Developmental events in ovules of the ornamental plant Rudbeckia bicolor Nutt

Microscopic observations of R. bicolor ovules showed that tetrasporic embryo sacs of Fritillaria type are formed. In the mature female gametophytes modifications in antipodal cell formation and egg apparatus organization were observed, e.g. morphological resemblance was evident of antipode or synergid to the egg cell. In the central cell cytoplasm of the mature gametophytes the presence of small bodies was a characteristic feature. Development of both embryo and endosperm was observed in ∼73% of ovules at the embryo stage, while retarded or arrested development of the endosperm was found in ∼26% of them. Occasionally, two embryos occurred in the embryo sac. This is the first record of polyembryony in this species. Although hemigamy has been previously described in Rudbeckia bicolor Nutt., in the present investigations mosaic structure of embryos was not detected. Measurements of the C-DNA amount (flow cytometry) revealed embryo nuclei with 2C DNA content only, and endosperm nuclei with 5C DNA content in the mature seeds. No peak corresponding to 1C nuclei was detected in the histograms obtained from the nuclear preparation of seeds or seedling parts. These results suggest that hemigamy is not an obligatory phenomenon in R. bicolor. The mean 2C DNA value was determined as 14.51 pg (the first estimation for this species).     

西瓜不同发育时期的助细胞超微结构的变化（简报）

The ultrastructure of synergids of watermelon (Citrullus Lanatus L.) was investigated using transmission electron microscopy at following stages of embryo sacs: 1. Unpollination, on the first flowering day. 2. Unpollination, on 2nd day after anthesis (DAA). 3. Fertilization, on DAA 2. The synergids with distinct filiform apparatus at the micropylar end have abundant organelle, such as mitochondria, endoplasmic reticulum, and plastids in cytoplasm, which indicate that they are active on the first flowering day. No wall is present at the chalazal part of synergid, and there are some flocculent materials and vesicles in the spaces of cytoplasma membranes among synergid, egg cell and central cell in embryo sacs at the first and the second stages. On DAA 2, in unpollinated embryo sacs, the central large vacuole of synergid is divided into several smaller ones and the starch grains decrease in cytoplasm. There is no newly synthesized wall at the chalazal end of persistent synergid in fertilized embryo sacs. The contents of degenerated synergid, in the form of electron dense granules, are located in the wide space among central cell, zygote and persistent synergid, and some of them migrate into central cell through cytoplasma membrane. Therefore, it is deduced that the contents of synergid might serve as a nutrient supplement to the development of endosperm, but not embryo.     

Abnormal Behavior of Nuclei and Microtubule (MT) Organizational Changes During Embryo Sac Development in the Poly-Egg Mutant,APⅣ of Rice

APⅣ is a rice mutant that develops poly-egg apparatus in its embryo sac. All the eggs that make up the poly-egg apparatus can be fertilized respectively resulting in the development of polyembryony. The routes taken in the development of polyembryony appear to fall mainly into three variant polygonum pattern types, designated as 5-2-1 , 5-3-0 and 6-2-0 types. Out of the embryo sacs of APⅣ studied about 50% exhibited variant polygonum type with associated abnormal nuclear behavior and microtubule organizational changes. Some of the major abnormal features shown by the three variant polygonum types were described and they included the following: For the 5-2-1 type At the beginning of the four-nucleate embryo sac development, one pair of nuclei became located to the micropylar end and the other pair to the chalazal end. As embryo sac further developed, long connecting microtubule (MT) bundles that existed between the two nuclei in the chalazal end play a role in the movement and positioning of that nucleus. As a result of the activities of these MT, one of the nuclei in the chalazal end moved to the micropylar end resulting in the micropylar end having three nuclei and the chalazal end only one. For the 5-3-0 type In the two-nucleate embryo sac of the 5-3-0 type, one nucleus remained at the micro-pylar end, while the other one became located near the central region. In the four-nucleate embryo sac, the pair of nuclei aligned in parallel to the micropylar-chalazal axis often having one of its nuclei relocated to the micropylar end as a result of associated MT activities. For the 6-2-0 type All the nuclei in the megaspore, two- and four-nucleate embryo sacs became located to the micropylar end. At the early stages of the eight-nucleate embryo sac development, the two nuclei in the central region of the embryo sac (originally at the micropylar end) became polar nuclei. All the other nuclei remained at the micropylar end were surrounded by reticulate MT. The relationship between abnormal behavior of nuclei and MT organi-zation in the development of rice embryo sac was discussed.     

西瓜不同发育时期的助细胞超微结构的变化

被子植物胚囊的“雌性生殖单位”,已在多种植物上进行了超微结构的观察,但大多都以卵细胞受精前后的结构变化为主要研究内容。对于“雌性生殖单位”中的另一重要成员——助细胞,在不同发育状态下其结构变化的详细资料不多,尤其是助细胞退化后的物质去向,少见报道。本研究主要观察了西瓜不同发育时期(受精前后)、不同发育状态(柱头授粉和未授粉)的助细胞超微结构,以期为研究助细胞在双受精中所起作用提供新的资     

龙须草无融合生殖的胚胎学证据

采用石蜡切片技术对龙须草(Eulaliopsis binata(Rotz)C.E.Hubb)进行了系统的胚胎学研究,证明龙须草为禾本科植物中一种新的无融合生殖材料.龙须草无融合生殖方式为无孢子生殖,在胚珠发育早期,多个珠心细胞特化为无孢子生殖原始细胞,由原始细胞发育为单核胚囊,经两次有丝分裂形成4核胚囊,进一步分化形成两种类型的成熟胚囊:(1)具1个卵细胞,1个助细胞和2个极核,占观察总数的67.6%;(2)具1个卵细胞,2个助细胞和1个极核,占观察总数的32.4%.胚囊发育属大黍型.多个无孢子生殖原始细胞可以同时发育,最后形成2个或多个胚囊,其比例为17.7%.胚珠内没有有性胚囊的发育.胚的发生有两种类型:(1)早发生胚(74%),开花前1～2 d,极核未分裂前卵细胞分裂形成胚;(2)迟发生胚(26%),开花后2～3 d,极核分裂形成多个胚乳游离核后,卵细胞启动分裂形成胚.存在多胚现象,多胚来自不同胚囊内卵细胞的孤雌生殖,多胚发生率为13%.胚乳由极核不经受精自发分裂产生.     

Isolation of Fertilized Embryo Sacs and Zygotes and Triggering of Zygote Division in Vitro in Nicotiana tabacum

Three methods were established to isolate fertilized embryo sacs in Nicotiana tabacum, i. e. enzymatic maceration combined either with shaking, microdissection or grinding respectively. Living fertilized embryo sacs of various developmental stages after fertilization could be isolated successfully by these methods. Each method had its own adoptation to the materials of different developmental stages. Among them the method of enzymatic maceration combined with grinding was the best:Ovules were first treated in enzymatic mixture (1% cellulase R-10, 0.5% macerozyme R-10, 12% mannitol, pH 5.7) for about 30 min. Then droplets of the ovule suspension were gentlely grinded by a flat-headed glass rod. After grinding several droplets of mannitol solution (8%～ 10%) were added for releasing and washing embryo sacs. Compared with the other two methods this method was more convenent and had higher isolation efficiency. Isolation of fertilized embryo sacs offered a good means for microscopic observation on the postfertilization development including synergid degeneration, endosperm formation and zygotic changes without interference by the surrounding sporophytic tissue. Living zygotes and endosperm cells could be further isolated by a second enzymatic maceration procedure followed by brief micromanipulation. Several characters had been found to distinguish the protoplas'ts of free zygotes from those of other cell sources. Isolated zygotes were cultured in microchambers (Millicell-CM) feeded with macrocultured mesophyll protoplasts. The first division of zygotes was induced, resulting in proembryos consisting of two cells.     

Embryogenesis of Polyembryonic Rice ApⅢ: Structural and Histochemical Studies of Egg Apparatus Around Fertilization

The structural and histochemical changes of the egg apparatus in the polyembryonic rice (Oryza sativa L.), ApⅢ with the highest frequence of additional embryos among the polyembryonic rice investigated, before and after fertilization were studied and compared with those of normal and other polyembryonic rices in a similar developmental period. A total of 2 932 ovules were observed and each of them contained only asingle embryo sac with a set of egg apparatus. Among 1 655 embryo sacs, there were 1 643 embryo sacs (99.27%) with one normal egg apparatus in each embryo sac, and only 12 embryo sacs (0.73%) from the remainder with 4 celled egg apparatus, i.e. two eggs and two synergids. Neither the numerous poly egg apparatus and egg like cells, nor the double set of embryo sacs each containing one egg apparatus and other abnormal egg apparatus in single ovary, which were reported by earlier investigators to have high frequency of embryo production in SB 1 and ApⅣ, were observed. The egg cell was located at the subterminal site of the micropylar end of embryo sac. The cytoplasm of egg cell was rich in protein materials and poly saccharide grains, which did not disappear until the division of zygote. The prominent nucleus was closely surrounded by protein and polysaccharide grains, which did not disappear until the division of zygote. No cytological difference was found between egg cells from the normal and abnormal egg apparatus. The two synergids were fully developed and situated at the upper most part of the micropylar end of the mature embryo sac. In most embryo sacs, the synergids were flask shaped with longer necks, and a widened cap shaped top, in close contact with the micropyle. The synergids had a well developed filiform apparatus. The characteristic appearance of the filiform apparatus as well as the cap neck region of synergids before and after pollen tube penetration were easily distinguishable from the egg cell. The structure, the stainability with Coomassie Brilliant Blue and PAS reaction, the process of accumulation, distribution and disapperance of the cytoplasmic protein materials and polysaccharide grains of the two synergids, the persistent and rarely the receptive synergids before and after pollen tube penetration, were closely similar to those of egg cell of the same developmental stage. In comparison with normal and other polyembryonic rice reported, the size of nucleus and nucleolus and their stainability also strongly resembled those of egg cell. Based on the results observed, the main conclusions are summarized as follows: (1) the additional embryos very frequently developed in the young and mature seed of polyembryonic rice ApⅢ were produced by one or two synergids of normal egg apparatus, rarely by 4 celled egg apparatus; (2) during fertilization, the synergids, in addition to the natural specific function of introducing pollen tube and transferring sperms to egg cell and central cell, could be closely associated with the potentiality to breed one or two additional embryos; and (3) as compared with that of normal or other polyembryonic rice it is firstly disclosed that in a few embryo sacs of ApⅢ, the cytoplasmic and nuclear structure, the active anabolism and catabolism of protein and polysaccharide materials and the delayed disorganization at the mid basal region of the receptive and persistent synergid still remained unchanged before the division of zygote. Such salient features could be the predisposition for the origin of additional embryos in ApⅢ.     

Effects of partial endosperm removal on embryo dormancy breaking and salt tolerance of <Emphasis Type="Italic">Hordeum spontaneum</Emphasis> seeds

Seed damage is a common phenomenon in nature and in agricultural production. In this experiment, partial endosperm removal from wild barley (Hordeum spontaneum) caryopses, sampled from three ecotypes originated from xeric environments in Israel, was conducted. The aim was to examine seed dormancy and germination states in damaged caryopses and salt tolerance of young seedlings derived from them. Six treatments were made: (1) control seeds with intact caryopses; (2–4) removal of 0.25, 0.5, and 0.75 of the length of intact caryopses; (5) transection at the points, at which the endosperm and embryo meet; and (6) slitting of endosperm opposite the embryo. A significant negative correlation was found between germination percentage (dormancy release) and the relative distance from the dissection point to embryo. Partial removal of the endosperm could accelerate dormancy release. Seedling salt tolerance was assessed by the ratio of root or coleoptile length in a seedling grown in 100 or 200 mM NaCl solution to that of a seedling grown in water. The seedling salt tolerance was positively correlated with the removed portion of the seed endosperm. For each level of endosperm removal, the salt tolerance to 200 mM NaCl of the seedlings derived from the Dead Sea ecotype was higher than those from both the Sede Boker and the Mehola ecotypes. The results suggest that partial damage to seed endosperms in natural conditions may play a role in increasing the phenotypic plasticity of germination and salt tolerance.     

Further Embryological Studies on the in Vitro Apogamy in Oryza saliva L.

In the cultured young ovaries of rice, the processes of megagametophyte develop- ment could be switched to the formation of various abnormally organized embryo sacs and then to the initiation of synergid apogamy. The main pathway leading to apogamy was found to go via a linearly oriented 4-nucleate embryo sac to the formation of a li- nearly oriented egg apparatus, from which it was usually the chalazal synergid giving rise to an apogamous proembryo, and the micropylar synergid degenerated. The proembryo thus produced was located at the base of a vacuolated egg cell (Plate Ⅰ, 1–7). The second pathway went through a nonlinearly oriented 4-nucleate embryo sac to the formation of an egg apparatus in which the two synergids were located at one side of the egg and oriented longitudinally. In this case it was often the chalazal synergid that could be triggered to apogamy, resulting in a hook-shaped proembryo embracing the egg cel1 from one side (Plate Ⅰ, 8–11). When ovaries with nearly matured embryo sac were cultured, in a few cases where apogamy was induced, the proembryos observed were all situated at one side of the egg and were hook-shaped (Plate Ⅰ, 12). All these pathways are summarized in a diagram (Fig. 23). Some interesting changes were observed in the synergid and the egg cell of the cultured ovaries by PAS reaction and mercuric bromphenol blue staining. The egg cells, in contrast to in vivo condition, often contained abundant starch grains,. The synergids and synergid proembryos were rich of cytoplasmic protein (Plate Ⅱ, 13, 14). We supposed that the egg may supply some nutrients as well as stimulants to the developing synergid in the course of apogamy. The distribution of starch and protein in apogamous embryoids during subsequent development was also described in this paper (Plate, 15–22).     

Embryological Observation on the Apomictic Rice-ApⅢ (Shuang 13)

Since 1988s, the phenomenon of multiple seedlings and multiple embryoes of apomictic rice, Ap Ⅲ (Shuang 13) has been interestingly concerned. Embryological investigation of Ap Ⅲ has been carried out with the whole dissection and conventional sectioning technique. The main conclusions are as follows: 1.8. 9 % of 5000 matured caryopsises, contained one embryo in a caryopsis, from which single seedling arose, while 8.9 % twin embryoes and 1.2 % triplet embryoes of which developed two seedlings and triple seedlings respectively; 2. In over 700 young caryopsises, 90.0%～95.0% contained only one embryo, 5.0%～7.0% twin embryoes, except a few of the ovules with absorptive embryo sac or embryo and endosperm. Triplet embryoes caryopsis could not be traced further due to their low frequency; 3. Authors' materials showed that all the single, twin and triplet embryoes were situated at the micropylar end in one embryo sac of young ovule and no adventitious embryo was seen outside the embryo sac of ovules. From the aforementioned results, it can be infered that albeit single embryo is derived from the egg cell yet it could be possible twin or triplet embryocs may be developed from the egg cell and one or two of the synergids either or not through fertilization.     

Polyembryony increases embryo and seedling mortality but also enhances seed individual survival in Handroanthus species (Bignoniaceae)

Polyembryony seems to be advantageous to mother plants in detriment of their siblings which face competition since the beginning of seed development. This competition may limit the turnover of embryos into seedlings and their survival ability. We analysed polyembryony frequency and embryo to seedling turnover in three Handroanthus species with sporophytic apomixis. We tested if the embryo number per seed affected seed and embryo morphometry, seedling survival ability and seed individual survival (i.e. survival of at least one seedling per seed). The number of embryos per seed was compared with seedling number at different developmental stages. All 14 populations showed high frequencies of polyembryonic seeds (21–91%). As the number of embryos per seed increased (up to eight embryos/seed), there was a reduction of mean embryo mass, area, seedling length, individual seedling survival ability, and embryo to seedling turnover. There was also an increase in embryo morphological anomalies. However, enhanced seed individual survival was also observed. Thus, the high frequency of polyembryonic seeds and the increase in seed individual survival support the idea that polyembryony represents an alternative reproductive mechanism which can favours these species.     

Rice alcohol dehydrogenase 1 promotes survival and has a major impact on carbohydrate metabolism in the embryo and endosperm when seeds are germinated in partially oxygenated water

Background and Aims

Rice (Oryza sativa) has the rare ability to germinate and elongate a coleoptile under oxygen-deficient conditions, which include both hypoxia and anoxia. It has previously been shown that ALCOHOL DEHYDROGENASE 1 (ADH1) is required for cell division and cell elongation in the coleoptile of submerged rice seedlings by means of studies using a rice ADH1-deficient mutant, reduced adh activity (rad). The aim of this study was to understand how low ADH1 in rice affects carbohydrate metabolism in the embryo and endosperm, and lactate and alanine synthesis in the embryo during germination and subsequent coleoptile growth in submerged seedlings.

Methods

Wild-type and rad mutant rice seeds were germinated and grown under complete submergence. At 1, 3, 5 and 7 d after imbibition, the embryo and endosperm were separated and several of their metabolites were measured and compared.

Key results

In the rad embryo, the rate of ethanol fermentation was halved, while lactate and alanine concentrations were 2·4- and 5·7- fold higher in the mutant than in the wild type. Glucose and fructose concentrations in the embryos increased with time in the wild type, but not in the rad mutant. The rad mutant endosperm had lower amounts of the α-amylases RAMY1A and RAMY3D, resulting in less starch degradation and lower glucose concentrations.

Conclusions

These results suggest that ADH1 is essential for sugar metabolism via glycolysis to ethanol fermentation in both the embryo and endosperm. In the endosperm, energy is presumably needed for synthesis of the amylases and for sucrose synthesis in the endosperm, as well as for sugar transport to the embryo.     

柽柳胚和胚乳发育的观察

利用常规石蜡制片技术,对柽柳（Tamarix chinensis Lour.）胚和胚乳的发育过程进行了观察。结果表明,胚发育属茄型,其基细胞先行纵裂。胚柄基部发育迅速,具吸器作用,球形胚期胚柄最为发达,其细胞质丰富,贮藏淀粉类物质,至晚心形胚期胚柄依然存在。助细胞被受精产生多胚现象。胚乳发育属核型,初生胚乳核常常晚于合子分裂,胚乳核的分裂速度慢于胚体细胞的分裂速度。当胚乳游离核为 32个时,以自由生长细胞壁的方式进行胚乳细胞化。胚乳细胞进一步增殖极少。珠心细胞只有两层,细胞核大,胞质丰富,内含贮藏物质,至心形胚期逐渐解体。     

竹节参雌配子体发育的研究

本文报道了竹节参(Panax japonicus C.A.Mey)雌配子体(胚囊)的发育过程。竹节参大孢子母细胞减数分裂产生线形排列的大孢子四分体。胚囊发育属蓼型,由合点端大孢子发育而成。游离核胚囊时期,胚囊珠孔端的细胞器种类和数量都较胚囊合点端多;胚囊合点端相邻的珠被细胞中有含淀粉粒的小质体,与胚囊珠孔端相邻的退化中的非功能大孢子中则有含淀粉粒的大质体和大类脂体。成熟胚囊中,反足细胞较早退化;极核融合成次生核;卵细胞高度液泡化,细胞器数量较少;助细胞则有丰富的细胞器和发达的丝状器。PAS反应表明,受精前的成熟胚囊中积累淀粉粒。次生核受精后,很快分裂产生胚乳游离核,到几十至数百个核时形成胚乳细胞。卵细胞受精后则要经过较长的休眠期。     

大葱卵器及受精后助细胞的超微结构

章丘大葱（Ａllium fistulosum L.cv.Zhangqiu)的卵器由１个卵细胞及２个助细胞组成,观察到不少卵器没有卵细胞,只有２个助细胞。卵细胞的核及大部分细胞质位于细胞的合点端,１个大液泡占据了细胞其他部位。卵细胞含有很多的核糖体及多聚核糖体、嵴明显的线粒体、粗面内质网、高尔基体具小泡,卵细胞似是一个活跃的细胞。细胞外被细胞壁,其合点端及侧方与助细胞共同壁不连续,助细胞有一较大的核,位于细胞膨大的部位,众多的小液泡遍布细胞中。核糖体及聚合核糖体、线粒体,粗面内质网及风心圆环状粗面内质丰富,高尔基体及小泡常见,反映了其活跃的代谢作用。助细胞合点端及侧方与卵细胞、中央细胞的共同壁不连续,与卵细胞共同壁含胞间连丝,壁不连续处,有不状多层膜结构伸入卵细胞质,显示助细胞可能对卵细胞提供营养,伟粉后,一个助细胞退化,宿存助细胞至随胚胚期尚存在,它经历了一个缓慢的退化过程,出现质壁分离,细胞质变稀,液泡扩大,细胞器逐渐减少,在椭形胚期,宿存助细胞核内的染色质及核仁消失,有细胞质侵入核内,因宿存助细胞壁变厚,细胞质出现现脂滴,宿存助细胞可能仍有合成功能,宿存助细胞壁出现若干无壁部位,细胞内的营养物质可能通过无壁部位向胚乳转运,供游离核胚乳及胚乳细胞化初期的发育。     

Morphological Observation on “Polyembryonic Seedling” of Rice

The formation of the so-called polyembryonic seedling and its morphology were observed. The main conclusions are as follows: 1. All caryopses contain only one embryo; 2, “The polyembryonic seedling” reported is actually single seedling with 1 or 2 lateral shoots sprouted from the main shoot. The first lateral shoot arises from the axil of coleoptile and the second one from the axil of lower leaf in the first lateral shoot. These lateral shoots are not independent seedlings. The formation of lateral shoot in wheat is the same as that of rice as mentioned above. The authors had dissected 1500 rice caryopses, 1600 young seedlings from the field and 1102 seedlings germinated under artificial conditions. Thus, polyembryonic seedlings as preriously reported is not present, at least, in rice C1001B line.     

The Ultrastructural Study on the Early Embryonic Development of Radish

The ultrastructure of the mature embryo sac, the early stages of the embryo and endosperm development of common radish, Raphanur sativus was examined. The embryo sac consists of 7 cells with antipodal ceils disappeared when it matures. The egg cell is highly polarized. The wall surrounded the chalazal end of the egg cell is incomplete, showing a discontinuous structure of an electron dense material deposited intermittently in the space between the two plasma membranes of the egg cell and central cell. The synergid has filiform apparatus, rich in organelles and well developed ER. The two polar nuclei of the central cell are located near the egg apparatus because of the big vacuole, and the finger-like protrutions from the cell wall, as that in synergid, are found. The first division of the zygote occurs 4–5 days after pollination and the development of the embryo follows the Onagrad type, and the structure of the embryo cell is quite simple for containing small quantity of ER, plastids and other organelles. The primary endosperm nucleus deviates 2 days earlier than zygote. The endosperm is of nuclear-endosperm containing chloroplasts, well developed ER, and plentiful of mitochondria and golgi bodies and the nodule-like aggregation in both. the chalazal and micropylar ends of the embryo sac during the early development appeared, and cell wall starting at the micropylar end by freely-growing forms about 16 days after pollination.     

同源四倍体水稻受精与胚胎形成过程的观察

激光扫描共聚焦显微术具有“组织与细胞CT”的功能,可以对整体组织进行扫描并构建三维结构。在水稻胚囊发育研究上建立的整体染色透明激光扫描共聚焦显微术辅助D IC法,对同源四倍体水稻广陆矮4号-4x和L202-4x受精和胚胎发育过程进行了研究,描述授粉后不同时段胚囊发育的特点,发现同源四倍体水稻受精、胚胎和胚乳发育过程及特点与正常的二倍体水稻的基本一致,但在不同发育时段中存在无胚、无胚乳胚囊、胚乳吞噬胚、胚胎发育停滞、胚囊退化等异常。2份材料的异常情况存在差异。这些异常均可能导致结实率降低。     

Synergids and filiform apparatus in the sexual and apomictic dandelions from section Palustria (Taraxacum, Asteraceae)

An evolutionary trend to reduce “unnecessary costs” associated with the sexual reproduction of their amphimictic ancestors, which may result in greater reproductive success, has been observed among the obligatory apomicts. However, in the case of the female gametophyte, knowledge about this trend in apomicts is not sufficient because most of the ultrastructural studies of the female gametophyte have dealt with amphimictic angiosperms. In this paper, we tested the hypothesis that, in contrast to amphimictic plants, synergids in apomictic embryo sacs do not form a filiform apparatus. We compared the synergid structure in two dandelions from sect. Palustria: the amphimictic diploid Taraxacum tenuifolium and the apomictic tetraploid, male-sterile Taraxacum brandenburgicum. Synergids in both species possessed a filiform apparatus. In T. brandenburgicum, both synergids persisted for a long time without any degeneration, in spite of the presence of an embryo and endosperm. We propose that the persistent synergids in apomicts may play a role in the transport of nutrients to the embryo.     

Polar distribution dynamics of Con A binding sites in embryo sacs is temporally coupled by the fertilization process

The binding site distribution of concanavalin agglutinin (Con A) and wheat germ agglutinin (WGA) on embryo sacs at various developmental stages of Torenia fournieri L was studied by using a cooled Charge Coupled Device (CCD) and fluorescent Con A and WGA probes. The distribution patterns of Con A and WGA binding sites on embryo sacs changed during the fertilization process. The fluorescent signal indicating Con A binding sites was distributed evenly on the surface of the embryo sac wall before anthesis, was much denser on the micropylar end of the embryo sac wall and looked like a corona on the day of anthesis. After pollination, stronger fluorescence was present on the micropylar end of the embryo sac wall and the filiform apparatus (FA), showing an obvious polar distribution. When the pollen tube entered the embryo sac and reached a synergid, the fluorescence was still concentrated on the micropylar end and FA, and started to appear on the synergid. After fertilization, the polar distribution of the fluorescence gradually disappeared and an even distribution pattern was observed again on the embryo sac wall. These results revealed that the dynamic distribution of Con A binding sites was temporally coupled with the process of fertilization. WGA binding site distribution on the embryo sac was also investigated and showed a simple pattern but also regularly changed during the process of fertilization. The variation of these lectin binding sites during the fertilization process suggests that lectin binding site interactions may play a role in the process.