植物细胞壁同聚半乳糖醛酸的代谢与功能

果胶是细胞壁多糖的重要组成成分,对植物正常的生长发育十分重要。作为初生细胞壁中果胶的一种主要组成成分,同聚半乳糖醛酸（homogalacturonan,HG）是由α-D-半乳糖醛酸单体经α-（1,4）-糖苷键连接起来的一种长链大分子物质。HG的合成和降解参与了细胞壁中的多糖代谢,影响了细胞壁的结构和功能。同时,HG精确的去甲酯化以及HG所参与的细胞壁关联激酶（WAKs）和促分裂原活化蛋白激酶（MAPKs）相关的信号转导途径,在植物生长发育中也发挥着重要作用。该文主要从HG的合成、降解和循环利用以及HG的作用等方面对植物细胞壁中HG的研究进展进行了阐述。     

水稻84-15细胞胚胎学的研究

粳稻品种８４＿１５是非洲长花药野生稻（Ｏ．ｌｏｎｇｉｓｔａｍｉｎａｔａ）和栽培稻８０＿６１９５杂交,在杂种第三代出现的不分离粳稻品系。它们的杂种Ｆ１０代农艺性状保持整齐一致（赵世绪,１９９０;陈建三,１９９５）。它比水稻品种郑粳１０７增产２２．２％。用粳稻８４＿１５与水稻喜峰杂交,在杂种第二代选育出中新一号比秋光增产１１％,已种植Ｆ１０代农艺性状保持一致。为了证实粳稻８４＿１５固定杂种优势的原因,我们进行了细胞胚胎学的研究。通过研究发现了粳稻８４＿１５珠心胚生殖现象（陈建三,１９８８;１９９０;１９９１）。本文旨在进一步研究此种现象。     

桃果实采后贮藏过程中细胞壁多糖的变化

以‘雨花三号’水蜜桃果实为试材,分别在5℃（低温）和20℃（常温）贮藏一段时间后,研究桃果实采后细胞壁多糖降解、硬度以及乙烯释放速率的变化特征。结果表明,乙烯释放高峰明显滞后于果实采后硬度的快速下降期。不同温度下贮藏过程中果实细胞壁多糖变化的对比表明,低温抑制了细胞壁果胶和细胞壁其余组分的变化,从而抑制了果实的软化。富含半乳糖醛酸的果胶主链断裂。果胶和细胞壁其余组分也发生了半乳糖和阿拉伯糖等中性糖的损失,说明果胶和细胞壁其余组分的增溶及其侧链中性糖的降解也是桃果实采后软化的重要因素,这可能是由多种相关多糖降解酶的作用所导致的。但半纤维素多糖中中性糖的降解对桃果实采后软化的进程并没有影响。     

水稻84-15细胞胚胎学的研究

粳稻品种84-15是非洲长花药野生稻(O．longistaminata)和栽培稻80-6195杂交,在杂种第三代出现的不分离粳稻品系。它们的杂种F10代农艺性状保持整齐—致(赵世绪,1990;陈建三,1995)。它比水稻品种郑粳107增产 22.2％。用粳稻84-15与水稻喜峰杂交,在杂种第二代选育出中新一号比秋光增产11％,已种植F10代农艺性状保持—致。为了证实粳稻84-15固定杂种优势的原因,我们进行了细胞胚胎学的研究。通过研究发现了粳稻84-15珠心胚生殖现象(陈建三,1988;1990;1991)。本文旨在进一步研究此种现象。     

益智传粉生物学的研究

 益智（Alpinia oxyphylla）的花期从2月底至4月下旬;单株花期（花序）约为16～26 d,通常为23～26 d;单花花期一般为1 d。正常情况下,益智和其它山姜属植物一样,具有花柱卷曲性促进异花授粉的机制,表现出两种类型：花柱上举型和花柱下垂型,其花柱卷曲运动的节律与其它已报道的山姜属植物基本一致。但观察发现,当遭遇低温天气时(日最高气温<18℃),单花花期延长为2 d,无论是上举型个体还是下垂型个体,均只表现出一种花型——下垂型：上午开花时花柱弯向上,柱头位于已开裂散发出花粉的花药上方,直到第二天上午6∶30～11∶00间,花柱才陆续地慢慢向下运动,柱头下降至与花药等高或位于花药下方。益智的主要传粉昆虫是蜜蜂（Apidae sp.）、木蜂（Xylocopa sp.）,绝大多数的访花者的访花目的是吸蜜。益智的花蜜分泌量（8.37～15.79 μl）和花蜜含糖量（30.12%～32.83%）较高,花蜜是益智作为传粉者访花的最主要的报酬。实验结果还表明,益智花部中唇瓣对昆虫访花有显著的招引作用;益智的花蜜对蜜蜂的访花频率有显著的影响,对木蜂有一定的招引作用,但并不显著。而花粉（花药）则对昆虫的访花频率影响不大。人工授粉实验结果表明益智存在自交亲和性,无论是上举型或下垂型个体自交和异交均有较高的结实率;人工自交和异交的结实率在上举型植株中存在较大的差异,而在下垂型个体中则差异不明显;去雄套袋、去柱头套袋和完全套袋不授粉等处理均不结实,表明益智不存在无融合生殖现象和自动自花授粉现象。益智的繁育系统是异花授粉交配系统。     

云南油杉原胚发育过程中组织化学的变化

应用组织化学方法对云南油杉(Keteleeria evelyniana Mast)受精前后,原胚及幼胚形成早期细胞内的DNA、RNA、碱性蛋白质,酸性蛋白质及多糖物质进行了观察。结果表明,DNA在卵核受精前后为孚尔根弱正反应。在原胚及早期幼胚发育过程中,胚原细胞核DNA含量恢复正常,RNA及酸性蛋白质含量均较丰富,特别是在胚原细胞内。新细胞质中碱性蛋白质呈负反应,而DNA、RNA、酸性蛋白质及多糖物质均呈现正反应。     

南药益智AFLP-PCR体系的建立与优化

[目的]建立适合南药益智的扩增片段长度多态性(AFLP)扩增体系来研究不同地理居群益智遗传多样性。[方法]利用植物基因组试剂盒法提取高质量的益智基因组DNA,采用单因素和正交试验对AFLP过程中的酶切和PCR相关影响因素进行优化,并对适合益智AFLP分析的引物组合进行筛选。[结果]实验结果表明最佳酶切反应体系:模板DNA 0.6μg,酶量20 U,酶切时间2 h;最佳AFLP-PCR选择性扩增反应体系(总体积为25μL):10×PCR Buffer(不含Mg2+)2.5μL,d NTPs 2μL,Mg2+(25mmol/L)1.5μL,引物(10 pmol/μL)各2.0μL,Taq酶(5 U/ml)0.5μL,模板稀释25倍2μL。利用建立的最佳扩增体系从64对引物中筛选获得8对选择性引物适合益智AFLP分析。[结论]建立了稳定的AFLP-PCR体系,为研究益智遗传多样性的AFLP分析奠定了基础。     

桃果实成熟前后细胞壁成分和降解酶活性的变化及其与果实硬度的关系

比较桃品种‘双久红’和‘川中岛白桃’果实成熟前后20 d内果肉硬度、细胞壁成分和细胞壁降解酶活性变化的结果表明,桃果实成熟5 d后,‘双久红’桃果实的硬度、纤维素含量和原果胶含量均极显著高于‘川中岛白桃’:从成熟前15 d开始,‘双久红’的水溶性果胶含量、多聚半乳糖醛酸酶活性和纤维素酶活性均极显著低于‘川中岛白桃’;整个成熟期间,‘双久红’的果胶甲酯酶活性明显低于‘川中岛白桃’。相关分析表明,果实硬度与原果胶、纤维素含量呈极显著正相关,而与可溶性果胶含量、多聚半乳糖醛酸酶活性和纤维素酶活性呈极显著负相关。     

胚乳细胞壁的建成及其与胞质微管的关系

综述了被子植物核型胚乳发育的不同阶段(合胞体时期、初始垂周壁形成期、初始平周壁形成期和胚乳细胞分裂增生期)胚乳细胞壁建成的各种观点,以及在各个阶段中微管与胚乳细胞壁建成之间关系的最新研究进展。并分别比较了胚乳细胞化过程不同阶段胚乳游离核或胚乳细胞有丝分裂与分生组织细胞有丝分裂微管周期的差异。     

HISTOLOGICAL AND HISTOCHEMICAL CHANGES IN DEVELOPING AND RIPENING PEACHES. II. THE CELL WALLS AND PECTINS

Reeve , R. M. (U.S.D.A., Albany, California.) Histological and histochemical changes in developing and ripening peaches. II. The cell walls and pectins. Amer. Jour. Bot. 46(4): 241–247. Illus. 1959.—Histological and histochemical observations on developing and ripening clingstone and freestone peaches have revealed that, after cell divisions have ceased in the mesocarp, cell wall thickening and cell enlargement in the mesocarp parenchyma increase until the fruit is nearly full cell size. The cell walls then decrease in thickness as the fruit ripens and softens. Degree of methyl esterification of the pectic substances, as estimated histochemically, remains at about 75–80% in immature fruits during their cell-enlargement phase of growth. Percent of methyl esterification apparently is much lower, or amounts of esterified pectates are very low during the meristematic phases of fruit growth. Just prior to ripening, degree of esterification increases and approaches 100% in hard, ripe fruit at about the same time that the parenchyma cell walls exhibit their greatest thickness or degree of hydration. The degree of esterification of the pectic substances then rapidly decreases and the cell walls become appreciably thinner as the ripening fruit softens. Further relation of these changes in wall thickness, in degree of esterification of the pectins, and in other cell wall carbohydrates to the textural qualities of ripening fruits is discussed. Interpretations concerning cell wall plasticity, cell growth and relation between auxin and changes in pectins also are presented.     

CHEMICAL COMPOSITION AND STRUCTURE OF THE CELL WALLS OF THE CONCHOCELIS AND THALLUS PHASES OF PORPHYRA TENERA (RHODOPHYCEAE)1,2

Purified cell walls were prepared from both the conchocelis and thallus phases of Porphyra tenera (Kjellm.). The nitrogen content of cell walls from the conchocelis was significantly greater than that for the thallus cell walls, being 3.35 ± 0.26% and 2.39± 0.03%, respectively. Amino acid analysis revealed important differences. The conchocelis cell wall hydrolyzates were richer in aspartic acid, glutamic acid, methionine, and basic amino acids. The thallus cell wall hydrolyzates, however, contained much more glycine and alanine than did those of the conchocelis. Hydroxyproline was not detected in cell walls of either phase. The neutral sugar content of cell wall hydrolyzates from the thallus was more than double that from the conchocelis being 83.6% and 34.5%, respectively. The former contained predominantly mannose which accounted for 72.2% of the neutral sugars while the latter was principally galactose (49.9%) and glucose (36.4%). Methylation analysis confirmed the presence of cellulose microfibrils in the conchocelis in contrast to xylan microfibrils in the thallus. The results establish that the conchocelis and thallus phases of P. tenera differ markedly in the structure and composition of the cell walls.     

COMPARATIVE STUDIES ON THE CELL WALLS OF SEXUAL AND ASEXUAL BANGIA ATROPURPUREA (RHODOPHYTA). II ELECTROPHORETIC PATTERNS OF POLYSACCHARIDES1

Cellulose acetate electrophoresis of the hot water soluble polysaccharide extracts from whole filaments, as well as base, mid and tip segments, of marine asexual and sexual Bangia atropurpurea (Roth) C. Ag. Yielded distinctive patterns which demonstrated that changes occur in the outer cell walls during sexual reproduction. Heterogeneity of the sulfated polysaccharide components isolated from outer cell walls was shown to be specifically related to sexual reproduction. Two components (Band I and II) were detected in extracts from tips of sexual filaments, whole only one (Band I) was present in the vegetative segments of all filaments and in asexual reproductive regions. The faster running component (Band II) was detected during the later stages of sexual development, prior to maturation.     

VARIATIONS IN THE CELL WALLS AND PHOTOSYNTHETIC PROPERTIES OF PORPHYRA YEZOENSIS (BANGIALES,RHODOPHYTA) DURING ARCHEOSPORE FORMATION1

The formation of archeospores is characteristic of Porphyra yezoensis Ueda and is important for Porphyra aquaculture. Recently, it has been regarded as a valuable seed source for propagation of thalli in mariculture. Cell wall composition changes are associated with archeospore formation in P. yezoensis. Here, we report changes of cell walls of P. yezoensis during archeospore formation. The surfaces of vegetative cells that were originally smooth became rougher and more protuberant as archeosporangia were formed. Ultimately, the cell walls of archeosporangia ruptured, and archeospores were released from the torn cell walls that were left at distal margins of thalli. With changes in cell walls, both effective quantum yield and maximal quantum yield of the same regions in thalli gradually increased during the transformation of vegetative cells to archeospores, suggesting that the photosynthetic properties of the same regions in thalli gradually increased. Meanwhile, photosynthetic parameters for different sectors of thalli were determined, which included the proximal vegetative cells, archeosporangia, and newly released archeospores. The changes in photosynthetic properties of different sectors of thalli were in accordance with that of the same regions in thalli at different stages. In addition, the photosynthetic responses of archeosporangia to light showed higher saturating irradiance levels than those of vegetative cells. All these results suggest that archeosporangial cell walls were not degraded prior to release but were ruptured via bulging of the archeospore within the sporangium, and ultimately, archeospores were discharged. The accumulation of carbohydrates during archeospore formation in P. yezoensis might be required for the release of archeospores.     

CHITIN AND CELLULOSE IN THE CELL WALLS OF RHIZIDIOMYCES SP

Fuller , Melvin S. (Brown U. Providence, R. I.), and Isaac Barshad . Chitin and cellulose in the cell walls of Rhizidiomyces sp. Amer. Jour. Bot. 47(2): 105-109. Illus. 1960.–Chemically isolated cell wall preparations of the aquatic Phycomycete, Rhizidiomyces sp., were analyzed by means of X-rays. The resulting diffraction patterns had maxima corresponding with known values for chitin and mercerized cellulose. The findings in this study are discussed with respect to Von Wettstein's hypothesis that the aquatic Phycomycetes can be separated into groups on the basis of whether their cell walls contain chitin or cellulose.     

玉竹生殖细胞壁在发育中的变化

应用光镜细胞化学和电镜方法,研究了玉竹生殖细胞发育过程中壁的结构和性质,证明了生殖细胞在刚形成时分隔它与营养细胞的壁是含胼胝质和纤维素的,从生殖细胞行将与内壁脱离开始,直至完全游离在花粉粒的营养细胞质中的发育时期,壁变薄和不显示苯胺蓝和荧光增白剂的荧光,但对ＰＡＳ是正反应的,当生殖细胞进入花粉管后和在有丝分裂前,细胞具有弱的ＰＡＳ正反应的包被,在结构形态上与曾在精细胞中描周质相似。研究结果证明玉竹     

Alpinia oxyphylla Miq. bioactive extracts from supercritical fluid carbon dioxide extraction

In this study, supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a native plant, Alpinia oxyphylla Miq. We studied the biological effects of A. oxyphylla extracts via multiple assays and demonstrated bio-functions at various concentration ranges. Investigations of A. oxyphylla extracts indicated that anti-oxidative properties in dose-dependant manners on radical scavenging activities, reducing power and metal chelating power. The cultured human normal peripheral blood mononuclear cells (PBMCs) were used to test the properties of the extracts in inflammatory cytokine release, and the data did not induce inflammatory molecule releases from un-stimulated PBMCs. A. oxyphylla extracts were able to induce Th1 cytokine IFN-γ released, but not Th2 cytokine IL-13, showing an enhanced anti-bacterial/viral immune function without possible allergic response mediated by IL-13. The extracts also had in vitro mushroom tyrosinase inhibition and cellular tyrosinase melanin decreasing activities in B16F10 cells. In addition, the cell proliferation assay illustrated anti-growth and anti-migration effects in dose-dependent manners of the extracts on human skin melanoma cells, A375 and A375.S2, indicating that the extracts exerted the anti-cancer properties. To our knowledge, this was the first report presenting these bioactivities on A. oxyphylla extracts including antioxidant, anti-inflammation, de-pigmentation and anti-melanoma     

COMPARATIVE STUDIES ON THE CELL WALLS OF SEXUAL AND ASEXUAL BANGIA ATROPURPUREA (RHODOPHYTA). I. HISTOCHEMISTRY OF POLYSACCHARIDES1

A comparative histochemical study of the nature and distribution of acidic and neutral cell wall polysaccharides was conducted on marine sexual and asexual filaments of the red alga Bangia atropurpurea (Roth) C. Ag. Outer and inner walls of this species were clearly partitioned according to staining and transmission electron microscopic characteristics. Neutral polysaccharides were detected in the outer coating (cuticle) but were absent from outer and inner walls of all filaments. Acidic polysaccharides were noted in the outer wall material but not in the inner wall layers of any filaments at any developmental stages. The major staining component of vegetative regions of sexual material and all regions of asexual filaments was a highly sulfated polymer. During sexual reproduction only there was a generalized change in the nature of the acidic component, characterized by a decrease in intensity of staining for sulfates in both male and female filaments and the appearance, in female filaments only, of polysaccharides which presumably were carboxylated. Spermatia attached to both male and female filaments in regions where sexual differentiation was initiated and where changes in the outer wall components commenced.     

SUGAR COMPOSITION OF THE CELL WALL AND THE TAXONOMY OF CHLORELLA (CHLOROPHYCEAE)1

Cell walls of forty Chlorella strains covering all species of the Algal Collection of Göttingen (C. fusca var. vacuolata, C. kessleri, C. luteoviridis, C. minutissima, C. protothecoides, C. saccharophila, C. sorokiniana, C. vulgaris, and C. zofingiensis) were compared. The nine species were divided into two groups according to the major sugar in the rigid wall. The first group had a glucose-mannose-rigid wall and included C. fusca var. vacuolata, C. luteoviridis, C. minutissima, C. protothecoides, C. saccharophila, and C. zofingiensis. The second group, with a glucosamine-rigid wall, included C. kessleri, C. sorokiniana, and C. vulgaris. Chlorella strains of the nine species were further classified by constituent sugars, ruthenium red stainability, and anisotropy of the cell walls.