Orchestration of transpiration, growth and carbohydrate dynamics in rice during a dry-down cycle

Luquet Delphine, Clément-Vidal Anne, Fabre Denis, This Dominique, Sonderegger Nicole, Dingkuhn Michaël. 2008. Orchestration of transpiration, growth and carbohydrate dynamics in rice during a dry-down cycle. Functional Plant Biology, 35 (8) : 689-704.

Résumé : The regulation of carbohydrate metabolism and source-sink relationships among organs play a key role in plant adaptation to drought. This study aimed at characterising the dynamics of transpiration, development, growth and carbon metabolism, as well as the expression of invertase genes, in response to drought during a dry-down cycle. Three 1-month experiments were conducted in controlled environment using the rice genotype IR64 (Oryza sativa L., indica). Plant leaf relative transpiration and expansion rates decreased linearly when fraction of transpirable soil water (FTSW) dropped below 0.66 and 0.58, respectively. Hexose and starch concentration responses to FTSW in a given organ were generally linear and opposite: in source leaves, hexose concentration increased and starch decreased, and vice versa in sink leaves and roots. Sucrose remained constant in source leaves and increased slightly in sink leaves. Starch reserves built up during stress in sink organs were rapidly mobilised upon rewatering, indicating its involvement in a mechanism to ensure recovery. Expression of cell-wall and vacuolar invertase genes under stress increased in sink leaves, interpreted as a mechanism to maintain sink activity (cell wall) and osmotic adjustment (vacuolar). It is concluded that carbohydrate metabolism in sink organs under drought is highly regulated, and important for stress adaptation.

Mots-clés Agrovoc : Oryza sativa, métabolisme des glucides, résistance à la sécheresse, croissance, transpiration, organe de réserve, relation source puits, fructofuranosidase, expression des gènes

Classification Agris : F62 - Physiologie végétale - Croissance et développement
F30 - Génétique et amélioration des plantes

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Luquet Delphine, CIRAD-BIOS-UPR Modélisation intégrative (FRA) ORCID: 0000-0002-2543-7140
• Clément-Vidal Anne, CIRAD-BIOS-UPR Modélisation intégrative (FRA)
• Fabre Denis, CIRAD-BIOS-UPR Modélisation intégrative (FRA) ORCID: 0000-0002-6222-2587
• This Dominique, ENSAM [Ecole nationale supérieure agronomique de Montpellier] (FRA)
• Sonderegger Nicole, CIRAD-BIOS-UPR Modélisation intégrative (FRA)
• Dingkuhn Michaël, CIRAD-BIOS-UPR Modélisation intégrative (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/546010/)

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