bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soluble carbohydrates in desiccation tolerance of yellow lupin seeds during maturation and germination
Authors: Górecki R. J. , Piotrowicz-Cieślak A. I. , Lahuta L. B. , Obendorf R. L. 
Published: September 2008

AbstractMaturing yellow lupin seeds were desiccation tolerant. Glucose, sucrose and cyclitols (mainly D-pinitol, D-chiro-inositol and myo-inositol) were predominant at the early stages of seed growth. Accumulation of the raffinose family oligosaccharides (RFOs) and the galactosyl cyclitols including galactinol, digalactosyl myo-inositol, galactopinitol A, galactopinitol B, trigalactopinitol A, ciceritol, fagopyritol B1 and fagopyritol B2 appeared during seed maturation; their increase correlated with seed germinability after desiccation. The loss of desiccation tolerance after seed germination was also studied. For the desiccation tolerance test, intact seedlings were dried rapidly or slowly followed by rehydration. Soluble carbohydrates were assayed before and after drying. Root tissues were more sensitive to desiccation than hypocotyl tissues and completely lost desiccation tolerance within 36 h of imbibition after both fast and slow-drying treatments. Survival of hypocotyls decreased gradually up to 96 h after imbibition. Loss of RFOs and galactosyl cyclitols in axis tissues preceded visible germination. Loss of desiccation tolerance was accompanied by loss of RFOs and galactosyl cyclitols and an increase in reducing sugars in cotyledon, hypocotyl and radicle tissues. Drying did not induce the accumulation of RFOs and galactosyl cyclitols in seedling tissues.
Heat-soluble proteins extracted from wheat embryos have tightly bound sugars and unusual hydration properties
Authors: Walters Christina , Ried Jeffrey L. , Walker-Simmons M. K. 
Published: September 2008

AbstractLate embryogenesis abundant (LEA) proteins accumulate in developing seeds prior to maturation drying and are presumed to help protect embryos from desiccation stress. The unusual solubility properties of these proteins, such as resistance to heat coagulation, have led to suggestions that they alter the hydration properties of cellular constituents. Hydration characteristics and water potential range at which wheat heat-soluble LEA proteins were expressed have been determined. Levels of heatsoluble proteins decline in germinating seeds but can be induced by dehydration (ψ ≤ −0.5 MPa) in crown meristematic tissue that is desiccation tolerant. The heatsoluble extract from mature wheat embryos contained proteins and sugars at about a 1:1 (w/w) ratio. Only about half of the sugars could be removed by exhaustive dialysis; the rest appeared to be tightly associated with the proteins. The water sorption characteristics of undialysed and dialysed heat-soluble protein/sugar fractions were compared with other water-soluble proteins (bovine serum albumin, lysozyme or gluten) and with sucrose. At relative humidities greater than 50%, the amount of water absorbed by protein-sugar mixes was a function of the sugar content. For the same sugar content, the heat-soluble protein preparation absorbed 2–3 times more water than a lysozyme/sucrose preparation. The rate at which heat-soluble protein fractions dried was also different to desorption rates of lysozyme/sucrose mixes. While lysozyme/sucrose mixtures dried either very rapidly (within 20 min) or very slowly (about 2 months) depending on the sugar content, desorption rates of the heat soluble protein-sugar preparations were intermediate (2–10 days) and modulated by sugar concentration. Based on the presumption that the hydrophilic properties of LEA heat-soluble proteins are important to their function, it is suggested that these proteins function to control drying so that cells stay at critical water potentials for the proper time. In this respect, the heat-soluble LEA proteins do not prevent desiccation, but serve as hydration buffers.
Effects of temperature on the desiccation responses of seeds of Zizania palustris
Authors: Ntuli Tobias M. , Berjak Patricia , Pammenter Norman W. , Smith Michael T. 
Published: September 2008

AbstractSeeds of wild rice (Zizania palustris var. interior) have been reported to show maximum survival when dehydrated at 25°C. It has also been reported that axis cells sustain least damage at this drying temperature. In the present study, a linear relationship between drying rate and dehydration temperature was established. Whereas the highest positive tetrazolium staining and lowest leakage were recorded for seeds dehydrated at 25°C, maximum germination was recorded for seeds dried at 20°C. A proportion of seeds showed glass formation irrespective of the dehydration temperatures used. Parameters of the glass to liquid transition, however, correlated with neither water content nor sugar profiles. The ratio of raffinose to sucrose was similar in all the treatments. A hydroperoxide test revealed a linear relationship between peroxide levels and drying temperature, although fatty acid amounts were not correlated with hydroperoxide amounts. Butanal amounts and total aldehydes evolved, on the other hand, showed a high negative correlation with peroxide amounts. Electron microscopy showed that the variability and relative abundance of peripheral membrane complexes (PMCs) was highest for embryonic axes dehydrated at 25°C and lowest for cells of embryonic axes of seeds dried at 10°C. Furthermore, intramembrane particles (IMPs) were evenly distributed in cells of axes dried at 25 or 37°C. In contrast, membranes of cells of axes dehydrated at 10°C showed large IMP-free areas. The relative abundance of IMPs was highest in cells of embryonic axes dried at 25°C and lowest in cells of axes dehydrated at 10°C. From these observations, it is suggested that membrane phase transitions, with the concomitant elimination of proteins, accompany dehydration of Z. palustris seeds at 10°C, whereas at 37°C peroxidation may predominate.
Cell cycle events in developing neem (Azadirachta indica) seeds: are they related to intermediate storage behaviour?
Authors: Sacandé Moctar , Groot Steven P. C. , Hoekstra Folkert A. , Castro Renato D. De , Bino Raoul J. 
Published: September 2008

AbstractSeeds of neem (Azadirachta indicaA. Juss.), a multipurpose tropical tree, have limited desiccation tolerance. Whether their intermediate storage behaviour might be caused by an elevated percentage of 4C nuclei in the embryo at maturity was investigated. Morphological development of neem seeds was monitored on selected trees in Ouagadougou, Burkina Faso. Developing seeds were tested for germinability, and cell cycle events were determined by using flow cytometry and analysing the level of β-tubulin. Germination could occur after 8 weeks of seed development, but normal seedlings resulted only after 10 weeks or more. The change in fruit colour from green to yellow began after approximately 12 weeks of seed development. Immature, 4-week-old embryos about 2 mm in length had 15% of cells in the G2phase and 60% in the G1phase of the cell cycle, as indicated by 4C and 2C nuclear DNA levels, respectively. During maturation, the proportion of G2cells declined to 3% at full maturity and slightly further after drying, and the proportion of G1cells increased to approximately 90%. A strong β-tubulin signal was observed in tips of young embryonic radicles and cotyledons, but a weak or non-detectable signal was found in 9-week-old ones and in those from green-mature and yellow fruits. Because DNA replication and β-tubulin level were almost negligible at seed maturity, as in orthodox tomato seeds, it is suggested that these factors are not involved in the intermediate storage behaviour of neem seeds.
Soluble sugars and flatulence-producing oligosaccharides in maturing yellow lupin (Lupinus luteusL.) seeds
Authors: Górecki Ryszard J. , Piotrowicz-Cieślak Agnieszka , Obendorf Ralph L. 
Published: September 2008

AbstractThe flatulence-producing soluble oligosaccharides are an important component of lupin seeds and were assayed to establish the pattern of their accumulation in relation to germinability during seed development and maturation. Maturing yellow lupin cv. Juno seeds were harvested at 5-day intervals from 15 to 45 days after flowering (DAF). Seed fresh mass increased to a maximum at 35 DAF followed by a decrease when axis and cotyledon tissues changed colour from green to yellow. Maximum seed fresh mass corresponded to the maximum seed size. Seed dry mass continuously increased until 40 DAF. About 75% of mature seed dry mass was in cotyledons, 22% in testa, and 3% in axis. Maximum seed germinability occurred at 45 DAF after maximum seed dry mass and desiccation. Maturing yellow lupin seeds were desiccation tolerant. Mature dry seeds contained 10.9% oligosaccharides and 1.5% sucrose. During seed growth stachyose accumulation preceded accumulation of raffinose and verbascose. The highest rate of oligosaccharide accumulation appeared during seed desiccation and correlated with the acquisition of the ability to germinate. The sucrose:oligosaccharide ratio continuously decreased reaching 0.13 in mature seeds. Accumulation of oligosaccharides in maturing yellow lupin seeds is associated with seed germinability and seed desiccation tolerance.
Variable regeneration behaviour ofUlmus davidianavar.Japonicain response to disturbance regime for risk spreading
Authors: Seiwa Kenji 
Published: September 2008

AbstractRecruitment-related traits (development and dispersal of seeds, emergence, leaf dynamics, growth and survival of seedlings) were studied in Japanese elm (Ulmus davidianavar.japonica) in relation to disturbance at the soil level (bare soil, litter and control) or the canopy level (forest edge (FE), small gaps (SG) and forest understorey (FU)), or both, in a riverside forest from 1990 to 1993. Seed germination was also tested in the laboratory. Litter accumulation severely inhibited seedling emergence. Seedling emergence from a single seed rain occurred in summer immediately after seed dissemination and in the following spring. In summer, seedling emergence was higher in FE than in FU. In the following spring more seedlings emerged in FU than in FE and SG, resulting in non-significant differences in the percentage emergence among the three sites in bare soil. Darkness or far-red light induced seed dormancy, but after chilling they started to germinate again under white or red light conditions. These results explained emergence phenology under changing light conditions in the field. In FU, the spring emerging cohort grew and survived better than the summer emerging one. In FE the reverse was true. Japanese elm avoids unfavourable periods by escaping either in time (dormancy) or in space (dispersal). Such traits compensate for late and compressed seed dissemination, and improve seedling growth and survival not only when disturbance occurs at both canopy and soil level (bare soil in FE) but also only at soil level (bare soil in FU), which may occur more frequently in riverside forests.
The solubilization of the basic subunit of sugarbeet seed 11-S globulin during priming and early germination
Authors: Job Claudette , Kersulec Alain , Ravasio Laurence , Chareyre Sandrine , Pepin Régis , Job Dominique 
Published: September 2008

AbstractThe basic B-subunit of the seed storage protein 11-S globulin (an 11-S-legumin type protein) is the major polypeptide in soluble protein extracts from primed sugarbeet (Beta vulgarisL.) seeds. In contrast, only a small amount of this protein is present in corresponding extracts from untreated dry mature seeds. Here, and as for all 11-S globulins described so far, the B-chain is linked to other polypeptide(s), corresponding most presumably to an acidic A-chain, through the formation of disulphide bridge(s). Polyacrylamide gel electrophoretic analyses of total and soluble protein extracts from untreated and primed seeds strongly indicate that this priming-induced solubilization of the B-chain resulted from an endoproteolytic attack on the A-chain. Microscopical immunolocalization showed a uniform distribution of the 11-S globulin B-chain over the protein bodies of the embryonic cells from the untreated seeds. For the primed seeds, however, the B-subunit of 11-S globulin diffused out of the protein bodies and invaded the cytosolic compartment. This phenomenon occurred independently of the manner of priming, being observed with hydroprimed and osmoprimed seeds, as well as with sugarbeet seeds that had been primed by a prehydration treatment. Quantitative analyses of the amounts of soluble 11-S globulin B-chain have enabled the priming of sugarbeet seeds to be optimized.
Active oxygen and their scavengers in rice seeds (Oryza sativacv. IET 4094) aged under tropical environmental conditions
Authors: Nandi S. , Sen-Mandi S. , Sinha T.P. 
Published: September 2008

AbstractElectron paramagnetic resonance studies of high vigour (99% viable) and low vigour (38% viable) dry embryos of rice seeds (Oryza sativaL.) stored in a natural (warm and humid) environment were carried out. Loss in viability due to hot and humid conditions was found to be correlated with a decrease in free radical levels. The free radicals could be carbon-based and derived from quinones. Presence of the active oxygen scavenging enzyme, superoxide dismutase (EC 1.15.1.1) in embryos isolated from dry seeds showed a positive corrrelation with the state of vigour or viability. Anodic peroxidase (EC 1.11.1.7) activity in imbibed seeds also declined with the decline in vigour and viability. It is concluded that the deterioration of cells in the embryonic axis depends on the balance between free radical accumulation and the activity of active oxygen-scavenging enzymes which constitutes the active oxygen scavenging system (AOSS) during early imbibition. During prolonged storage under hot and humid conditions, cumulative effects of macromolecular damage due to oxidative chain products, compounded with the loss of enzyme activity, result in the final catastrophe, the death of the embryo.
Seed mass and nutrient content in nutrient-starved tropical rainforest in Venezuela
Authors: Grubb Peter J. , Coomes David A. 
Published: September 2008

AbstractMean seed dry mass values were determined for 27 species of trees and shrubs in Amazonian caatinga (a forest-type especially short of nitrogen) and for 11 species in adjacent much taller forest on less poor soil. The tall trees (> 15 m) of caatinga have smaller seeds than the tall trees in adjacent forest on less infertile soil (both overall and in six taxonomically controlled comparisons), and than the tall trees in lowland rainforests elsewhere. The smaller seed size is interpreted in terms of a major advantage of keeping up seed number outweighing the marginal advantages of larger seed size. For trees of caatinga and adjacent forest considered together, there is a significantly greater concentration of P and Mg, and almost significantly greater concentration of N, in the embryo-cum-endosperm fraction of smaller-seeded species, but the content per seed of N, P and Mg is smaller in smaller seeds. The mean contribution of the seed coat (including endocarp for pyrenes) was 17% for dry mass, 3% for content of P, 10% for N and Mg, 15% for K, and 30% for Ca.
Soil seed banks in primary and secondary deciduous forest in Białowieża, Poland
Authors: Jankowska-Błaszczuk Małgorzata , Grubb Peter J. 
Published: September 2008

AbstractGermination over 3 years was followed in 25 soil samples of 31 × 31 × 5 cm each from primary and secondary stands in Białowieża forest, Poland. The number of seedlings emerging and the number of species declined over the 3 years. In year 1 the mean densities of emerging seedlings for the primary and secondary stands were similar (2142 m−2 and 2488 m−2 respectively); in year 3 the difference was greater (248 vs 498 m−2) but not statistically significant. The trend reflected the greater longevity of the seed bank species characteristic of the secondary forest. Two functional groups of herb and shrub species were distinguished in the seed bank based on (a) frequency as adults in the present vegetation, and (b) relative abundance in the seed banks of primary and secondary forest. Group A species need large-scale gaps in the tree canopy; most have very small seeds (<0.15 mg mean dry mass) and are very persistent in the soil. Group B species benefit from single-treefall gaps in the tree canopy, but appear to be suited primarily to gaps in the canopy of the herb layer and in the root layer made mainly by animals; their seeds are not as small (mostly >0.15 mg) and not as persistent in the soil. Group B species made up 86% of the seedlings emerging over 3 years in soil from the primary stand, and 56% of those from the secondary stand. In the laboratory all five Group B species tested showed some inhibition of germination in darkness, but only one showed unequivocal inhibition by far-red-enrichment of low irradiance light.
A comparative study of the seed germination biology of a narrow endemic and two geographically-widespread species ofSolidago(Asteraceae). 3. Photoecology of germination
Authors: Walck Jeffrey L. , Baskin Jerry M. , Baskin Carol C. 
Published: September 2008

AbstractRegardless of whether or not seeds of the geographically-widespreadSolidago altissimaandS. nemoraliswere exposed to light in autumn, those ‘dispersed’ in autumn (15/°C) or winter (5°C) required 12 weeks of light in winter to germinate to ≥80% in darkness in spring (2 weeks at 20/10°C). On the other hand, seeds of the narrow-endemicS. shortiidispersed in autumn and exposed to ≥2 weeks of light in early winter germinated to ≥77% in darkness in spring, and those dispersed in winter and exposed to ≥6 weeks of light germinated to ≥82%.S. altissimaandS. nemoralisseeds not exposed to light during any season germinated to only 0–1% in darkness in spring, whereasS. shortiiseeds germinated to 45–56%. Seeds ofS. altissimaandS. nemoraliskept in darkness in autumn and winter needed a 1-day (14-h photoperiod) light exposure in spring to germinate to ≥75% in darkness, whereas those ofS. shortiirequired only one 5-s exposure. Cold-stratified (nondormant) seeds ofS. altissima, S. nemoralisandS. shortiiexposed to light with a high far-red/red ratio germinated to significantly higher percentages than dark controls and freshly-matured and lab-stored seeds. Results of this study suggest that a soil seed bank ofS. shortiishould be smaller and be depleted at a faster rate than those ofS. altissimaandS. nemoralis, and portions of the seeds of the three species can germinate in the far-red-enriched light under plant canopies.
A comparative study of the seed germination biology of a narrow endemic and two geographically-widespread species ofSolidago(Asteraceae). 4. Role of soil moisture in regulating germination
Authors: Walck Jeffrey L. , Baskin Jerry M. , Baskin Carol C. 
Published: September 2008

AbstractSeeds of the narrow-endemicSolidago shortiiand of the geographically-widespreadS. altissimaandS. nemoralisburied in December 1993 were exhumed in June 1995 and given 10 cycles of 1 day wet/5 days dry, 9 of 2/5, 8 of 3/5, 7 of 4/5 and 6 of 5/5 in light at 30/15°C; the control was kept continuously wet during the experiment. Seeds of the three species incubated on wet substrate for 3, 4 or 5 days germinated to ≥47% during the first cycle. On the other hand, seeds kept moist 2 days germinated to only 4–26% in the first cycle, and none kept moist for 1 day germinated. Cumulative germination percentages of seeds of all three species at the end of the final cycle of the 1/5 treatment were 0–4%. In the 2/5 treatment, cumulative germination percentages ofS. altissimaandS. shortiiseeds at the end of the final cycle were 50 and 41%, respectively, but that ofS. nemoraliswas only 4%. For all three species, cumulative germination percentages were ≥55% at the end of the final cycle of the 3/5, 4/5 and 5/5 treatments. Control seeds of the three species germinated to 85–99% after 2 weeks, and no additional seeds germinated during the remainder of the experiment. High percentages of seeds were viable in the treatments and control at the end of the experiment; however, some seeds ofS. nemoralisandS. shortiigiven 1/5, 2/5 and 3/5 treatments became dormant. The ecological implication of this study is that seeds of the three species will not germinate on the soil surface after brief rainfall events in summer. The germination response of the narrow endemic is similar to that of its two geographically-widespread congeners.
Inhibition of cell division during cabbage (Brassica oleraceaL.) seed germination
Authors: Górnik Krzysztof , de Castro Renato D. , Liu Yongqing , Bino Raoul J. , Groot Steven P. C. 
Published: September 2008

AbstractLinks between germination, DNA replication and β-tubulin accumulation were studied with cabbage (Brassica oleraceaL.) seeds, by using flow cytometric analysis of nuclear DNA content and immunodetection of β-tubulin levels. The seeds were incubated in water or 0.1–500 mM hydroxyurea solutions. Radicle tips isolated from dry cabbage seeds revealed most 2C (Goor G1stage) and some 4C (G2stage) signals of nuclear DNA contents and a constitutive level of β-tubulin. The onset of DNA replication in the radicle tip was observed between 12 and 24 h of imbibition in water and was preceded by an increase of β-tubulin levels. Incubation of the seeds in 1 mM hydroxyurea retarded DNA replication, whereas an arrest of DNA replication occurred upon incubation in 10 mM hydroxyurea or higher concentrations. The arrest of DNA replication and cell division did not block radicle protrusion and allowed some extension of the radicle. This demonstrated that DNA replication is not a prerequisite for radicle protrusion and initial extension. However, further seedling development, including root growth and root hair development, was dependent on DNA replication. Accumulation of β-tubulin was not affected by hydroxyurea. Thus, it can be deduced that both DNA replication and β-tubulin accumulation are two parallel and independent cell cycle events during seed germination.
Transcript levels for a mung bean cysteine protease during early seedling growth
Authors: Lee Kangmoon , Liu Zhouwen , Tan-Wilson Anna , Wilson Karl 
Published: September 2008

AbstractcDNAs for the major cysteine endopeptidase (CEpase) of mung bean (Vigna radiata [L.] Wilczek) seedling cotyledons have been cloned using gene-specific primers with the polymerase chain reaction (PCR) in a 3'-RACE system. A cDNA clone for CEpase, pKL042, that is 1221 bp long excluding the poly A tail was isolated. It appears to contain the entire coding sequence for a 362-residue-long polypeptide. The N-terminal sequence for the mature CEpase begins at position 128 of the putative translation product, suggesting removal of an N-terminal hydrophobic signal peptide and additional sequences to produce the mature protease. Northern blot hybridization with CEpase cDNA pKL042 as probe indicates that CEpase transcript is not detectable in the cotyledons or the embryonic axis of dry seeds, but is first detectable in the day 1 cotyledons and in the day 3 axis. The level of CEpase mRNA in both cotyledons and axis increases as growth proceeds. A decline of protease activity, however, is observed after day 3 in the cotyledons, even though the level of protease transcripts continues to increase until day 8. Detachment of the axis from the cotyledons before day 3 results in the prevention of the normal increase in both protease activity and CEpase mRNA.
Qualitative changes in protein content during cold and warm stratification of Norway maple (Acer platanoidesL.) seeds
Authors: Pawlowski Tomasz , Szczotka Zofia 
Published: September 2008

AbstractProtein synthesis in embryonic axes of Norway maple (Acer platanoides) was studied in seeds stratified at 3 or 15°C. At 3°C stratification, germination of seeds started between 6 and 7 weeks; at 15°C stratification germination did not occur. During imbibition of embryonic axes undergoing cold and warm stratification many new proteins became visible. Two of these proteins may be connected with the release from dormancy at 3°C. In seeds stratified at 15°C, these proteins occur in low amounts or are completely absent.