Morphological aspects of self-repair of lesions caused by internal growth stresses in stems of Aristolochia macrophylla and Aristolochia ringens
Busch S; Seidel R; Speck T; Speck O
Proceedings of the Royal Society London B
This study reveals in detail the mechanism of self-repair during secondary growth in the vines Aristolochia macrophylla and Aristolochia ringens based on morphological data. For a comprehensive understanding of the underlying mechanisms during the self-repair of lesions in the sclerenchymatous cylinder of the stem which are caused by internal growth stresses a classification of morphological changes in the cells involved in the repair process is required. In an early stage of self-repair we observed morphological changes as a mere extension of the turgescent cortex cells surrounding the lesion whereby the cell wall extends locally through visco-elastic/plastic deformation without observable cell wall synthesis. Later stages involve typical cell growth and cell division. Several successive phases of self-repair were investigated by light microscopy of stained samples and confocal laser-scanning microscopy in fluorescence mode. The results indicate that A. macrophylla and A. ringens respond to lesions caused by internal growth stresses with a sophisticated self-repair mechanism comprising several phases of different repair modes.