Wheat seedlings as a model to understand desiccation tolerance and sensitivity

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dc.contributor.authorFarrant, Jill M
dc.contributor.authorBailly, Christophe
dc.contributor.authorLeymarie, Juliette
dc.contributor.authorHamman, Brigitte
dc.contributor.authorCôme, Daniel
dc.contributor.authorCorbineau, Franc¸oise
dc.date.accessioned2016-08-04T14:17:15Z
dc.date.available2016-08-04T14:17:15Z
dc.date.issued2004
dc.date.updated2016-08-02T13:39:56Z
dc.description.abstractThe coleoptiles of wheat (Triticum aestivum L.) seedlings of cultivar Tre´mie are desiccation tolerant when 3 days old, although the roots are not. Cutting some of the coleoptiles open prior to dehydration rapidly increased the drying rate. This rendered the coleoptiles sensitive to desiccation, providing a useful model with which to study desiccation tolerance. Both sensitive and tolerant seedlings were dehydrated to 0.3 g H2O g 1 dry mass (g.g) and thereafter rehydrated. Sensitive tissues accrued the lipid peroxidation products H2O2 and MDA, and substantial subcellular damage was evident in dry tissues. H2O2 and MDA accumulated slightly only in dry tolerant coleoptiles and no subcellular damage was evident. The activity of antioxidant enzymes glutathione reductase (EC1.6.2.4), superoxide dismutase (EC 1.14.1.1) and catalase (EC 1.11.1.6) increased on drying in both tolerant and sensitive tissues, but were sustained on rehydration in only the tolerant tissues. It is proposed that free radical damage sustained during rapid drying exceeded the ameliorating capacity of antioxidant systems, allowed accrual of lethal subcellular damage. Slow drying enabled sufficient detoxification by antioxidants to minimize damage and allow tolerance to drying. Three LEA- (p11 and Asp 52) and dehydrin- (XV8) like proteins were detected by western blots in tolerant coleoptiles dried to 3.0 g.g and below. Only one (Asp 52) was induced at low water content in rapidly dried sensitive coleoptiles. None were present in root tissues. XV8 RNA (northern analyses) was induced on drying only in tolerant coleoptiles and correlated with protein expression. These putative stress-protein protectants (and XV8 transcripts) appear to be down-regulated during germination but wheat seedlings temporarily retain the ability to reproduce them if drying is slow. Sucrose accumulation during dehydration was similar for both sensitive and tolerant tissues, suggesting that this sugar has little role, or is not effective in isolation, in protecting against desiccation damage in wheat seedlings. In summary, the slower rate at which tolerant coleoptiles were dried allowed for the mobilization of protection mechanisms with which to survive desiccation. Rapid drying of tissues precluded induction of some putative stress protein protectants and caused damage in excess of the ameliorating capacity of the antioxidant protection system.en_ZA
dc.identifierhttp://dx.doi.org/10.1111/j.0031-9317.2004.0281.x
dc.identifier.apacitationFarrant, J. M., Bailly, C., Leymarie, J., Hamman, B., Côme, D., & (2004). Wheat seedlings as a model to understand desiccation tolerance and sensitivity. <i>Physiologia Plantarum</i>, http://hdl.handle.net/11427/21126en_ZA
dc.identifier.chicagocitationFarrant, Jill M, Christophe Bailly, Juliette Leymarie, Brigitte Hamman, Daniel Côme, and "Wheat seedlings as a model to understand desiccation tolerance and sensitivity." <i>Physiologia Plantarum</i> (2004) http://hdl.handle.net/11427/21126en_ZA
dc.identifier.citationFarrant, J. M., Bailly, C., Leymarie, J., Hamman, B., Côme, D., & Corbineau, F. (2004). Wheat seedlings as a model to understand desiccation tolerance and sensitivity. Physiologia Plantarum, 120(4), 563-574.en_ZA
dc.identifier.issn0031-9317en_ZA
dc.identifier.ris TY - Journal Article AU - Farrant, Jill M AU - Bailly, Christophe AU - Leymarie, Juliette AU - Hamman, Brigitte AU - Côme, Daniel AU - Corbineau, Franc¸oise AB - The coleoptiles of wheat (Triticum aestivum L.) seedlings of cultivar Tre´mie are desiccation tolerant when 3 days old, although the roots are not. Cutting some of the coleoptiles open prior to dehydration rapidly increased the drying rate. This rendered the coleoptiles sensitive to desiccation, providing a useful model with which to study desiccation tolerance. Both sensitive and tolerant seedlings were dehydrated to 0.3 g H2O g 1 dry mass (g.g) and thereafter rehydrated. Sensitive tissues accrued the lipid peroxidation products H2O2 and MDA, and substantial subcellular damage was evident in dry tissues. H2O2 and MDA accumulated slightly only in dry tolerant coleoptiles and no subcellular damage was evident. The activity of antioxidant enzymes glutathione reductase (EC1.6.2.4), superoxide dismutase (EC 1.14.1.1) and catalase (EC 1.11.1.6) increased on drying in both tolerant and sensitive tissues, but were sustained on rehydration in only the tolerant tissues. It is proposed that free radical damage sustained during rapid drying exceeded the ameliorating capacity of antioxidant systems, allowed accrual of lethal subcellular damage. Slow drying enabled sufficient detoxification by antioxidants to minimize damage and allow tolerance to drying. Three LEA- (p11 and Asp 52) and dehydrin- (XV8) like proteins were detected by western blots in tolerant coleoptiles dried to 3.0 g.g and below. Only one (Asp 52) was induced at low water content in rapidly dried sensitive coleoptiles. None were present in root tissues. XV8 RNA (northern analyses) was induced on drying only in tolerant coleoptiles and correlated with protein expression. These putative stress-protein protectants (and XV8 transcripts) appear to be down-regulated during germination but wheat seedlings temporarily retain the ability to reproduce them if drying is slow. Sucrose accumulation during dehydration was similar for both sensitive and tolerant tissues, suggesting that this sugar has little role, or is not effective in isolation, in protecting against desiccation damage in wheat seedlings. In summary, the slower rate at which tolerant coleoptiles were dried allowed for the mobilization of protection mechanisms with which to survive desiccation. Rapid drying of tissues precluded induction of some putative stress protein protectants and caused damage in excess of the ameliorating capacity of the antioxidant protection system. DA - 2004 DB - OpenUCT DP - University of Cape Town J1 - Physiologia Plantarum LK - https://open.uct.ac.za PB - University of Cape Town PY - 2004 SM - 0031-9317 T1 - Wheat seedlings as a model to understand desiccation tolerance and sensitivity TI - Wheat seedlings as a model to understand desiccation tolerance and sensitivity UR - http://hdl.handle.net/11427/21126 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21126
dc.identifier.vancouvercitationFarrant JM, Bailly C, Leymarie J, Hamman B, Côme D, . Wheat seedlings as a model to understand desiccation tolerance and sensitivity. Physiologia Plantarum. 2004; http://hdl.handle.net/11427/21126.en_ZA
dc.languageengen_ZA
dc.publisherWileyen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.sourcePhysiologia Plantarumen_ZA
dc.source.urihttp://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1399-3054
dc.titleWheat seedlings as a model to understand desiccation tolerance and sensitivityen_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
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