Changes in starch and soluble sugars in relation to the acquisition of desiccation tolerance during maturation of <i>Brassica campestris</i> seed

Leprince, Olivier; Bronchart, R.; Deltour, R.

doi:10.1111/j.1365-3040.1990.tb01070.x

Cited by 98 publications

(63 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The precise causes that trigger the metabolic arrest during drying are not known. Electron microscopy studies have suggested that the progressive shutdown of metabolism is associated with a general dedifferentiation of organelles (Leprince et al, 1990; for review, see Vertucci and Farrant, 1995). In cowpea we observed a biphasic pattern in the relation between viscosity and respiration.…”

Section: A Functional Role For Cytoplasmic Viscosity In Depressing Mementioning

confidence: 68%

“…Two mechanisms of protection against the deleterious effects of water loss have received major attention: (a) the synthesis of the so-called lateembryogenesis-abundant proteins (Close, 1996;Kermode, 1997) and (b) the accumulation of di-and oligosaccharides (Leprince et al, 1990;Horbowicz and Obendorf, 1994;Vertucci and Farrant, 1995). In model systems these sugars protect the structural integrity of dehydrated membranes and proteins (Crowe et al, 1992;Hoekstra et al, 1997).…”

mentioning

confidence: 99%

See 1 more Smart Citation

The Responses of Cytochrome Redox State and Energy Metabolism to Dehydration Support a Role for Cytoplasmic Viscosity in Desiccation Tolerance

Leprince

Hoekstra

1998

Plant Physiology

View full text Add to dashboard Cite

To characterize the depression of metabolism in anhydrobiotes, the redox state of cytochromes and energy metabolism were studied during dehydration of soaked cowpea (Vigna unguiculata) cotyledons and pollens of Typha latifolia and Impatiens glandulifera. Between water contents (WC) of 1.0 and 0.6 g H 2 O/g dry weight (g/g), viscosity as measured by electron spin resonance spectroscopy increased from 0.15 to 0.27 poise. This initial water loss was accompanied by a 50% decrease in respiration rates, whereas the adenylate energy charge remained constant at 0.8, and cytochrome c oxidase (COX) remained fully oxidized. From WC of 0.6 to 0.2 g/g, viscosity increased exponentially. The adenylate energy charge declined to 0.4 in seeds and 0.2 in pollen, whereas COX became progressively reduced. At WC of less than 0.2 g/g, COX remained fully reduced, whereas respiration ceased. When dried under N 2 , COX remained 63% reduced in cotyledons until WC was 0.7 g/g and was fully reduced at 0.2 g/g. During drying under pure O 2 , the pattern of COX reduction was similar to that of air-dried tissues, although the maximum reduction was 70% in dried tissues. Thus, at WC of less than 0.6 g/g, the reduction of COX probably originates from a decreased O 2 availability as a result of the increased viscosity and impeded diffusion. We suggest that viscosity is a valuable parameter to characterize the relation between desiccation and decrease in metabolism. The implications for desiccation tolerance are discussed.

show abstract

Section: A Functional Role For Cytoplasmic Viscosity In Depressing Mementioning

confidence: 68%

mentioning

confidence: 99%

The Responses of Cytochrome Redox State and Energy Metabolism to Dehydration Support a Role for Cytoplasmic Viscosity in Desiccation Tolerance

Leprince

Hoekstra

1998

Plant Physiology

View full text Add to dashboard Cite

show abstract

“…Trehalose has been shown to be a particularly effective protectant in anhydrobiotic organisms such as yeast, nematodes, fungi, and bacteria, whereas in seeds and pollen, Suc appears to play the same role (Crowe et al, 1992). Many orthodox seeds accumulate high amounts of Suc and oligosaccharides during maturation (Amuti and Pollard, 1977), and sugar accumulation has been correlated with an increase in desiccation tolerance (Leprince et al, 1990;Blackman et al, 1992). Oligosaccharides have been proposed to inhibit Suc crystallization, a situation that is favored by slow drying (Koster and Leopold, 1988), and may be involved in desiccation tolerance by promoting glass formation at water contents 4 0 % (Bruni and Leopold, 1991).…”

mentioning

confidence: 99%

Development of Desiccation Tolerance during Embryogenesis in Rice (Oryza sativa) and Wild Rice (Zizania palustris) (Dehydrin Expression, Abscisic Acid Content, and Sucrose Accumulation)

1994

View full text Add to dashboard Cite

The ability of seeds to withstand desiccation develops during embryogenesis and differs considerably among species. Paddy rice (Oryza sativa 1.) grains readily survive dehydration to as low as 2% water content, whereas North American wild rice (Zizania palusfris var inferior [Fasset] Dore) grains are not tolerant of water contents below 6% and are sensitive to drying and imbibition conditions. During embryogenesis, dehydrin proteins, abscisic acid (ABA), and saccharides are synthesized, and all have been implicated in the development of desiccation tolerance. We examined the accumulation patterns of dehydrin protein, ABA, and soluble saccharides (sucrose and oligosaccharides) of rice embryos and wild rice axes in relation to the development of desiccation tolerante during embryogenesis. Dehydrin protein was deteded immunologically with an antibody raised against a conserved dehydrin amino acid sequence. Both rice and wild rice embryos accumulated a 21-kD dehydrin protein during development, and an immunologically related 38-kD protein accumulated similarly in rice. Dehydrin protein synthesis was deteded before desiccation tolerance had developed in both rice embryos and wild rice axes. However, the major accumulation of dehydrin occurred after most seeds of both species had become desiccation tolerant. ABA accumulated in wild rice axes to about twice the amount present in rice embryos. There were no obvious relationships between ABA and the temporal expression patterns of dehydrin protein in either rice or wild rice. Wild rice axes accumulated about twice as much sucrose as rice embryos. Oligosaccharides were present at only about one-tenth of the maximum sucrose concentrations in both rice and wild rice. We conclude that the desiccation sensitivity displayed by wild rice grains is not due to an inability to synthesize dehydrin proteins, ABA, or soluble carbohydrates.Most seeds enter a period of desiccation and physiological quiescence during the last phase of development. However, there are considerable differences among species in their ability to survive desiccation. Orthodox seeds such as paddy rice (Oryza sativa L.) caryopses readily tolerate desiccation to <5% water content, and their longevity in storage increases as temperature and water content decrease (Roberts, 1973 for example, are tolerant of desiccation only under restricted dehydration and rehydration conditions. Wild rice is an aquatic grass whose seeds (caryopses) normally abscise at a relatively high moisture content, fall into the water, remain dormant through the winter, and genninate the following spring. Wild rice seeds were thought to be intolerant of dehydration <30% moisture content (Probert and Brierly, 1989; Probert and Longley, 1989), but the seeds can survive dehydration to as low as 6% moisture content if dehydration and rehydration occur at 15 to 25OC and imbibitional damage is avoided (Kovach and Bradford,

show abstract

“…Many of the bryophytes are highly desiccation-tolerant, so their carbohydrate composition is of interest. High sucrose concentration has been suggested as a prerequisite for desiccation tolerance in seeds and pollen (Koster & Leopold, 1988 ;Leprince, Bronchart & Deltour, 1990) and in the desiccationtolerant leaves of angiosperm ' resurrection ' plants (Ingrams & Bartels, 1996). By contrast, the desiccation tolerance of the pteridophyte Selaginella lepidophylla, of fungal spores and of desiccationtolerant invertebrates is associated with the di-saccharide trehalose (Ingram & Bartels, 1996).…”

mentioning

confidence: 99%

Carbohydrate composition and invertase activity of the leafy liverwort Porella platyphylla

1998

View full text Add to dashboard Cite

The major soluble carbohydrates in the desiccation-tolerant leafy liverwort Porella platyphylla (L.) Lindb. are sucrose and a homologous series of fructans including the trisaccharide 1-kestose. Exogenous glucose and fructose (10 mol m −$ ) did not affect the composition of the soluble carbohydrate pool. Sucrose caused an increase in the fructan pool. Sucrose also inhibited photosynthetic oxygen evolution and respiration. The fructan pool was maintained in preference to sucrose during dark starvation. Low temperature and low water potential increased the fructan pool whereas desiccation increased the proportion of high molecular weight fructan. Acid invertase activity was detected in a taxonomically diverse range of liverworts but was very low or undetectable in a range of mosses. The invertase activity from P. platyphylla was partially purified by ammonium sulphate precipitation. The reaction products of the partially purified enzyme were equimolar glucose and fructose. Kestose and higher DP fructans were not detected suggesting that, at least under the assay conditions used, the enzyme does not have sucrose : sucrose fructosyl transferase activity. The pH optimum was 4n5-5 and the K m for sucrose was 1n7 mol m −$ . Pyridoxal hydrochloride (5 mol m −$ ) caused 50 % inhibition. The coexistence of sucrose and invertase suggests that either the invertase is inactive in vivo or is in a different subcellular compartment from sucrose. The pH response shows that it would have very low activity at cytosolic pH. A large acidic vacuole was detected in P. platyphylla leaf cells by neutral-red staining in which either invertase or sucrose could be sequestered. Rehydrating desiccated P. platyphylla for 10 min resulted in a 60 % loss of extractable invertase activity. By contrast, extractable malate dehydrogenase activity increased during rehydration. Rehydrating desiccated leaves caused an increase in glucose and fructose suggesting that the sucrose pool was susceptible to invertase at this time. It is suggested that the partial inactivation of invertase during rehydration minimizes sucrose hydrolysis while membrane structure and subcellular compartmentation are re-established.

show abstract

Changes in starch and soluble sugars in relation to the acquisition of desiccation tolerance during maturation of Brassica campestris seed

Cited by 98 publications

References 19 publications

The Responses of Cytochrome Redox State and Energy Metabolism to Dehydration Support a Role for Cytoplasmic Viscosity in Desiccation Tolerance

The Responses of Cytochrome Redox State and Energy Metabolism to Dehydration Support a Role for Cytoplasmic Viscosity in Desiccation Tolerance

Development of Desiccation Tolerance during Embryogenesis in Rice (Oryza sativa) and Wild Rice (Zizania palustris) (Dehydrin Expression, Abscisic Acid Content, and Sucrose Accumulation)

Carbohydrate composition and invertase activity of the leafy liverwort Porella platyphylla

Contact Info

Product

Resources

About