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1.
石刁柏已形成细胞的幼嫩胚乳,接种在附加有不同浓度的生长素(NAA)和细胞分裂素(BA)的 MS 培养基上,获得了愈伤组织。愈伤组织的诱导频率随生长素的浓度不同而异,可达65.9—83.1%。将胚乳愈伤组织转移到降低了生长素浓度或只含有低浓度生长素的分化培养基上,可陆续分化芽、根、芽丛和少量胚状体,个别的芽和胚状体能发育成小植株。切取1.5—5cm 长的芽,接种在诱导根的培养基上,或在 IBA50ppm 溶液中浸泡2小时,转移到 MS 基本培养基上,部分芽能生根形成完整植株。 相似文献
2.
Gametangial interaction and oogenesis in the phycomycete Ciliomyces spectabilis (Fungi,Lagenidiales)
I. Foissner 《Archives of microbiology》1987,147(2):143-151
Gametangial interaction and oospore formation were studied in Ciliomyces spectabilis, a Lagenidiaceous fungus which is parasitic on ciliate cysts. Electron dense and granular vesicles of the antheridium are engaged in formation of the copulation porus between adjacent thalli. The oosphere is delimited by Golgi-derived cisternae which give rise to the membranes of the oosphere and the periplasm. The contents of the antheridium and the periplasm degenerate. The outer oospore wall is formed by wall vesicles originating from the endoplasmic reticulum. No vesicles are involved in the development of the thick inner oospore wall. Vacuoles with electron dense spherical contents fuse and form the central reserve globule. Lipid bodies aggregate first and disintegrate later into numerous small ones. The number of cytoplasmic organelles decreases. The possibility of wall formation via secretion of soluble wall material is discussed. 相似文献
3.
To assess the dynamics of synthesis of the wall by regenerating Candida albicans protoplasts deposition of chitin and mannoproteins were investigated ultrastructurally using wheat germ agglutinin conjugated with either horseradish peroxidase or colloidal gold, and Concanavalin A coupled to ferritin respectively.Freshly prepared protoplasts lacked wheat germ agglutinin receptor sites but after 1–2 h of regeneration, they were detected. After 4–5 h of regeneration, the cell wall showed a discrete structure which was only labelled with wheat germ agglutinin in thin sections. At this stage of regeneration the outermost layer of the wall was labelled with clusters of Concanavalin A-ferritin particles.After 8 h regeneration, the cell wall appeared compact, and homogenously marked with wheat germ agglutinin whereas only the surface layers appeared consistently labelled with Concanavalin A-ferritin.From these observations we conclude that C. albicans protoplasts are able to regenerate in liquid medium a cell wall consisting of a network of chitin fibrils and mannoproteins at least (glucan polymers were not determined in the present cytological study). The former are the fundamental component of the inner layers at early stages of regeneration, whereas the latter molecules are predominant in the outer layers of the wall.Abbreviations WGA-HRP
wheat germ agglutinin conjugated with horseradish peroxidase
- WGA-Au
wheat germ agglutinin conjugated with colloidal gold
- Con A-ferritin
Concanavalin A coupled to ferritin 相似文献
4.
烟草花粉管亚原生质体的分离和培养行为 总被引:1,自引:0,他引:1
应用酶法从烟草花粉管分离出大量亚原生质体。具核的和无核的亚原生质体之比约为1:1。这种亚原生质体在D_2培养基中培养后,不论有核的或是无核的都能生长管状结构和再生厚的壁。管状结构的生长有节律性,常呈结节状。随着管状结构的生长,细胞内含物逐渐流入生长中的管状结构内,有时会从薄的管状结构的顶端排出到培养液中。已生长管状结构的亚原生质体,具核的和无核的比例约为1:1.7,表明管状结构的生长和壁的再生与是否有核的存在无关。对酶液处理后花粉管亚原生质体从花粉管的释放和从单独的花粉管亚原生质体生长管状结构的过程,进行了活体连续观察和照相记录。实验结果说明,结节状的管状结构确实是从单独的一个亚原生质体形成的。管状结构的生长和壁的再生似乎与细胞质进入新生的管状结构有关。讨论了花粉管亚原生质体在植物遗传操作中应用的可能性。 相似文献
5.
Summary There are many contradictory observations on the mechanohydraulic relation of growing higher plant cells and tissues. Graphical analysis of the simultaneous equations which govern irreversible wall yielding and water absorption has made more comprehensive the understanding of this relation when relative growth rate is plotted against turgor pressure. It suggests that some respiration-dependent and auxin sensitive process might regulate the difference of osmotic potential between cells and water source. Based on anatomical and electrophysiological knowledge of the pea stem xylem, we propose the wall canal system as the mechanism of respiration-dependent water uptake which is sensitive to auxin. This system consists of the xylem apoplastic walls, the xylem proton pumps, active solute uptake system and cell membranes. In the simplest case, third-order simultaneous differential equations are involved. Numerical analysis showed that net uptake of solutes enables water to be taken up against an opposing gradient of water potential. The behaviour of this wall canal system describes well the mechano-hydraulic relation of enlarging plant cells and tissues. Recent typical, but incompatible, interpretations of this relation are critically discussed based on our model.Abbreviations V
the volume of enlarging symplast
-
the average extensibility of the wall
- Pi
turgor pressure
- Y
the yield threshold of the wall
- L
the relative hydraulic conductance
-
the solute reflection coefficient of the plasmamembrane
- Ci
the osmotic concentration of the symplast cells
- Cx
the osmotic concentration of the xylem vessels
- Px
hydrostatic pressure in the xylem vessels
- R
the gas constant
- T
absolute temperature
- o
water potential of xylem fluid
- i
water potential of symplast cells 相似文献
6.
Survival of cultured cells and somatic embryos of Asparagus officinalis cryopreserved by vitrification 总被引:2,自引:0,他引:2
Cultured cells and somatic embryos derived from the mesophyll tissue of asparagus (Asparagus officinalis L.) were cryopreserved by vitrification. The vitrification solution (PVS) contains (w/v) 22% glycerol, 15% ethylene glycol, 15% propylene glycol and 7% DMSO in Murashige-Skoog medium enriched with 0.5M sorbitol. After initial cryoprotection with sorbitol supplemented MS medium containing 12% ethylene glycol, cells or embryos were exposed stepwise to 85% PVS at 0°C. They were loaded into 0.5 ml transparent straws, and were then plunged directly into liquid nitrogen. After rapid warming, PVS was removed and diluted stepwise. The highest survivals of vitrified cells and embryos were about 65 and 50%, respectively. Surviving embryos developed into plantlets.Abbreviations DMSO
dimetyl sulfoxide
- PVS
vitrification solution
- LN
liquid nitrogen
- DSC
differential scanning calorimeter
- MS
Murashige-Skoog salt medium
- NAA
naphthalene acetic acid
- BA
6-benzyladenine 相似文献
7.
<正> 灌木,高约2米。小枝微弯曲,黑褐色,无毛。冬芽长卵圆形。叶片呈不等的五角形,长7—13匣米,宽8—16厘米,先端长渐尖,基部深心形,边缘有不等重锯齿,上面深绿色,散生硬毛,下面淡绿色,沿脉被短柔毛,主脉和侧脉均突起;叶柄长5—9.5厘米,近无毛。总状花序,下垂,花梗长3—4毫米,和总花梗均被短柔毛,常混生星状毛。果实长圆形,红色,直径约6毫米;萼片宿存,反折,近无毛。 相似文献
8.
The effects of microtubule and microfilament disrupting agents on cytoskeletal arrays and wall deposition in developing cotton fibers 总被引:7,自引:0,他引:7
R. W. Seagull 《Protoplasma》1990,159(1):44-59
Summary The effects of various cytoskeletal disrupting agents (cholchicine, oryzalin, trifluralin, taxol, cytochalasins B and D) on microtubules, microfilaments and wall microfibril deposition were monitored in developing cotton fibers, using immunocytochemical and fluorescence techniques. Treatment with 10–4 M colchicine, 10–6 M trifluralin or 10–6 M oryzalin resulted in a reduction in the number of microtubules, however, the drug-stable microtubules still appear to influence wall deposition. Treatment with 10–5 M taxol increased the numbers of microtubules present within 15 minutes of application. New microtubules were aligned parallel to the existing ones, however, some evidence of random arrays was observed. Microtubules stabilized with taxol appeared to function in wall organization but do not undergo normal re-orientations during development. Microtubule disrupting agent had no detectable affect on the microfilament population. Exposure to either 4×10–5 M cytochalasin B or 2×10–6M cytochalasin D resulted in a disruption of microfilaments and a re-organization of microtubule arrays. Treatment with either cytochalasin caused a premature shift in the orientation of microtubules in young fibers, whereas in older fibers the microtubule arrays became randomly organized. These observations indicate that microtubule populations during interphase are heterogeneous, differing at least in their susceptibility to disruption by depolymerizing agents. Changes in microtubule orientation (induced by cytochalasin) indicate that microfilaments may be involved in regulating microtubule orientation during development. 相似文献
9.
Summary The microproblematicumPycnoporidium ? eomesozoicum
Flügel, 1972, from Upper Triassic reefs of the Alpine-Mediterranean region, Turkey Oman and Iran (originally interpreted as possible
alga) represents the type species of a new strophomenid brachiopod genus (Gosaukammerella n.g.). The genus is characterized by a very small, millimeter-sized plano-convex shell, whose ventral valve is attached to
the substratum (mainly sponges) by symmetrically arranged outgrowths developing from a pseudopunctate, lamellose foliated
shell wall and composed of densely spaced subparallel ‘tubes’ comparable with productide spines secreted by papillose extensions
of the mantle.Gosaukammerella seems to be the only reliable candidate for the existence of post-Paleozoic strophomenid (productid ?) brachiopods.
Gosaukammerella eomesozoica is restricted to possibly cryptic, shaded reef environments inhabited predominantly by sponges serving as substrates for
micromorphic brachiopods. 相似文献
10.
黑节草从传粉到受精约需130d,精子在花粉管中形成,胚囊发育属蓼型胚囊,因反足细胞较早退化,故受精前胚囊多只由卵器和中央细胞组成。精卵核融合时,精核染色质进入卵核后凝集成颗粒状,并在原位与卵核的染色质融合,雌、雄性核仁一直维持至合子的第一次分裂期前。双受精作用正常,属于有丝分裂前配子融合类型,初生胚乳核发生2-3次分裂后逐渐退化消失,胚的发育局限于球形胚阶段。 相似文献