scholarly journals Transcriptome profiling of radiata pine branches reveals new insights into reaction wood formation with implications in plant gravitropism

BMC Genomics ◽  
2013 ◽  
Vol 14 (1) ◽  
pp. 768 ◽  
Author(s):  
Xinguo Li ◽  
Xiaohui Yang ◽  
Harry X Wu
IAWA Journal ◽  
2006 ◽  
Vol 27 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Linda C.Y. Hsu ◽  
John C.F. Walker ◽  
Brian G. Butterfield ◽  
Sandra L. Jackson

We investigated the potential for the roots of Pinus radiata D. Don to form compression wood. Compression wood was not observed in either the tap or any lateral roots further than 300 mm from the base of the stem. This suggests that either the roots do not experience the stresses required to induce compression wood formation, or that they lack the ability to form it. Roots artificially subjected to mechanical stress also failed to develop compression wood. It is therefore unlikely that an absence of a compressive load on buried roots can account for the lack of compression wood. Application of auxin to the cambia of lateral roots was similarly ineffective at inducing the formation of compression wood. These observations suggest that the buried roots of radiata pine lack the ability to develop compression wood. We also report the formation of an atypical S3 wall layer in the mechanically-stressed and auxin-treated tracheids and suggest that a reaction wood that is different to compression wood may well form in roots.


IAWA Journal ◽  
2014 ◽  
Vol 35 (4) ◽  
pp. 385-394
Author(s):  
Xinguo Li ◽  
Robert Evans ◽  
Washington Gapare ◽  
Xiaohui Yang ◽  
Harry X. Wu

The formation of reaction wood is an adaptive feature of trees in response to various mechanical forces. In gymnosperms, reaction wood consists of compression wood (CW) and opposite wood (OW) that are formed on the underside and upperside of bent trunks and branches. Although reaction wood formed in bent trunks has been extensively investigated, relatively little has been reported from conifer branches. In this study SilviScan® technology was used to characterize radiata pine branches at high resolution. Compared to OW formed in the branches, CW showed greater growth, darker colour, thicker tracheid walls, higher coarseness, larger microfibril angle (MFA), higher wood density, lower extensional stiffness and smaller internal specific surface area. However, tracheids of CW were similar to those of OW in their radial and tangential diameters. These results indicated that gravity influenced tracheid cell division and secondary wall formation but had limited impact on primary wall expansion. Furthermore, seasonal patterns of CW formation were not observed in the branches from cambial age 4 while earlywood and latewood were clearly separated in all rings of OW. The marked change of MFA during reaction wood formation suggested that branches could be ideal materials for further study of cellulose microfibril orientation.


Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 267-274 ◽  
Author(s):  
Tatsuya Shirai ◽  
Hiroyuki Yamamoto ◽  
Miyuki Matsuo ◽  
Mikuri Inatsugu ◽  
Masato Yoshida ◽  
...  

Abstract Ginkgo (Ginkgo biloba L.) forms thick, lignified secondary xylem in the cylindrical stem as in Pinales (commonly called conifers), although it has more phylogenetic affinity to Cycadales than to conifers. Ginkgo forms compression wood-like (CW-like) reaction wood (RW) in its inclined stem as it is the case in conifers. However, the distribution of growth stress is not yet investigated in the RW of ginkgo, and thus this tissue resulting from negative gravitropism is still waiting for closer consideration. The present study intended to fill this gap. It has been demonstrated that, indeed, ginkgo forms RW tissue on the lower side of the inclined stem, where the compressive growth stress (CGS) was generated. In the RW, the micorofibril angle in the S2 layer, the air-dried density, and the lignin content increased, whereas the cellulose content decreased. These data are quite similar to those of conifer CWs. The multiple linear regression analysis revealed that the CGS is significantly correlated by the changes in the aforementioned parameters. It can be safely concluded that the negative gravitropism of ginkgo is very similar to that of conifers.


1964 ◽  
Vol 12 (1) ◽  
pp. 24 ◽  
Author(s):  
AB Wardrop ◽  
GW Davies

The cell wall organization of tracheids of natural and chemically induced compression wood of Pinus radiata and Actinostrobus pyramidalis has been shown to be the same, and is similar to that established in previous studies of natural compression wood. In the secondary wall only two layers were present. In the second of these there was a well-developed system of helical cavities, separating ribs of cellulose. The ribs of cellulose were parallel to the direction of microfibril orientation; were complex in form; and the cellulose lamellae lay parallel with the wall surface. A well-developed wart structure was present. During the differentiation of compression wood tracheids, the intercellular spaces were formed during the phase of surface enlargement of the differentiating tracheids. At an early stage the intercellular spaces appeared to contain cytoplasmic ground substance. During the development of the layer S1 the cytoplasmic organization was similar to that of normal tracheids, the cells containing a large vacuole with a well-developed tonoplast and plasmalemma. During the development of the layer S2 the cytoplasm contained numerous small vesicles with no large vacuoles, and in many instances the plasmalemma was absent. At the conclusion of the differentiation of the cell the plasmalemma was again present and penetrated the helical cavities of the wall. Compression wood induced by 3-indoleacetic acid (IAA) alone, gibberellic acid (GA) alone, or IAA and GA in combination was identical with that formed under natural conditions. The localized lateral application of IAA to vertical stems caused conspicuous bending of the stem as well as compression wood formation.


2007 ◽  
Vol 49 (2) ◽  
pp. 131-143 ◽  
Author(s):  
Sheng Du ◽  
Fukuju Yamamoto
Keyword(s):  

2017 ◽  
Vol 63 (3) ◽  
pp. 307-312
Author(s):  
Haruna Aiso ◽  
Futoshi Ishiguri ◽  
Tatsuya Toyoizumi ◽  
Yuya Takashima ◽  
Mineaki Aizawa ◽  
...  

1954 ◽  
Vol 2 (1) ◽  
pp. 22 ◽  
Author(s):  
GL Amos

In certain conifers anatomical evidence suggests that young trees may become exposed to conditions conducive to collapse during late wood formation, causing partial collapse and radial cleavages in the early wood. Living ray cells are exposed to the cavity after cleavage. Different species show different responses conditioned by the anatomy and physiology of the ray parenchyma. The cavities fill with cellular tissue in radiata pine (Pinus radiata D. Don), with resin in Douglas fir (Pseudotsuga tarcifolia (Poir.) Britt.), and remain empty in white spruce (Picea glauoa (Moench) Voss). Evidence is presented to show that when a living protoplast is given free access to moist air, a powerful growth stimulus is applied to the cell. In radiata pine, ray parenchyma cells have primary walls only, and the response is a proliferation of these cells. In Douglas fir and white spruce, the ray parenchyma has secondary thickening and small ray tracheid pitting, precluding growth. The response is an increased metabolic rate, producing resin in Douglas fir (heartwood-forming species) and without solid end-products in white spruce (species with little contrast between sapwood and heartwood).


Sign in / Sign up

Export Citation Format

Share Document