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Comparative Detection of Calcium Fluctuations in Single Female Sex Cells of Tobacco to Distinguish Calcium Signals Triggered by in vitro Fertilization

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Journal of Integrative Plant Biology 2009年第8期51卷 782-791页

作者： xiong-bo peng meng-xiang sun Hong-Yuan Yang Key Laboratory of Ministry of Education for Plant Developmental Biology College of Life Sciences Wuhan University Wuhan 430072 China

Double fertilization is a key process of sexual reproduction in higher plants. The role of calcium in the activation of female sex cells through fertilization has recently received a great deal of attention. The establishment of a Ca^2＋-imaging technique for living, single, female sex cells is a difficult but necessary prerequisite for evaluating the role of Ca^2＋ in the transduction of external stimuli, including the fusion with the sperm cell, to internal cellular processes. The present study describes the use of Fluo-3 for reporting the Ca^2＋ signal in isolated, single, female sex cells, egg cells and central cells, of tobacco plants. A suitable loading protocol was optimized by loading the cells at pH 5.6 with 2 μM Fluo-3 for 30 min at 30 ℃. Under these conditions, several key factors related to in vitro fertilization were also investigated in order to test their possible effects on the [Ca^2＋]cyt of the female sex cells. The results indicated that the bovine serum albumin-fusion system was superior to the polyethlene glycol-fusion system for detecting calcium fluctuations in female sex cells during fertilization. The central cell was fertilized with the sperm cell in bovine serum albumin; however, no evident calcium dynamic was detected, implying that a transient calcium rise might be a specific signal for egg cell fertilization.

关键词： cytosolic calcium fertilization Fluo-3 sex cells

A novel in vitro system for gamete fusion in maize

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Cell Research 2005年第9期 59-63页

作者： xiong bo peng, meng xiang sun*, Hong Yuan YANG Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China

Various systems by using electric pulse, calcium, or polyethylene glycol have been developed in the past decade for the in vitro fusion of plant gametes. These in vitro systems provide a new way to study the fertilization mechanisms of plants. In this study, we developed a bovine serum albumin (BSA)-mediated fusion system for the in vitro fusion of maize gametes. The in vitro fusion of the isolated single egg cell and sperm cell of maize was observed microscopically in the BSA solution and the fertilized egg cell showed normal cell wall regeneration and nuclear division. The effects of the BSA concentration, pH value and calcium level on the efficiency of the maize gamete fusion were also assessed. BSA concentration and pH value did significantly affect the efficiency of the gamete fusion. Calcium was not necessary for the gamete fusion when BSA was present. The optimal solution for the gamete fusion contained 0.1% BSA, pH 6.0. The fusion frequency was as high as 96.7% in that optimal solution. This new in vitro fertilization system offers an alterna- tive tool for the in vitro study of fertilization mechanisms with much simpler manipulating procedure than PEG system, and it will be especially useful for the in vitro study of the calcium dynamics during plant fertilization.

关键词： in vitro fertilization bovine serum albumin calcium maize.

A versatile synthetic strategy towards rare earth based metal-organic frameworks

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Science China Chemistry 2025年

作者： Quan Shi Yun-Hao Xu Ming-Hui Chen peng Zhao Wen-bo Deng Ji xiong Kai Guo Ya-Qing Feng Bao Zhang School of Chemical Engineering and Technology Tianjin University Tianjin Collaborative Innovation Center of Chemical Science and Engineering Guangdong Laboratory Chemistry & Fine Chemical Industry Jieyang Center

Rare earth metal-organic frameworks (RE-MOFs) have drawn wide attention owing to diverse network structures and various application ***,due to the unpredictable formation of the nodes,it is still challenging to design novel RE-MOFs.A novel versatile strategy was developed employing a RE-acetate complex (RE2(CH3COO)6·4H2O) as a precursor to construct RE-MOFs.2D RE-MOFs (RE-DBP) and 3D RE-MOFs (RE-TCPP) could be obtained by using dicarboxylic porphyrin ligands H2DBP and tetracarboxylic porphyrin ligands H2TCPP,*** RE-MOFs were further synthesized to verify the universality of the *** crystalline RE-MOFs could also be prepared at room temperature via the developed strategy,which could significantly promote large-scale preparation and practical application of *** proof of the concept,the performance of porphyrin-based RE-MOFs was investigated in the photocatalytic cycloaddition of CO2with *** the RE-DBP(Co) MOFs,Tb-DBP(Co) exhibited the best photocatalytic performance,which was also greater than that of the corresponding 3D MOF Tb-TCPP(Co) due to the optimal 2D structure and thus the accelerated photogenerated charge separation and transfer *** work not only provides a novel versatile strategy to design and develop RE-MOFs,but also proposes a promising approach for the potential bulk production of RE-MOFs at room temperature.

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New insights into cell-cell communications during seed development in flowering plants

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Journal of Integrative Plant Biology 2022年第2期64卷 215-229页

作者： Wei Wang Hanxian xiong Kaiting sun bo Zhang meng-xiang sun State Key Laboratory of Hybrid Rice College of Life SciencesWuhan UniversityWuhan430072 China

The evolution of seeds is a major reason why flowering plants are a dominant life form on *** developing seed is composed of two fertilization products,the embryo and endosperm,which are surrounded by a maternally derived seed *** evidence indicates that efficient communication among all three seed components is required to ensure coordinated seed *** communication within plant seeds has drawn much attention in recent *** this study,we review current knowledge of cross-talk among the endosperm,embryo,and seed coat during seed development,and highlight recent advances in this field.

关键词： cell-cell communication embryo endosperm seed coat

A VPE-like protease NtTPE8 exclusively expresses in the integumentary tapetum and is involved in seed development

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Journal of Integrative Plant Biology 2019年第5期61卷 598-610页

作者： Wei Wang Hanxian xiong Rongxin Lin Nantian Zhao peng Zhao meng-xiang sun State Key Laboratory of Hybrid Rice College of Life Sciences Wuhan University

Programmed cell death(PCD)is an essential process for development,and shows conserved cytological features in both plants and *** are well-known critical components of the PCD machinery in ***,currently few typical counterparts have been identified in plants and only several caspase-like proteases are known to be involved in plant PCD,indicating the existence of great challenge for confirming new caspase-like proteases and elucidating the mechanisms regulating plant ***,we report a novel cysteine protease,NtTPE8,which was extracted from tobacco seeds and confirmed as a new caspase-like *** NtTPE8 exhibited legumain and caspase-like proteolytic activities,both of which could be inhibited by the pan-caspase inhibitor(Z-VAD-FMK).Notably,NtTPE8 possessed several caspase activities and the capacity to cleave the cathepsin H substrate FVR,indicating a unique character of ***8 was exclusively expressed in the integumentary tapetum and thus,is the first specific molecular marker reported to date for this cell *** of NtTPE8 caused seed abortion,via disturbing early embryogenesis,indicating its critical role in embryogenesis and seed *** conclusion,we identified a novel caspase-like cysteine protease,NtTPE8,exclusively expressed in the integumentary tapetum that is involved in seed development.

关键词： Programmed cell death shows conserved cytological exclusively expressed

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塔中隆起奥陶系油气性质及运聚富集模式

岩性油气藏 2025年第1期37卷 53-67页

作者：熊昶王彭刘小钰王伟赵星星孙冲中国石油塔里木油田公司勘探开发研究院中国石油天然气集团有限公司超深层复杂油气藏勘探开发技术研发中心新疆维吾尔自治区超深层复杂油气藏勘探开发工程研究中心中国石油塔里木油田公司油气田产能建设事业部

以构造、断裂分布、生产动态以及地球化学等资料为基础，对塔中地区奥陶系油气性质与产能分布特征进行了分析，从油气充注、输导体系、构造与油气运聚关系等3个方面对油气富集因素进行了分析，并建立了成藏模式。研究结果表明：（1）塔... 详细信息

以构造、断裂分布、生产动态以及地球化学等资料为基础，对塔中地区奥陶系油气性质与产能分布特征进行了分析，从油气充注、输导体系、构造与油气运聚关系等3个方面对油气富集因素进行了分析，并建立了成藏模式。研究结果表明：（1）塔中地区奥陶系原油以轻质原油为主，具有低密度、低黏度、低含硫的特征，密度为0.75～0.85 g/m3，油气藏气油比为119～82 367 m3/m3，多相态油气藏并存，且油气相态无明显边界；天然气干燥系数为0.70～0.98，天然气甲烷碳同位素为-35.7‰～-61.4‰，变化范围大；不同区域金刚烷指数（MDI）差异较大，为0.33～0.64;8个主要油气充注点具有原油密度低、气油比高、天然气甲烷同位素及MDI高的特征，沿走滑断裂带向南或远离断裂带方向密度变大，气油比、甲烷碳同位素及MDI均变小，不同区块气侵强度不同造成变化规律存在局部差异。（2）研究区油气分布格局主要受点状油气充注影响，8个油气充注点周缘油气井通常具有较高的产量，受储层发育规模影响会出现低产井，产能分布具有“北气南油”、“中间气、两边油”及“普遍富气、局部含油”3种类型；远离充注点的低产井及水井大范围分布。（3）研究区奥陶系油气富集模式为张扭性大断裂控制油气垂向充注，不整合面及走滑断裂控制油气的侧向调整，断裂破碎带叠加层间岩溶为油气聚集提供了储集空间，局部构造高部位及平台区为油气聚集有利指向区。

关键词：轻质原油金刚烷指数张扭性大断裂走滑断裂不整合面断裂破碎带岩溶作用奥陶系塔中隆起塔里木盆地

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A female in vivo haploid-induction system via mutagenesis of egg cell-specific peptidases

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Molecular Plant 2023年第2期16卷 471-480页

作者： Xuecheng Zhang Ce Shi Siling Li bo Zhang Pan Luo xiongbo peng peng Zhao Thomas Dresselhaus meng-xiang sun State Key Laboratory of Hybrid Rice College of Life SciencesWuhan UniversityWuhan 430072China Hubei Hongshan Laboratory Wuhan 430070China Cell Biology and Plant Biochemistry University of RegensburgRegensburgGermany

Crop breeding schemes can be significantly accelerated by using(doubled)haploid *** vivo haploid induction has been applied in plant breeding for decades but is still not available for all crops and genotypes,and haploidization rates are generally very ***,methodological improvements to and new concepts for haploidization are ***,we report a novel system for the induction of haploid plants by mutating genes encoding egg cell-specific aspartic endopeptidases(ECSs).We show that after successful sperm–egg cell fusion,ECSs play a critical role to ensure male and female nucleus fusion after *** ecs1 ecs2 double mutant can induce haploids by both selfing and hybridization in Arabidopsis and ECS mutation is also capable of producing haploids in *** summary,our study develops a novel approach for maternal haploidization and provides new insights into the molecular basis of fertilization.

关键词： haploid induction egg cell maternal inducer semigamy fertilization

Effects of process parameters on morphology and distribution of externally solidified crystals in microstructure of magnesium alloy die castings

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China Foundry 2018年第2期15卷 139-144页

作者： meng-wu Wu Xiao-bo Li Zhi-peng Guo Shou-mei xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of Technology School of Materials Science and Engineering Tsinghua University

During the cold-chamber high pressure die casting(HPDC) process, samples were produced to investigate the microstructure characteristics of AM60B magnesium alloy. Special attention was paid to the effects of process parameters on the morphology and distribution of externally solidified crystals(ESCs) in the microstructure of magnesium alloy die castings, such as slow shot phase plunger velocity, delay time of pouring and fast shot phase plunger velocity. On the basis of metallographic observation and quantitative statistics, it is concluded that a lower slow shot phase plunger velocity and a longer delay time of pouring both lead to an increment of the size and percentage of the ESCs, due to the fact that a longer holding time of the melt in the shot sleeve will cause a more severe loss of the superheat. The impingement of the melt flow on the ESCs is more intensive with a higher fast shot phase plunger velocity, in such case the ESCs reveal a more granular and roundish morphology and are dispersed throughout the cross section of the castings. Based on analysis of the filling and solidification processes of the melt during the HPDC process, reasonable explanations were proposed in terms of the nucleation, growth, remelting and fragmentation of the ESCs to interpret the effects of process parameters on the morphology and distribution of the ESCs in the microstructure of magnesium alloy die castings.

关键词： magnesium alloy high pressure die casting microstructure externally solidified crystals process parameters

Characterization of the Grain Structures in Vacuum-Assist HighPressure Die Casting AM60B Alloy

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Acta Metallurgica Sinica(English Letters) 2016年第7期29卷 619-628页

作者： Xiao-bo Li Shou-Mei xiong Zhi-peng Guo School of Materials Science and Engineering Tsinghua University Key Laboratory for Advanced Materials Processing Technology Ministry of EducationTsinghua University

The structures in vacuum-assist high-pressure die casting （HPDC） AM60B alloy were studied by using an optical microscope and a scanning electron microscope with an energy dispersive spectrometer. It was found that the HPDC under the vacuum could significantly change the morphology and distribution of the microstructure. For both conventional and vacuum-assist HPDC processes, the externally solidified crystals （ESCs） tended to aggregate in the center along the thickness direction of the castings. Besides, the aggregation was more pronounced, and the number of ESCs decreased, and the ESCs tended to become smaller and more globular, as the distance between the specimen location and runner increased. Compared with the conventional castings, the vacuum-assist HPDC can significantly reduce the size and amount of ESCs, and the ESCs tended to be more globular. For the distribution of ESCs along the thickness of the specimens, the aggregation tendency was more pronounced in vacuum-assist die castings than that in conventional castings. Besides, the distribution of ESCs at different locations was more converged in the vacuum-assist HPDC than that in the conventional HPDC.

关键词： AM60B alloy Grain structure Vacuum-assist high-pressure die casting Externally solidifiedcrystals