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PubMed2003

Effect of trehalose on survival of Bradyrhizobium japonicum during desiccation.

AIMS: A major reason for the ineffectiveness of legume inoculants in the field is the rapid death of rhizobia because of desiccation. The major purpose of this study was to identify conditions under which alpha,alpha-trehalose would improve survival of Bradyrhizobium japonicum during desiccation. METHODS AND RESULTS: Trehalose was added to cultures just prior to desiccation or was supplied to bacteria during the 6-day growth period. A wide variety of trehalose concentrations was tested. Trehalose added to cultures at the time of desiccation improved survival slightly, but trehalose loading during growth was much more effective in protection against desiccation. Growth of bacteria with 3 mmol l-1 trehalose increased trehalose concentration in cells by about threefold and increased survival of cells placed on soya bean [Glycine max (L.) Merr.] seeds by two- to four-fold after 2 or 24 h. Average of overall results indicate that growth of bacteria with trehalose in the medium resulted in a 294% increase in survival after 24 h of desiccation. The concentration of trehalose in cells was very highly correlated with survival of bacteria. When trehalose-loaded cells were suspended in buffer or water, 60-85% of cellular trehalose was lost in about 1 h and, in spite of these losses, survival during desiccation was not reduced. CONCLUSIONS: Accumulation of trehalose in the cytoplasm is critical to the survival of B. japonicum during desiccation. Increasing the periplasmic concentration of trehalose is also beneficial but is not so critical as the concentration of trehalose in the cytoplasm. Because B. japonicum cannot utilize trehalose as a carbon source, cells can be loaded with trehalose by providing the disaccharide during the growth period. SIGNIFICANCE AND IMPACT OF THE STUDY: Although it may not be practical to use trehalose as a carbon source in inoculant production, it may be possible to engineer greater trehalose accumulation in rhizobia. Trehalose concentration in cells should be a useful predictor of survival during desiccation.

Bacteriological Techniques↗
PubMed2001

Desiccation resistance in pre-diapause, diapause and post-diapause larvae of Choristoneura fumiferana (Lepidoptera: Tortricidae).

Desiccation resistance was examined in pre-diapause, diapause and post-diapause larvae of the spruce budworm, Choristoneura fumiferana (Clemens), in terms of passive water evaporation under three desiccation conditions: freeze-drying, desiccant-drying at 2 degrees C and desiccant-drying at 18 degrees C. Diapausing second instar larvae and post-diapause non-feeding second instar larvae showed strongest desiccation resistance: a significant amount of water was retained after repeated drying under desiccating conditions, while pre-diapause first instar larvae and post-diapause feeding second instar larvae lost almost all their water content after one or two drying cycles. A hibernaculum covering had no effect on water evaporation. While dead larvae tended to lose significantly more water than their living counterparts, particularly among first instar larvae, such an impact was much weaker among diapausing second instar larvae. Desiccation resistance was lost when post-diapause second instar larvae were allowed access to water while the level of desiccation resistance was maintained or enhanced when the larvae did not have access to water. These results are discussed in the context of overwintering ecology of the species and possible mechanisms for the desiccation resistance are also discussed.

Animals↗
PubMed2006

Generational differences in response to desiccation stress in the desert moss Tortula inermis.

BACKGROUND AND AIMS: Active growth in post-embryonic sporophytes of desert mosses is restricted to the cooler, wetter months. However, most desert mosses have perennial gametophytes. It is hypothesized that these life history patterns are due, in part, to a reduced desiccation tolerance for sporophytes relative to gametophytes. METHODS: Gametophytes with attached post-embryonic sporophytes of Tortula inermis (early seta elongation phenophase) were exposed to two levels of desiccation stress, one rapid-dry cycle and two rapid-dry cycles, then moistened and allowed to recover, resume development, and/or regenerate for 35 d in a growth chamber. KEY RESULTS: Gametophytes tolerated the desiccation treatments well, with 93 % survival through regenerated shoot buds and/or protonemata. At the high stress treatment, a significantly higher frequency of burned leaves and browned shoots occurred. Sporophytes were far more sensitive to desiccation stress, with only 23 % surviving after the low desiccation stress treatment, and 3 % surviving after the high desiccation stress treatment. While the timing of protonemal production and sporophytic phenophases was relatively unaffected by desiccation stress, shoots exposed to one rapid-dry cycle produced shoots more rapidly than shoots exposed to two rapid-dry cycles. CONCLUSIONS: It is concluded that sporophytes of Tortula inermis are more sensitive to rapid drying than are maternal gametophytes, and that sporophyte abortion in response to desiccation results from either reduced desiccation tolerance of sporophytes relative to gametophytes, or from a termination of the sporophyte on the part of the gametophyte in response to stress.

Bryopsida↗
PubMed2006

Thermal energy dissipation in reaction centres and in the antenna of photosystem II protects desiccated poikilohydric mosses against photo-oxidation.

Seasonal differences have been observed in the ability of desiccated mosses to dissipate absorbed light energy harmlessly into heat. During the dry summer season desiccation-tolerant mosses were more protected against photo-oxidative damage in the dry state than during the more humid winter season. Investigation of the differences revealed that phototolerance could be acquired or lost even under laboratory conditions. When a desiccated poikilohydric moss such as Rhytidiadelphus squarrosus is in the photosensitive state, the primary quinone, Q(A), in the reaction centre of photosystem II is readily reduced even by low intensity illumination as indicated by reversibly increased chlorophyll fluorescence. No such reduction is observed even under strong illumination in desiccated mosses after phototolerance has been acquired. In this state, reductive charge stabilization is replaced by energy dissipation. As a consequence, chlorophyll fluorescence is quenched. Different mechanisms are responsible for quenching. One is based on the presence of zeaxanthin provided drying occurs in the light. This mechanism is known to be controlled by a protonation reaction which is based on proton-coupled electron transport while the moss is still hydrated. Another mechanism which also requires light for activation, but no protonation, is activated during desiccation. While water is slowly lost, fluorescence is quenched. In this situation, an absorption band formed at 800 nm in the light is stabilized. It loses reversibility on darkening. Comparable kinetics of fluorescence quenching and 800 nm signals as well as the linear relationship between non-photochemical fluorescence quenching (NPQ) and loss of stable charge separation in photosystem II reaction centres suggested that desiccation-induced quenching is a property of photosystem II reaction centres. During desiccation, quenchers accumulate which are stable in the absence of water but revert to non-quenching molecular species on hydration. Together with zeaxanthin-dependent energy dissipation, desiccation-induced thermal energy dissipation protects desiccated poikilohydric mosses against photo-oxidation, ensuring survival during drought periods.

Bryopsida↗
PubMed2005

Barium hydroxide lime turns yellow after desiccation.

Ethyl violet is added to carbon dioxide absorbents and normally serves as an indicator of absorbent exhaustion. During the course of several prior studies of anesthetic breakdown, we noted (but did not publish) that barium hydroxide lime (BL), but not soda lime, turns yellow upon desiccation. We hypothesize that ethyl violet undergoes chemical reaction to produce a yellow colorant in desiccated BL. We qualitatively studied the time course of yellow color development during desiccation of these absorbents with dry oxygen. The yellow colorant was extracted from desiccated absorbent with diethyl ether, separated with chromatography, and analyzed with proton nuclear magnetic resonance and combined gas chromatography and mass spectrometry. The yellow color develops after BL has reached nearly complete desiccation. We successfully identified that ethyl violet decomposes into the yellow colorant 4,4'-bis(diethylamino)benzophenone upon desiccation of BL. The color is not intense, is not useful for identifying low levels of absorbent desiccation, and may be difficult to see through tinted canisters. It may be possible for BL to be sufficiently desiccated to allow chemical breakdown of anesthetics, but not yet show yellow coloration. However, if yellow coloration exists, one should assume that it has become desiccated.

Anesthesiology↗
PubMed2000

Postponed aging and desiccation resistance in Drosophila melanogaster.

Studies with the fruit fly, Drosophila melanogaster, have repeatedly shown that selection for postponed reproduction leads to increases in mean life span and increased stress resistance; including increased resistance to desiccation, starvation and ethanol vapors. We show that desiccation resistance declines with age in both short- and long-lived flies suggesting that desiccation resistance may serve as a useful biomarker for aging-related declines in physiological performance. We examined the physical basis of desiccation resistance in five replicate populations selected for postponed reproduction and five replicate control populations. The variables examined were water content, rates of water loss during desiccation, and water content at time of death due to desiccation. In the absence of desiccation stress, both the flies exhibiting postponed senescence and their controls maintained constant water content throughout their lifetimes. In the presence of desiccation stress, the short-lived flies showed significantly higher rates of water loss at all ages than did the long-lived flies. Flies from the two treatments did not differ in water content at death. Our results indicate that water loss rates are the major determinant of desiccation resistance. Water loss rates are under genetic control and covary with age in populations with genetically-determined postponed senescence.

Aging↗
PubMed1999

Water content, raffinose, and dehydrins in the induction of desiccation tolerance in immature wheat embryos

Desiccation tolerance is initiated in wheat (Triticum aestivum L.) embryos in planta at 22 to 24 d after anthesis, at the time that the embryo water content has decreased from about 73% fresh weight (2.7 g water/g dry weight) to about 65% fresh weight (1.8 g water/g dry weight). To determine if desiccation tolerance is fully induced by the loss of a relatively small amount of water, detached wheat grains were treated to reduce the embryo water content by just a small amount to approximately 69% (2.2 g water/g dry weight). After 24 h of such incipient water loss, subsequently excised embryos were able to withstand severe desiccation, whereas those embryos that had not previously lost water could not. Therefore, a relatively small decrease in water content for only 24 h acts as the signal for the development of desiccation tolerance. Embryos that were induced into tolerance by a 24-h water loss had no detectable raffinose. The oligosaccharide accumulated at later times even in embryos of detached grains that had not become desiccation tolerant, although tolerant embryos (i.e. those that previously had lost some water) contained larger amounts of the carbohydrate. It is concluded that desiccation tolerance and the occurrence of raffinose are not correlated. Immunodetected dehydrins accumulated in embryos in planta as desiccation tolerance developed. Detachment of grains induced the appearance of dehydrins at an earlier age, even in embryos that had not been made desiccation tolerant by incipient drying. It is concluded that a small reduction in water content induces desiccation tolerance by initiating changes in which dehydrins might participate but not by their interaction with raffinose.

Journal Article↗
PubMed2002

Biomphalaria tenagophila (Orbigny, 1835) (Mollusca): adaptation to desiccation and susceptibility to infection with Schistosoma mansoni Sambon, 1907.

Experiments were carried out to test the susceptibility of Biomphalaria tenagophila to the infection with strain SJ of Schistosoma mansoni in the F1, F2 and non-selected parental generation. The potential adaptation of B. tenagophila to desiccation, in healthy mollusks and those exposed to the larvae of S. mansoni of the F1, F2 and non-selected parental generations was also studied. The presence of mucus and soil, at the shell opening, protected the snails against desiccation, favoring survival. The healthy mollusks performed more attempts against desiccation than those exposed to the larvae of the parasite. The mortality rate, during desiccation, was higher among mollusks that remained buried and with the shell opening unobstructed. During the desiccation period the stage of development of the parasite was influenced by the weight loss and the survival of the snails. The longer the period of desiccation, the greater was the weight loss observed, abbreviating survival. The non-selected parental generation was more sensitive to desiccation than the F1 and F2 generations, both in healthy mollusks and in those exposed to S. mansoni larvae. Healthy mollusks were more resistant to desiccation than those exposed to the larvae of the S. mansoni. Desiccation did not interrupt the development of S. mansoni larvae in mollusks, causing a delay in the cercariae elimination. The susceptibility of B. tenagophila to the SJ strain of S. mansoni, in mollusks maintained in water during the larvae incubation period, was similar in all three generations.

Animals↗
PubMed2001

The competence to acquire cellular desiccation tolerance is independent of seed morphological development.

Acquisition of desiccation tolerance and the related changes at the cellular level in wheat (Triticum aestivum cv. Priokskaya) kernels during normal development and premature drying on the ear were studied using a spin probe technique and low temperature scanning electron microscopy. During normal development, the ability of embryos to germinate after rapid drying and rehydration was acquired after completion of morphological development, which is a few days before mass maturity. The acquisition of desiccation tolerance, as assessed by germination, was associated with an upsurge in cytoplasmic viscosity, the onset of accumulation of protein and oil bodies, and the retention of membrane integrity upon dehydration/rehydration. These features were also used to assess cellular desiccation tolerance in the cases when germination could not occur. Slow premature drying was used to decouple the acquisition of cellular desiccation tolerance from morphogenesis. Upon premature drying of kernels on the ears of plants cut at 5 d after anthesis, desiccation-tolerant dwarf embryos were formed that were able to germinate. When plants were cut at earlier stages poorly developed embryos were formed that were unable to germinate, but cellular desiccation tolerance was nevertheless acquired. In such prematurely dried kernels, peripheral meristematic endosperm cells had already passed through similar physiological and ultrastructural changes associated with the acquisition of cellular desiccation tolerance. It is concluded that despite the apparent strong integration in seed development, desiccation tolerance can be acquired by the meristematic cells in the developing embryo and cambial layer of endosperm, independently of morphological development.

Adaptation, Physiological↗
PubMed1994

The Involvement of Respiration in Free Radical Processes during Loss of Desiccation Tolerance in Germinating Zea mays L. (An Electron Paramagnetic Resonance Study).

When germinating Zea mays L. seeds are rapidly desiccated, free radical-mediated lipid peroxidation and phospholipid de-esterification is accompanied by a desiccation-induced buildup of a stable free radical associated with rapid loss of desiccation tolerance. Comparison of the electron paramagnetic resonance and electron nuclear double resonance properties of this radical with those of the radical in dried, desiccation-intolerant moss showed that the two were identical. At the subcellular level, the radical was associated with the hydrophilic fraction resulting from lipid extraction. Isolated mitochondria subjected to drying were also found to accumulate an identical radical in vitro. When increasing concentrations of cyanide were used, a significant positive correlation was shown between rates of respiration and the accumulation of the radical in desiccation-intolerant tissues. Another positive correlation was found when rates of O2 uptake by radicles at different stages of germination were plotted against free radical content following desiccation. This indicates that free radical production is closely linked to respiration in a process likely to involve the desiccation-induced impairment of the mitochondrial electron transport chain to form thermodynamically favorable conditions to induce accumulation of a stable free radical and peroxidized lipids. Modulation of respiration using a range of inhibitors resulted in broadly similar modulation of the buildup of the stable free radical. One site of radical generation was likely to be the NADH dehydrogenase of complex I and probably as a direct consequence of desiccation-impaired electron flow at or close to the ubiquinone pool.

Journal Article↗
PubMed1991

Maturation proteins associated with desiccation tolerance in soybean.

A set of proteins that accumulates late in embryogenesis (Lea proteins) has been hypothesized to have a role in protecting the mature seed against desiccation damage. A possible correlation between their presence and the desiccation tolerant state in soybean seeds (Glycine max L. Chippewa) was tested. Proteins that showed the same temporal pattern of expression as that reported for Lea proteins were identified in the axes of soybean. They were distinct from the known storage proteins and were resistant to heat coagulation. The level of these "maturation" proteins was closely correlated with desiccation tolerance both in the naturally developing and in the germinating seed: increasing at 44 days after flowering, when desiccation tolerance was achieved, and decreasing after 18 hours of imbibition, when desiccation tolerance was lost. During imbibition, 100 micromolar abscisic acid or Polyethylene glycol-6000 (-0.6 megapascals) delayed disappearance of the maturation proteins, loss of desiccation tolerance, and germination. During maturation, desiccation tolerance was prematurely induced when excised seeds were dried slowly but not when seeds were held for an equivalent time at high relative humidity. In contrast, maturation proteins were induced under both conditions. We conclude that maturation proteins may contribute to desiccation tolerance of soybean seeds, though they may not be sufficient to induce tolerance by themselves.

Journal Article↗
PubMed2004

The evolution of recovery from desiccation stress in laboratory-selected populations of Drosophila melanogaster.

We examined the capacity for physiological recovery from the effects of desiccation in five replicate populations of Drosophila melanogaster that have been selected for enhanced desiccation resistance (D populations) and in five replicate control populations (C populations). The capacity to recover was signified by the ability to restore three somatic components, namely whole-body water, dry mass and sodium content, all of which are reduced during desiccation. Throughout a period of recovery following a bout of desiccation, the flies were offered one of three fluids: distilled water, saline solution, or saline+sucrose solution. Our findings indicate that, when allowed to recover on saline+sucrose solution, D populations have the capacity to restore water at a greater rate than C populations and are able to fully restore dry mass and sodium content to the levels observed in non-desiccated, hydrated D flies. When provided with this same solution during recovery, C flies are unable to restore dry mass and are faced with an elevated sodium load. Desiccation resistance of the flies subsequent to recovery was also examined. We provide evidence that the greatest desiccation resistance in the D populations is associated with the restoration of all three somatic components, suggesting that not only water content, but also dry mass and sodium, may contribute to the enhanced desiccation resistance that has evolved in these populations.

Adaptation, Physiological↗
PubMed1993

Characterization of the expression of a desiccation-responsive rd29 gene of Arabidopsis thaliana and analysis of its promoter in transgenic plants.

We characterized the expression of genes that correspond to a cDNA clone, RD29, which is induced by desiccation, cold and high-salt conditions in Arabidopsis thaliana. Northern analysis of desiccation-induced expression revealed a two-step induction process. Early induction occurs within 20 min and secondary induction occurs 3 h after the start of desiccation. Exogenous abscisic acid (ABA) induces RD29 mRNA within 3 h. Two genes corresponding to RD29, rd29A and rd29B, are located in tandem in an 8 kb region of the Arabidopsis genome and encode hydrophilic proteins. Desiccation induces rd29A mRNA with two-step kinetics, while rd29B is induced only 3 h after the start of desiccation. The expression of both genes is stimulated about 3 h after application of ABA. It appears that rd29A has at least two cis-acting elements, one involved in the ABA-associated response to desiccation and the other induced by changes in osmotic potential. The beta-glucuronidase (GUS) reporter gene driven by the rd29A promoter was induced at significant levels by desiccation, cold, high-salt conditions and ABA in both transgenic Arabidopsis and tobacco. Histochemical analysis of GUS activity revealed that the rd29A promoter functions in almost all the organs and tissues of vegetative plants during water deficiency.

Abscisic Acid↗
PubMed2004

The importance of cuticular permeability, osmolyte production and body size for the desiccation resistance of nine species of Collembola.

Euedaphic collembolans have recently been shown to actively regulate internal osmotic pressure by means of sugars and polyols in response to desiccation. In contrast, studies of cuticular permeability have shown that some, especially epedaphic, species of collembolans may primarily rely on a low cuticular permeability to survive desiccation. To elucidate to what extent these strategies are important for desiccation resistance, the survival of 7-day acute desiccation stress (LRH(50)), the cuticular water conductance constant and osmolyte production were investigated in nine species of collembolans, covering euedaphic, hemiedaphic and epedaphic species. The LRH(50) values ranging from 98.8% to 95.2% RH showed no correlation with the vertical distribution of species, since both the highest and lowest values were found in epedaphic species. The water conductance varied from 698+/-141 to 41+/-13 microg h(-1) cm(-2) mmHg(-1) and showed good agreement with the vertical distribution of species in their natural habitats. Modelling the drying curves showed that, in addition to cuticular permeability and osmolyte production, body size also plays an important role in the survival of short-term severe desiccation stress. Furthermore, the model pointed to the need for behavioural responses to desiccation, particularly in epedaphic species. Thus, in keeping with expected humidity regimes in their respective microhabitats, euedaphic species rely on small body size, high cuticular permeability and the ability to actively regulate the osmotic pressure of their body fluids, hemiedaphic species have similar strategies but with reduced cuticular permeability, whereas in epedaphic species, active regulation of osmotic pressure is replaced by combinations of greatly reduced cuticular permeability or greatly reduced surface area to volume ratio combined with behavioural responses to desiccation.

Adaptation, Physiological↗
PubMed1998

Desiccation resistance of two semiterrestrial isopods, Ligia exotica and Ligia taiwanensis (Crustacea) in Taiwan.

The ability to resist desiccation stress was examined in two semiterrestrial Ligia species, Ligia exotica Roux and L. taiwanensis Lee, in Taiwan, under a certain desiccation condition. L. exotica exhibited the longer survival time, lower weight-specific rates of water loss, and the slightly higher ability of tolerance to water loss, compared to L. taiwanensis. In each species, the animal size displays a positive correlation to the survival time and total ability to resist desiccation, yet this size effects on the weight-specific water loss rate is negative. Neither water content nor maximum tolerance to water loss shows the association with the animal size in both species. The path ways and magnitudes of the interactions between these traits of desiccation resistance are analyzed and diagrammed using a stepwise regression model. In this model, the body sizes of animal can explain the most part of the variations in the survival time. The body size has a direct effect and an indirect effect, through the effect on water loss rate, on the time that the experimental animals can survival under this desiccated condition. These results suggest that L. exotica attains larger size than does L. taiwanensis, a lower transpiration rate and, consequently, a greater ability in desiccation resistance. The performances of these interactions in the desiccated resistance are more advantageous for L. exotica to migrate and colonize in variable land habitats within a certain limit, and as a result that L. exotica shows a broader distribution pattern than did L. taiwanensis in Taiwan.

Animals↗
PubMed2002

Corneal protection by the ocular mucin secretagogue 15(S)-HETE in a rabbit model of desiccation-induced corneal defect.

The mucin secretagogue 15(S)-HETE was found to stimulate glycoprotein secretion in human ocular tissue at submicromolar concentrations in the present studies. Therefore, the ability of topically applied 15(S)-HETE to preserve corneal integrity was investigated in a rabbit model of desiccation-induced corneal defect. Desiccation-induced corneal injury was elicited in anesthetized rabbits by maintaining one eye open with a speculum. Corneal staining and corneal thickness changes were determined immediately following desiccation. 15(S)-HETE dose-dependently reduced corneal damage (ED50 = 120 nM) during a two-hour desiccation. Corneal staining was unchanged relative to control using a 1 microM dose of 15(S)-HETE. Through four hours of desiccation, 15(S)-HETE (500 nM) decreased corneal staining by 71% and completely prevented corneal thinning. 15(S)-HETE (1 microM) was significantly more efficacious than an artificial tear product over the 4-hour desiccation period. There was no evidence of tachyphylaxis following repeated topical ocular dosing of 15(S)-HETE. These studies demonstrate that 15(S)-HETE stimulates ocular mucin secretion in vitro and effectively protects the cornea in a rabbit model of desiccation-induced injury. The results suggest that the ocular mucin secretagogue 15(S)-HETE may have therapeutic utility in dry eye patients, alleviating corneal injury and restoring corneal integrity.

Administration, Topical↗
PubMed2000

Desiccation tolerance of recalcitrant Theobroma cacao embryonic axes: the optimal drying rate and its physiological basis.

Recalcitrant seed axes were reported to survive to lower water contents under fast-drying conditions. The present study was to examine the hypothesis that drying rate and dehydration duration could interact to determine desiccation tolerance through different physico-chemical mechanisms. The effect of drying rate on desiccation tolerance of Theobroma cacao seed axes at 16 degrees C was examined. Rapid-drying at low relative humidity (RH) and slow-drying at high RH were more harmful to cocoa axes, because electrolyte leakage began to increase and axis viability began to decrease at high water contents. Maximum desiccation tolerance was observed with intermediate drying rates at RH between 88% and 91%, indicating the existence of an optimal drying rate or optimal desiccation duration. This maximum level of desiccation tolerance for cocoa axes (corresponding to a critical water potential of -9 MPa) was also detected using the equilibration method, in which axes were dehydrated over a series of salt solutions or glycerol solutions until the equilibrium. These data confirmed that the physiological basis of the optimal drying rate is related to both mechanical stress during desiccation and the length of desiccation duration during which deleterious reactions may occur. The optimal drying rate represents a situation where combined damages from mechanical and metabolic stresses become minimal.

Adaptation, Physiological↗
PubMed2006

Intracellular trehalose is neither necessary nor sufficient for desiccation tolerance in yeast.

Trehalose is thought to be important for desiccation tolerance in a number of organisms, including Saccharomyces cerevisiae, but there is limited in vivo evidence to support this hypothesis. In wild-type yeast, the degree of desiccation tolerance has been shown previously to increase in cultures after diauxic shift and also in exponential-phase cultures after exposure to heat stress. Under both these conditions, increased survival of desiccation correlates with elevated intracellular trehalose concentrations. Our data confirm these findings, but we have tested the apparent importance of trehalose using mutant strains with a deleted trehalose-6-phosphate synthase gene (tps1Delta). Although tps1Delta strains do not produce trehalose, they are nevertheless capable of desiccation tolerance, and the degree of tolerance also increases after diauxic shift or heat stress, albeit slightly less than in the wild type. Conversely, when wild-type yeast is subjected to osmotic stress, mid-exponential-phase cultures produce high concentrations of intracellular trehalose but show little improvement in desiccation tolerance. These results show that there is no consistent relationship between intracellular trehalose levels and desiccation tolerance in S. cerevisiae. Trehalose seems to be neither necessary nor sufficient for, although in some strains might quantitatively improve, survival of desiccation, suggesting that other adaptations are more important.

Cytoplasm↗