排序方式: 共有9条查询结果,搜索用时 578 毫秒
1
1.
Salt-Induced Ultrastructural Damage to Mitochondria in Root Tips of a Salt-Sensitive Ecotype of Agrostis Stolonifera 总被引:4,自引:0,他引:4
SMITH M. M.; HODSON M. J.; OPIK HELGI; WAINWRIGHT S. J. 《Journal of experimental botany》1982,33(5):886-895
In root tips of a salt-sensitive ecotype of Agrostis stolonifera,treatment with 100 mmol I1 NaCl for two weeks resultedin conspicuous structural damage to mitochondria, which becamedeficient in cristae, swelled and vacuolated. A salt-tolerantecotype maintained normal root tip mitochondrial structure underthe same salt treatment, in spite of accumulating higher levelsof sodium and chloride in its roots. The subcellular distributionof chloride, as judged by electron microscopy after precipitationwith silver ions, was identical in both ecotypes. 相似文献
2.
Changes in Cell Fine Structure in the Cotyledons of Phaseolus vulgaris L. during Germination 总被引:1,自引:0,他引:1
When germination begins, the storage cells of Phaseolus vulgariscotyledons are packed with starch grains and protein bodies.Digestion of these reserves starts in cells furthest away fromthe vascular bundles and is practically completed in eight daysat 25° C. After the reserves are hydrolysed, the storagecells die. The changes in fine structure during the processof digestion and protoplasmic breakdown are described. Vascularbundle and epidermal cells survive till the cotyledons absciss,but in these tissues also profound changes occur in cellularorganization. The observations on fine structure are discussedwith reference to the metabolic activities of the cotyledons. 相似文献
3.
The Fine Structure of some Dry Seed Tissues Observed after Completely Anhydrous Chemical Fixation 总被引:1,自引:0,他引:1
Completely anhydrous fixation with acrolein vapour or osmiumtetroxide vapour was applied to tissues of air-dry seeds: thecoleoptile of wheat (Trilicum aestivum), and plumule and radicleof mung bean (Vigna radiata). Great shrinkage of cells and organelleswas noted, but all the usual organelles could be identified,except for Golgi bodies and (in most cases) ribosomes. The endoplasmicreticulum was very abundant and endoplasmic reticulum tubuleswere closely associated with the storage organelles, namelylipid bodies in the wheat coleoptile, and protein bodies inthe mung bean embryo axis. Aqueous fixation resulted in considerabledistortion of cellular structure. Triticum aestivum L., wheat, Vigna radiata L., mung bean, seed, fine structure, anhydrous fixation 相似文献
4.
DAVID SCHUBERT HELGI TARIKAS A. JOHN HARRIS STEPHEN HEINEMANN 《Nature: New biology》1971,233(37):79-80
TISSUE culture lines of mouse neuroblastoma C1300 contain acetylcholine esterase1, the specific activity of which depends on the conditions of growth, for the inhibition of cell division leads to an increase in esterase activity2,3. Although this suggests that the cessation of division is directly responsible for increased enzyme synthesis, it may also be that the increase of specific activity is the result of (1) neurite formation by differentiating neuroblast cells or (2) events accompanying ageing and cell death. This article describes experiments designed to distinguish between these hypotheses and to examine the regulation of esterases in other tissue culture lines. 相似文献
5.
A Västermark JA Jacobsson A Johansson R Fredriksson U Gyllensten HB Schiöth 《Journal of genetics》2012,91(2):237-240
6.
Parallel observations have been made on changes in respirationrate, mitochondrial activity, and the fine structure of mitochondria,in the cotyledons of Phaseolus vulgaris germinating at 25? Cin the dark. While oxygen uptake of the intact cotyledons risesto a peak between the third and fifth days of germination, mitochondrialactivity falls from 36 hours onwards. In most of the storagecells, mitochondrial cristae have become swollen and the matrixhas darkened by the third day. The continulng rise in respirationrate beyond 36 hours could be accounted for by the increasein soluble oxidative activity, which occurs while mitochondrialactivity is falling. Alternatively, it could be mediated bymitochondria from the vascular bundle cells, where swellingand darkening are delayed till after the fifth day of germination,and where there is proliferation of cristae till the fourthday. 相似文献
7.
Changes in weight, nitrogen content, and cell fine structurewere followed in ripening cotyledons of greenhouse-grown beans.The seeds mature within 5356 days from flowering, cotyledonweight and nitrogen content increasing most rapidly betweendays 22 and 34. The cotyledon parenchyma cells first becomevery highly vacuolate, but soon the large vacuoles are dividedup and converted to reserve protein bodies, while cell expansioncontinues. Vacuole subdivision is accompanied by synthesis ofcytoplasm containing masses of rough-surfaced ER (endoplasmicreticulum), which persists till the cotyledons dry out, andpresumably synthesizes the reserve protein. Starch grains growwithin plastids to reach diameters of 50 µ. Young cotyledonsare green but chlorophyll disappears when the seed dries. Mostorganelles are recognizable in dry cotyledon cells; the ER is,however, replaced by small vesicles. Ribosomes are dispersedfree in the cytoplasm during dehydration; this could indicatea destruction of mRNA (messenger ribonucleic acid) in preparationfor a switch to a different metabolic activity during germination. Some comparisons are drawn between cell fine structure in thecotyledons during ripening and germination. 相似文献
8.
The course of water uptake and respiration rate rise in cotyledonsof Phaseolus vulgaris is divided into three phases. In the first phase lasting 1016 hrs. respiration rateis controlled by water content; desiccation and reimbibitioninfluence cotyledon water content and respiration rate alikeand the changes are reversible; low temperature prevents watercontent rising above 50 per cent. and also limits respirationrate; both processes have Q10 near unity. The second phase lasting 38 hrs. is characterized bya pause in both water uptake and respiration rate rise. In the third phase respiration rate continues to rise untilthe fifth day, after which it falls steadily until eventuallythe cotyledons absciss. The period of rising respiration isone of metabolic activity, the rise having a high Q10 and beingprevented by low temperature. Desiccation at this stage is irreversible. 相似文献
9.
1