TY  - JOUR
AU  - Roussel, J.-R.
AU  - Clair, B.
PY  - 2015//
TI  - Evidence of the late lignification of the G-layer in Simarouba tension wood, to assist understanding how non-G-layer species produce tensile stress
T2  - Tree Physiology
JO  - Tree Physiology
SP  - 1366
EP  - 1377
VL  - 35
IS  - 12
KW  - maturation stress generation
KW  - ontogeny
KW  - Simarouba amara Aubl.
KW  - tension wood cell wall
KW  - tree biomechanics
N2  - To recover verticality after disturbance, angiosperm trees produce 'tension wood' allowing them to bend actively. The driving force of the tension has been shown to take place in the G-layer, a specific unlignified layer of the cell wall observed in most temperate species. However, in tropical rain forests, the G-layer is often absent and the mechanism generating the forces to reorient trees remains unclear. A study was carried out on tilted seedlings, saplings and adult Simarouba amara Aubl. trees – a species known to not produce a G-layer. Microscopic observations were done on sections of normal and tension wood after staining or observed under UV light to assess the presence/absence of lignin. We showed that S. amara produces a cell-wall layer with all of the characteristics typical of G-layers, but that this G-layer can be observed only as a temporary stage of the cell-wall development because it is masked by a late lignification. Being thin and lignified, tension wood fibres cannot be distinguished from normal wood fibres in the mature wood of adult trees. These observations indicate that the mechanism generating the high tensile stress in tension wood is likely to be the same as that in species with a typical G-layer and also in species where the G-layer cannot be observed in mature cells. © 2015 The Author 2015. Published by Oxford University Press. All rights reserved.
UR  - http://www.scopus.com/inward/record.url?eid=2-s2.0-84960324900&partnerID=40&md5=b7d1641122e583280037cd29eaf09edd
N1  - Export Date: 25 March 2016
ID  - Roussel+Clair2015
ER  -