Respiratory pathways in germinating maize radicles correlated with desiccation tolerance and soluble sugars

1992 ◽  
Vol 85 (4) ◽  
pp. 581-588 ◽  
Author(s):  
Olivier Leprince ◽  
Adrie van der Werf ◽  
Roger Deltour ◽  
Hans Lambers
2000 ◽  
Vol 10 (3) ◽  
pp. 393-396 ◽  
Author(s):  
Nathalie Chabrillange ◽  
Stéphane Dussert ◽  
Florent Engelmann ◽  
Sylvie Doulbeau ◽  
Serge Hamon

AbstractLarge differences in seed desiccation sensitivity have been observed previously among ten coffee species (Coffea arabica, C. brevipes, C. canephora, C. eugenioides, C. humilis, C. liberica, C. pocsii, C. pseudo-zanguebariae, C. sessiliflora and C.stenophylla). Of these species,C. libericaandC. humiliswere the most sensitive to desiccation andC. pseudozanguebariaethe most tolerant. A study was carried out using the same seed lots to investigate if these differences in desiccation tolerance could be correlated with differences in soluble sugar content. Soluble sugars were extracted from dry seeds and analysed using high performance liquid chromatography. The seed monosaccharide (glucose and fructose) content was very low (1.5 to 2 mg g-1dry weight [dw]) in all species studied. The sucrose content ranged from 33 mg g-1dw inC. libericaseeds to 89 mg g-1dw in seeds ofC. pocsii. Raffinose was detected in the seeds of only five species (C.arabica, C.brevipes, C.humilis, C.sessiliflora, C.stenophylla), among which only three species (C.arabica, C.sessilifloraandC.brevipes) also contained stachyose. Both raffinose and stachyose were present in very low quantities (0.3–1.4 mg g-1dw and 0.1–0.7 mg g-1dw, respectively). Verbascose was never detected. No significant relationship was found between seed desiccation sensitivity and: (i) the sugar content; (ii) the presence/absence of oligosaccharides; and (iii) the oligosaccharide:sucrose ratio.


1994 ◽  
Vol 4 (2) ◽  
pp. 127-133 ◽  
Author(s):  
W. E. Finch-Savage ◽  
P. S. Blake

AbstractFruit and seed development in Quercus robur L. were studied on a single tree over five consecutive seasons. Patterns of growth in the cotyledons and embryonic axes differed between years and resulted in seeds of very different sizes. Moisture content at shedding also differed between years, and late-shed seeds had lower moisture contents than early-shed seeds. Moisture content at shedding was negatively correlated with desiccation tolerance. Seed development in Q. robur therefore appeared indeterminate and did not end in a period of rapid desiccation.Sensitivity to desiccation in Q. robur was not due to an inability to accumulate dehydrin proteins, ABA or soluble sugars, substances that have been linked with the acquisition of desiccation tolerance in orthodox seeds. There were great similarities between several aspects of Q. robur seed development and that of orthodox seeds before the latter entered the terminal phase of rapid desiccation. This pattern of seed development contrasted with that reported for the highly desiccation-sensitive seeds of Avicennia marina.


Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 20
Author(s):  
Angel J. Matilla

To survive in the dry state, orthodox seeds acquire desiccation tolerance. As maturation progresses, the seeds gradually acquire longevity, which is the total timespan during which the dry seeds remain viable. The desiccation-tolerance mechanism(s) allow seeds to remain dry without losing their ability to germinate. This adaptive trait has played a key role in the evolution of land plants. Understanding the mechanisms for seed survival after desiccation is one of the central goals still unsolved. That is, the cellular protection during dry state and cell repair during rewatering involves a not entirely known molecular network(s). Although desiccation tolerance is retained in seeds of higher plants, resurrection plants belonging to different plant lineages keep the ability to survive desiccation in vegetative tissue. Abscisic acid (ABA) is involved in desiccation tolerance through tight control of the synthesis of unstructured late embryogenesis abundant (LEA) proteins, heat shock thermostable proteins (sHSPs), and non-reducing oligosaccharides. During seed maturation, the progressive loss of water induces the formation of a so-called cellular “glass state”. This glassy matrix consists of soluble sugars, which immobilize macromolecules offering protection to membranes and proteins. In this way, the secondary structure of proteins in dry viable seeds is very stable and remains preserved. ABA insensitive-3 (ABI3), highly conserved from bryophytes to Angiosperms, is essential for seed maturation and is the only transcription factor (TF) required for the acquisition of desiccation tolerance and its re-induction in germinated seeds. It is noteworthy that chlorophyll breakdown during the last step of seed maturation is controlled by ABI3. This update contains some current results directly related to the physiological, genetic, and molecular mechanisms involved in survival to desiccation in orthodox seeds. In other words, the mechanisms that facilitate that an orthodox dry seed is a living entity.


1994 ◽  
Vol 4 (2) ◽  
pp. 143-147 ◽  
Author(s):  
F. A. Hoekstra ◽  
A. M. Haigh ◽  
F. A. A. Tetteroo ◽  
T. van Roekel

AbstractChanges in soluble sugars in cauliflower seeds were followed during 50 h of imbibition in relation to desiccation tolerance. Sucrose and stachyose contents decreased, and glucose and fructose accumulated. This occurred in radicles first and subsequently in hypocotyls and cotyledons. Loss of desiccation tolerance in the various seed parts coincided with an increase in glucose and fructose and the complete loss of stachyose, but sucrose content, the major sugar, was still high. Drying imbibed seeds over silica gel did not evoke resynthesis of stachyose, but did increase sucrose and decrease glucose and fructose contents. Seeds primed in solutions of 30% polyethylene glycol for 10 days showed a loss of stachyose, while sucrose remained high and glucose and fructose contents were still very low. Redrying of primed seeds did not change the sugar contents. The primed seeds were still tolerant of desiccation. We conclude that stachyose is not a prerequisite for desiccation tolerance, but that sucrose may be. We suggest that glucose and fructose may be involved in desiccation damage.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 580c-580
Author(s):  
Paul H. Jennings ◽  
Cecil Stushnoff

Various carbohydrates have been shown to be associated with stress tolerance in some plant species. Specifically, the content of soluble sugars have been correlated with desiccation tolerance and winter hardiness. We have previously demonstrated that radicles of cucumber seed become progressively more sensitive to chilling injury during the early stages of germination and that cultivar differences exist. Sucrose, raffinose, and stachyose contents of `Poinsett 76' and `Ashley' seed were determined in dry seed during imbibition and at three stages of radicle emergence. The more chilling-tolerant cultivar (Ashley) contained lower raffinose and higher stachyose contents than the less chilling-tolerant `Poinsett 76'. In both cultivars, the contents of raffinose and stachyose declined dramatically between the 1-mm and 5- to 7-mm stage of radicle emergence. At the 1-mm stage, when cultivar chilling-tolerance differences are most pronounced, `Ashley' appears to have a higher content of stachyose and lower raffinose content.


1992 ◽  
Vol 85 (4) ◽  
pp. 581-588 ◽  
Author(s):  
Olivier Leprince ◽  
Adrie Werf ◽  
Roger Deltour ◽  
Hans Lambers

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