ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1995-1999  (3)
  • 1
    ISSN: 1573-5028
    Keywords: auxin ; cell expansion ; cellulase ; endo-1,4-β-glucanase ; ethylene ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plant developmental processes involving modifications to cell wall structure, such as cell expansion, organ abscission and fruit ripening, are accompanied by increased enzyme activity and mRNA abundance of endo-1,4-β-glucanases (EGases). An EGase cDNA clone, Ce14, isolated from tomato (Lycopersicon esculentum) has been shown to be identical to a tomato pistil-predominant EGase cDNA, TPP18. In addition to its previously reported expression during certain stages of early pistil development, Ce14 mRNA was also detected at high levels in the growing zones of etiolated hypocotyls (about 2.5-fold less than in pistils) and in young expanding leaves (about 3.5-fold less than in pistils). The abundance of Ce14 mRNA declined precipitously in older tissues as cells became fully expanded, and was barely detectable in mature vegetative tissues. Ce14 mRNA abundance was also low in abscission zones, and did not increase as abscission progressed. In fruit, Ce14 mRNA was present at low levels during fruit expansion, but was essentially absent during subsequent fruit development and ripening. Treatment of etiolated hypocotyls with ethylene or high concentrations of auxin sufficient to induce rapid lateral cell expansion and hypocotyl swelling also brought about an approximate doubling of Ce14 mRNA abundance, suggesting that Ce14 mRNA accumulation may be promoted directly or indirectly by ethylene. Thus, accumulation of Ce14 mRNA was found to be correlated with rapid cell expansion in pistils, hypocotyls and leaves.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 39 (1999), S. 161-169 
    ISSN: 1573-5028
    Keywords: expansin ; fruit growth ; fruit softening ; gene expression ; Lycopersicon esculentum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract cDNA clones encoding homologues of expansins, a class of cell wall proteins involved in cell wall modification, were isolated from various stages of growing and ripening fruit of tomato (Lycopersicon esculentum). cDNAs derived from five unique expansin genes were obtained, termed tomato Exp3 to Exp7, in addition to the previously described ripening-specific tomato Exp1 (Rose et al. (1997) Proc Natl Acad Sci USA 94: 5955–5960). Deduced amino acid sequences of tomato Exp1, Exp4 and Exp6 were highly related, whereas Exp3, Exp5 and Exp7 were more divergent. Each of the five expansin genes showed a different and characteristic pattern of mRNA expression. mRNA of Exp3 was present throughout fruit growth and ripening, with highest accumulation in green expanding and maturing fruit, and lower, declining levels during ripening. Exp4 mRNA was present only in green expanding fruit, whereas Exp5 mRNA was present in expanding fruit but had highest levels in full-size maturing green fruit and declined during the early stages of ripening. mRNAs from each of these genes were also detected in leaves, stems and flowers but not in roots. Exp6 and Exp7 mRNAs were present at much lower levels than mRNAs of the other expansin genes, and were detected only in expanding or mature green fruit. The results indicate the presence of a large and complex expansin gene family in tomato, and suggest that while the expression of several expansin genes may contribute to green fruit development, only Exp1 mRNA is present at high levels during fruit ripening.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-5028
    Keywords: abscission ; cell wall ; cellulase ; endo-1,4-β-glucanase ; fruit softening ; Lycopersicon esculentum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plants of tomato (Lycopersicon esculentum Mill. cv. T5) were transformed with an antisense endo-1,4-β-glucanase (cellulase, EC 3.2.1.4) Cel2 transgene under the control of the constitutive cauliflower mosaic virus 35S promoter in order to suppress mRNA accumulation of Cel2. In two independent transgenic lines, Cel2 mRNA abundance was reduced by 〉95% in ripe fruit pericarp and ca. 80% in fruit abscission zones relative to non-transgenic controls. In both transgenic lines the softening of antisense Cel2 fruit pericarp measured using stress-relaxation analysis was indistinguishable from control fruit. No differences in ethylene evolution were observed between fruit of control and antisense Cel2 genotypes. However, in fruit abscission zones the suppression of Cel2 mRNA accumulation caused a significant (P〈0.001) increase in the force required to cause breakage of the abscission zone at 4 days post breaker, an increase of 27% in one transgenic line and of 46% in the other transgenic line. Thus the Cel2 gene product contributes to cell wall disassembly occurring in cell separation during fruit abscission, but its role, if any, in softening or textural changes occurring in fruit pericarp during ripening was not revealed by suppression of Cel2 gene expression.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...