The distribution of monolignol glucosides coincides with lignification during the formation of compression wood in Pinus thunbergii.

The distributions of monolignol glucosides (MLGs) in compression and opposite woods of Pinus thunbergii were assessed using cryo-time-of-flight secondary ion mass spectrometry to investigate their involvement in lignification. p-Glucocoumaryl alcohol (PG) was identified in the region of the differentiating xylem adjacent to the cambial zone only in compression wood, whereas coniferin (CF) was similarly localized in both compression and opposite woods. Their distribution from the phloem to the xylem was evaluated by high-performance liquid chromatography (HPLC) using serial tangential sections.

Identification of activity-based biomarkers for early-stage pancreatic tumors in blood using single-molecule enzyme activity screening.

Single-molecule enzyme activity-based enzyme profiling (SEAP) is a methodology to globally analyze protein functions in living samples at the single-molecule level. It has been previously applied to detect functional alterations in phosphatases and glycosidases. Here, we expand the potential for activity-based biomarker discovery by developing a semi-automated synthesis platform for fluorogenic probes that can detect various peptidases and protease activities at the single-molecule level.

Localised laccase activity modulates distribution of lignin polymers in gymnosperm compression wood.

The woody stems of coniferous gymnosperms produce specialised compression wood to adjust the stem growth orientation in response to gravitropic stimulation. During this process, tracheids develop a compression-wood-specific S L cell wall layer with lignins highly enriched with p-hydroxyphenyl (H)-type units derived from H-type monolignol, whereas lignins produced in the cell walls of normal wood tracheids are exclusively composed of guaiacyl (G)-type units from G-type monolignol with a trace amount of H-type units. We show that laccases, a class of lignin polymerisation enzymes, play a crucial role in the spatially organised polymerisation of H-type and G-type monolignols during compression wood formation in Japanese cypress (Chamaecyparis obtusa).

In situ detection of laccase activity and immunolocalisation of a compression-wood-specific laccase (CoLac1) in differentiating xylem of Chamaecyparis obtusa.

The secondary cell wall of compression wood tracheids has a highly lignified region (S2L) in its outermost portion. To better understand the mechanism of S2L formation, we focussed on the activity of laccase (a monolignol oxidase) and performed in situ studies of this enzyme in differentiating compression wood. Staining of differentiating compression wood demonstrated that laccase activity began in all cell wall layers before the onset of lignification.

Changes in xylem tissue and laccase transcript abundance associated with posture recovery in Chamaecyparis obtusa saplings growing on an incline.

Lignin is a major component of plant cell walls and is synthesised through oxidative polymerisation of monolignols. The transcription level of laccase, an enzyme implicated in monolignol polymerisation, is higher in the tissue forming compression wood than in normal wood. Compression wood, which is a special xylem tissue that develops to reorient inclined stems, also has a higher lignin content than normal wood.