共查询到20条相似文献，搜索用时 125 毫秒
1.
Galina F. Antonova Tamara N. Varaksina Tatiana V. Zheleznichenko Victoria V. Stasova 《Wood Science and Technology》2014,48(5):919-936
Lignin deposition at consecutive secondary wall thickening stages of early and late xylem cells during annual ring wood formation in Scots pine (Pinus sylvestris L.) stems was studied. Lignin patterns, isolated by thioglycolic acid method, consisted of alcohol-soluble (LTGA-I) and alkali-soluble (LTGA-II) fractions. The sum of two fractions, being the total lignin content, gradually increased in the course of lignification. However, the increments of lignin amount at each development stage of early and late tracheids were different. The intensity of lignin deposition increased in the course of earlywood tracheid maturation and decreased toward the end of latewood cell differentiation. The deposition of two lignin fractions in each layer of forming wood also occurred oppositely. The increment of LTGA-I descended, whereas that of LTGA-II increased from the beginning to the end of early xylem lignification. In contrast, LTGA-I increment dropped, whereas LTGA-II rose during late xylem lignification. Gel permeation chromatography showed that the lignins, formed at the beginning of lignification, were more homogeneous and had higher molecular weight compared with the lignins at the end of cell differentiation. Besides, the content of cellulose, estimated as the residue after lignin isolation, and of cell wall substances, presented as cell wall cross-section areas, at consecutive maturation stages of early and late xylem cells have been found to be different. The data show that lignin deposition occurred in different conditions and with opposite dynamics during early and late xylem formation. 相似文献
2.
毛白杨形成层的活动周期及其POD同工酶的变化 总被引：6，自引：3，他引：6
北京地区生长的毛白杨 (PopulustomentosaCarr .)在春季芽膨大前 ,形成层带已经进入了恢复活动期。在芽展开后一周形成层进入活动期 ,细胞开始分裂 ,细胞层数也有所增加 ,同时分化出未成熟的韧皮部细胞。未成熟韧皮部细胞的数量在形成层活动初期快速增长 ,随后是一个持续而缓慢的连续过程。木质部的产生比韧皮部要晚 3周 ,未成熟的木质部细胞层数在开始变化不大 ,5月底～ 6月底 ,增长速度明显高于初期 ,随后便急剧下降。成熟木质部细胞的出现比成熟的韧皮部细胞要晚约一个月。与其他研究结果不同 ,毛白杨在4月底到 6月底这段时间 ,形成层细胞层数迅速下降 ,未成熟韧皮部细胞也略有减少 ,而未成熟和成熟的木质部细胞则大量增加。木质部在 9月底停止分化 ,较韧皮部要晚约 2 0d。 9月底形成层进入休眠期后 ,形成层细胞层数基本保持不变 ,直到翌年春天恢复活动。毛白杨形成层区域的过氧化物酶 (POD)同工酶在形成层活动期其活性低、酶带少 ,而恢复活动期和休眠期其活性高且酶带多 ,组织化学反应还表明 ,不同时期POD在不同的细胞和组织中的活性不同。本文对POD同工酶在形成层活动周期中的变化与其组织分化的关系进行了讨论。 相似文献
3.
利用克隆得到的毛白杨c3h1基因构建其RNAi抑制表达载体,通过根癌农杆菌介导的叶盘法转化银腺杨无性系84 K,Realtime PCR检测表明其转基因株系323、325和322中c3h1基因表达量较野生型植株分别下调89.04%、82.22%和68.38%;茎横切片组化染色和显微结构观察表明转基因植株木质部发育和木质素沉积方式发生了改变;木质素、纤维素含量测定及苯酚—硫酸法总糖含量与HPLC法可溶性总糖和单糖含量检测结果表明:转基因植株木质素含量平均降低23.00%,最高可达39.71%;酸前处理效率最高提高了41.39%;未经酸处理直接酶解的糖化效率是对照植株的2.34～2.72倍,322株系和323株系比对照植株经酸前处理后再酶解的糖化效率高出81.18%和375.53%。 相似文献
4.
A 3 125 bp cellulose synthase gene, PtoCesA1, which has a 98% identity to PtrCesA1 from Populus tremuloides, was cloned from cDNA prepared from secondary xylem of P tomentosa. Four anti-expression vectors with different fragments of PtoCesAl, named as pBIPF, pBICC1, pBIPR and pBIBR, were constructed. Some traits of transformed tobacco of pBICC1, pBIPR and pBIBR differed from wild types, such as small leaves, ＂dwarf＂ phenotype and thinner xylem and fiber cell walls than wild plants consistent with a loss of cellulose. It indicated that the growth of transgenic tobacco was restrained by the expression of anti-PtoCesA1. Transgenic tobacco was obtained and the contents of cellulose and lignin were analyzed as well as the width and length of fiber cells, and xylem thickness for both transgenic and control plants. Transformed tobacco showed a different phenotype from control plants and it implied that PtoCesA1 was essential for the cellulose biosynthesis in poplar stems. 相似文献
5.
Distribution of lignin and lignin precursors in differentiating xylem of Japanese cypress and poplar
Lignin is an integral component of the cell wall of vascular plants. The mechanism of supply of lignin precursors from the cytosol into the cell wall of differentiating xylem has not yet been elucidated. The present study showed that a certain amount of coniferyl alcohol glucoside (coniferin) occurred in the differentiating xylem of Japanese cypress (Chamaecyparis obtusa), as previously reported in gymnosperms. Coniferin content peaked in the early stages of secondary wall formation and decreased during lignification. In contrast to gymnosperms, coniferin content was limited in the differentiating xylem of poplar (Populus sieboldii × Populus grandidentata). Moreover, coniferyl alcohol was not detected in all specimens. In the differentiating xylem of poplar, a higher amount of sinapyl alcohol occurred than glucoside (syringin). However, the phloem contained syringin and not sinapyl alcohol. The sinapyl alcohol content in the xylem peaked in the cells with ceasing cell wall formation, and decreased gradually towards the boundary of the annual ring, where the lignin content kept increasing. Sinapyl alcohol in the differentiating xylem of poplar may be used for the lignification of the xylem. 相似文献
6.
To learn more about lignin formation in response to wounding in trees, we adopted two complementary approaches: (1) microscopic and histochemical studies of the wound response in 3.5‐month‐old Eucalyptus gunnii plantlets and (2) biochemical investigations of hydroxycinnamyl alcohol dehydrogenase activities in wounded 6‐year‐old, field‐grown E. gunnii trees. The first approach revealed that a barrier zone was formed in response to wounding in both ground tissues (cortex barrier and pith reaction zone) and vascular tissues. The barrier zone was barely detectable after 24 h but well‐developed 7 days after wounding. Microscopic analyses indicated that the barrier zone was formed by the reinforcement of cell walls with ‘lignin‐like material’ in both ground tissues and vascular tissue, and that, in addition, the lumen of certain xylem cells (vessels and fibres) were blocked by the deposition of polymeric phenolic material. Histochemical characterization revealed that the lignin‐like material (‘defence lignin’) deposited in ground tissue cell walls and xylem cell blockages was poor in syringyl (S‐type) lignin units and therefore differed from the usual mixed guaiacyl–syringyl (G–S) lignin unit composition of E. gunnii developmental lignin. In contrast, S‐type lignin appeared to be deposited in the cell walls of immature developing secondary xylem cells at a stage when the cell walls of comparable cells from unwounded control stems contained lignin poor in syringyl units. The second approach indicated that two different types of cinnamyl alcohol dehydrogenase activity are induced, and apparently regulated differentially, in response to wounding in E. gunnii trees. Coniferyl alcohol dehydrogenase activity was induced immediately and continued to increase throughout the first 15 days of the 17‐day experimental period, while sinapyl alcohol dehydrogenase activity was first detected at 8 days after wounding and continued to increase throughout the experimental period. The biological roles of the two alcohol dehydrogenase activities are discussed in relation to the formation of defence lignin versus developmental lignin in trees. 相似文献
7.
Masato Yoshida Daiji Fujiwara Yukiko Tsuji Kazuhiko Fukushima Teruko Nakamura Takashi Okuyama 《Journal of Wood Science》2005,51(5):448-454
To examine the effect of gravity on lignin content and deposition in plant cells, we used ultraviolet (UV) microspectrophotometry
and chemical methods to investigate the secondary xylem of Prunus jamasakura grown on a three-dimensional (3D) clinostat, which simulates microgravity. The stem of the 3D-clinostat specimens elongated
with bending and the width of their secondary phloem increased. The UV absorbance of the 3D-clinostat specimens at 278 nm
was higher than that of the control specimens, which were grown on the ground, in the wood fiber cell corner middle lamella,
compound middle lamella, and fiber secondary wall; the UV absorbance in the vessel secondary wall did not differ between the
specimens. The lignin content in the stem, including the bark, of the 3D-clinostat specimens, as determined using an acetyl
bromide method, was less than that of the control specimens. In the specimens that differentiated on a 3D clinostat, the amount
of lignin in the wood fibers increased, while the proportion of the lignified xylem in the stem decreased relative to control
values. 相似文献
8.
Test samples of Japanese larch (Larix leptolepis) heartwood and Japanese beech (Fagus crenata) sapwood were heated for 22 h at constant temperatures (50°–180°C) under three water content conditions. Raman spectra of
the samples were recorded before and after the heat treatments, and spectral changes in the range from 1000 cm−1 to 1800 cm−1 were evaluated using the difference spectrum method. For both wood species, the Raman band intensity at 1655–1660 cm−1 due mainly to the C=C and C=O groups in lignin clearly decreased with increasing heat-treatment temperature (HTT). The spectral
change was thought to reflect the progress of condensation reactions of lignin molecules during the heat treatment. Moreover,
the decrease in band intensity was considerably facilitated by the presence of water in the cell wall, suggesting that the
condensation is closely related to the softening of lignin. From the spectral changes in the wavenumber region of 1200–1500 cm−1, it was considered that wood constituents are partially decomposed at the higher HTT.
Part of this article was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, March 2003 相似文献
9.
In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex （LCC） and the residual lignin from kraft pulp （KP） and sulfite pulp （SP） were isolated and analyzed by Fourier transform infrared （FTIR） spectrum and ^13C nuclear magnetic resonance （NMR）. The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP. 相似文献
10.
The lignification process and lignin distribution at different stages of cell wall differentiation in the secondary xylem of compression and normal woods of Pinus thunbergii were investigated by thioacidolysis and subsequent desulfuration. We prepared 50-µm-thick, contiguous tangential sections of pine shoots, cut from the cambial zone through to mature xylem. In compression wood, uncondensed guaiacyl (G) and p-hydroxyphenyl (H) lignins were deposited simultaneously from early to late stages of lignification. The various types of G-G, G-H, and H-H dimers were detected in compression wood, and the ratio of G-H and H-H dimers to total dimers increased as lignification proceeded. In contrast, uncondensed and condensed H units were detected in trace amounts in normal wood. Significant differences in the relative distributions of lignin interunit linkages were not observed between compression and normal woods or between differentiating and mature xylems in either compression or normal woods.Part of this report was presented at the 10th International Symposium on Wood and Pulping Chemistry, Yokohama, June, 1999 相似文献
11.
Yoshihiro Katayama Yoko Mashino Nobuyuki Nishikubo Kaori Yoshitomi Ryo Funada Shinya Kajita 《Journal of Wood Science》2002,48(6):457-466
We have investigated the spatial regulation of the accumulation of enzymes involved in the biosynthesis of shikimate and lignin during differentiation of primary xylem from the apical meristem via procambium in hybrid aspen (Populus sieboldii x Populus grandidentata). Immuohistochemical staining revealed that, in the top part of shoots, lignification began in a single or just a few adjacent vessel elements and subsequently spread to neighboring cells. The spatial localization of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS), which is one of the key enzymes in the shikimate pathway, was tightly correlated with the cell-specific deposition of lignin in the primary xylem. We also found that the spatial localization of enzymes in the general phenylpropanoid pathway and in the lignin-specific pathway was closely associated with the cell-specific deposition of lignin and the accumulation of DAHPS. Our data suggest that enzymes that act in the shikimate, general phenylpropanoid, and lignin-specific pathways are initially produced and function coordinately in a single or a few adjacent elements at the start of primary xylem development. 相似文献
12.
Marjamaa K Kukkola E Lundell T Karhunen P Saranpää P Fagerstedt KV 《Tree physiology》2006,26(5):605-611
We partially purified peroxidase isoform fractions from xylem extracts of a gymnosperm, Norway spruce (Picea abies (L.) Karst.), and an angiosperm, silver birch (Betula pendula Roth.), to determine the participation of xylem-localized peroxidases in polymerization of different types of lignin in vivo. Several peroxidase fractions varying in isoelectric point values from acidic to basic were tested for their ability to catalyze the oxidation of the monolignols coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol in vitro. All of the xylem peroxidases extracted from Norway spruce and most of those from silver birch showed the highest rate of oxidation with coniferyl alcohol in the presence of hydrogen peroxide. The exception was an acidic peroxidase fraction (pI 3.60-3.65) from silver birch that exhibited higher oxidation activity for sinapyl alcohol than for coniferyl alcohol. For the xylem enzyme fractions extracted from silver birch, the ability to oxidize the artificial phenolic substrate syringaldazine coincided with high specific activity for sinapyl alcohol. Therefore, we conclude that the acidic, neutral and basic xylem peroxidases of Norway spruce all function in the synthesis of guaiacyl-type lignin, whereas in silver birch the acidic peroxidases preferentially oxidize sinapyl subunits. The latter provides a mechanism for synthesis of guaiacyl-syringyl lignin typical of tracheid cell walls in angiosperm trees. 相似文献
13.
The anatomy characteristics of cell wall and lignin distribution in different anatomical regions for 12-month-old bamboo species Pseudosasa amabilis was investigated.The lignin distribution was studied by means of optical microscope and confocal laser scanning microscope and the color reaction. In addition,the distribution of lignin in different tissues(fiber,parenchyma and vessel) was investigated by visible-light microspectrophotometry coupled with the Wiesner and Maule reaction.The cell walls of different tissues were all lignified and the lignin was widely distributed in different tissues, in which there was a difference between tissues and anatomical regions in lignin content.Guaiacyl lignin and syringyl lignin unit could be found in cell wall of fiber,parenchyma and vessel through Wiesner and Maule reaction and the absorbance peak of spectrum. There was no regular variation in lignin content with different radial location of culms and different location in fiber strands.The lamellation of the fiber cell wall was generally had as alternating broad and narrow layers with alternating low and high concentration of lignin. 相似文献
14.
对12个月的茶秆竹进行细胞壁解剖特性和木质素微区分布的研究,运用光学显微镜、激光共聚焦扫描显微镜以及颜色反应鉴定木质素的存在,利用组织化学染色方法及其可见光显微分光光度计半定量测定竹材纤维、薄壁组织和导管细胞壁各微区的木质素含量。12个月时细胞壁全部木质化,木质素在各组织中均有分布,其含量因组织类型及其细胞壁微区不同而有差异。从组织化学染色及可见光吸收光谱图的吸收峰值,说明细胞壁各微区中存在愈创木基(G)和紫丁香基(S)2种木质素组成单元。竹壁径向和纤维帽不同位置的木质素含量未有明显的规律性变化。纤维次生壁具有薄厚层交替的多层结构,薄层木质素含量大于厚层。 相似文献
15.
Haruna Aiso-Sanada Futoshi Ishiguri Denny Irawati Imam Wahyudi Shinso Yokota 《Journal of Wood Science》2018,64(6):872-879
This study investigated the anatomical and chemical characteristics of the reaction wood of a gymnpsperm species, Gnetum gnemon, and discussed on contributing factor for the type of reaction wood in this species. Cell morphology, microfibril angle (MFA) of the S2 layer and lignin distribution in secondary walls of tracheary elements, and lignin content were examined on three branches. Observations included no G-layer formation, significant decreases in vessel frequency, and altered MFA, and visible-light absorbance after lignin colour reactions in tracheid and fiber tracheid walls on the upper side in almost all samples. These results suggest that reaction wood in G. gnemon was similar to that in ‘tension-wood-like-reaction wood’ in angiosperms. On the other hand, reaction wood showed decrease in the lignin concentration in the fiber tracheid walls compared to the tracheid walls. In addition, the lignin in the tracheid and fiber tracheid walls was originally rich in syringyl units, suggesting that changes in the anatomical and chemical characteristics of secondary xylem due to reaction wood formation might relate to the ratio of the syringyl to guaiacyl units in lignin in the cell walls which function for mechanical support. 相似文献
16.
Robles-Zepeda RE Lozoya-Gloria E López MG Villarreal ML Ramírez-Chávez E Molina-Torres J 《Fitoterapia》2009,80(1):12-17
Montanoa tomentosa has been used in traditional medicine in Mexico to treat diverse female health disorders; it is particularly useful in inducing childbirth. Microscopic analysis of leaf surfaces of M. tomentosa revealed the presence of glandular trichomes. The chemical profile and distribution of glandular trichomes from different developmental stages of M. tomentosa leaves were investigated. Two diterpenic acids, kaurenoic and grandiflorenic were detected in glandular trichomes through the glandular microsampling technique and GC/MS analysis. In the glandular trichomes of the leaves also up to twenty-six volatile terpenes were identified, where beta-eudesmol and valencene were the most abundant terpenes. 相似文献
17.
毛白杨PtCDD基因5'片段的原核表达及功能分析 总被引：2，自引：0，他引：2
根据GenBank中毛白杨钙离子依赖型脱氧核糖核酸酶(PtCDD)基因序列,以毛白杨形成层区域的cDNA为模板,经PCR扩增出该基因上游637 bp的cDNA片段.将该片段与PET-30b( )载体连接,构建杨树PtCDD基因片段原核表达载体并进行表达研究,获得大量的PtCDD-(HIS)6 融合蛋白.并进一步对该蛋白进行纯化和功能检测.结果表明:PtCDD基因片段能够在大肠杆菌体内表达出具有DNase功能的蛋白,克服了因表达全酶可能强烈降解DNA所带来的不能最终获得表达产物的问题,为今后PtCDD蛋白的抗体制备以及进一步研究奠定了基础. 相似文献
18.
廖俊国 《中南林业科技大学学报(自然科学版)》1996,(1)
杨树是西藏河谷地区的主要造林树种．其中北京杨为传统的主栽品种．１９９４年引进毛白杨、中林诸杨和优胜杨进行扦插育苗试验，结果表明，其成活率可达到７０％左右，毛白杨的成活率可达到８７％，与北京杨差异不大．在栽培措施相同的条件下，毛白杨的地径生长量、高生长量、光合速率、总叶面积和最大光合速率，分别比北京杨高１４．２％，２２．３％，２４．６％，４６．１％和６２％．说明在该区引种毛白杨具有发展潜力． 相似文献
19.
T. E. Timell 《Wood Science and Technology》1980,14(3):161-179
Summary This electron microscopy study is concerned with the dormant cambial cells in compression wood of Picea abies (L.) Karst. The cambial zone comprised 4–8 rows of fusiform cells. Each radial file contained the group known as Sanio's four, namely an initial, a mother, and two daughter cells. Groups of three, resulting from a failure of a mother or a daughter cell to divide, were also present. Undifferentiated xylem tissue cells occurred singly, in pairs, or in groups of four. These cells and the last-formed tracheids were often enclosed by a common primary wall. The fusiform cells had a large, elongated nucleus, numerous small vacuoles, and a frequently infolded plasma membrane. Golgi apparatus and endoplasmic reticulum were rare, while plastids, amyloplasts, and lipid droplets were common. Cambial ray cells contained much lipid material. The tissues were similar to cambial tissues in normal wood of conifers. The present results can only be interpreted in terms of the single layer of initials and sequence of cell divisions established by Sanio. The initial can be located by several criteria in dormant and active cambial regions in conifers. It could be shown that the existence of the group of Sanio's four is better documented in the literature than has so far been recognized. The occurrence of a variable number of primary cell walls is discussed with reference to the concentration of lignin in the middle lamella of mature xylem. 相似文献
20.
在对马关都龙镇锌铟矿山废弃地所设置的10种植被恢复配置模式试验所形成的群落进行植被调查和土壤养分测定的基础上,分析了山黄麻在各群落类型中的生长差异、分布与生态因子的相关性。结果表明,在该废弃地上,山黄麻迁入定居除受种子散布及植被恢复过程中草本层盖度影响外,能适应不同植物群落、不同土壤养分环境,其树高年均生长量为1.8 m,胸径的年均生长量达1.6 cm,树高和胸径的生长速度分级达速生水平,表现出对马关锌铟矿山废弃地较强的生态适应能力。山黄麻可作为马关锌铟矿山废弃地植被恢复初期的先锋树种加以利用。 相似文献