Diffuse cavity formation in soft rot of pine

Abstract

pine Summary A new type of soft rot of southern pine longitudinal tracheids is described. In this type, soft-rot cavities form by diffuse degradation of the $2 cell wall layer by hyphae growing within the cell wall. Cavity formation is diffuse and irregular as opposed to the restricted, periodic cavity formation typical of type i soft rot. Proboscis hyphae are small (diameter 0.6 to 0.9 gm) and rapidly autolyse. These proboscis hyphae are not easily recognizable with light microscopy, especially at later stages of decay, but require transmission electron microscopy to confirm their presence. This may be an alternative interpretation of the type 2 soft rot of softwoods described previously as being caused by lumenal hyphae through an intact $3. Chemical analysis of pine test blocks revealed a greater loss of glucose and an increase of galactose with diffuse type i species compared to typical type 1 soft rot species. The term "diffuse type 1" is suggested to describe this soft rot.

Stimulating growth and xylindein production of Chlorociboria aeruginascens in agar-based systems

“…It is possible that a combination of the two sugars, sucrose and glucose, plays a role in stimulation of fungal growth and pigment production. However, the simple sugar analysis does confirm the results of Robinson et al ( Robinson et al 2011 ) and Anagnost et al ( Anagnost et al 1994 ), both of which noted an increase in galactose in wood colonized by S. cuboideum .…”

Diversity and community structure of wood-inhabiting fungi found in Japanese wooden houses analyzed by the next-generation sequencing

“…The families Aspergillaceae, Leotiomycetes, and genus Scytalidium were detected frequently. Scytalidium lignicola was the most frequently detected ascomycete species in this study, which was classified as soft-rot fungus type 2 [29,30]. Fungal species that comprised more than 5% of fungal community in each sample are listed in Table 2.…”

Advances in Understanding Microbial Deterioration of Buried and Waterlogged Archaeological Woods: A Review

“…The decay pattern (cavities in the cell wall) produced by SR can be readily recognised using a light microscope (LM) [64] (Figure 2), which provides sufficient high resolution to follow fungal pathway within wood tissues and obtain details on the micromorphology of forming and developed cavities, as well as to assess the orientation of cavities relative to cell wall microfibrils. Because LM also enables rapid evaluation, it has been widely used as a diagnostic tool and to study processes associated with wood degradation by SR. Further advances using SEM and TEM, which offer much greater resolution compared to LM, have yielded valuable additional information on the processes of soft-rot cavity formation and the ultrastructure of cavity-forming fungal hyphae [65], presence of a granular material within cavities (Figure 3), considered to represent a mixture of slime, melanin and modified lignin residues [59] and in some cases presence of a wider irregular zone around cavityforming hyphae [66] (Figure 3) compared to the usual concentric form of cavities observable in transverse sections [29,67] (Figures 2 and 4). The process of cavity formation has been reviewed by several workers, including Daniel and Nilsson [59] and Daniel [68].…”

“…For brown rot fungi, it has been proposed that in addition to producing enzymes, these fungi deploy a non-enzymatic system [77,78] consisting of small molecular substances which can modify the cell wall, enabling cellulolytic and hemicellulolytic enzymes to gain entry into the cell wall and access holocellulosic components. It is not known whether SR also produce a non-enzymatic diffusible system, but it is a distinct possibility at least for those fungi causing diffuse degradation [66,67] (Figure 3), where cell wall dissolution extends well beyond the cell wall regions where hyphae are present. The compositional changes due to cell wall degradation by SR have been reported by several workers [reviewed in 59].…”