle lamella, whereas cellulase activity is responsible for the degradation of the cell wall.     

Cytochemical localization of adenosine triphosphatase in the phloem of Pisum sativum and its relation to the function of transfer cells

The cytochemical localization of ATPase in differentiating and mature phloem cells of Pisum sativum L. has been studied using a lead precipitation technique. Phloem transfer cells at early stages of differentiation exhibit strong enzyme activity in the endoplasmic reticulum (ER) and some reaction product is deposited on the vacuolar and plasma membranes. As the phloem transfer cells mature and develop their characteristic wall structures, strong enzyme activity can be observed in association with the plasma membranes and nuclear envelopes. Mature phloem transfer cells with elaborate cell-wall ingrowths show ATPase activity evenly distributed on plasma-membrane surfaces. Differentiating sieve elements show little or no enzyme activity. When sieve elements are fully mature they have reaction product in the parietal and stacked cisternae of the ER. There is no ATPase activity associated with P-protein at any stage of sieve-element differentiation or with the sieve-element plasma membranes. It is suggested that the intensive ATPase activity on the plasma membranes of the transfer cells is evidence for a transport system involved in the active movement of photosynthetic products through these cells.Key to labeling in the figures ER endoplasmic reticulum - P parenchyma cell - PP P-protein - SE sieve element - SPP sieve-plate pore - TC transfer cell     

Development, Ultrastructure and Secretion of Gum Ducts in Lannea coromandelica (Houtt.) Merrill (Anacardiaceae)

In Lannea coromandelica (Houtt.) Merrill, the gum ducts in theprimary phloem of the stem initiate and develop schizogenously.Formation of an intercellular space amongst a group of denselystained phloem procambial cells signals the initiation of aduct. Initiation of a duct starts by dissolution of the middlelamella of the walls. It widens by separation of cells alongthe radial walls by swelling and dissolution of the middle lamella.During separation of radial walls dictyosomes and paramuralbodies are observed in the peripheral cytoplasm at the siteof dissolution. Plasmodesmata occur in the radial and innertangential walls of epithelial cells of developing gum ducts.The epithelial cells have a dense cytoplasm and contain roughendoplasmic reticulum, ribosomes, polysomes, mitochondria withswollen cristae, plastids with poorly developed membranes, dictyosomesand vesicles. Dictyosomes and rough endoplasmic reticulum seemto be involved in the secretion of the gum. The polysaccharidegum constituents apparently originate from the outer wall layersof the epithelial cells. Following gum secretion, the epithelialcells degenerate. Lannea coromandelica (Houtt.) Merrill, Anacardiaceae, gum ducts, ultrastructure, gum secretion     

地钱卵发育超微结构和细胞化学的研究

采用电镜和细胞化学技术对地钱(Marchantia polymorpha)卵发生过程进行了研究,根据卵发生过程中细胞化学和超微结构特征可将卵发育过程分为幼卵、中期卵和成熟卵3个阶段.幼卵阶段,卵细胞、腹沟细胞及颈沟细胞间有发达的胞间连丝,但卵与腹沟细胞间的胞间连丝很快退化,幼卵细胞内具大量透明的囊泡,均匀分布于细胞质中;卵发育中期,突出特征是卵细胞质内产生嗜锇性的脂滴,位于囊泡中,与此同时,腹沟细胞退化,其细胞质内产生大型囊泡,囊泡内分泌物与卵细胞外的物质类似,呈PAS反应阳性,表明该物质应为多糖类;卵成熟时,腹沟细胞和颈沟细胞完全退化,卵细胞外包被大量粘性多糖类物质,卵细胞核表面不规则,产生明显的核外突,众多的小泡围绕着细胞核,脂滴聚集成簇,卵细胞内其他细胞器不易区分.卵发育过程中,质体不含淀粉粒,线粒体退化,高尔基体相对发达.地钱卵发育的这些特征显著区分于蕨类植物.