Lignin distribution in mild compression wood of Pinus radiata

1999 ◽  
Vol 77 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Lloyd A Donaldson ◽  
Adya P Singh ◽  
Arata Yoshinaga ◽  
Keiji Takabe

Lignin distribution in the tracheid cell wall of mild compression wood in Pinus radiata D. Don was examined by interference microscopy, confocal fluorescence microscopy, and ultraviolet (UV) microscopy. Two anatomically different samples of mild compression wood were compared with a sample of normal wood using quantitative interference microscopy and microdensitometry combined with confocal fluorescence microscopy to estimate the quantitative or semiquantitative lignin distribution in the S2 and S2L regions of the secondary cell wall and of the cell corner middle lamella (CCML). One of these samples was briefly examined by UV microscopy for comparison. Quantitative interference microscopy provided information on lignin concentration in different regions of the cell wall with values of 26, 46, and 57%, respectively, for the S2, S2L, and CCML regions of sample 1 and 20, 29, and 46%, respectively, for the same regions of sample 2. Microdensitometry of confocal fluorescence images provided semiquantitative information on the relative lignin distribution based on lignin autofluorescence. Comparison between the two compression wood samples using autofluorescence gave results that were in partial agreement with interference microscopy with respect to the relative lignification levels in the S2, S2L, and CCML regions. Some improvement was achieved by using calibration values for hemicellulose rather than holocellulose for interference data in the S2L region. Results for UV microscopy performed on sample 1 indicated that the lignification of the CCML region was comparable with that of the S2L region in this sample but with some variation among cells. All three techniques indicated significant variation in lignification levels of the S2L and CCML regions among adjacent cells and a significant reduction in the lignification of the CCML region compared to normal wood.Key words: lignin distribution, interference microscopy; confocal fluorescence microscopy, UV microscopy, mild compression wood, Pinus radiata D. Don.

2012 ◽  
Vol 18 (6) ◽  
pp. 1459-1466 ◽  
Author(s):  
Zhiheng Zhang ◽  
Jianfeng Ma ◽  
Zhe Ji ◽  
Feng Xu

AbstractThe anatomy and topochemistry in normal and compression wood tracheid cell wall of Pinus bungeana Zucc. were investigated by fluorescence microscopy and confocal Raman microscopy. Using fluorescence microscopy, the severity of compression wood was classed as a mild type for the reason that it did not contain all compression wood features. Chemical imaging by confocal Raman microscopy was used for analyzing the distribution of lignin and cellulose, as well as the functional groups of lignin in tracheid cell walls. By comparison with normal wood, highly lignified outer S2 layer [S2(L)], thicker S1 layer, and obviously reduced lignification in the middle lamella were characteristic of compression wood. In addition, smaller microfibril angle was observed in the S2(L) region. The distribution of coniferyl alcohol and coniferyl aldehyde in normal and compression wood was enriched in S1 and S2 layers but lack in cell corner and/or S2L regions, which showed an opposite pattern to lignin distribution. Confocal Raman microscopy with high spatial resolution contributes to a further understanding of the differences between normal and compression wood in polymers distribution and molecules orientation in situ.


IAWA Journal ◽  
1992 ◽  
Vol 13 (4) ◽  
pp. 381-387 ◽  
Author(s):  
L.A. Donaldson

Lignin distribution during formation of latewood tracheids in Pinus radiata, was determined by quantitative interference microscopy, and by potassium permanganate staining combined with transmission electron microscopy. Lignin distribution varied among trees sampled on the same date in late winter. In one tree, latewood tracheids were fully lignified up to the growth ring boundary. However in most trees sampled, latewood was only partially lignified. The extent of lignification varied from tree to tree but in all cases, at least some lignin was present in the middle lamella and primary wall at the growth ring boundary. Latewood was ideal for examining the lignification process because of the large number of different stages present in a single specimen.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1582
Author(s):  
Verónica Cánovas ◽  
Salvador Garcia-Chumillas ◽  
Fuensanta Monzó ◽  
Lorena Simó-Cabrera ◽  
Carmen Fernández-Ayuso ◽  
...  

Haloferaxmediterranei is a haloarchaeon of high interest in biotechnology because it produces and mobilizes intracellular polyhydroxyalkanoate (PHA) granules during growth under stress conditions (limitation of phosphorous in the culture media), among other interesting metabolites (enzymes, carotenoids, etc.). The capability of PHA production by microbes can be monitored with the use of staining-based methods. However, the staining of haloarchaea cells is a challenging task; firstly, due to the high ionic strength of the medium, which is inappropriate for most of dyes, and secondly, due to the low permeability of the haloarchaea S-layer to macromolecules. In this work, Haloferax mediterranei is used as a halophilic archaeon model to describe an optimized protocol for the visualization and analysis of intracellular PHA granules in living cells. The method is based on double-fluorescence staining using Nile red and SYBR Green by confocal fluorescence microscopy. Thanks to this method, the capability of PHA production by new haloarchaea isolates could be easily monitored.


2006 ◽  
Vol 11 (3) ◽  
pp. 034014 ◽  
Author(s):  
Silvia Versari ◽  
Anna Maria Villa ◽  
Alessandro Villa ◽  
Silvia Maria Doglia ◽  
Giorgio A. Pagani ◽  
...  

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