Effect of Lignin Genetic Modification on Wood Anatomy of Aspen Trees

IAWA Journal ◽  
2010 ◽  
Vol 31 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Balazs Horvath ◽  
Ilona Peszlen ◽  
Perry Peralta ◽  
Bohumil Kasal ◽  
Laigeng Li

The directed modification of specific traits of trees through genetic engineering provides opportunities for making significant genetic improvements to wood properties in matter of years instead of extended time frames required for traditional natural selection. An attractive target of forest- tree engineering is the modification of lignin content and lignin structure. While lower lignin content improves pulping efficiency, a decrease in lignin content could affect wood characteristics that are critical for solid wood use.After one year of growth in a greenhouse, a total of forty transgenic aspen (Populus tremuloides Michx.) with reduced lignin content and increased syringyl to guaiacyl ratio were harvested and diameter growth and cell morphology were investigated using quantitative wood anatomy and fiber quality analysis techniques. Comparing genetic groups to the wild-type as the control, similar radial growth and quantitative anatomical properties were observed for the genetic group with reduced lignin content. The genetic group with increased S/G ratio had lower diameter growth, lower vessel lumen diameter, but more numerous vessels. The combined effect of changes in lignin content and structure on radial growth and cell morphology seems to be more complex and gave inconsistent results.

2004 ◽  
Vol 82 (5) ◽  
pp. 590-597 ◽  
Author(s):  
Brin Jones ◽  
Jacques Tardif ◽  
Richard Westwood

The present study investigated the effect of artificial defoliation on weekly radial xylem production in trembling aspen (Populus tremuloides Michx.). It was hypothesized that defoliated trees would show reduced xylem and vessel production and thinner secondary walls in fibres. Two adjacent natural forest sites were selected within Winnipeg, Manitoba. Microcores were extracted weekly from the stems of 30 aspen trees from May to October 2002. Ten aspen trees were defoliated using pole pruners between 22 June and 6 July. Measurements included weekly xylem increment, annual vessel characteristics, and late growing season fibre dimensions. No significant difference in overall ring width was observed; however, trees from both groups showed a significant reduction in ring width in 2002. The ratio of radial growth in 2002 / radial growth in 2001 was significantly less in defoliated trees, suggesting a higher reduction in radial growth due to defoliation. Sigmoidal regression models suggested early growth cessation in defoliated trees. No significant differences in vessel characteristics were observed between groups; however, the diameter and lumen width of fibres was significantly reduced in defoliated trees. It is speculated that a shorter radial growing season may have led to a reduced cell elongation period. An early cessation of the radial growing season associated with a reallocation of carbohydrates to produce a second flush of leaves could explain the reduced size of fibres from defoliated trees.Key words: wood anatomy, diffuse porous, image analysis, radial growth, cell dimension, dendrochronology.


Holzforschung ◽  
2012 ◽  
Vol 66 (1) ◽  
Author(s):  
Richard Giles ◽  
Ilona Peszlen ◽  
Perry Peralta ◽  
Hou-Min Chang ◽  
Roberta Farrell ◽  
...  

AbstractBetter access to wood carbohydrates as a result of reduced, or altered, lignin is a goal of biopulping, as well as biofuel research. In the present article, woods from three transgenic trees and one wild-type quaking aspen (Populus tremuloidesMichx.) were analyzed in terms of mass loss of cellulose and lignin after incubation with lignocellulolytic fungi. The transgenic trees had reduced lignin content through transfer of an antisense -4CL gene, elevated syringyl/guaiacyl (S/G) ratio through insertion of a sense CAld5H gene and low lignin content and elevated S/G ratio through simultaneous insertion of -4CL and CAld5H genes, respectively. The lignocellulolytic fungi employed were a lignin-selective white rot fungusCeriporiopsis subvermispora, a simultaneous white rot fungusTrametes versicolorand a brown rot fungusPostia placenta. Reduced lignin degradation was observed in woods with increased S/G ratios indicating that this analytical feature influences decay resistance, regardless of the fungal decay mechanism.


2015 ◽  
Vol 33 ◽  
pp. 54-60 ◽  
Author(s):  
Paul Copini ◽  
Mathieu Decuyper ◽  
Ute Sass-Klaassen ◽  
Holger Gärtner ◽  
Frits Mohren ◽  
...  

2022 ◽  
pp. 125922
Author(s):  
Paweł Matulewski ◽  
Agata Buchwal ◽  
Holger Gärtner ◽  
Andrzej M. Jagodziński ◽  
Katarina Čufar

CERNE ◽  
2015 ◽  
Vol 21 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Fábio Venturoli ◽  
Augusto César Franco ◽  
Christopher William Fagg

In the Cerrado biome of Brazil, savannas and dry forests are intimately linked and form mosaics. These forests are composed of species of high commercial value, well accepted in the timber market, which causes intensive deforestation on the remaining vegetation. Thus, the management of these forests is an important alternative to reduce deforestation in the remaining vegetation. The objective of this study was to analyze the response of tree species in relation to silvicultural treatments of competition and liana cutting in a semi-deciduous forest in Central Brazil. The results showed that community basal area increased 24% over 4.8 years and the median periodic annual increment in diameter was about 20% higher in plots with silvicultural treatments: 2.9 mm.yr-1 in the control compared to 3.2 mm.yr-1 to 3.6 mm.yr-1 between treatments. This study demonstrated that it is possible to increase the rates of radial growth through silvicultural techniques.


2008 ◽  
Vol 132 (10) ◽  
pp. 1623-1629 ◽  
Author(s):  
Amy A. Sanchez ◽  
Tsung-Teh Wu ◽  
Victor G. Prieto ◽  
Asif Rashid ◽  
Stanley R. Hamilton ◽  
...  

Abstract Context.—Primary esophageal melanoma (PEM) is a rare disease and is difficult to distinguish from other esophageal malignancies and from metastatic melanoma. Objective.—To develop diagnostic criteria for PEM, we compared the clinicopathologic features of 5 PEMs and 5 metastatic melanomas to esophagus. Design.—Ten cases of esophageal melanoma, including 4 surgically resected specimens, 2 autopsy cases, and 4 cases reported on mucosal biopsies, were reviewed. The histologic parameters used in this study were well-characterized features for cutaneous melanoma, including junctional component (in situ melanoma), radial growth phase, modified Breslow thickness, depth of invasion, lymphovascular invasion, satellitosis, predominant type of cytology, and regional lymph node metastasis. Clinical and follow-up information was obtained by reviewing patients' medical records. Results.—Previous history of cutaneous melanoma was present in all 5 cases of metastatic esophageal melanoma but was not present in the 5 patients with PEMs. In situ melanoma and/or radial growth phase were identified in all 5 PEMs but were not present in any of the metastatic cases. Among the 4 resected and 2 autopsy cases, melanocytosis and mixed epithelioid and spindle cell morphology was present in 2 (50%) of 4 PEMs but was not present in 2 (40%) of the metastatic melanomas. Melanin pigment was detectable in all cases. Patients with PEM had better survival than those who had metastatic melanoma to esophagus (P = .03). Conclusions.—The presence of in situ melanoma, radial growth phase, melanocytosis, and mixed epithelioid and spindle cell morphology, in the context of no history of melanoma, distinguishes PEM from metastatic melanoma.


Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 686 ◽  
Author(s):  
M. Quiñonez-Piñón ◽  
Caterina Valeo

The translucence and color change in wood methods, which are commonly used to differentiate sapwood from heartwood in tree cores, are compared against the microscopic analysis of wood anatomy method for determining sapwood depth. The translucence method was tested on collected wood cores of White Spruce (Picea glauca (Moench) Voss) and Jack Pine (Pinus banksiana Lamb.). The color change in wood method was tested on Trembling Aspen (Populus tremuloides Michx.). For every statistical comparison, sapwood depth values obtained with the translucence or color-change methods were significantly different from those obtained using the microscopic analysis. Using the sapwood depth values obtained with microscopy as a reference, the bias associated with the translucence or color-change methods used on Picea glauca, Pinus banksiana and Populus tremuloides constantly under- or overestimated sapwood depths within −0.3 cm to 1.6 cm; −4.9 cm to 0.5 cm; and 0 to 1.8 cm, respectively. The different ranges of over- and underestimation arise from species-specific anatomical characteristics. Estimates for the errors in sapwood depth, when the depth is measured using either the translucence or color-change methods, are presented. These relationships and research outcomes will lead to more efficient forest monitoring and improved estimates of forest water balance, which in turn will lead to improved forest management in the face of climate change.


2014 ◽  
Vol 44 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Derek F. Sattler ◽  
Philip G. Comeau ◽  
Alexis Achim

Radial patterns of modulus of elasticity (MOE) were examined for white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuoides Michx.) from 19 mature, uneven-aged stands in the boreal mixedwood region of northern Alberta, Canada. The main objectives were to (1) evaluate the relationship between pith-to-bark changes in MOE and cambial age or distance from pith; (2) develop species-specific models to predict pith-to-bark changes in MOE; and (3) to test the influences of radial growth, relative vertical height, and tree slenderness (tree height/DBH) on MOE. For both species, cambial age was selected as the best explanatory variable with which to build pith-to-bark models of MOE. For white spruce and trembling aspen, the final nonlinear mixed-effect models indicated that an augmented rate of increase in MOE occurred with increasing vertical position within the tree. For white spruce trees, radial growth and slenderness were found to positively influence maximum estimated MOE. For trembling aspen, there was no apparent effect of vertical position or radial growth on maximum MOE. The results shed light on potential drivers of radial patterns of MOE and will be useful in guiding silvicultural prescriptions.


2008 ◽  
Vol 57 (1-6) ◽  
pp. 235-242 ◽  
Author(s):  
H. Tiimonen ◽  
T. Aronen ◽  
T. Laakso ◽  
P. Saranpää ◽  
V. Chiang ◽  
...  

Abstract The ability of the PtCOMT (caffeate/5-hydroxyferulate O-methyltransferase from Populus tremuloides L.) - modified Betula pendula Roth. lines to form symbiosis with an ectomycorrhizal (ECM) fungus Paxillus involutus Batsch Fr. was studied in vitro. Lignin precursor gene PtCOMT was introduced into two B. pendula clones under the control of the cauliflower mosaic virus 35S promoter or the promoter of the sunflower polyubiquitin gene UbB1. Of the four transgenic lines, one 35SPtCOMT line (23) had a decreased syringyl/guaiacyl (S/G) ratio of root lignin, and two UbB1-PtCOMT lines (110 and 130) retarded root growth compared to the control clone. Both control clones and all transgenic lines were able to form ECMs with P. involutus, but the transgenic lines differed from the controls in the characteristics of the ECMs. The number of lateral roots covered with fungal hyphae and/or development of a Hartig net (HN) were reduced in line 23 with a decreased S/G ratio, and in lines 110 and 130 with slower root formation and changed root morphology, respectively. However, line 23 benefited more from the inoculation in lateral root formation than the control, and in lines 110 and 130 the percentage of viable plants increased most due to inoculation. The results show that B. pendula plants genetically transformed with the lignin gene PtCOMT could form mycorrhizal symbiosis regardless of changes in either the root S/G ratio or development. The benefits of the symbiosis were variable even in the closed in vitro system, and dependent on the clone or transgenic line and the ECM fungal symbiont.


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