Molecular and physiological responses to water deficit in drought-tolerant and drought-sensitive lines of sunflower. Accumulation of dehydrin transcripts correlates with tolerance

Cellier Françoise, Conejero Geneviève, Breitler Jean-Christophe, Casse Francine. 1998. Molecular and physiological responses to water deficit in drought-tolerant and drought-sensitive lines of sunflower. Accumulation of dehydrin transcripts correlates with tolerance. Plant Physiology, 116 : 319-328.

Résumé : To investigate correlations between phenotypic adaptation to water limitation and drought-induced gene expression, we have studied a model system consisting of a drought-tolerant line (R1) and a drought-sensitive line (S1) of sunflowers ( Helianthus annuus L.) subjected to progressive drought. R1 tolerance is characterized by the maintenance of shoot cellular turgor. Drought-induced genes ( HaElip1 , HaDhn1 , and HaDhn2 ) were previously identified in the tolerant line. The accumulation of the corresponding transcripts was compared as a function of soil and leaf water status in R1 and S1 plants during progressive drought. In leaves of R1 plants the accumulation of HaDhn1 and HaDhn2 transcripts, but not HaElip1 transcripts, was correlated with the drought-adaptive response. Drought-induced abscisic acid (ABA) concentration was not asso- ciated with the varietal difference in drought tolerance. Stomata of both lines displayed similar sensitivity to ABA. ABA-induced accu- mulation of HaDhn2 transcripts was higher in the tolerant than in the sensitive genotype. HaDhn1 transcripts were similarly accumu- lated in the tolerant and in the sensitive plants in response to ABA, suggesting that additional factors involved in drought regulation of HaDhn1 expression might exist in tolerant plants.

Mots-clés Agrovoc : Helianthus annuus, adaptation physiologique, tolérance à la sécheresse, résistance à la sécheresse, phénotype, déficit d'humidité du sol, physiologie végétale, teneur en eau du sol, potentiel hydrique foliaire, ABA, expression des gènes, transcription

Mots-clés géographiques Agrovoc : Rhône-Alpes, France

Classification Agris : F60 - Physiologie et biochimie végétale
F30 - Génétique et amélioration des plantes

Auteurs et affiliations

• Cellier Françoise, ENSAM [Ecole nationale supérieure agronomique de Montpellier] (FRA)
• Conejero Geneviève, INRA (FRA)
• Breitler Jean-Christophe, CIRAD-AMIS-BIOTROP (FRA)
• Casse Francine, ENSAM [Ecole nationale supérieure agronomique de Montpellier] (FRA)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/581916/)

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