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Dynam,c and Antagonistic Allele-Specific Epigenetic Modifications Controlling the Expression of Imprinted Genes in Maize Endosperm

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Molecular Plant 2017年第3期10卷 442-455页

作者： Xiaomei Dong Mei Zhang Jian Chen Lizeng Peng Nan Zhang Xin Wang Jinsheng Lai State Key Laboratory of Agrobiotechnology and National Maize Improvement Center Department of Plant Genetics and Breeding~ China Agricultural UniversityBeijing 100193 PR. China Department of Biology Stanford University Stanford CA 94305 USA These authors contributed equally to this article.

Genomic imprinting is often associated with aUele-specific epigenetic modifications. Although many reports suggested potential roles of DNA methylation and H3K27me3 in regulating genomic imprinting, the contribu- tions of allele-specific active histone modifications to imprinting remain still unclear in plants. Here, we report the identification of 337 high-stringency allele-specific H3K4me3 and H3K36me3 peaks in maize endosperm. Paternally preferred H3K4me3 and H3K36me3 peaks mostly co-localized with paternally expressed genes （PEGs）, while endosperm-specific maternally expressed genes （endo-MEGs） were associated with mater- nally preferred H3K4me3 and H3K36me3 peaks. A unique signature for PEGs was observed, where the active H3K4me4 and H3K36me3 as well as repressive H3K27me3 appeared together. At the gene body of con-PEGs （constitutively expressed PEG）, H3K27me3 and H3K36me3 were specifically deposited on hypomethylated maternal alleles and hypermethylated paternal alleles, respectively. Around the transcription start sites of endo-MEGs, DNA methylation and H3K4me3 specifically marked paternal and maternal alleles, respectively. In addition, 35 maternally expressed non-coding RNAs exhibited the same allele-specific epigenetic features as endo-MEGs, indicating similar mechanisms for the regulation of imprinted genes and non-coding RNAs. Taken together, our results uncover the complex patterns of mutually exclusive epigenetic modifications deposited at different alleles of imprinted genes that are required for genomic imprinting in maize endosperm.

关键词： genomic imprinting H3K4me3 H3K36me3 endosperm maize

Wood liquefaction with phenol by microwave heating and FTIR evaluation

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Journal of Forestry Research 2015年第4期26卷 1043-1048页

作者： Gaiyun Li Chungyun Hse Tefu Qin Research Institute of Wood Industry Chinese Academy of Forestry Southern Research Station USDA Forest Service

We examined wood liquefaction using phenol and mixed acid catalysts with microwave heating, and compared that with similar processes that use oil bath heating. The reaction time for microwave heating to achieve a residue content was one sixth, one eighteenth, and one twenty-fourth of that from oil bath heating, respectively, for phenol to wood （P/W） ratios of 2.5/1, 2/1 and 1.5/1. A low P/W ratio tended to result in carbonization of liquefied wood due to an insufficient amount of phenol and localized microwave superheating. Fourier transform infrared spectroscopic （FTIR） evaluation of the liquefied residue, showed that the liquefaction rates of wood com- ponents differed. Hemicellulose was most susceptible to liquefaction, crystalline cellulose was most recalcitrant, and guaiacyl units the most prone to re-condensation. From FTIR, the chemical components and substitution patterns of bonded phenol were similar for both methods.

关键词： Wood liquefaction Phenol Microwaveheating Oil bath heating Fourier transform infraredspectroscopy (FTIR)

Thermo-plasticity of high-strength and high-ductility 7050 aluminum ingot

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Journal of Central South University 2012年第5期19卷 1169-1174页

作者：邓英尹志民丛福官 School of Materials Science and Engineering Central South University Northeast Light Alloy Co Ltd

Thermo-plasticity of homogenized 7050 aluminum ingot was investigated by instantaneous tensile tests conducted at different temperatures. The results show that, with the increase of testing temperatures, the strength decreases, and the plasticity increases firstly and then decreases in homogenized 7050 ingot. When the studied alloy is deformed between 380℃ and 420℃, the deformation resistance is lower and plasticity is better. And the actual heating temperature for ingot before hot extrusion should be controlled between 360 ~C and 400 ~C. At low tensile temperatures, the deformation structure is mainly composed of dislocation substructure. With the increase of testing temperatures, transgranular fracture transforms into intergranular fracture progressively during deformation. At high tensile temperatures, the grain boundaries are weakened, deformation is concentrated at the grain boundaries and the re-orientation of equilibrium phases at grain boundaries appears.

关键词： 7050 alloys tensile test thermo-plasticity microstructure mechanical property

Spatiotemporal Patterns and Dynamics of Species Richness and Abundance of Woody Plant Functional Groups in a Tropical Forest Landscape of Hainan Island,South China

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Journal of Integrative Plant Biology 2008年第5期50卷 547-558页

作者： Zhi-Dong Zhang Run-Guo Zang Yao-Dong Qi Key Laboratory of Forest Ecology and Environment the State Forestry Administration Institute of Forest Ecology Environment and Protection Chinese Academy of Forestry Beijing 100091 China Yantai Institute of Coastal Zone Research for Sustainable Development the Chinese Academy of Sciences Yantai 264003 China

Tropical forests are among the most species-diverse ecosystems on Earth. Their structures and ecological functions are complex to understand. Functional group is defined as a group of species that play similar roles in an ecosystem. The functional group approach has been regarded as an effective way of linking the compositions of complex ecosystems with their ecological functions. To understand the variation of functional groups in species-rich ecosystems after disturbance, the present study investigated the spatial pattern and temporal dynamics of woody plants in a typically fragmented natural forest landscape of Hainan Island in South China. The study area was classified into eight landscape types based on vegetation type, disturbance manner and the time of recovery. The woody plant species were aggregated into seven functional groups based on the growth form, successional status and plant size. The results gained from the present study showed that all functional groups, except for the emergent and canopy tree species, were present in all eight landscape types. Each landscape type had different numbers of dominant functional groups. There are similar species richness and stem abundance structure among functional groups between mid-successional clear cut lowland rainforest and old growth tropical coniferous forest. This similarity exists in selective logged lowland rainforest and old-growth lowland rainforest, as well as among landscape types of montane rainforest. The functional groups with the same successional status had similar patterns of species richness and stem abundance ratios among different landscape types. The variation patterns of functional groups along the successional stages in terms of species richness and stem abundance among the tropical lowland rainforest landscape types were more similar to each other than those in the tropical montane rainforest landscape types. This study provides further support for the competition-colonization tradeoff and

关键词： forest landscape types functional groups Hainan Island recovery dynamics spatial variation species diversity stem abundance tropical forests,

Modelling tree mortality across diameter classes using mixedeffects zero-inflated models

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Journal of Forestry Research 2020年第1期31卷 131-140页

作者： Yang Li Xingang Kang Qing Zhang Weiwei Guo Ministry of Education Key Laboratory for Silviculture and Conservation College of ForestryBeijing Forestry University

The mortality of trees across diameter class model is a useful tool for predicting changes in stand *** data commonly contain a large fraction of zeros and general discrete models thus show more *** on the traditional Poisson model and the negative binomial model,different forms of zero-inflated and hurdle models were applied to spruce-fir mixed forests data to simulate the number of dead *** comparing the residuals and Vuong test statistics,the zero-inflated negative binomial model performed best.A random effect was added to improve the model accuracy;however,the mixed-effects zero-inflated model did not show increased *** to the model principle,the zeroinflated negative binomial model was the most suitable,indicating that the"0"events in this study,mainly from the sample"0",i.e.,the zero mortality data,are largely due to the limitations of the experimental design and sample *** results also show that the number of dead trees in the diameter class is positively correlated with the number of trees in that class and the mean stand diameter,and inversely related to class size,and slope and aspect of the site.

关键词： Tree mortality Mixed forest Zero-inflated model Hurdle model Mixed-effects

Effect of cooking conditions on quality of sweetened adzuki an

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International Journal of Agricultural and Biological Engineering 2014年第4期7卷 134-142页

作者： Yao Xinmiao Lu Shuwen Zheng Xianzhe Sun Jingkun Ren Chuanying Zhang Yinglei Xie Xuejun Sun Xiangdong College of Engineering Northeast Agricultural UniversityHarbin 150030China Food Processing Research Institute Heilongjiang Academy of Agricultural SciencesHarbin 150086China Quality and Safety Institute of Agricultural Products Heilongjiang Academy of Agricultural SciencesHarbin 150086China

To produce high sensory quality sweetened adzuki an,the effects of cooking conditions including cooking time,heating power,sugar soaking time and soaking liquid pH on textural properties and sensory scores were evaluated using central composite experimental *** treatment and sodium tripolyphosphate were adopted to improve the mouthfeel of the whole bean an *** showed that the optimal parameters were as follows:cooking time of 50 min,heating power of 1.1 kW,sugar soaking time of 2 h and soaking liquid pH of 8.0,which resulted in the highest sensory score of *** this study,the effectiveness of the method to process sweetened whole bean adzuki an was validated and a sensory evaluation method for whole grain adzuki an product was developed.

关键词： sweetened adzuki an quality cooking conditions processing sensory evaluation

Phylogenetic relationships among five species of Armeniaca Scop. (Rosaceae) using microsatellites (SSRs) and capillary electrophoresis

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Journal of Forestry Research 2016年第5期27卷 1077-1083页

作者： Dali Fu Lüyi Ma Yue Qin Mengpei Liu Han Zhao Gaopu Zhu Hao Fu College of Forestry Beijing Forestry UniversityBeijing 100083 China Non-timber Forestry Research and Development Center Chinese Academy of Forestry Zhengzhou 450003 China College of Forestry Central South University of Forestry and Technology Changsha 410004 China

The genus Armeniaca Scop. is well known for its popular cultivated edible fruit trees such as Armeniaca vul- garis Lam. and ornamental flowers such as A. mume Sieb. Another species, A. cathayana Fu et al., one of six important dry fruits （kernel-using apricot）, is cultivated for its edible seeds in North China. In the present study, DNA from 70 individuals of A rmeniaca, including 38 of A. cathayana, 18 ofA. vulgaris, 12 ofA. sibirica, 1 ofA. dasycarpa and 1 of A. mume, was extracted and analyzed using microsatellites and capillary electrophoresis. For 20 polymorphic loci selected, 339 alleles and 140.7 effective alleles were detected. The number of alleles per locus ranged from 8 to 28, with an average of 16.95 alleles per locus. The observed heterozygosity （Ho） and the expected heterozygosity （He） ranged from 0.427 to 0.971 and from 0.737 to 0.912, respectively. The polymorphism information content varied from 0.708 to0.905, with an average of 0.827. Based on the genetic similarity among 70 individuals, a UPGMA was used to establish the phylogenetic relationships. The taxonomic positions among five species were clearly revealed, and A. cathayana was more closely related to A. vulgaris than to A. sibirica. The results will provide a scientific basis for research on the taxonomy, germplasm resources and breeding ofArmeniaca, especially for A. cathayana.

关键词： Armeniaca Scop. - Armeniaca cathayana Microsatellite Capillary electrophoresis Phylogenetic relationship Polymorphism Simple sequence repeat

Cytological Observation of Microsporogenesis in Male-Sterile Lines of Chinese Pink(Dianthus chinensis L.)

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Agricultural Sciences in China 2008年第5期7卷 547-553页

作者： FU Xiao-peng HU Jin-yi HU Hui-rong BAO Man-zhu Key Laboratory of Horticultural Plant Biology Ministry of Education~College of Horticulture and Forestry Sciences Huazhong AgriculturalUniversity Wuhan 430070 P.R.China

This study addressed the differences in microsporogenesis between male sterile and fertile lines of Chinese pink. The microsporogenesis processes of male sterile and fertile lines were histologically examined in squashed pollen grains and in paraffin embedded sections. A stable male-sterile line （H-37B） was obtained following six generations of inbreeding in a self-fertile line, followed by two generations of backcrossing. In the corresponding fertile line, development of the mature pollen grains was followed through the initiation of the sporogenous cell, microsporocyte formation, and the tetrad developmental period. In the male-sterile line, abortion of the developing pollen grains was observed to take place at various stages, namely, sporogenous cell growth, mother cell meiosis, and tetrad transformation to the uninuclear state. The pollen grains of the fertile line were spheroid, turgid, and viable. By contrast, the male-sterile line produced pollen that was irregular in shape, empty, and nonviable. The abortion of the microspore in the male-sterile line appeared to relate to abnormal growth of the tapetum layer.

关键词： Dianthus chinensis L. microsporogenesis paraffin section cytology

Recent Trends and Recommendations for Nitrogen Fertilization in Intensive Agriculture in Eastern China

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Pedosphere 2004年第4期14卷 449-460页

作者： M.ROELCKE HANYong K.H.SCHLEEF ZHUJian-Guo LIUGang CAIZu-Cong J.RICHTER InstituteofGeoecology TechnicalUniversityCarolo-WilhelminaLangerKamp19c38106Braunschweig（Germany） InstituteofSoilScience ChineseAcademyofSciencesP.O.Box821Nanjing210008（China） InstituteofFarmEconomics FederalAgriculturalResearchCentre（FAL）BundesaUee5038116Braunschweig（Ger-many）

The Taihu Region in eastern China is one of China's most intensive agricultural regions and also one of the economically most developed areas. High nitrogen balance surpluses in the summer rice-winter wheat double-cropping systems are leading to large-scale non-point source pollution of aquifers. In an interdisciplinary approach, four-year (1995-1998) field trials were carried out in two representative areas (Jurong County and Wuxi City) of the Taihu Region. Five farmers' field sites were chosen in each of the 2 locations, with each site divided into 'standard' (farmers' practice) and 'reduced' (by 30%-40%) N fertilization. For both fertilization intensities, N balance surpluses and monetary returns from grain sales minus fertilizer expenditures were calculated in an economic assessment. Based on the field trials, the mineral N fertilizer application rates reduced by about 10% for rice and 20%-30% for wheat were recommended in 1999. Since 1999, the research focused on the trends in N fertilizer application rates and changes in grain and agricultural commodities *** rice N fertilizer use, in Wuxi City as of 2001, dropped by roughly 25%, while for winter wheat it decreased by 10%-20%, compared to the 1995-1998 period. This has been achieved not only by grain policy and price changes, but also by an increased environmental awareness from government officials. Nitrogen balance surpluses in Anzhen Town (of Wuxi City) have consequently diminished by 50%-75% in rice and by up to 40% in wheat, with reductions being achieved without concomitant decreases in physical grain yields or returns from sales minus fertilizer costs.

关键词： agro-economy N fertilization non-point source pollution rice-wheatrotation Taihu Region