SUCROSE ACCUMULATION AND THE INITIATION OF FRUCTAN BIOSYNTHESIS IN <i>LOLIUM TEMULENTUM</i> L.

Pollock, C. J.

doi:10.1111/j.1469-8137.1984.tb03586.x

Cited by 91 publications

(53 citation statements)

References 17 publications

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“…Tbe K^, for SST from Agropyron was significantly lower tban tbose reported for Allium cepa (230 mol m^^) (Henry & Darbysbire, 1980) and Chicorimn intybus (285 mol m •') (Singb & Bbatia, 1971). Similar to our findings witb Agropyron, Pollock (1984) found a mucb bigber /C,,, for SST activity tban for invertase activity in enzyme preparations from Lolium temulentum.…”

Section: Resultssupporting

confidence: 91%

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Characterization of sucrose: sucrose fructosyltransferase from crested wheatgrass*

et al. 1988

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SUMMARYBiosynthesis of the trisaccharide precursor of fructan occurs through the action of sucrose: sucrose fructosyltransferase (SST). This study defines the optimal conditions for in vitro SST and invertase activities from a crested wheatgrass hybrid developed from a cross between Agropyron cristatum (L.) Gaertn. x^. desertorum (Fisch. ex Link) Schult. PInzyme extracts were prepared from field-gtown plants. The optimum pH for SST and invertase activities were 5-0 and 4-5, respectively. The effective ^C,,, for SST (100 mol m •') is much larger than invertase (15 mol m"'). Sodium pyrophosphate differentially reduced invertase activity without affecting SST activity. Conversely, CaCl.^ and CsCl reduced SST activity without altering invertase activity. Optitnal in vitro reaction temperatures for SST and invertase were 30 and 50 °C, respectively. SST activity was 30 "o of maximum at temperatures as cool as 5 °C. In contrast, invertase activity was only 10",, of maximum at 15 °C. The responses of SST and invertase to changes in pH, temperature, and additives provide additional evidence that the two activities are the result of two distinct enzymes. It is hypothesized that cool-season grasses such as crested wheatgrass have the ability to fix carbon photosynthetically at lower temperatures than starch-accumulating species because of their capacity to synthesize fructans.

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Section: Resultssupporting

confidence: 91%

“…(Wagner, 1986), Chicorium intybus L. (5-6) (Singb & Bbatia, 1971), and Lolium temulentum L. (55) (Pollock, 1984), but somewbat lower tban tbe optima measured for Agava americana L. (61) (Bbatia & Nandra, 1979). Soluble (acid) invertase activity was found to be maximal near pH 4-5 (Fig.…”

Section: Resultsmentioning

confidence: 99%

Characterization of sucrose: sucrose fructosyltransferase from crested wheatgrass*

et al. 1988

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“…Frutans, sucrose-derived oligosaccharides, accumulate when grasses from temperate and cool climatic areas are exposed to chilling temperatures (Eagles, 1967;Pontis & del Campillo, 1985;Chatterton et al, 1989;Suzuki, 1989;Livingston HI, Knievel & Gildow, 1994), an accumulation that is preceded by an increase in the concentration of sucrose (Pontis, 1970;Chandorkar & Collins, 1974). The increase in fructan content might be connected with acclimation to low temperatures (Pontis, 1989;Tognetti, Calderon & Pontis, 1989;Santoiani et al, 1993), it might be a consequence of the low demand for photosynthates at chilling temperatures (Pollock, 1984), or both might occur simultaneously. Tognetti et al (1989) and Santoiani et al (1993) studied fructan metabolism in young leaves and roots of wheat at chilling temperatures, whilst Spollen & Nelson (1994) investigated their relationship to water deficit in growing leaves of tall fescue.…”

Section: Introductionmentioning

confidence: 99%

Fructan metabolism in two species of Bromus subjected to chilling and water stress

1997

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SUMMARYTwo species of Bromus adapted to different climatic conditions were studied to determine their responses to chilling and water stress. Enzymes of sucrose and fructan metabolism as well as fructoside content were measured in roots and shoots. The results indicate that Bromuspictus (adapted to a cold desert area) has a constitutive fructan synthesis, whilst B. auleticiis (adapted to a warmer northern climate) only accumulated fructan under cold stress. Microscopic observations of roots exposed to fluorescent probes ascertained cell viability and showed that the apex of roots in the northern species were more affected by the water-deficit treatment than the southern species. The presence of fructans in B. pictus and their absence in B. auleticus support the hypothesis that fructans play a role in plant tolerance to environmental stress.

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“…One may conclude that the aibcumulation of sugars was mainly due to differences in carbon partitioning and utilization and was not caused by significant differences in carbon fixation. Low ambient temperatures also alter the balance between carbon assimilation and utilization and result in a pronounced increase in fructan content (Pollock, 1984;Bancal & Gaudillere, 1989;Wagner & Wiemken, 1989;Tognetti et al, 1990). However, it is not known whether fructans are directly involved in the mechanism of cold adaptation.…”

Section: Discussionmentioning

confidence: 99%

Accumulation of fructans following oxygen deficiency stress in related plant species with different flooding tolerances

Albrecht

BIEMELT

Baumgartner³

1997

New Phytologist

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SUMMARYIn the present work we compare responses to hypoxia of the carbohydrate content of related plant species, which grow naturally on sites prone to flooding {Senecio aquaticus Hill., Myosotispalustris (L.) Lehm. Rchb.) with plants from habitats with only a low risk of oxygen shortage (Senecio jacobaea L., Myosotis arvensis (L.) Hill.). Whilst the amounts of glucose, fructose and sucrose changed only slightly following hypoxia and peaked at a maximum approximately double that of the aerated control specimens, the fructan content increased fivefold to tenfold. In nearly all the plants studied, fructan became the main polysaccharide reserve. For example, the flooding-tolerant Senecio aquaticus accumulated the highest amount, in particular fructans with a degree of pol^^merization up to 35 compared with 10 under control conditions. Nearly 70% of the soluble carbohydrates were fructans, compared with 30 % under aerated conditions.In all species tested the starch fraction marginally increased or remained constant. Fructans were found to accumulate as a response to oxygen deficiency in both flooding-tolerant and intolerant species but with higher absolute values and ratios between fructan and starch in the fiooding-tolerant species. At 24 h after the otiset of hypoxic treatment, the sugar content rose, in spite of the diminished photosynthetic rates. The ability to accumulate fructans seems to vary in plants coping with oxygen shortage but could be interpreted as advantageous in comparison to starch synthesis in terms of (i) the location of the fructan metabolism in the vacuoles, with no negative feedback in the photosynthetic apparatus and (ii) the possibility of storage of sucrose in the form of fructose polymers without the intermediate stages and energy-using processes which are indispensable for starch synthesis. These results might indicate that fructan metabolism could play a role in the tolerance of oxygen deficiency.

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SUCROSE ACCUMULATION AND THE INITIATION OF FRUCTAN BIOSYNTHESIS IN LOLIUM TEMULENTUM L.

Cited by 91 publications

References 17 publications

Characterization of sucrose: sucrose fructosyltransferase from crested wheatgrass*

Characterization of sucrose: sucrose fructosyltransferase from crested wheatgrass*

Fructan metabolism in two species of Bromus subjected to chilling and water stress

Accumulation of fructans following oxygen deficiency stress in related plant species with different flooding tolerances

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