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Desiccation-time limits of photosynthetic recovery in Equisetum hyemale (Equisetaceae) spores / Jefferson Lebkuecher in American Journal of Botany, vol. 84, n°6 (Année 1997)

Public [article]  inAmerican Journal of Botany > vol. 84, n°6 (Année 1997) . - pp. 723-872 Titre : Desiccation-time limits of photosynthetic recovery in Equisetum hyemale (Equisetaceae) spores Auteurs : Jefferson Lebkuecher, Auteur Année de publication : 1997 Article en page(s) : pp. 723-872 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Equisetaceae [Espèces (in biblio)] Equisetum Mots-clés : dessiccation  fluorescence de la chlorophylle a  photosynthèse Résumé : "The chlorophyllous spores of Equisetum survive desiccation, yet cannot tolerate this quiescent state for more than ¯2 wk. The hypothesis that spore viability of Equisetum hyemale L. is limited by inhibition of photosynthetic recovery was tested using chlorophyll a fluorescence and oxygen-exchange analyses. Experimental spores were desiccated at 2% relative humidity and 258C for time periods of 24 h, 1 wk, and 2 wk, and then rehydrated at 200 mmol photons·m22·s21 (PAR) and 258C for up to 24 h. Spores desiccated for 24 h recovered photosynthetic competence very rapidly during rehydration, reaching the O2 compensation point in 6.3 6 0.3 (X¯ 6 SE) min. Recovery of photosynthetic performance of spores desiccated for 1 wk was slower, as judged by significantly slower increases of (1) photochemical efficiency of photosystem (PS) II, (2) PS II quinoneB -reducing center concentration, (3) quinone B22 concentration, (4) water-oxidation activity, (5) rate of light-induced O2 evolution, and (6) apparent quantum yield of net O2 exchange. Photosystem-II and whole-spore photosynthetic competence of 2-wk desiccated spores was increasingly impaired, and did not recover during rehydration. Origin fluorescence yield and dark respiration were not affected by desiccation time following rehydration. The results suggest that the extremely short viability of disseminated spores of Equisetum hyemale is due to the inability to recover losses of water oxidation and photosystem II-core function following 2 wk of desiccation." (source : auteur) Type de publication : périodique Référence biblio : Lebkuecher J., 1997 - Desiccation-time limits of photosynthetic recovery in Equisetum hyemale (Equisetaceae) spores. American journal of botany, 84 (6) : 723-872. ID PMB : 72214 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=72214 [article]

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Letters to the twenty-first century botanist, second series. “What is a seed ? – 2. Regulation of desiccation tolerance and longevity in developing seeds : two faces of the same coin" / Julia Buitink in Botany letters, vol. 165, n°2 (Année 2018)

Public [article]  inBotany letters > vol. 165, n°2 (Année 2018) . - pp. 181-185 Titre : Letters to the twenty-first century botanist, second series. “What is a seed ? – 2. Regulation of desiccation tolerance and longevity in developing seeds : two faces of the same coin" Type de document : texte imprimé Auteurs : Julia Buitink, Auteur ; Olivier Leprince, Auteur Année de publication : 2018 Article en page(s) : pp. 181-185 Langues : Anglais (eng) Mots-clés : dessiccation  longévité des graines  maturation  développement  semence  graine Résumé : "Desiccation tolerance and longevity are two essential properties that enable seeds to ensure the plant life cycle. Desiccation tolerance is defined as the ability to tolerate a rapid drying that brings the seed moisture content in equilibrium with ambient air, whereas longevity is the capacity to remain alive in the dry state over long periods. Both properties are progressively acquired during seed development and are of considerable agronomic and ecological relevance. Here, we argue that desiccation tolerance and longevity should be considered and studied separately. Recent progress in elucidating the protective and regulatory mechanisms contributing to these two aspects of seed survival in the dry state is presented." (source : auteurs) Type de publication : périodique Référence biblio : Buitink J., Leprince O., 2018 - Letters to the twenty-first century botanist, second series. “What is a seed ? – 2. Regulation of desiccation tolerance and longevity in developing seeds : two faces of the same coin". Botany letters, 165 (2) : 181-185. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67964 [article]

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P0177-6	Brest	Exclu du prêt