Publications des scientifiques de l'IRD

Trueba Sanchez Santiago, Muñoz N.G., Burlett R., Lamarque L.J., Gibon Y., Gimeno T.E., Kaisermann A., Benard C., Lemaire C., Torres-Ruiz J.M., Wingate L., Delzon S. (2024). The rates of starch depletion and hydraulic failure both play a role in drought-induced seedling mortality. Annals of Forest Science, 81 (1), 27 [33 p.]. ISSN 1297-966X.

Titre du document
The rates of starch depletion and hydraulic failure both play a role in drought-induced seedling mortality
Année de publication
2024
Type de document
Article référencé dans le Web of Science WOS:001282753200001
Auteurs
Trueba Sanchez Santiago, Muñoz N.G., Burlett R., Lamarque L.J., Gibon Y., Gimeno T.E., Kaisermann A., Benard C., Lemaire C., Torres-Ruiz J.M., Wingate L., Delzon S.
Source
Annals of Forest Science, 2024, 81 (1), 27 [33 p.] ISSN 1297-966X
Key message : The elapsed times to deplete starch concentrations and to reach a null hydraulic safety margin were related to tree seedling mortality under experimental drought. Starch concentration showed an accelerated decline across all species during the early stages of dehydration, while the concentrations of soluble sugars and total nonstructural carbohydrates remained stable. Concomitant carbohydrate depletion and hydraulic failure drive seedling mortality under drought. Context : Current upsurges of drought events are provoking impacts on tree physiology, resulting in forest mortality. Hydraulic dysfunction and nonstructural carbohydrate (NSC) depletion have been posited as the main mechanisms leading to plant mortality under drought. Aims : This study explores the dynamics of the two mortality-inducing processes during drought stress using an experimental approach with 12 evergreen tree species. Methods : Seedlings were subjected to drought until 100% mortality was observed. Midday (Psi MD) and predawn (Psi PD) water potentials, xylem pressure leading to a 50% loss of hydraulic conductivity (Psi 50), along with NSC concentrations in different organs (leaves, stems, and roots) were measured regularly during drought. Results : Total NSC concentrations and soluble sugar pools did not decline during drought. However, starch pools showed strong reductions early during drought stress as Psi PD decreased, and the time leading to starch depletion emerged as a strong mortality predictor. Psi 50 alone did not provide an accurate estimate of mortality, while the elapsed time to reach a null hydraulic safety margin (Psi MD - Psi 50=0) was related to seedling mortality.
Plan de classement
Hydrologie [062] ; Sciences du monde végétal [076]
Localisation
Fonds IRD [F B010091604]
Identifiant IRD
fdi:010091604
Contact