xylem-water-distribution-woody-plants-visualized-with-cryo-scanning

Xylem Water Distribution in Woody Plants Visualized with a Cryo-scanning Electron Microscope

A scanning electron microscope installed cryo-unit (cryo-SEM) allows specimen observation at subzero temperatures and has been used for exploring water ...

University of Wisconsin

When the orientation of the stems of conifers departs from the vertical as a result of environmental influences, conifers form compression wood that results in restoration of verticality. It is well known that intercellular spaces are formed between tracheids in compression wood, but the function of these spaces remains to be clarified. In the present study, we evaluated the impact of these spaces in artificially induced compression wood in Chamaecyparis obtusa seedlings.

Cavitation of intercellular spaces is critical to establishment of hydraulic properties of compression wood of Chamaecyparis obtusa seedlings.

Colonization of wood blocks by brown and white rot fungi rapidly resulted in detectable wood oxidation, as shown by a reduced phloroglucinol response, a loss of autofluorescence, and acridine orange (AO) staining. This last approach is shown to provide a novel method for identifying wood oxidation. When lignin was mildly oxidized, the association between AO and lignin was reduced such that stained wood sections emitted less green light during fluorescence microscopy. This change was detectable after less than a week, an interval that past work has shown to be too short for significant delignification of wood. Although fungal hyphae were observed in only a few wood lumina, oxidation was widespread, appearing relatively uniform over regions several hundred micrometers from the hyphae. This observation suggests that both classes of fungi release low molecular weight mild oxidants during the first few days of colonization. 

Acridine Orange Indicates Early Oxidation of Wood Cell Walls by Fungi.

Cambial activity in some tropical trees varies intra-annually, with the formation of xylem rings. Identification of the climatic factors that regulate cambial activity is important for understanding the growth of such species. We analyzed the relationship between climatic factors and cambial activity in four tropical hardwoods, Acacia mangium, Tectona grandis, Eucalyptus urophylla, and Neolamarckia cadamba in Yogyakarta, Java Island, Indonesia, which has a rainy season (November-June) and a dry season (July-October).

Article	Year
Cavitation of intercellular spaces is critical to establishment of hydraulic properties of compression wood of Chamaecyparis obtusa seedlings. Annals of botany\| PubMed ID: 26818592	2016
Acridine Orange Indicates Early Oxidation of Wood Cell Walls by Fungi. PloS one\| PubMed ID: 27454126	2016
Changes in cambial activity are related to precipitation patterns in four tropical hardwood species grown in Indonesia. American journal of botany\| PubMed ID: 31157413	2019

Peter Kitin

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