Cell cycle inHelianthus tuberosus tuber tissue in relation to dormancy

Bennici, A.; Gennai, D.; Cionini, G.

doi:10.1007/bf01280224

Cited by 9 publications

(2 citation statements)

References 11 publications

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“…This 4% (v/v) /?-mercaptoethanol and centrifuged for 5 min at cycling culture system is highly reproducible when in-10 000 g prior to gel loading. Protein bands were visualduced in the same physiological stage (deep dormancy) ized by staining with Coomassie blue R-250 or the gels (Bennici et al 1982, Tomgiani et al 1987, Se-were electroblotted according to Towbin et al (1979). rafini-Fracassini 1991).…”

Section: Introductionmentioning

confidence: 99%

Ubiquitin conjugation to endogenous proteins in the dormant tuber of Helianthus tuberosus and during the first cell cycle

Scoccianti¹,

Corsi²,

Magnani³

1997

Physiol Plant

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M. 1997. Ubiquitin conjugation to endogenous proteins in the dormant tuber of Helianthus tuberosus and during the first cell cycle. -Physiol. Plant. 101:77-85.Ubiquitin is a small protein involved in an ATP-dependent proteoiytic pathway in all eukaryotes. This pathway has been demonstrated to be required for both the bulk degradation of cellular proteins and the targeted proteolysis of specific regulatory proteins. We have investigated the presence of ubiquitin (Ub) and the ubiquitin-conjugating system in dormant and activated tubers of Helianthus tuberosus L. cv. OB 1 that represent a widely used model system for studies on the cell cycle in plants. Immunoblot experiments revealed the presence of free ubiquitin and ubiquitin conjugates. Furthermore, the presence of an active ubiquitin-conjugating system, both time-and ATP-dependent, was demonstrated by incubation with ''^I-labeled ubiquitin. A few proteins able to form thiol esters with '~^I-Ub and probably corresponding to ubiquitin-conjugating enzymes. El and E2s, were also found. During the first cell cycle, several proteins become ubiquitinated. In particular a large amount of protein conjugates was present at 6 h when the lowest content of free ubiquitin was found. Subsequently, a dramatic decrease in ubiquitin conjugates occurred. It is well known that cell cycle progression in eukaryotes depends on cyclin levels and cyclin B degradation is ubiquitin-and ATP-dependent. By immunoblot experiments we showed that cyclin B in H. tuberosus is present as at least two protein bands of 50 and 54 kDa and that their amounts undergo profound changes during the cell cycle. The 54-kDa band was also recognized by an anti-ubiquitin antibody. These data seem to indicate that in H. tuberosus activated tuber slices, the ATP-dependent ubiquitin proteolytic pathway is involved in the dedifferentiation process occurring after the artificial break of dormancy when the cells acquire the characteristics linked to the meristematic state.

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Section: Introductionmentioning

confidence: 99%

Ubiquitin conjugation to endogenous proteins in the dormant tuber of Helianthus tuberosus and during the first cell cycle

Scoccianti¹,

Corsi²,

Magnani³

1997

Physiol Plant

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“…In H. tuberosus, an ethanol treatment caused apical bud dormancy to be masked (during treatment tuber cell growth occurred), but after the ethanol treatment stopped, cell growth stopped and dormancy was restored (Petel et al, 1993). 2,4-dichlorophenylacetic acid has been shown to break dormancy in cultured H. tuberosus tuber cells (Bennici et al, 1982). In potato tubers, ethylene and gibberellic acid have been implicated in both breaking dormancy and initiating growth after dormancy, but the role of these hormones has not been clearly defined (Coleman, 1998).…”

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confidence: 99%

Breaking Tuber Dormancy in Helianthus tuberosus L. and Interspecific Hybrids of Helianthus annuus L. × Helianthus tuberosus

Kantar

Betts

Hulke³

et al. 2012

horts

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Tubers of Helianthus tuberosus L. are dormant after production in the late fall until the next spring. In the wild, tuber dormancy is broken after exposure to winter cold, resulting in sprouting and shoot development in the spring when conditions are favorable. The dormancy period typically limits H. tuberosus populations to one growth cycle per year. An efficient method for breaking tuber dormancy is needed to have an additional growth cycle per year in a breeding program, which could take place in winter in the nursery or the greenhouse allowing for increased breeding efficiency. The objective of this research was to compare chemical and cold temperature treatments for artificially breaking tuber dormancy in 12 genotypes of H. tuberosus and interspecific hybrids of Helianthus annuus L. × H. tuberosus. Five cold exposures (2, 4, 6, 8, 10 weeks at 2 °C), three plant hormones (ethylene, cytokinin, and gibberellic acid), and one untreated control were examined. Gibberellic acid was the best chemical treatment, initiating plant growth within 6.5 to 11.5 days in the majority of genotypes tested. The best cold treatment was exposure to 2 °C for 8 weeks, where plant growth began 63.6 to 67.5 days after treatment initiation. Although longer cold treatments shortened the time to emergence while in the greenhouse, the penalty of the long cold treatment per se was too long to be useful. The gibberellic acid treatment strategy described here may not need further optimization, because it is short enough to allow for two growth cycles of H. tuberosus per year.

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Extra DNA synthesis in the dedifferentiating cells ofVicia faba roots

Zolfino

Cavallini

1985

Protoplasma

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Cell cycle inHelianthus tuberosus tuber tissue in relation to dormancy

Cited by 9 publications

References 11 publications

Ubiquitin conjugation to endogenous proteins in the dormant tuber of Helianthus tuberosus and during the first cell cycle

Ubiquitin conjugation to endogenous proteins in the dormant tuber of Helianthus tuberosus and during the first cell cycle

Breaking Tuber Dormancy in Helianthus tuberosus L. and Interspecific Hybrids of Helianthus annuus L. × Helianthus tuberosus

Extra DNA synthesis in the dedifferentiating cells ofVicia faba roots

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