Lignification and lignin topochemistry — an ultrastructural view

Donaldson, Lloyd

doi:10.1016/s0031-9422(01)00049-8

Cited by 504 publications

(369 citation statements)

References 114 publications

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“…The latter observation is in good agreement with former studies showing that soft-rot type 1 occurs in secondary walls with high concentration of guaiacyl, whereas soft-rot type 2 is often associated with syringyl rich cell walls (Liese 1961;Nilsson et al 1989;Schwarze et al 2004;Singh et al 2006). Norway spruce wood has a high concentration of guaiacyl, and thus is moderately resistant to soft-rot fungi (Liese 1961;Blanchette et al 1988;Nilsson et al 1989;Baum 2001;Donaldson 2001), whereas beech wood that consists predominantly of syringyl-rich fibre tracheids is more susceptible to soft-rot fungi (Schwarze et al 2000(Schwarze et al , 2004Baum 2001). The latter difference in the lignin composition partly explains the higher weight losses recorded by soft-rot fungi in beech wood.…”

Section: Fungal Colonisation and Degradationsupporting

confidence: 91%

Degradation of thermo-hygro-mechanically (THM)-densified wood by soft-rot fungi

Skyba

Niemz

Schwarze

2008

HFSG

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Thermo-hygro-mechanical (THM)-densified wood is more resistant to colonisation and degradation by brown-rot fungi than untreated wood. Colonisation and degradation by soft-rot fungi was investigated in treated Norway spruce (Picea abies) and treated beech (Fagus sylvatica) to assess their suitability for utility class 4. Three different treatments were applied: thermal-hygro (TH) treatment, mechanical densification and THM-treatment including densification and post-treatment under saturated steam conditions at different temperatures. For comparison, additional wood specimens were treated with two concentrations of a chromium-copper (CC) wood preservative. After 32 weeks incubation, weight losses induced by soft-rot fungi were lowest in wood treated with CC. Highest weight losses were recorded from TH-treated wood, in which soft-rot erosion attack (type 2) was exclusively observed in spruce. In comparison to controls, significantly lower weight losses by soft-rot fungi were recorded in THM-treated spruce wood, but no such differences were found in beech wood. Microscopical examination showed that in THM-treated wood of spruce, soft-rot type 1 commenced from the outer wood surfaces and cavity formation was not found in deeper regions of the wood samples. THM-treated beech wood was more susceptible to degradation than that of spruce which can be partly explained by the higher syringyl lignin content in beech wood, which is more susceptible to all kinds of degradation. Hyphal colonisation and soft-rot was facilitated within deeper regions of beech wood mainly in the non-occluded lumina of parenchyma cells in multiseriate xylem rays. It can be concluded that THtreated spruce wood and THM-treated beech wood is susceptible to soft-rot and therefore inappropriate for utility class 4.

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Section: Fungal Colonisation and Degradationsupporting

confidence: 91%

Degradation of thermo-hygro-mechanically (THM)-densified wood by soft-rot fungi

Skyba

Niemz

Schwarze

2008

HFSG

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“…Donaldson (2001) also observed in angiosperms lignin contains a mixture of guaiacyl and syringyl units.…”

Section: Lignification Status Of Rootmentioning

confidence: 68%

“…The process of lignification has been the subject of various scientific articles (Monties, 1989;Donaldson, 2001;Martone et al, 2009), identified as a fundamental building block in the evolutionary process of plants and land colonization. Plants have adapted to natural adversities, developing a vertical growth antagonizing gravity; structural resistance for water conduction; plague and disease resistance, etc.…”

Section: Introductionmentioning

confidence: 99%

“…It begins in cell corners, in middle lamella and in S-layers, and continues towards the lumen (Donaldson, 2001). It is variable among species, tissues, development stage and cell location.…”

Section: Introductionmentioning

confidence: 99%

“…It is variable among species, tissues, development stage and cell location. Several methodologies have been applied in lignification studies (Terashima and Fukushima, 1988;Donaldson, 2001;De Micco and Aronne, 2007). The use of biotechnological tools has brought about new findings, especially those defining the in loco lignin formation (Morais et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

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Anatomy and lignification status of the Lophanthera lactescens Ducke plant grown in vitro

et al. 2012

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This aim of this study was to evaluate the lignification in young stems of the Lophanthera lactescens Ducke plant grown in vitro L. lactescens (Malpighiaceae), a species endemic in the Brazilian Amazon that possesses both medicinal properties and could be used in the forest product industry. Plants grown in vitro condition in MS medium were analyzed using Infrared (IR) microspectroscopy in a diffuse reflectance mode, fluorescence microscopy. Moreover, histochemical tests such as the Wiesner and Maüle test were run to monitor the process of lignification in cell walls. The spectra of IR microscopy recorded using cross section tissue are representative of guaiacyl/syringyl lignin, based on the 1336 and 1246 cm -1 signal. Individuals presenting stem sprains, resulting from the marked development, produced gelatinous fibers with a clear cellulose layer. Initially, fluorescence microscopy demonstrated lignin deposition in the cell corner region having progressive deposition in the secondary wall of tracheary elements of the stem.Keywords: lignification, fluorescence, infrared microspectroscopy. Anatomia e status da lignificação de plantas de Lophanthera lactescens Ducke crescidas in vitro ResumoEsta pesquisa teve como objetivo avaliar a lignificação em caules jovens de plantas de Lophanthera lactescens Ducke crescidas in vitro. L. lactescens (Malpighiaceae) é uma espécie endêmica da Amazônia Brasileira que, além de propriedades medicinais, apresenta potencial para a indústria de produtos florestais. As plantas foram crescidas in vitro, usando-se meio nutritivo MS. As análises foram realizadas por microespectrometria no infravermelho, no modo reflectância difusa. Microscopia com fluorescência e testes histoquímicos de Wiesner e Maüle foram realizados para o acompanhamento do processo de lignificação. Os espectros registrados a partir da microscopia no infravermelho mostraram sinais em 1336 e 1246 cm -1 , característicos de ligninas siringílica e guaiacílica. Indivíduos que apresentaram entorses no caule, em decorrência do acentuado desenvolvimento, produziram fibras gelatinosas, com a camada de celulose evidente. A microscopia com fluorescência evidenciou deposição de lignina inicialmente nos ângulos das células, com depósito progressivo ocorrendo na parede secundária dos elementos traqueais do caule.Palavras-chave: lignificação, fluorescência, microscopia infravermelho.

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Pulp

Kadla¹,

Dai²

2006

Kirk-Othmer Encyclopedia of Chemical Technology

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Pulp, the raw material used in the production of paper, paperboard, fiberboard, and other similar manufactured products, is produced from wood and nonwood plant matter by separating cellular components using mechanical and/or chemical methods. Wood is the dominant source of fiber used in the manufacture of pulp in the western hemisphere. Nonwood fiber sources are used in those locations where wood is in short supply or for pulps requiring special characteristics. In addition to wood, recovered (recycled) fiber represents a growing segment of the overall fiber supply worldwide. Commercial pulp is classified according to the method of manufacture as mechanical, chemical, chemimechanical, and semichemical. Economic factors, product requirements, and desired fiber properties determine the method of pulping. Mechanical pulps, produced through the application of mechanical energy, give rise to materials having high yield, small average particle size, high opacity, and excellent printing characteristics. Mechanical pulps have some undesirable properties, such as low tensile strength and lack of permanence. Chemical pulps are produced by digesting wood using chemicals to remove lignin, extractives, and low molecular weight polysaccharides, frequently resulting in the loss of wood solids that are dissolved during the pulping and bleaching processes. Chemical pulps are used in the bleached or the unbleached state and are composed of longer, stronger fibers that are more stable than mechanical pulps, but have lower yields and less desirable print qualities. Chemimechanical and semichemical pulps are produced in hybrid processes based on the application of both chemicals and mechanical energy. Wood solids originating in the pulping process are recovered in the form of steam and electrical energy. Pulping chemicals are also recovered for reuse in the manufacturing process. Environmental management includes improvements in chemical recovery, process modification to minimize the use of elemental chlorine, and the treatment of process waste streams.

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Lignification and lignin topochemistry — an ultrastructural view

Cited by 504 publications

References 114 publications

Degradation of thermo-hygro-mechanically (THM)-densified wood by soft-rot fungi

Degradation of thermo-hygro-mechanically (THM)-densified wood by soft-rot fungi

Anatomy and lignification status of the Lophanthera lactescens Ducke plant grown in vitro

Pulp

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