Demonstration of plant adaptation syndrome in plants and possible molecular mechanisms of its realization under conditions of anaerobic stress

Electron-microscopic examination of mitochondrial membrane ultrastructure in detached leaves of four-day-old wheat (Triticum aestivum L.) seedlings incubated under conditions of strict anoxia in the presence of exogenous glucose and cycloheximide or in the absence of these compounds revealed a paradoxical phenomenon: in the absence of exogenous glucose and cycloheximide, even a short-term (15–30 min) anaerobiosis resulted in a pathological destruction of mitochondria (swelling and the loss of cristae); however, a longer uninterrupted anaerobiosis (3–4 h) did not induce further mitochondria degradation but, in contrast, resulted in the recovery of their initial ultrastructure. Irreversible mitochondria degradation was observed only during subsequent still longer leaf anaerobic treatment (24–48 h). When, under conditions of strict anoxia, leaves were fed with glucose to stimulate glycolysis and ethanolic fermentation, we did not observe any signs of early destruction of mitochondrial ultrastructure and their swelling. Blockage of anaerobic protein synthesis with cycloheximide resulted in early destruction and subsequent irreversible degradation of mitochondria without any indications of their structural recovery. Based on the results of the experiments, we concluded that cell energy metabolism controlled byboth the presence of utilizable carbohydrates and also by the induction of anaerobic protein synthesis played a key role during early mitochondria destruction under extreme conditions of anaerobic stress, their subsequent recovery, and irreversible degradation during continuous long-term strict anoxia.     

Exogenous Nitrate as a Terminal Acceptor of Electrons in Rice (Oryza sativa) Coleoptiles and Wheat (Triticum aestivum) Roots under Strict Anoxia

To elucidate the physiological role of exogenous nitrate under anaerobic conditions, we studied the effect of 10 mM KNO₃ on the mitochondrial ultrastructure in rice (Oryza sativa L.) coleoptiles and in wheat (Triticum aestivum L.) roots, detached from four-day-old seedlings, under strict anoxia. In wheat roots, following 6-h-long anoxia in the absence of exogenous nitrate, the mitochondrial membranes were partially degraded and, after 9 h under anoxia, the mitochondrial membranes and the membranes of other organelles were completely destroyed. In rice coleoptiles, the partial membrane degradation was observed only after 24 h and their complete breakdown after 48 h of anaerobiosis. In the presence of exogenous nitrate, no membrane destruction was noticed even after 9 and 48 h of anaerobiosis in wheat roots and rice coleoptiles, respectively. These results indicate that exogenous nitrate exerts protective action as a terminal electron acceptor, alternative to the molecular oxygen. Our findings are compared with the results of other researchers concerning the adverse or favorable nitrate action on plant growth, metabolism, and energy status under anaerobic stress.     

Physiological role of nitrate under anaerobic stress in Saccharum officinarum callus cells tolerant and sensitive to anoxia

The physiological role of nitrate as a protective factor against anaerobic stress was studied in experiments with tolerant to anoxia sugarcane (Saccharum officibarum L.) callus lines obtained by in vitro selection in the absence of exogenous carbohydrates. Original cell lines, which were not subjected to selection and therefore more sensitive to oxygen shortage, served as a control. In these lines, anaerobic stress was created in the presence or absence of nitrate in nutrient medium. The presence of nitrate in nutrient medium increased markedly tolerance to anaerobic stress of both lines differing in their sensitivity to anaerobiosis. However, the degree of tolerance differed substantially in compared lines. In the presence of exogenous nitrate, in tolerant cells there were no signs of mitochondrial membrane destruction or degradation even after 72 h of anoxia, whereas in control cells 48-h anaerobic incubation led to the complete degradation of mitochondrial membranes and membranes of other organelles. It is concluded that significant increase in the tolerance of S. officinarum cells in the process of in vitro selection most likely occurred due to induction and stimulation of not only the processes of glycolysis and fermentation, but also nitrate and maybe nitrite utilization.     

Mitochondrial Ultrastructure of Three Hygrophyte Species at Anoxia and in Anoxic Glucose-Supplemented Medium

Mitochondrial ultrastructure of excised roots of Alisma plantago-aqisaticaL., Lycopus europaeus L and Glyceria fluitans L. were electron-microscopicallystudied at anoxia and in anoxic glucose- supplemented mediumin order to find Out if the roots of the three hygrophytes growingon water-logged anaerobic soils have an increased resistanceto anoxia. Irreversible destruction of mitochondrial membranes and othersubcellular structures was shown to occur in the above plants'roots after 24 h at anoxia or in anoxic glucose-supplementedmedium. Only in roots of Glyceria had exogenous glucose a protectiveaction, yet in this case, too, a 48 h anacrobic exposure resultedin a deep-going degradation of cell ultrastructure. It is concluded that though the plants in question grow on soilsdevoid of O₂ their roots avoid anaerobiosis through translocationof O₂ from aerated parts, which appears to explain why theseplants have not developed a biochemical mechanism of adaptationto anaerobiosis in the process of evolution. Key words: Anaerobiosis, hygrophytes, mitochondrial ultrastructure     

Mitochondrial ultrastructure in roots of mesophyte and hydrophyte at anoxia and after glucose feeding

Summary In order to investigate the nature of the tolerance of mesophytes and hydrophytes to root anaerobiosis, changes in the mitochondrial ultrastructure of excised roots (with and without added glucose under anoxia) were studied in plants from two ecologically opposite types-pumpkin and rice.A 12-hour exposure to anoxia led to mitochondrial degradation in roots of adult rice and pumpkin plants. The addition of glucose preserved cell ultrastructure for up to 72–96 hours. During this period mitochondrial ultrastructure changed. In rice roots this primarily involved an increased number of cristae and a change in their arrangement into parallel rows. Cells of pumpkin roots displayed long mitochondria (up to 55 m) of different profiles which fused to form a complex mitochondrial network that was in close association with parts of the endoplasmic reticulum carrying a large number of ribosomes. This may be regarded as an adaptive development that facilitates the transport of glycolytic energy along mitochondrial membranes to the sites of protein synthesis.It is concluded that root cells of a hydrophyte are not more tolerant to anoxia than mesophyte. Thus, the ability of hydrophytes to grow on anaerobic soils should be attributed not so much to peculiar features of the roots' metabolism but to the ability of these plants to perform an easy transport of O₂ from leaves to roots. With respect to mesophytes it is stressed that the supply of assimilates is important for the resistance of roots to soil anaerobiosis.     

On the Physiological Role of Anaerobically Synthesized Lipids in <Emphasis Type="Italic">Oryza sativa</Emphasis> Seedlings

The objective of this work was to elucidate a possible adaptive role of lipid biosynthesis and unsaturated fatty acids (FAs), esterified to lipids, as terminal acceptors of electrons, alternative to molecular oxygen, in the shoots of rice seedlings (Oryza sativa L.) under conditions of strict anoxia. Biosynthesis of lipids and their accumulation, as well as the reduction of double bonds in unsaturated FAs, were studied by electron microscopic observation of the accumulation of lipid bodies in the cytoplasm and by the biochemical analysis of FAs in shoot lipids before and after anaerobic incubation of the shoots. The experiments were carried out with intact coleoptiles after 5 and 8 days of anaerobic germination of seeds (primary anoxia) and with detached shoots, preliminarily grown in air and then subjected to anoxia in the presence of 2% glucose for 48 h (secondary anoxia). In these experiments, lipid bodies did not accumulate in the cytoplasm under anoxic conditions. Lipid bodies appeared only during 48-h anaerobic incubation of detached coleoptiles in the absence of exogenous glucose, when mitochondria degraded. There was no change either in the double bond index of FAs, or in the qualitative and quantitative composition of FAs during shoot anaerobic incubation. We conclude that neither lipids synthesized under anaerobic conditions nor esterified unsaturated FAs are involved in plant adaptation to anaerobiosis as terminal acceptors of electrons, alternative to molecular oxygen. Lipid biosynthesis under anoxic conditions, which was demonstrated for anoxia-tolerant seedlings of Oryza sativa and Echinochloa phyllopogon in experiments with radioactive precursors, ¹⁴C-acetate and ³H-glycerol, is only the manifestation of a turnover of saturated FAs and various classes of lipids, which stabilizes cell membranes under adverse conditions of strict anoxia.__________Translated from Fiziologiya Rastenii, Vol. 52, No. 4, 2005, pp. 540–548.Original Russian Text Copyright © 2005 by Generosova, Vartapetian.     

Protective effect of exogenous nitrate on the mitochondrial ultrastructure ofOryza sativa coleoptiles under strict anoxia

Summary The effect of exogenous KNO₃, the terminal acceptor of electrons in oxygen-free medium, on mitochondrial ultrastructure and on the growth rate of 4-day-old rice coleoptiles under strictly anoxic conditions was studied. Exogenous nitrate (10 mM) did not exert any significant effect on the growth rate of coleoptiles of intact seedlings compared to their growth in KNO₃-free medium. Anaerobic incubation of detached coleoptiles in KNO₃-free medium for 48 h resulted in the complete destruction of mitochondrial and other cell membranes. In the presence of KNO₃, no mitochondrial-membrane destruction was observed even after 48 h anoxia although the mitochondrial ultrastructure was modifed. Cristae were arranged in parallel rows and elongated dumbbell-shaped mitochondria appeared in some cells. The data obtained indicate a protective role of exogenous nitrate as electron acceptors in oxygen-free medium. The results of the present investigation are discussed and compared with reports of either markedly damaging or favorable effects of exogenous nitrate on the growth, metabolism, and energetics of rice and other plants under hypoxic and anoxic conditions.     

Surface Ultrastructure of the Heteromorphic Cells of Nostoc muscorumCALU 304 in a Mixed Culture with the RauwolfiaCallus Tissue

The ultrastructure of the heteromorphic cells (HMCs) of the cyanobacterium Nostoc muscorumCALU 304 grown in pure culture, monoculture, and a mixed culture with the Rauwolfiacallus tissue was studied. The comparative analysis of the cell surface of HMCs, the frequency of the generation of cell forms with defective cell walls (DCWFs), including protoplasts and spheroplasts, and the peculiarities of their ultrastructure under different growth conditions showed that, in the early terms of mixed incubation, the callus tissue acts to preserve the existing cyanobacterial DCWFs, but begins to promote their formation in the later incubation terms. DCWFs exhibited an integrity of their protoplasm and were metabolically active. It is suggested that structural alterations in the rigid layer of the cell wall may be due to the activation of the murolytic enzymes of cyanobacteria and the profound rearrangement of their peptidoglycan metabolism caused by the Rauwolfiametabolites diffused through the medium. These metabolites may also interfere with the functioning of the universal cell division protein of bacteria, FtsZ. In general, the Rauwolfiacallus tissue promoted the unbalanced growth of the cyanobacterium N. muscorumCALU 304 and favored its viability in the mixed culture. The long-term mixed cultivation substantially augmented the probability of the formation of L-forms of N. muscorumCALU 304.     

Manipulation of ethanol production in anoxic rice coleoptiles by exogenous glucose determines rates of ion fluxes and provides estimates of energy requirements for cell maintenance during anoxia

Ethanol production by anoxic, excised, 7-10 mm tips of rice coleoptiles was manipulated using a range of exogenous glucose concentrations. Such a dose-response curve enabled good estimates at which level of ethanol production (and hence by inference ATP production), injury commenced and also allowed assessments of energy requirements for maintenance in anoxia. Rates of net uptake or loss of K+ and P by these excised coleoptile tips were related to rates of ethanol production (r2 of 0.59 and 0.68, respectively). At 72 h anoxia, ATP levels in excised tips were similar at 0, 2.5, and 50 mol m(-3) exogenous glucose, despite large differences in the inferred rates of ATP production. At 96 h anoxia, tips without exogenous glucose had low ATP concentrations; these may be the cause or the consequence of cell injury. In tips without glucose, injury was indicated by losses of K+ and Cl- between 72-96 h anoxia, and during the first hour after re-aeration, while later than 1 h after re-aeration, rates of net uptake were substantially lower than for re-aerated tips previously in anoxia with exogenous glucose. Between 96 h and 124 h anoxia, ion losses from tips without exogenous glucose increased while recovery of net uptake after re-aeration was very sluggish and incomplete. The energy requirement for maintenance of health and survival of anoxic coleoptile tips, expressed on a fresh weight basis, was lower than for three other anoxia-tolerant plant tissues/cells, studied previously. However, the energy requirement on a protein basis was assessed at 1.4 micromol ATP mg(-1) protein h(-1) and this value is 2.6-5.4-fold higher than for the other plant tissues/cells. Yet, this requirement was still only 58-88% of the published values for aerated tissues. The reason for this relatively high ATP requirement per unit protein in anoxic rice coleoptiles remains to be elucidated.     

Ultrastructure of the cell surface of heteromorphic Nostoc muscorum CALU 304 cocultured with Rauwolfia tissue]

The ultrastructure of the heteromorphic cells (HMCs) of the cyanobacterium Nostoc muscorum CALU 304 grown in pure culture, monoculture, and a mixed culture with the Rauwolfia callus tissue was studied. The comparative analysis of the cell surface of HMCs, the frequency of the generation of cell forms with defective cell walls (DCWFs), including protoplasts and spheroplasts, and the peculiarities of the cell surface ultrastructure under different growth conditions showed that, in the early terms of mixed incubation, the callus tissue acts to preserve the existing cyanobacterial DCWFs, but begins to promote their formation in the later incubation terms. DCWFs exhibited an integrity of their protoplasm and were metabolically active. It is suggested that structural alterations in the rigid layer of the cell wall may be due to the activation of the murolytic enzymes of cyanobacteria and the profound rearrangement of their peptidoglycan metabolism caused by the Rauwolfia metabolites diffused through the medium. These metabolites may also interfere with the functioning of the universal cell division protein of bacteria, FtsZ. In general, the Rauwolfia callus tissue promoted the unbalanced growth of the cyanobacterium N. muscorum CALU 304 and favored its viability in the mixed culture. The long-term incubation of the Rauwolfia tissue with the N. muscorum CALU 304 cells led to their transformation to L-forms.     

Anaerobic Glycolysis Protection against 1-Methy-4-Phenylpyridinium (MPP<Superscript>+</Superscript>) Toxicity in C6 Glioma Cells

The neurotoxin 1-methy-4-phenylpyridinium (MPP⁺) is used for its’ capacity to induce Parkinsonism through its inhibitory effects on mitochondrial complex I. This inhibition disrupts cellular energy formation and aerobic glycolysis. The objective of this study was to demonstrate that the toxic effect of mitochondrial aerobic pathway inhibition with MPP⁺ can be reduced by stimulating anaerobic glycolysis using glucose supplementation. In this study, C6 Glioma cell viability was examined in the presence of different concentrations of MPP alone and with the addition of glucose. The results obtained indicate that there was a significant increase (P < 0.001) in cell viability in cells treated with glucose and MPP⁺ verses cells treated with MPP⁺ alone. Fluorometric analysis using 100 uM Rhodamine 123 indicated mitochondrial membrane potential was not restored in MPP⁺ treated cells with glucose; however, normal cell viability was confirmed using 2 ug/ml Fluorescein diacetate. This dual fluorescence indicated mitochondrial damage from MPP⁺ while glucose augmented cell survival. Further confirmation of cell survival upon damage to the mitochondria was evident in TUNEL staining. Positive staining was prominent only in MPP⁺ treatment groups alone, while control and co-treated groups exhibited little to no TUNEL staining. ATP measurements of all MPP⁺ treated groups exhibited a significant (P < 0.001) decrease verses control. Groups co-treated with MPP⁺ and glucose revealed a significant increase (250 μM group: P < 0.001) in ATP. It was concluded from this study that glucose supplementation was able to sustain cellular viability and ATP production through anaerobic glycolysis despite the inhibitory effect of MPP⁺ on aerobic glycolysis.     

Regulation of the synthesis of mitochondrial enzymes and cytochromes

Summary The possibility that decreased mitochondrial function in anaerobic cultures of Saccharomyces cerevisiae is due to catabolite repression rather than anaerobiosis has been examined using a glucose-limited chemostat. Respiration, cytochromes, ubiquinone and a number of soluble and bound mitochondrial enzymes were measured in cells and cell-free homogenates. Derepression by growth in the chemostat under anaerobic conditions resulted in only small increases in the activity of bound enzymes, and in the amount of ubiquinone and respiration, compared with cells grown batch-wise (repressed). The extent of these increases was much smaller than that seen when cells were grown under aerobic conditions whether repressed or derepressed.     

Oxygen starvation induces cell death in Candida shehatae fermentations of d-xylose, but not d-glucose

Candida shehatae cells, cultivated on d-glucose and d-xylose, were subjected to a shift from fully aerobic to anaerobic fermentative conditions. After anaerobic conditions were imposed, growth was limited to approximately one doubling or less as C. shehatae rapidly entered a stationary phase of growth. Following the shift to anoxia, cell viability rapidly declined and the total cell volume declined in the d-xylose fermentations. Moreover, the cell volume distribution shifted to smaller volumes. Cell viability, measured by plate counts, declined nine times faster for d-xylose fermentations than for d-glucose fermentations. Anaerobic growth did not occur on either d-glucose or d-xylose. Selected vitamins and amino acids did not stimulate anaerobic growth in C. shehatae, but did enhance anaerobic growth on d-glucose in S. cerevisiae. The decline in cell viability and lack of anaerobic growth by C. shehatae were attributed to oxygen deficiency and not to ethanol inhibition. The results shed light on why C. shehatae anaerobic fermentations are not currently practical and suggest that research directed towards a biochemical understanding of why C. shehatae can not grow anaerobically will yield significant improvements in ethanol fermentations from d-xylose. Received 26 October 1998 / Received revision: 26 January 1999 / Accepted: 12 February 1999     

碳源对早花百子莲愈伤组织诱导及其增殖的生理特性影响

为揭示碳源对早花百子莲愈伤组织诱导与增殖的影响机理,该研究以早花百子莲的小花梗为外植体,比较分析30.0 g/L蔗糖、葡萄糖、麦芽糖在愈伤组织诱导、增殖中的效果,测定不同碳源种类处理下愈伤组织增殖相关生理特性,并根据细胞增殖效果、生理指标相关性进行优化验证。结果表明:(1)蔗糖、葡萄糖和麦芽糖碳源处理下,愈伤组织诱导率分别为86.00%、72.00%和59.67%,蔗糖碳源的愈伤组织诱导率比葡萄糖和麦芽糖分别显著提高19.44%和44.13%(P<0.05),蔗糖碳源较葡萄糖和麦芽糖碳源的愈伤组织大小分别显著增加22.44%和90.09%(P<0.05);愈伤组织增殖阶段,蔗糖碳源能够同时维持良好的细胞增殖效率及活性,而葡萄糖碳源的愈伤组织增殖快、状态差,麦芽糖处理增殖慢、状态佳;蔗糖转换葡萄糖碳源后愈伤组织细胞团大小、细胞活性明显下降;蔗糖转换蔗糖、蔗糖转换麦芽糖的效果较好。(2)培养基碳源显著调节愈伤组织增殖阶段的糖代谢、内源激素代谢和氧化胁迫平衡。(3)愈伤组织的主要糖组分为淀粉、葡萄糖;淀粉、麦芽糖含量与细胞团大小相关性高,以蔗糖为碳源的培养基中添加麦芽糖,愈伤组织...     

The effects of anaerobiosis and metabolic inhibitors on mitochondrial ultrastructure inAmoeba proteus

Summary Anaerobiosis or exposure to the metabolic inhibitors potassium cyanide and Antimycin A produced changes in the form of living amoebae. These were accompanied by mitochondrial changes in fixed cells. Increasing the anaerobic period increased the percentage of mitochondria affected and resulted in a gradual reduction and eventual loss of the condensed Type I mitochondria ofAmoeba proteus. The rounder Type II mitochondria were not lost but underwent varying degrees of disruption, vesiculation of the cristae being evident after 5 hours exposures and matrical inclusions after 18 hours exposures. Similar cristal vesiculation was seen after 30 minutes treatments with potassium cyanide. Providing treatments were terminated before cell viability was lost, all mitochondrial abnormalities were reversible on return to normal culturing conditions. The longer the period of anaerobiosis the longer was the recovery time required for the return of normal mitochondrial structure and the re-equilibration of control Type I to Type II mitochondrial frequencies. The relationship between mitochondrial conformation and functional integrity is discussed in the light of these findings.     

The anaerobic oyster heart: Coupling of glucose and aspartate fermentation

Summary The interrelationships of carbohydrate and amino acid metabolism during anaerobiosis were investigated in the ventricle of the intertidal oyster,Crassostrea gigas. While the ventricle accumulates alanine and succinate in a 21 ratio during anoxia, these end products appear to arise from different precursors. Thus glucose-¹⁴C is metabolized mainly to alanine-¹⁴C (55% of glucose carbon appears in alanineversus 3% in succinate) by the anoxic ventriclein vitro while succinate-¹⁴C is the principle end product of aspartate-¹⁴C catabolism. Glutamate-¹⁴C is poorly metabolized by the anoxic ventricle, and correspondingly, while ventricular aspartate concentrations drop during anoxia, those of other amino acids do not. A metabolic scheme coupling glucose and aspartate catabolism in this facultative anaerobe is proposed. The detection of a third, as yet incompletely identified, anaerobic end product produced by the ventricle is reported.     

Anaerobic incorporation of radioactivity from 2,3-14C-succinic acid into citric acid cycle intermediates and related compounds in the sea musselMytilus edulis L.

Summary Sea mussels were exposed to nitrogen for various periods (0, 1, 3 and 6 days) and subsequently injected with 2,3-¹⁴C-succinic acid. After 2.5 h anaerobic incubation concentrations of succinate, some amino acids and volatile fatty acids were determined as well as the distribution of radioactivity.Conversion of the precursor decreased from 80 to 40%, due to increased dilution with endogenous succinate, accumulated during the anaerobic preincubation period.More than 80% of the activity of the converted 2,3-¹⁴C-succinic acid was incorporated into malate, aspartate, glutamate, alanine and propionate. This indicates that succinate is not only an end product of anaerobic glycogen breakdown, but remains an active intermediate of the tricarboxylic acid cycle, which can still operate under anaerobic conditions.Concentration and radioactivity of propionate were markedly increased after prolonged anoxia, which gives evidence that succinate is actively converted to propionate during anaerobiosis.Observed accumulation of glutamate during anoxia is explained by incomplete oxidation of pyruvate, which leaves the tricarboxylic acid cycle at the stage of 2-ketoglutarate.     

Ultrastructure of mitochondria apparatus of cardiomyocytes in apoptosis induced by long-term anoxia in rats

Apoptosis in cardiomyocytes was induced by incubation of pieces of cardiac tissues under condition of anoxia. Electronmicroscopic investigation detected previously unknown changes in mitochondrial ultrastructure. The mitochondrial population was characterized by morphological heterogeneity. In addition to a mitochondrial population characterized with irrigated cleared matrix, anoxia induced the appearance of an atypical and previously unknown population of small electron-dense cardiomyocyte mitochondria. They were characterized by unusual localization inside electron-light mitochondria ("mitochondria inside mitochondria"). The most part of mitochondria with the irrigated matrix are commonly characterized by unusual types of rearrangements of the inner mitochondrial membrane. Under anoxic conditions, the inner mitochondrial membrane formed electron-dense ordered structures. This is a spongy structure with cells of equal size. Results of our study are discussed in terms of conception of changes in mitochondrial reticulum ultrastructure during apoptosis.     

Isolation and properties of promitochondria from anaerobic stationary-phase yeast cells

Under anaerobiosis, the mitochondrion of Saccharomyces cerevisiae is restricted to unstructured promitochondria. These promitochondria provide unknown metabolic functions that are required for growth. Since high glucose concentrations are mainly fermented by S. cerevisiae during stationary phase (due to nitrogen starvation), an optimized promitochondria isolation procedure was investigated. Firstly, the unusual promitochondria ultrastructure was checked in intact cells by electron microscopy using a cryo-fixation and freeze-substitution method. The rapid response of anaerobic cells toward oxygen justified the adoption of several critical steps, especially during spheroplasting. Control of spheroplasting was accompanied by a systematic analysis of spheroplast integrity, which greatly influence the final quality of promitochondria. Despite the presence of remnant respiratory chain components under anaerobiosis, characterization of isolated promitochondria by high-resolution respirometry did not reveal any antimycin A- and myxothiazol-sensitive NADH and NADPH oxidase activities. Moreover, the existence of a cyanide-sensitive and non-phosphorylating NADH-dependent oxygen consumption in promitochondria was demonstrated. Nevertheless, promitochondria only slightly contribute to the overall oxygen consumption capacity observed in highly glucose-repressed anaerobic cells.     

GFP-FABD2和GFP-MBD标记蛋白对拟南芥悬浮细胞培养及应激响应能力的影响

以转GFP-FABD2和GFP-MBD基因的拟南芥为材料,研究了GFP-FABD2和GFP-MBD这两种细胞骨架标记蛋白对拟南芥愈伤组织诱导、悬浮细胞培养及应激响应能力的影响.结果表明:(1)GFP-MBD标记蛋白延长愈伤的出愈时间,改变愈伤形态,使转基因拟南芥种子的出愈量减少为野生型的59%、悬浮细胞的长短轴比缩小为1.20±0.21、第7天细胞活力下降为0.66±0.09,影响细胞的生长曲线.(2)GFP-FABD标记蛋白虽对愈伤生长影响不大,但却使悬浮细胞的长短轴比显著增加为2.49±1.18、第7天细胞的活力下降为0.87±0.06,造成悬浮细胞生长曲线的改变.(3)通过调整培养条件的激素水平,以上两种细胞骨架标记蛋白对悬浮细胞生长的影响可以得到修复.(4)检测优化条件下培养的GFP-FABD2或GFP-MBD悬浮细胞对温度、渗透压、机械应力等环境改变的应激响应能力,结果未发现与野生型有明显区别.