营养细胞

During the process of long-time adaptive evolution, wetland plants adopted a series of special strategies to acclimate to salt stress. The main strategies are: 1 life history adjustment, e. g., to adjust seed germination time, implement seed dormancy and viviparity, and change reproductive manner to escape from direct salt stress, 2 morphological adjustment, e. g., to adjust biomass allocation pattern, age stem, defoliate, and carnify vegetative organs to isolate the redundant Na(superscript +) to the inactive-metabolism shoots or exclude the Na(superscript +)from tissues; 3 anatomic adjustment, e. g., to sink stoma, develop aerenchyma, and thicken cuticle and phellogen to maintain normal photosynthesis and respiration; 4 physiological and biochemical adjustment, e. g., to exclude and excrete salt, compartmentalize ions, adjust osmosis, do selective absorption, regulate hormones, and induce antioxidative enzymes to maintain the osmotic equilibrium and eliminate the active oxygen in cell; and 5 molecular level adjustment, e. g., to start up many salt-induced genes to regulate the metabolic responses to salt stress.

在长期的适应进化过程中，湿地植物形成了多种适应盐胁迫的策略，主要有：1生活史方面，植物可通过种子萌发时间的调整、种子体眠、胎生、繁殖方式的改变等逃避盐度的直接伤害；2形态学方面，植物可通过生物量分配模式的调整、茎的老化、落叶及营养器官的肉质化等将多余的Na隔离到代谢不活跃的茎中或将其排出体外；3解剖学方面，植物可通过气孔下陷、发达的通气组织、增加细胞木栓层、角质层及栅栏组织的厚度等以维持植物正常的光合作用和呼吸作用；4生理生化方面，植物可通过离子区隔化、拒盐、泌盐、选择性吸收、渗透调节、激素调节及抗氧化物酶的诱导等来维持细胞内正常的渗透压，清除胞内活性氧分子；5分子水平方面，植物可通过多种与盐胁迫相关的基因来调控细胞内的多种代谢反应。

In contrast with the rapid nucleus degradation, cell organelles in cytoplasm, such as rough endoplasmic reticulum, amyloplast, and mitochondrion, maintained their metabolic functions for a longer time.

在核衰退的同时，其胞质中的粗面内质网、淀粉质体和线粒体等细胞器具有正常的代谢功能，细胞仍在合成并积累营养物质，淀粉胚乳细胞一边衰退一边行使其功能，直至死亡。

Results indicated that the variation was significant from treatment to treatment. S-deficiency caused bulging chloroplasts, loosening and dishevelled grana lamella, reducing organelle, and damaged chondriosome in mesophyll cells of the leaves, and empty cells of the roots, while S-excess, however, led to densification, condensation and randomization of grana lamella of the chloroplasts of the leaves, and separation of cytoplasms from walls of the cells of the roots.

结果表明，受S素营养胁迫的水稻，其根系及叶片的超微结构均发生了显著的变化：低S胁迫会造成水稻叶片叶肉细胞内的叶绿体结构肿胀，基粒片层松驰、散乱，细胞器减少，线粒体结构被破坏，根系细胞内几乎没有内含物；S浓度高则会使叶片叶绿体基粒片层致密、浓缩，无规则化，根系细胞发生质壁分离。

Most aneurysms specimens showed structure changes, including injury of endothelial cell, disrupture or disappearance of the internal elasticlayer, scarce of contractile fiber cells.

动脉瘤瘤壁中有不同程度的单个核细胞成分的浸润(淋巴细胞或单核/巨噬细胞样细胞)，尤其在"中膜"层或"中膜"与内膜交界处较为明显，同时，在细胞集中区伴有数量不等的新生的营养血管，以上改变类似"肉芽组织"样改变。

Using cytohischemical staining methods, with the results of comparison the dynamics of proteins and polysaccharides in the anthe wall cells and colule cells of different developmental phases in female and male flowers, the anormogenesis of anther tapetum in the inflecting phase of from bisexual flower to unisexual flower was observed. In microspore developed phase, the tapetum functions of preserving and transportingmutritive material for microspore development and of secreting callosal enzyme for decompositing callosal cell lost no normal guadrant formed, of being abnormal meiose of pollen mother cells, and then, the stamen aborted selectively in female flowers and pistil in male flower.

利用细胞组织化学染色技术，对雌、雄花雄蕊花药壁细胞及花药内细胞发育过程中多糖及蛋白质动态进行了比较，实验中观察到雌花在从两性至单性花转变时期雄蕊绒毡层在整个发育过程中表现异常，在小孢子发育过程中未能起到贮藏、转运营养物质供小孢子发育及适时分泌胼胝质酶溶解胼胝质壁的功能，并且花粉母细胞减数分裂异常而未形成四分体结构，进而导致雌花雄蕊选择性败育，而雄花中雌蕊组织也发生了选择性败育过程。

It has been found that ectogenic GDNF has nervous protective effec,but ectogenic GDNF cannot enter blood brain barrier.

传统观点认为，星形胶质细胞是神经系统的支持细胞，构成神经组织的网架而起支持作用，与神经元的解剖位置关系紧密，参与中枢神经系统的免疫反应，参与构成血脑屏障，目前研究发现，脑缺血时星形胶质细胞异常活跃，通过合成多种蛋白质、细胞因子和神经营养因子等对神经元起保护作用，对缺血性脑损伤的发展和转归具有重要意义。

Association of vascular endothelial growth factor expression with intratumoral microvessel density and tumor cell proliferation in human epidermoid lung carcinomas.

我们观察到随着细胞周期启动，VEGF也表达，其意义可能在于Hep G2细胞虽不表达VEGF受体，但VEGF诱导血管形成，使肿瘤细胞获得充分的营养和氧气，为细胞增殖创造有利的外部条件。

When pea ( Pisum sativum L.,Alaska strain) was grown in short\|day conditions,the apical bud senescence started with the transformation of the bud from vegetative to reproductive growth.DNA fragmentation was detected during the senescence using the terminal deoxynucleotidyl transferase\|mediated dUTP nick end in situ labeling method.The cell ultrastructural changes were similar to apoptosis in animal cells:the apical meristemetic cells underwent the programmed cell death.This wa...

显微、超微结构研究表明，短日照条件下豌豆顶芽的衰老过程是从营养生长锥向花芽的转化，而用DNA原位末端标记、Caspase 8WesternBlot和 14 0bpDNA片断积累的试验结果证明，转化为花芽的整个生长锥细胞发生了编程性死亡，而且其最顶端部分细胞首先发生PCD ，而顶端周围的分生组织细胞逐渐分化出花芽的各部分，但顶芽最后并没有发育成为完整的花，所有细胞就都发生PCD ，从而顶芽衰老

The situation of abnormal development of male cells is as follows:microspore mother cell can't enter into meiosis because of intense vacuolation,shrink and disintegration of its cytoplasm;although vacuolated microspore mother cell can enter into meiosis,it can't form normal dyad and degenerate in the middle process;dyad and tetrad become vacuolated and can't develop normally;cytoplasm of microspore shrinks around the nucleus at the stage of central nucleus microspore,the shape of microspore is twisted into crescent or irregular shape,at last its cytoplasm and nucleus are disintegrated and crescent vacant microspore presents;nutritive substances can't be accumulated at the stage of vacuolated microspore,cytoplasm is disintegrated,and microspore turns into a big vacant pollen.

雄性细胞异常发育有几种情况：小孢子母细胞强烈液泡化，细胞质收缩解体，不能进入减数分裂；小孢子母细胞液泡化，虽能进入减数分裂，但不能形成正常二分体而中途退化；二分体、四分体细胞液泡化，不能进行正常发育；单核小孢子中央期，细胞质收缩包围核，小孢子形状扭曲呈月牙形或不规则形，最终细胞质和核解体而呈月牙形的空壳小孢子；单核液泡期的小孢子不能积聚营养物质，细胞质解体而成为大的空壳花粉粒。

Art A presents a comprehensive coverage of all necessary laboratory techniques for the initiation, nutrition, maintenance and storage of plant cell and tissue cultures, including discussions on these topics, as well as on morphogenesis and regeneration, meristem and shoot tip culture, plant protoplasts, mutant cell lines, variation in tissue cultures, isogenic lines, fertilization control, cryopreservation, transformation, and the production of secondary metabolites.

lant Cell and Tissue Culture|植物细胞和组织文化植物细胞和组织文化彻底描述植物细胞文化和遗传学的转变，在全部主要的田地和种植园庄稼上包括详细的章。提出一全部必要实验室技术给开始，营养，维护和植物细胞和组织文化的贮存的综合新闻报导，包括关於这些题目的讨论，包括谷类，豆科植物，菜蔬，马铃薯，其他根和块茎，油菜籽，适度水果，热带水果，种植园庄稼，森林树和ornam

Fancy gold-plated dangling earrings with facetted White Opal crystals.

花式镀金悬垂耳环与facetted白欧泊水晶。

This essay chooses the study aim from biology teachers in middle school in Shi Jiazhuang which tells us that most of the middle school biology teachers in Shi Jiazhuang have the"burnout", lower successfulness, individualize.

本文选取石家庄市初中生物教师作为研究对象，运用问卷调查的方法对石家庄市初中生物教师职业倦怠的现状进行调查，调查结果发现，石家庄市初中生物教师这一群体普遍存在职业倦怠，情感枯竭程度偏高，成就感偏低，去个性化程度最为严重。