Éditeur(s) : HAL CCSD
Résumé : Communication orale + résumé
absent
Plant Biomechanics International Conference
Clermont-Fd, France

hal-01190786
https://hal.archives-ouvertes.fr/hal-01190786
PRODINRA : 215235

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Background and Aims: In rain forests, sapling survival is highly dependent on the regulation of trunk slenderness (height/diameter ratio): shade-intolerant species have to grow in height as fast as possible to reach the canopy but also have to withstand mechanical loadings (wind and their own weight) to avoid buckling. Recent studies suggest that mechanosensing is essential to control tree dimensions and stability-related morphogenesis. Differences in species slenderness have been observed among rainforest trees; the present study thus investigates whether species with different slenderness and growth habits exhibit differences in mechanosensitivity. Methods: Recent studies have led to a model of mechanosensing (sum-of-strains model) that predicts a quantitative relationship between the applied sum of longitudinal strains and the plant's responses in the case of a single bending. Saplings of five different neotropical species (Eperua falcata, E. grandiflora, Tachigali melinonii, Symphonia globulifera and Bauhinia guianensis) were subjected to a regimen of controlled mechanical loading phases (bending) alternating with still phases over a period of 2 months. Mechanical loading was controlled in terms of strains and the five species were subjected to the same range of sum of strains. The application of the sum-of-strain model led to a dose-response curve for each species. Dose-response curves were then compared between tested species. Key Results: The model of mechanosensing (sum-of-strain model) applied in the case of multiple bending as long as the bending frequency was low. A comparison of dose-response curves for each species demonstrated differences in the stimulus threshold, suggesting two groups of responses among the species. Interestingly, the liana species B. guianensis exhibited a higher threshold than other Leguminosae species tested. Conclusions: This study provides a conceptual framework to study variability in plant mechanosensing and demonstrated interspecific variability in mechanosensing.
ISSN: 0305-7364

halsde-00454145
https://hal.archives-ouvertes.fr/halsde-00454145
DOI : 10.1093/aob/mcp286

Éditeur(s) : HAL CCSD Springer Verlag
Résumé :  
Mechanical signals have an impact on plant development. Tropical rainforest trees display large variability for life-history traits related to biomechanics and therefore are a unique study system to better understand biomechanical trait variability from an evolutionary perspective. From sequences and gene expression data available in model species, we developed specific primers for six candidate genes for mechano-sensing in five tropical species. Most of the gene sequences were polymorphic in most species.
ISSN: 1614-2942

hal-01019738
https://hal.archives-ouvertes.fr/hal-01019738
DOI : 10.1007/s11295-010-0363-1