锌对砂糖橘果实发育过程细胞壁代谢的影响

为研究不同锌处理对砂糖橘果实发育成熟过程中果皮硬度、细胞壁结构物质及其相关酶活性的影响,以四年生砂糖橘（Citrus reticulata Blanco cv. Shatangju）为试材,在果实膨大期喷施不同锌肥,同时对与果皮力学性能相关的细胞壁代谢变化规律进行分析。结果表明,不同锌处理均可降低果实发育成熟过程中果皮硬度的变化幅度,降低多聚半乳糖醛酸酶（PG）、纤维素酶（Cx）、果胶甲酯酶（PE）的活性,其中Zn2++Ca2+处理的果皮硬度变化最均匀、陷痕果高发期Cx和PE活性低、原果胶和纤维素含量高。不同锌处理均可有效地降低果实发育成熟过程中细胞壁代谢酶的活性,抑制原果胶和纤维素的降解,延缓细胞壁水解,使得果实硬度变化更均匀,其中Zn2++Ca2+处理的效果最明显。     

裂果发生与果皮细胞壁修饰的关系研究进展

果皮发育状态和力学性能直接影响裂果的发生,而其力学性能与果皮细胞壁修饰有着密切的关系.从果皮细胞壁中的多糖、蛋白质、酚类物质、矿质元素以及有关细胞壁松弛基因等方面概述了果皮细胞壁组分代谢与生化修饰和裂果的关系,并展望该领域今后的研究方向.     

硼在植物细胞壁上营养机理的研究进展

论述了硼在植物细胞壁中的结合形态,及其对细胞壁物理结构和功能的影响;探讨了细胞壁中硼、钙关系,及其与细胞壁信号传导的相互作用.简述了硼与细胞壁中多种蛋白质的密切关系,尤其是酶蛋白和影响细胞壁延展性的蛋白;以及硼在细胞壁的吸附、跨膜运输与细胞壁和细胞膜的关系.     

Role of aleurone cell walls in water diffusion and distribution within cereal grains

Wheat (Triticum aestivum L) and barley (Hordeum vulgare L) are two important cereals cultivated worldwide. The effect of aleurone cell wall structure on water diffusion and distribution within wheat and barley grains was evaluated at different relative humidity levels. Time domain nuclear magnetic resonance was used to measure the transverse relaxation time T₂ of grains. Two water states were distinguished within grains, namely W₁ (lower mobility) and W₂ (higher mobility). Grains with thicker aleurone layer cell walls had a higher W₂. The water-absorption and desorption rates were mainly determined by the thickness of the aleurone cell walls and decreased with increasing cell wall thickness. The higher W₂ values observed in grains with thicker aleurone cell walls with the a water content of 2.0% (w/w) and 12.1% (w/w) were probably related to a higher water motion within the grains, in response to higher porosity. Arabinoxylan and (1,3)(1,4)-β-glucan alternating multilayer films were prepared, each film had 20 layers, one layer was approximately 1 μm thick. The film was used as a model to simulate the aleurone layers. These results show that cell walls of the aleurone layer regulate the diffusion and distribution of water within grains.     

Physical aspects of the biopolymer matrix in wheat bran and its dissected layers

The objectives of this work were to 1) determine the physical structure of untreated wheat bran and the differences in physical structure between its dissected layers; 2) evaluate how bran hydration affected bran crystallinity and polymer order; and 3) determine how enzymatic treatment of wheat bran affected its physical structure. For the first time, X-ray diffraction (XRD), small angle X-ray scattering (SAXS), solid-state ¹³C cross-polarization magic-angle spinning nuclear magnetic resonance (¹³C CP/MAS NMR), and polarized light microscopy with a waveplate were used to study the physical structure of wheat bran and its dissected layers. The XRD and solid-state ¹³C CP/MAS NMR both confirmed the presence of crystalline cellulose in untreated bran, enzymatically treated bran, and dissected bran layers. The outer pericarp had the highest crystallinity of the dissected bran layers and showed negative birefringence. The aleurone layer was low in cellulose content and completely amorphous, yet the cell walls in the aleurone layer showed strong positive birefringence. The treatment of destarched and deproteinated bran with the Updegraff reagent removed amorphous material, leaving its crystalline cellulose structure intact. Hydration of the outer pericarp increased its crystallinity index and CP/MAS NMR resonance intensity, which indicated a possible increase in polymer order. The SAXS also confirmed that cell wall polymers, possibly aggregated cellulose microfibrils, increased in order as a result of hydration.     

酸性磷酸酶在萌发大豆种子中子叶细胞壁上的分布

本文应用光镜，电镜酸性磷酸酶的细胞化学定位法，对大豆种子萌发过程中酸性磷酸酶在子叶细胞壁上的分布进行了详细的观察与分析。大豆种子吸水膨胀１天时，子叶细胞的胞间层首先表现出酸性磷酸酶的活性；播种１－２天后，除胞间层外，胞间隙也表现了酸性磷酸酶的活性；播种４－６天期间，酸性磷酸酶不仅在胞间层，胞间隙处表现出活性，而且在细胞壁及质膜上也表现出较强的活性。根据本文的观察结果我们推测，萌发的大豆子叶细胞壁上     

枇杷果实发育过程中果肉质地与胞壁酶活性的变化

以果肉质地差异较大的白肉枇杷（Eriobotrya japonica Lindl.）“白梨”和黄肉枇杷“解放钟”为试材, 探讨果实发育过程中胞壁酶活性变化与果肉质地形成的关系。 结果表明, 2个品种枇杷果实发育过程中多聚半乳糖醛酸酶（PG, EC 3.1.1.15）、 果胶酯酶（PE, EC 3.1.1.11）与纤维素酶（Cx, EC 3.2.1.4）活性总体呈上升趋势, 这3种酶活性在果实发育后期（即花后100~115 d）极显著高于前期并出现峰值。“白梨”枇杷PE,PG和Cx酶活性高于“解放钟”, 果实发育前期, 2个品种枇杷PE, PG和Cx酶活性差异较小; 果实发育后期,“白梨”PE, PG和Cx酶活性显著或极显著高于“解放钟”。Cx, PG和PE与枇杷果肉质地形成密切相关, 而β-半乳糖苷酶（EC 3.2.1.23）、 α-葡萄糖苷酶（EC 3.2.1.20）、 α-半乳糖苷酶（EC 3.2.1.22）、 α-甘露糖苷酶（EC 3.2.1.24）等4种糖苷酶对“白梨”枇杷果实发育后期果肉软化起到一定的作用。     

Endosperm and aleurone cell structure in barley and wheat as studied by optical and Raman microscopy

Grain ultrastructure is of utmost importance when designing grain processing procedures in the food industry. In this study, wheat and barley grain components were localised using optical and Raman microscopy. The optical microscopic analyses were performed using several selective stains to localise β-glucan, protein and starch or autofluorescence to image the ferulic acid and other fluorescing substances. Alternatively, Raman microscopy was applied to localise the grain components without any need for preceding staining or other sample pretreatment. Both methods provided consistent information on the grain structures, illustrating the distribution of polysaccharides, aromatics and protein in endosperm and aleurone layers. In aleurone layers of both barley and wheat, a distinct difference between the anticlinal and periclinal cell walls was observed. The anticlinal cell walls were enriched with aromatic substances which were present in remarkably lower concentrations in the inner periclinal cell walls but for barley, an even higher concentration in the outer periclinal cell wall was observed. In addition, Raman spectroscopy illustrated the detailed distribution of substances across the aleurone cell walls: β-glucan was adjacent to proteins and it was deficient in the middle lamella whereas arabinoxylan was enriched in the outer cell wall layers and middle lamella.     

硼对不同硼效率甘蓝型油菜细胞壁硼钙含量的影响

采用营养液培养方法，研究硼对不同硼效率甘蓝型油菜细胞壁硼、钙含量及其比值的影响。结果表明，硼充足的条件下，两个油菜品种各部位细胞壁提取率为3.5%左右；高效品种上部叶、下部叶和根系细胞壁硼含量分别为63.29μg/g、61.90μg/g和25.67μg/g左右；而低效品种上部叶、下部叶和根系细胞壁硼含量均高于高效品种，分别为73.92μg/g、71.15μg/g和30.89μg/g左右；说明高效品种正常生长时需要相对较少的硼来构建其细胞壁。硼充足的条件下，品种间细胞壁钙含量及Ca/B比值差异不显著；其叶片和根系细胞壁钙含量为5 mg/g和15 mg/g左右，相应的Ca/B比值分别在50~100和500~600之间。缺硼导致两个油菜品种细胞壁提取率升高、Ca/B比值增大、细胞壁硼含量下降。随着硼水平的降低，细胞壁钙含量呈先上升后下降趋势。     

Genetic analysis and QTL mapping of stalk cell wall components and digestibility in maize recombinant inbred lines from B73 × By804

The cell wall composition and structure of the maize stalk directly affects its digestibility and in turn its feed value.Previous studies of stem quality have focused mostly on common maize germplasm,and few studies have focused on high-oil cultivars with high grain and straw quality.Investigation of the genetic basis of cell wall composition and digestibility of maize stalk using high-oil maize is desirable for improving maize forage quality.In the present study,a high-oil inbred line(By804)was crossed as male parent with the maize inbred line B73 to construct a population of 188 recombinant inbred lines(RILs).The phenotypes of six cell-wall-related traits were recorded,and QTL analysis was performed with a genetic map constructed with SNP markers.All traits were significantly correlated with one another and showed high broad-sense heritability.Of 20 QTLs mapped,the QTL associated with each trait explained 10.0%–41.1%of phenotypic variation.Approximately half of the QTL each explained over 10%of the phenotypic variation.These results provide a theoretical basis for improving maize forage quality by marker-assisted selection.     

禾谷镰刀菌产生的细胞壁降解酶的特性研究

禾谷镰刀菌(Fusarium gramimearum<\i>)是引起玉米茎腐病、穗腐病的主要病原菌之一。该病原菌在活体外能产生PG、PMG、PGTE和PMTE四种细胞壁降解酶,这些酶都具有酶的典型性动力学特性。细胞壁降解酶是F.gramimearum<\I>致病的一个重要因子。     

硼对甘蓝型油菜不同品种细胞壁盐溶蛋白质含量的影响

水培条件下,以典型的硼高效和硼低效甘蓝型油菜品种为试材,研究硼对细胞壁盐溶蛋白质含量的影响。结果表明,硼对油菜各器官细胞壁中的盐溶蛋白质含量均有不同程度的影响。缺硼时,高效品种和低效品种根系和上部茎细胞壁盐溶蛋白质含量均下降,但硼低效品种下降幅度大于硼高效品种,硼高效品种薹期供硼与缺硼处理间差异不显著。上部叶片细胞壁盐溶蛋白质含量,硼低效品种缺硼时显著下降,硼高效品种则显著升高,薹期高效品种供硼与缺硼处理间差异不显著。两品种下部叶片缺硼时的变化趋势与上部叶片相同,但不同时期的差异均不显著。     

The quantity of OA and activity of cellulase and polygalacturonase are involved in variation of virulence in Sclerotium rolfsii

In order to understand the pathogenic mechanisms of Sclerotium rolfsii on peanut and to analyze the variation of virulence in S. rolfsii strains, the highly virulent strain(ZY2) and weakly virulent strain(GP3-1) were investigated under both in vivo and in vitro conditions. The results indicated that S. rolfsii directly infected peanut by producing infection cushions. ZY2 formed infection cushions earlier than GP3-1, and ZY2 produced a greater number of infection cushions compare to GP3-1. Both s...     

变黄期和定色期不同烘烤工艺对翠碧一号烟叶细胞壁物质的影响

为了探讨不同烘烤工艺处理对烟叶细胞壁物质含量和品质的影响,试验设置4种变黄期和定色期不同烘烤工艺处理,分析烘烤过程和烤后烟叶纤维素、粗木质素、果胶等细胞壁物质含量及纤维素酶、果胶甲酯酶活性。结果表明:烟叶烘烤过程中纤维素、粗木质素、果胶含量在烘烤36 h前快速降低,48 h后降幅减小,36 h前降幅依次为T3、T4、T2、T1,48 h后为T4、T2、T1、T3;果胶甲酯酶24和72 h活性最高,48 h活性降到最低,形成双峰曲线;纤维素酶活性在48 h后达到最高。通径分析结果表明,T2处理烤后烟叶细胞壁物质含量最低,化学成分协调,感官质量总体得分最高,烟叶质量最好。T2处理降低细胞壁物质含量有利于提高感官质量,提升烤后烟叶质量。     

玉米茎腐病菌致病因子对玉米超微结构的影响

玉米茎腐病菌(Fusariumgramimearum和Pythumaphanidermatum)在玉米活体内和活体外均能产生一系列具有明显致病作用的细胞壁降解酶和毒素。通过电子显微镜对分离出的细胞壁降解酶和毒素进行致病性观察。结果表明,细胞壁降解酶能降解玉米根细胞壁,毒素能损伤玉米胚根细胞膜及亚细胞器的结构。     

Wheat arabinoxylans: Exploiting variation in amount and composition to develop enhanced varieties

Arabinoxylans (AX) are the major polymers of wheat grain cell walls. The content and the structure of AX polymers show large differences between tissues and between wheat cultivars that affect the end-use properties and nutritional quality of the grain. The development of new wheat cultivars with enhanced quality, therefore, requires methods to exploit this variation and it is essential to understand and modulate the mechanisms controlling the key events of cell-wall polymer synthesis.This paper summarises recent knowledge on the structure and physicochemical properties of AX including variation between cultivars and tissues, methods for analysis and screening, biosynthetic mechanisms and approaches to identifying key genes. This knowledge is essential to understand AX properties and defined possible targets for plant breeding.     

施氮量对两个粒型小麦品种籽粒胚乳细胞增殖及糖含量的影响

为了解小麦胚乳细胞增殖、糖代谢在粒型间的差异及氮营养的调控效应,2009-2010年度以大粒型品种郑育麦9987和小粒型品种郑麦004为材料,研究了施氮量对小麦籽粒胚乳细胞增殖、细胞壁转化酶活性及糖含量的影响。结果表明,郑育麦9987胚乳细胞数(11.92×105)较郑麦004(10.73×105)多11.1%。施氮量影响籽粒胚乳细胞数,其中郑育麦9987低氮处理(150kg·hm-2)的胚乳细胞数目较高氮处理(300kg·hm-2)增加29.1%,而郑麦004则表现为高氮处理较低氮处理增加44.7%。两品种籽粒细胞壁转化酶活性均于花后5~8d达到峰值,花后20d则降到较低水平;籽粒可溶性糖和蔗糖含量均随灌浆进程整体呈先上升后下降趋势,在花后25d有一个小波峰。增施氮肥可增加籽粒细胞壁转化酶活性,提高后期籽粒可溶性糖和蔗糖含量。表明增施氮肥有利于小麦籽粒胚乳细胞增殖、光合产物的积累与运转,从而提高了粒重。     

香蕉枯萎病菌菌株致病力分化及其原因研究

以田间表现出枯萎病症状的香蕉和粉蕉组织中分离获得的13株尖孢镰刀菌(Fusarium oxysporum)为试验材料,分别测定了不同菌株对香蕉(巴西蕉)和粉蕉(广粉一号)的致病力以及在不同培养液中产生的细胞壁降解酶的活性和毒素含量。结果表明:不同菌株对香蕉和粉蕉的致病力存在明显差异;相关性分析显示,不同菌株产细胞降解酶活性与相应菌株侵染引起的寄主病情指数无相关性,产镰刀菌酸的含量与寄主病情指数呈极显著正相关(r=0.9326)。认为香蕉枯萎病菌菌株间产镰刀菌酸能力的不同是导致其致病力出现分化的主要原因之一。     

用基因操作法改良糖甜菜（英）

甜菜的产糖量占世界蔗糖产量的４０％，从碳同化角度来说，甜菜是极高效的温带作物之一，但用基因操作法仍有提高其产质量的潜力。对甜菜贮藏器官发育过程的解剖、生理和蔗糖积累的研究，为制定增加产量和减少环境对甜菜生长影响的策略奠定了理论基础。为促进对发育操作过程以达到上述这些目标，必须增强对细胞分裂的调节机制的认识。我们先研究植物激素限定细胞分裂的方式，随后研究调节细胞分裂的一些分子生物学特征。目前，我们已分离和鉴定了一些与甜菜细胞周期相关的基因序列，并用甜菜细胞悬浮培养对这些与细胞分裂调节相关的基因表达进行了研究，细胞分裂调节基因特定位点表达的策略已被确定，进一步优化甜菜转化系统的研究正日趋完善。通过这个途径，有希望获得高根产、高含糖、高汁液纯度和低环境影响的甜菜植株。     

Replicate and die for your own good: Endoreduplication and cell death in the cereal endosperm

Development of the cereal endosperm involves different stages that include cell proliferation, endoreduplication, the biosynthesis and accumulation of storage compounds, and programmed cell death (PCD). During endoreduplication, repeated genome duplications without mitosis or cytokinesis result in large polyploidy nuclei. Endoreduplication is affected by genetic, epigenetic, hormonal and environmental factors, as well as by several cell cycle-controlling genes. Although endoreduplication is strongly correlated with an increase in cell size, the accumulation of storage reserves, and high metabolic rates, its exact role(s) in endosperm development has not been demonstrated.