三种观赏植物对土壤中镉的富集特征研究

以3种观赏植物海芋、肾蕨和蟛蜞菊为试材进行盆栽试验,研究其对土壤重金属镉的富集特征。结果表明：3种观赏植物对镉有不同的富集能力,其地上部和地下部富集的镉与土壤的镉含量呈显著正相关（r＞0.9）。蟛蜞菊地上部吸收富集能力最大,其次是海芋,肾蕨最弱;而海芋地下部镉含量最高,其次是肾蕨,蟛蜞菊最少。当土壤镉含量在0～120 mg/kg范围内,三种观赏植物根的富集系数都大于1,说明3种观赏植物根系对镉具有富集能力。3种植物中只有蟛蜞菊地上部和地下部的富集系数都大于1,说明其具有超积累植物的富集系数特征。因此,蟛蜞菊对重金属镉污染的土壤修复有一定的应用潜力。     

In vitro Reconstitution of Epicuticular Wax Crystals: Formation of Tubular Aggregates by Long-Chain Secondary Alkanediols

Cuticles of several plant species are covered by tubular wax aggregates that are known to consist mainly of (S)-nonacosan-10-ol. The present work addresses the question whether minor wax components may additionally contribute to these tubules. Thin layer chromatography was used to prepare secondary alkanediol fractions from leaf cuticular waxes of Nelumbo nucifera and Thalictrum flavum, containing nonacosane-3,10-diol, nonacosane-4,10-diol, nonacosane-5,10-diol, nonacosane-7,10-diol, nonacosane-9,10-diol and nonacosane-10,13-diol. From organic solutions all these compounds crystallized in tubular shapes. Possible crystal structures of relevant alkanediol isomers are proposed, in analogy to the lattice geometries of comparable aliphatic compounds. The resulting structural model shows that nonacosan-10-ol and various secondary alkanediols may join in metastable mixed crystals. According to the structural model proposed the admixture of alkanediols to nonacosan-10-ol aggregates should enhance the stability of their tubular habit.     

Occurrence and Structure of Epicuticular Wax on the Juice Vesicles of Citrus Fruits

The surface of the juice vesicles of some citrus fruits wasstudied with the aid of the transmission and scanning electronmicroscopes. The epidermis of the vesicles is covered with athin cuticle on top of which are found wax secretions of variousstructural patterns. It is assumed that the secreted epicuticularwax serves as an adhesive which holds the juice vesicles ineach fruit segment together.     

Gas Exchange of In Vitro and Ex Vitro Grown Grapevine Plants

Net photosynthetic rate (P _N) and dark respiration rate (R _D) were measured in Vitis vinifera L. cvs. Dimiat 4/24 (23^rd subculture), Dimiat 4/38 (22^nd subculture), and Italian Riesling 3/47 (22^nd subculture) on days 3, 2, and 1 (1^st series) before transfer from the in vitro culture and on days 14, 15, 16 (2^nd series) and 28, 29, 30 (3^rd series) after the transfer. P _N of in vitro and ex vitro plants was strongly affected by irradiance. P _N and R _D of in vitro plantlets were lower and transpiration rate (E) was higher compared to those of ex vitro plantlets. P _N, R _D, and E changed in the course of acclimation.     

Esterase Polymorphism and the Analysis of Genetic Diversity and Structure in Cactus Populations Descended from Cereus peruvianus Plants Regenerated In Vitro

The genetic structure of Cereus peruvianus populations descended from cultivated plants (F(1) populations) and from plants regenerated in vitro (R(1) populations) was analyzed using α- and β-esterase isozymes in native PAGE. The estimated proportion of polymorphic loci was higher (50%) in the R(1) populations than the F(1) populations (42.85%). The mean observed (0.5599) and expected (0.5620) heterozygosity in R(1) descendents was also higher than the rates in F(1) descendents (H (o)?=?0.4142; H (e)?=?0.4977). A low level of population differentiation was detected in R(1) descendents (F (st)?=?0.05). In contrast, population differentiation was high in F(1) descendents (0.2583). Esterase analysis using PAGE showed that artificial selection by silvicultural management provides high genetic diversity and a large genetic basis for C.?peruvianus, whereas in vitro selection from callus tissue culture involves an increase of heterozygosity levels in descendents from somaclones and a low level of interpopulational divergence.     

植物离体组织染色体加倍诱导同源四倍体

随着生物技术的迅速发展,通过植物离体组织人工诱导多倍体已经成为获得多倍体植株的有效途径。本文就植物离体组织染色体加倍诱导同源四倍体的研究进展做一介绍,详细评述了植物离体组织细胞加倍的途径、影响植物离体组织加倍的因素、利用不同诱导剂进行处理效果比较及离体组织材料的早期倍性鉴定技术等,并展望了植物离体诱导同源四倍体的前景。     

Effect of Methyl Jasmonate on Morphology and Dormancy Development in Lily Bulblets Regenerated In Vitro

Scales of lily bulbs are swollen petioles. Lily scale fragments cultured in vitro regenerate bulblets consisting of scales that may or may not carry a leaf blade. The bulblets are dormant and require a cold treatment to sprout. We added the gaseous plant growth regulator methyl jasmonic acid (MeJA) in the headspace of the tissue-culture container and studied the effect on plantlet morphology (scale/leaf-blade formation) and dormancy development in three lilies, Lilium speciosum “Rubrum No. 10,” L. longiflorum “Snow Queen,” and the Asiatic hybrid “Connecticut King.” Methyl jasmonic acid strongly reduced leaf-blade formation in Lilium longiflorum and Connecticut King. This was a specific effect as scale formation was affected much less. The specific inhibition of leaf-blade formation was not observed in Lilium speciosum. In this lily, high concentrations of methyl jasmonic acid (MeJA) inhibited leaf-blade and scale formation to similar extents. Methyl jasmonic acid reduced dormancy development in all three lilies, with the largest effect observed in Connecticut King. In this Asiatic hybrid, almost all bulblets that had regenerated at 300 or 1000 μl l⁻¹ MeJA in the headspace, did not require a dormancy-breaking treatment to achieve sprouting after planting in soil. Previously, it has been found in lily that treatments that reduce leaf-blade formation promote dormancy development. The present findings with MeJA do not agree with this. In the three lilies, the various parameters that were studied—regeneration, scale weight, leaf-blade weight, and dormancy development—were very differently affected by MeJA.     

22种植物水孔蛋白理化性质及其结构特征的生物信息学分析

水孔蛋白(aquaporins, AQPs)是高效转运水分子的膜内在蛋白,具有丰富的多样性,在调控植物的水分关系中有重要作用。本研究采用Blast、ProtParam、SignalP和Swiss-Model等生物信息学软件,对梨、苹果、黄瓜和番茄等22种植物AQP的理化性质、蛋白结构、系统发生树和功能域等进行了分析。结果表明, AQP蛋白氨基酸长度在284~295 aa之间,理论等电点在7.67~9.30之间,主要定位于质膜上,除红叶藜外均为稳定性蛋白。二级结构由α螺旋、β折叠、无规则卷曲和延伸链等结构元件组成,空间结构高度相似,属于主要内在蛋白(MIP)家族。     

In Vitro Reparative Dentin: a Biochemical and Morphological Study

In this study, starting from human dental pulp cells cultured in vitro, we simulated reparative dentinogenesis using a medium supplemented with different odontogenic inductors. The differentiation of dental pulp cells in odontoblast-like cells was evaluated by means of staining, and ultramorphological, biochemical and biomolecular methods. Alizarin red staining showed mineral deposition while transmission electron microscopy revealed a synthesis of extracellular matrix fibers during the differentiation process. Biochemical assays demonstrated that the differentiated phenotype expressed odontoblast markers, such as Dentin Matrix Protein 1 (DMP1) and Dentin Sialoprotein (DSP), as well as type I collagen. Quantitative data regarding the mRNA expression of DMP1, DSP and type I collagen were obtained by Real Time PCR. Immunofluorescence data demonstrated the various localizations of DSP and DMP1 during odontoblast differentiation. Based on our results, we obtained odontoblast-like cells which simulated the reparative dentin processes in order to better investigate the mechanism of odontoblast differentiation, and dentin extracellular matrix deposition and mineralization.Key words: dental tissue, in vitro differentiation, DMP1, DSP, type I collagen     

科尔沁沙地黄柳再生枝与现存枝形态和光合特征的比较

对黄柳经平茬后形成的再生枝和未平茬的现存枝的光合作用、株高、基径、叶片大小等形态特征进行了比较研究,结果表明再生枝比现存枝具明显的生长优势;再生枝高度及高度频度分布均与现存枝十分接近;再生枝基径显著大于现存枝,前者过细和过粗枝条的比例均较低,基径频度分布趋于正态分布,后者细枝条比例较高,基径频度分布符合对数正态分布;同时再生枝叶片更长、更宽,叶长和叶宽接近于平均值的叶子所占比例更大。在上午时段内叶片温度和光合有效辐射随气温同步上升,黄柳叶片的净光合速率总体上都比较高,再生枝和现存枝之间的表现差异明显。     

Rind Structure, Epicuticular Wax Morphology and Water Permeability of 'Fortune' Mandarin Fruits affected by Peel Pitting

Rind structure and surface wax morphology of 'Fortune' mandarinsaffected by pre-harvest peel pitting were examined as relatedto the severity of this disorder. In fruits with slight symptomsof pitting (< 10% surface area pitted) a discrete numberof epidermal cells were injured with signs of cellular breakdown.In fruits with moderate symptoms of pitting (10-50% surfacearea pitted) the injured zones also involved hypodermal cells.The surface of rind had an undulating appearance in fruits withsevere symptoms of pitting (> 50% surface area pitted). Thedepressed areas in these fruits were devoid of crystalline waxstructures and had a rough morphology. Broad regions of rindhad crushed epidermal and hypodermal cells with infolded walls.These cells were either empty or filled with reduced cytoplasmamounts located in central positions of the cell. No signs ofdisruption in the cuticle were observed. Under field conditions,pitting occurrence coincided with higher permeability valuesof isolated cuticles. Furthermore, length of cold treatmentsrequired to show post-harvest pitting symptoms was shorter infruits sampled at this stage than in those collected earlieror later. Our results indicate that the low temperatures inducethe breakdown of the more external cellular strata of the rind.Thus, the physiological function of cuticle is highly impairedwhich, in turn, increases water permeability considerably.Copyright1994, 1999 Academic Press Chilling injury, Citrus, cold storage, pre-harvest pitting     

The Influences of Epicuticular Wax Disruption and Cutinase Resistance on Penetration of Tomatoes by Colletotrichum gloeosporioides

Conidia of Colletotrichum gloeosporioides germinated on green and ripe tomato fruit with intact epicuticular wax, and formed penetration pegs below melanized appressoria. If the delicate layer of epicuticular wax was distupted by abrasion or removed by solvents before inoculation, apparent increased diffusion of fruit substances into the inoculum stimulated fungal growth, hyphal anastomosis and the production of penetration pegs from hyaline appressoria. This was followed by cutlcle erosion centred on the penetration pegs in green fruit allowing sec-ondary growth of infection hyphae. Due to the development of cutinase resistance when the cuticle became yellow at ripening, no cuticle erosion occurred at penetrations on ripe fruit Since cuticle erosion followed penetration of the cutinase-susceptible cuticle and since penetration peg formation was not hindered by the cutinase cuticle, the process of primary penetration is regarded as mechanical.     

唇形科益母草等7种植物果实化学成分分析及形态特征

益母草、白花益母草、紫苏、野紫苏、小鱼仙草、石荠苎和细风轮菜系唇形科常见的药用植物。常生于路旁、沟边及空旷草地 ,民间也有广泛栽培。分布于广东、广西、湖南、湖北、云南、贵州、浙江、安徽、福建等省区。益母草、白花益母草民间全草入药 ,有活血调经、去痰生津的功效 ,果实称茺蔚子。用于月经不调 ,产后子宫出血及复位不全等症 [14 ]。野紫苏和紫苏的果实有镇咳、平喘和祛痰的功效 ,用于治疗咳嗽气喘、肠热便秘等症 [3 ] 。小鱼仙草用于治疗感冒头痛 ,胃炎 ,肾积水等症。石荠苎全草入药 ,用于治疗胃炎 ,慢性气管炎和肺积水等症[1] …     

蝴蝶兰EMS离体化学诱变及再生植株RAPD检测

用EMS对离体培养的蝴蝶兰类原球茎薄切片进行化学诱变,研究了不同浓度、不同时间诱变处理对类原球茎薄切片生长、类原球茎再生及再生苗生长的影响,并对再生苗DNA进行了RAPD检测。结果表明,诱变剂EMS对类原球茎薄切片生长产生重要影响,部分薄切片褐化死亡,再生类原球茎生长受到抑制,再生苗数量减少,表现出明显的伤害作用,这种伤害作用随诱变剂浓度的加大和处理时间的延长而加重。诱变剂EMS使部分再生苗畸变,叶片皱缩、变厚。并产生2株叶形、叶色突变体。部分再生苗表现出RAPD图谱带型的多态性,暗示DNA序列发生了一定的变异。EMS适合诱变剂量为浓度0．4％处理2d～4d。     

In Vitro Reconstitution of Light-harvesting Complexes of Plants and Green Algae

In plants and green algae, light is captured by the light-harvesting complexes (LHCs), a family of integral membrane proteins that coordinate chlorophylls and carotenoids. In vivo, these proteins are folded with pigments to form complexes which are inserted in the thylakoid membrane of the chloroplast. The high similarity in the chemical and physical properties of the members of the family, together with the fact that they can easily lose pigments during isolation, makes their purification in a native state challenging. An alternative approach to obtain homogeneous preparations of LHCs was developed by Plumley and Schmidt in 1987¹, who showed that it was possible to reconstitute these complexes in vitro starting from purified pigments and unfolded apoproteins, resulting in complexes with properties very similar to that of native complexes. This opened the way to the use of bacterial expressed recombinant proteins for in vitro reconstitution. The reconstitution method is powerful for various reasons: (1) pure preparations of individual complexes can be obtained, (2) pigment composition can be controlled to assess their contribution to structure and function, (3) recombinant proteins can be mutated to study the functional role of the individual residues (e.g., pigment binding sites) or protein domain (e.g., protein-protein interaction, folding). This method has been optimized in several laboratories and applied to most of the light-harvesting complexes. The protocol described here details the method of reconstituting light-harvesting complexes in vitro currently used in our laboratory,and examples describing applications of the method are provided.     

Effect of Lanthanum on Rooting of In Vitro Regenerated Shoots of Saussurea involucrata Kar. et Kir

In present study, the effect of lanthanum (La) on the rooting of regenerated shoots of Saussurea involucrata Kar. et Kir was analyzed. Rooting occurred from regenerated shoots inoculated on a medium supplemented with La, the plant rooting hormone indole-3-acetic acid (IAA), or both La and IAA together. The highest rooting efficiency (96%), root number/shoot (8.5), and root length (63 mm) were recorded in shoots cultured on medium containing 2.5 μM IAA combined with 100 μM La(3+). In order to elucidate the mechanism of rooting enhancement by La, we examined dynamic changes in antioxidant enzyme activities in plant tissue over time in culture. We found that the activities of peroxidase (POX) and superoxide dismutase (SOD) were significantly higher in plant tissue cultured in IAA plus La than in La or IAA alone. At the same time, the highest H(2)O(2) content was detected in plant tissue in the presence of 2.5 μM IAA plus 100 μM La(3+). In light of these data and previous results, we speculate that La enhanced IAA-induced rooting by acting as a mild abiotic stress to stimulate POX and SOD activities in plant cells. Then, IAA reacted with oxygen and POX to form the ternary complex enzyme-IAA-O(2) that dissociated into IAA radicals and O(2)(-). Subsequently, IAA-induced O(2)(-) readily converted to hydroxyl radical (HO·) via SOD-catalyzed dismutation. Finally, cell wall loosening and cell elongation occurred as a consequence of HO-dependent scission of wall components, leading to root growth. The treatment of IAA combined with La resulted in the highest plantlet survival (80%) compared to single treatments with IAA or La alone. These data suggest that rare earth elements enhance root morphogenesis and the growth of S. involucrata.     

3种观赏植物对室内甲醛污染的净化及生长生理响应

在密封条件下,采取熏蒸法研究了常春藤、绿萝、驱蚊草对不同浓度梯度的甲醛气体胁迫的吸收能力及其生理响应。结果显示:(1)3种植物对室内甲醛气体均有不同程度的吸收能力,其吸收率随室内甲醛气体浓度的升高而逐渐增加,且吸收能力表现为常春藤>驱蚊草>绿萝。(2)与对照相比,随着室内甲醛气体胁迫浓度的增加,驱蚊草、绿萝、常春藤的叶绿素含量先升高再降低,而叶绿素a/b值的变化趋势各有不同。(3)不同浓度甲醛气体胁迫下,3种植物的超氧化物歧化酶(SOD)活性和过氧化物酶(POD)活性均显著升高,并以常春藤的增加量最大(分别为113.21%和120.84%),驱蚊草的增加量最小(分别为69.04%和60.76%);而3种植物的过氧化氢酶(CAT)活性与对照相比显著降低,并以驱蚊草的变化量最大(49.54%),绿萝的变化量最小(14.66%)。(4)驱蚊草、绿萝、常春藤的丙二醛(MDA)含量和脯氨酸含量随着甲醛气体浓度的增加呈升高趋势。综合分析表明,3种室内植物耐受甲醛胁迫的能力存在显著差异,常春藤属于吸收多、耐性强的植物,驱蚊草属于吸收多、耐性弱的植物,而绿萝属于吸收少、耐性强的植物。     

In Vitro Micropropagation of Freesia hybrida and the Assessment of Genetic and Epigenetic Stability in Regenerated Plantlets

Freesia hybrida is an important worldwide cut flower, especially in America and Europe. For efficient regeneration of this flower from young inflorescence and rachillae in tetraploid, we developed a simple in vitro micropropagation protocol. Explants of Freesia hybrida can regenerate plantlets through somatic embryogenesis via two kinds of pathways, that is, directly from the epidermal cells or indirectly from an embryonic callus, depending on the exogenous plant growth regulators (PGRs) used in the culture media. In direct embryogenesis, when the explants were cultured on Murashige and Skoog (MS) medium supplemented with 11.43 μM indole acetic acid (IAA) and 4.44 μM 6-benzylaminopurine (6-BA), the induction rate was 84% for young inflorescence and 100% for rachillae. After the multishoots were subcultured on the rooting MS medium containing 1.08 μM α-naphthalene acetic acid (NAA), the rooting rate was close to 100%. In indirect embryogenesis, embryonic calluses were formed when the culture medium contained 22.22 μM 6-BA and 4.52 μM 2,4-dichlorophenoxy acetic acid (2,4-D), and the induction rate was 92.4% for young inflorescence and 100% for rachillae. After the embryonic calluses were transferred to the medium supplemented with 11.43 μM IAA and 13.33 μM 6-BA, they could develop into plantlets with roots. In assessing the two regeneration pathways in terms of genetic and epigenetic fidelity of the regenerants, two kinds of molecular markers [amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP)] were employed. The AFLP analysis used 20 primer pairs that yielded 916 scorable bands among the donor plant and 11 regenerants from direct embryogenesis, of which 8 (0.87%) were polymorphic. The regenerants from indirect embryogenesis had 1075 clear bands of which 3 (0.27%) were polymorphic scorable bands from 18 primer pairs. Moreover, the variant band patterns included two types, that is, loss-of-original and gain-of-novel bands. MSAP analysis revealed that tissue culturing of the flower induced DNA cytosine methylation alterations in both CG and CNG levels and patterns compared with the donor plant. The variation rate was 1.1 and 1.3% for the direct and indirect embryogenesis pathways, respectively. The findings show that tissue culture of flowering plants is a form of stress which can induce some heritable epigenetic variations and should be considered in future long-term genotype preservation programs of Freesia hybrida.