Replication Data for : Influence of mechanical stress on biomass allocation in three species with contrasting posture control mechanisms: : Pachira aquatica, Sextonia rubra and Simarouba amara.

Data from experiments described in the paper : Influence of mechanical stress on biomass allocation in three species with contrasting posture control mechanisms submitted on March 2024 Abstract Context: All trees need a motor system to correct their position achieved through the generation of asymmetric tensile stress around the stem, leading to active bending. In angiosperms, depending on the species, tensile stress is generated either in wood (tension wood), in bark or in both. Aims: Here, we investigated how gravitropic stimuli (tilted stems without any movement) may affect growth and biomass allocation and whether this process depends on the posture control mechanism of the species. Methods: Tree growth kinetics, final biomass allocation and wood and bark proportion, localisation and density were measured on young tilted plants and straight plants as controls. Pachira aquatica, Sextonia rubra and Simarouba amara were selected according to their motor system located respectively within bark only, wood only or both wood and bark. Results: In response to tilting, trees from the three species increased their diameter and decreased their slenderness, but the total biomass (including stem and roots) was not different than that in the control trees, suggesting that reaction to artificial tilting does not imply a specific cost for the plant. However, the species exhibited strong differences in growth kinetics, in the amount and organisation of the tissues or in biomass allocation to different organs (root vs shoot, wood vs bark), adapted to the specificity of the posture control mechanisms and improving their motor function. Conclusion: Whatever the posture control mechanism, uprighting does not modify total biomass invested but its repartition in the organs is strongly modified according to the efficiency of the mechanisms.