Journal Article

More cells, bigger cells or simply reorganization? Alternative mechanisms leading to changed internode architecture under contrasting stress regimes

Jan de Brouwer, Heidrun Huber, Heinjo J. During, Eric J. von Wettberg, Niels P. R. Anten

2014

Overview

Shading and mechanical stress (MS) modulate plant architecture by inducing different developmental pathways. Shading results in increased stem elongation, often reducing whole-plant mechanical stability, while MS inhibits elongation, with a concomitant increase in stability. Here, we examined how these organ-level responses are related to patterns and processes at the cellular level by exposing Impatiens capensis to shading and MS. Shading led to the production of narrower cells along the vertical axis. By contrast, MS led to the production of fewer, smaller and broader cells. These responses to treatments were largely in line with genetic differences found among plants from open and closed canopy sites. Shading- and MS-induced plastic responses in cellular characteristics were negatively correlated: genotypes that were more responsive to shading were less responsive to MS and vice versa. This negative correlation, however, did not scale to mechanical and architectural traits. Our data show how environmental conditions elicit distinctly different associations between characteristics at the cellular level, plant morphology and biomechanics. The evolution of optimal response to different environmental cues may be limited by negative correlations of stress-induced responses at the cellular level.

• Publisher: New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: Adaptation, Physiological - genetics / adaptive plasticity / arabidopsis-thaliana / Architecture / B lymphocytes / biomechanical characteristics / Biomechanics / canopy / cell alignment and shape / Cell growth / cell size and proliferation / Cells / Correlation / Darkness / Elongation / Environment / Environmental conditions / Epidermal cells / evolution / Forest habitats / Genotype / Genotypes / Impatiens - anatomy & histology / Impatiens - genetics / Impatiens - growth & development / Impatiens - physiology / Impatiens capensis / Impatiens capensis (jewelweed) / impatiens-capensis balsaminaceae / internode length and diameter / Internodes / light availability / mechanical stress / mechanical stress (MS) / morphogenic responses / Morphology / nutrient availability / Phenotype / phenotypic plasticity / Phenotypic traits / plant architecture / Plant Cells - physiology / Plant cover / Plant Leaves / Plant morphology / Plant shading / Plant Stems - anatomy & histology / Plant Stems - growth & development / Plants / Plastic foam / plasticity / population differentiation / shade-avoidance responses / Shading / Stability / stem elongation / stoloniferous herb / Stress / Stress, Mechanical / Stress, Physiological - genetics / trifolium-repens