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Permeation of dimethyl sulfoxide into articular cartilage at subzero temperatures

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第3期13卷 213-220页

作者： Shao-zhi zhang Xiao-yi YU Guang-ming CHEN Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China

Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization would contribute to the commercialization or industrialization of this technology. Vitrification has been thought to be a promising method for successful preservation of articular cartilage （AC）, but high concentration cryoprotectants （CPAs） are used which may cause high cellular toxicity. An effective way to reduce CPA toxioity is to increase CPA concen- tration gradually while the temperature is lowered. Understanding the mechanism of （31~A permeation at subzero temperatures is important for designing the cryopreservation protocol. In this research, the permeation of dimethyl sulfoxide （MezSO） in ovine AC at subzero temperatures was studied experimentally. Pretreated AC discs were ex- posed in Me2SO solutions for different time （0, 5, 15, 30, 50, 80, and 120 min） at three temperature levels （-10, -20, and -30℃）. The Me2SO concentration within the tissue was determined by ultraviolet （UV） spectrophotometry. The diffusion coefficients were estimated to be 0.85×10-6, 0.48×10-8, and 0.27×10-6 cm2/s at -10, -20, and -,30℃, respectively, and the corresponding activation energy was 29.23 kJ/mol. Numerical simulation was performed to com- pare two Me2SO addition protocols, and the results demonstrated that the total loading duration could be effectively reduced with the knowledge of permeation kinetics.

关键词： Articular cartilage Vitrification Dimethyl sulfoxide Permeation Diffusion coefficient Subzero temperature

Genome-wide search for segregation distortion loci associated with the expression of complex traits in Populus tomentosa

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Forestry Studies in China 2007年第1期9卷 1-6页

作者： zhang De-qiang zhang zhi-yi Yang Kai Key Laboratory of Genetics and Breeding in Forest Trees and Omamental Plants Ministry of Education Institute of Populus tomentosa Beijing Forestry University Beijing 100083 P. R. China Beijing Agricultural College Beijing 102206 E R. China

Segregation distortion of molecular markers has been reported in a broad range of organisms. It has been detected in an interspecific BC1 Populus pedigree established by controlled crossing between clone ＂LM50＂（Populus tomentosa） and its hybrid clone ＂TB01＂（P. tomentosa × p. bolleana）. The study with a total of 150 AFLP markers （approximately 18.9% of the total loci） exhibited significant deviation from the Mendelian ratio （1：1）（p〈0.01）. Twenty-five percent of the markers were mapped on the parental specific genetic linkage maps of clones ＂LM50＂ and ＂TB01＂ with a pseudo-test-cross mapping strategy. Twelve linkage groups had markers with skewed segregation ratios, but the major regions were on linkage groups TLG2, TLG4 and TLG6 in the linkage map of clone ＂LM50＂. We also analyzed the association between distorted loci and expression of complex traits with Mapmaker/QTL software. A total of 16 putative QTLs affecting 12 traits were identified in the distorted regions on seven linkage groups. Therefore we could detect the distribution of skewed loci along the entire genome and identify the association between quantitative traits and segregation loci via genetic mapping in an interspecific BC1 P. tomentosa family. Furthermore, the genetic nature and possible causes of these segregation distortions for differentiation between female and male parents were also discussed.

关键词： Populus tomentosa genetic mapping segregation distortion QTL mapping

Comparison and early selection of new clones in Populus tomentosa

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Forestry Studies in China 2008年第3期10卷 162-167页

作者： zhang Zi-hui WANG Ze-liang LIN Shan-zhi zhang zhi-yi Forest-fire Forecast Watching and Information Management Center State Forestry Administration Beijing 100714 P. R. China Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education Beijing Forestry University Beijing 100083 P. R. China

In our study, two experimental plantations, respectively, with 24 and 32 new clones of P tomentosa, were established in Weixian County, Hebei Province and Wuzhi County, Henan Province using a completely randomized block design. A comparative study was conducted on the continuous 5-year-old height and diameter at breast height （DBH） of new clones in the two plantations. As well, based on genetic correlation over the years of testing of these clones, a preliminary study of early selection was carried out. Results indicate that the growth traits of the new clones in Weixian were better than those in Wuzhi. The traits show weak correlation between the two plantations. In some stands, the height, DBH and seedling volume of 5-year-old clones presented statistically significant differences among clones. In both plantations, the new clones showed over 0.6 repeatability of height, DBH and volume, as well as larger coefficients of variation （CV）. The fact that these clones achieved the largest repeatability and CV in the second year suggests that these traits are highly controlled by heredity. Thus, based on the growth traits of the second year, the new clones B305, B307, B303, H75, BT18, BT17 and 21J-1 were considered suitable in Weixian. In Wuzhi, the new clones had variable repeatability and CVs in various years and their correlation of growth traits among different years was not high. We conclude that early selection of new clones was not feasible in Wuzhi.

关键词： Populus tomentosa Carr. new clones comparative test early selection

A new route for the synthesis of ω-acyl carboxylic acids

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Chinese Journal of Chemistry 1991年第5期9卷 458-460页

作者： WU Shi-Hui zhang zhi-yi MA Zhen-Yong Department of Chemistry Fudan UniversityShanghai 200433

A new method for synthesis of ω-acyl carboxylic acids is described. Photooxygenation of cyclic silyl enol ethers sensitized by 9,10-dicyanoanthracene (DCA) provided ω-acyl carboxylic acids in modest to good yields.

关键词： A new route for the synthesis of DCA acyl carboxylic acids

The role of antioxidant system in freezing acclimation-induced freezing resistance of Populus suaveolens cuttings

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Forestry Studies in China 2007年第2期9卷 107-113页

作者： Luo Lei Lin Shan-zhi Zheng Hui-quan Lei Yang zhang Qian zhang zhi-yi Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of Education Beijing Forestry UniversityBeijing 100083 P. R. China

We investigated the changes in the contents of H202, malonaldehyde （MDA） and endogenous antioxidants, the activities of protective enzymes and some critical enzymes involved in the ascorbate-glutathione （ASA-GSH） cycle as well as freezing resistance （expressed as LT50） and correlations mentioned above, in detail using Populus suaveolens cuttings. The purpose was to explore the physiological mechanism of the enhancement of freezing resistance induced by freezing acclimation at -20℃, and to elucidate the physiological mechanisms by which trees adapt to freezing. The results showed that freezing acclimation enhanced the activities of superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT）, monodehydroascorbate reductase （MDAR）, ascorbate peroxidase （APX）, dehydroascorbate reductase （DHAR） and glutathione reductase （GR）. And it increased the contents of reduced ascorbate （ASA）, reduced glutathione （GSH）, dehydroascorbate （DHA） and oxidized glutathione （GSSG）. However, H202 and MDA contents and LT50 of cuttings were decreased. LTs0 in cuttings was found to be closely correlated to the levels of SOD, POD, CAT, APX, DHAR, MDAR, GR, H202, MDA, ASA, GSH, DHA and GSSG during freezing acclimation. This suggested that the enhancement of freezing resistance of cuttings induced by freezing acclimation may relate to the distinct increase for the levels of SOD, POD, CAT, APX, DHAR, MDAR, GR, ASA, GSH, DHA, and GSSG. In addition, the observed levels of APX, DHAR, MDAR, GR, ASA, DHA, GSH and GSSG were higher than those of SOD, POD and CAT during freezing acclimation. It indicated that a higher capacity of the ASA-GSH cycle is required for H202 detoxification, and growth and development of cuttings. Based on the obtained results, it can be concluded that the ASA-GSH cycle plays an important role in enhancement of freezing resistance of P. suaveolens cuttings during freezing acclimation.

关键词： Populus suaveolens freezing acclimation antioxidant system ASA-GSH cycle

Isolation and analysis of a TIR-specific promoter from poplar

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Forestry Studies in China 2007年第2期9卷 95-106页

作者： Zheng Hui-quan Lin Shan-zhi zhang Qian zhang Zhen-zhen zhang zhi-yi Lei Yang Hou Lu Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of Education Beijing Forestry UniversityBeijing 100083 P. R. China

A 5＇ flanking region of the well-conserved Toll/interleukin-1 receptor domain （TIR）-encoding sequence was isolated from the genomic DNA ofMelampsora magnusiana Wagner resistant clones of hybrid triploid poplars [（Populus tomentosa × P. bolleana） × P. tomentosa]. Sequencing results and alignment analysis show that the obtained TIR-specific promoter （named as PtTIRp01） was 1,732 bp in length; moreover 3＇ region of the PtTIRp01 contains a responds to the 5＇ composition of TIR-NBS type gene PtDRG02, of 747 bp long 5＇ region of TIR-NBS type gene PtDRG02 and its 398 bp complete TIR-encoding sequence, which significantly corindicating that the obtained TIR-specific promoter region consists upstream region of promoter （985 bp）. It was found that the 5＇ region of TIR-NBS type gene PtDRG02 was characterized in the downstream region of the transcriptional start, named as 5＇-untranslated region （5＇ UTR）, consisting of one 93 bp 5＇-untranslation exon, one 213 bp intron and one 441 bp TIR-encoding open reading frame （ORF）. In addition, several putative cis-acting motifs were present in the obtained TIR-specific promoter of PtDRG02, including one TATA box, one GC-rich, one AT-rich, one P-box, one 3-AF1 binding site, two CAAT boxes, two GT-1 motifs, three typical W-boxes, four I-boxes, and one multi-cis-acting fragment （MCF）. The latter contains five types of regulatory elements （E4, G-box, ABRE motif, box 1 and HVA 1 s）, most of which were homologous to the cis-acting regulatory elements involved in the activation of defense genes in plants. Thus, it can be suggested that TIR-specific promoter might be a pathogen-inducible promoter and be necessary for the inducible expression of defense-related genes. Key words Toll/interleukin- 1 receptor domain, promoter, Cis-acting element, poplar

关键词： Toll/interleukin- 1 receptor domain promoter Cis-acting element poplar

Interrelationships between leaf heat conductivity and tissue structures of different varieties of Populus tomentosa Carr

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Forestry Studies in China 2008年第3期10卷 173-178页

作者： WANG Min zhang Wen-jie XIAO Jian zhang zhi-yi LIU Jing College of Science Beijing Forestry University Beijing 100083 P. R. China Technical Institute of Physics and Chemistry Chinese Academic of Sciences ByiJing 100080 P. R. China Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education Beijing Forestry University Beijing 100083 P. R. China

Plant heat conductivity largely depends on tissue structure. Different structures lead to different heat conductivity. As well, water transfer also plays a very important role in heat transfer in plants. We have studied leaf heat conductivity and tissue structure of 3- and 30-year-old Populus tomentosa Carr. trees using infrared thermal imaging, steady state heat conductivity surveys and paraffin section and investigated the relationship between leaf heat conductivity, tissue structure and water content of leaves. The results show that the temperature on leaf surfaces among the various varieties of trees was almost the same. Leaf heat conductivity, temperature and water content of leaves are positively correlated. The thicker the leaf tissue structures, the larger the heat resistance. That is, the tighter the cells and the smaller the interspaces, the smaller the heat conductivity, which is not conducive for heat transfer.

关键词： Populus tomentosa Carr. leaf infrared thermal imaging heat conductivity paraffin section

Model of leaf energy distribution and its experimental validation of Populus tomentosa Carr

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Forestry Studies in China 2008年第3期10卷 168-172页

作者： zhang Wen-jie WANG Min SHEN ying-bai zhang zhi-yi College of Science Beijing Forestry University Beijing 100083 P. R. China Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education Beijing Forestry University Beijing 100083 P. R. China

Leaf temperature of a plant is the result of heat transfer between the plant and its environment. There are many factors that can affect leaf temperature, such as the solar radiation energy, environmental temperature, wind velocity, evaporation on the leaf surface, photosynthesis, respiration and so on, which have different effects on the temperature of leaves. In first instance, we analyzed the heat transfer on leaves of Populus tomentosa Carr. theoretically and constructed a model of energy distribution. We then validated the model by analyzing seven different kinds of one-year-old P. tomentosa leaves experimentally. The result shows that solar radiation is the main energy input and the dominant ways of thermal diffusion are heat transfer between the upper and lower leaf surfaces and evaporation from the leaf surface.

关键词： Populus tomentosa Carr. leaf heat transfer energy distribution

Establishment of cell suspension line of Populus tomentosa Carr

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Forestry Studies in China 2008年第3期10卷 158-161页

作者： YAO Na zhang zhi-yi AN Xin-min YANG Kai Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education Beijing Forestry University Beijing 100083 P. R. China Department of Biotechnology Beijing Agricultural College Beijing 102206 P. R. China

Leaves of fine Populus tomentosa genotype TC152 were used as explants to establish cell suspension lines. The effects of plant growth regulators on callus induction and establishment of cell suspension lines were studied. The callus induction rate was the highest on a MS solid medium supplemented with 1.0 mg·L^-1 2,4-D. A cell suspension line could be obtained by inoculating calli which were not subcultured into a MS liquid medium supplemented with 1.5 mg·L^-1 2,4-D. The best subculture medium was MS ＋ 0.8 mg＇L-1 2,4-D ＋ 30 g·L^-1 sucrose with a subculture cycle of seven days.

关键词： Populus tomentosa callus cell suspension line