Antifungal stilbene impregnation: transport and distribution on the micron-level

Felhofer, Martin; Prats-Mateu, Batirtze; Bock, P.; Gierlinger, Notburga

doi:10.1093/treephys/tpy073

Cited by 22 publications

(28 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although not soluble by the usual extraction procedure additional aromatics are impregnating the walnut tissue in the mature state. Raman imaging of pine wood showed a similar accumulation of aromatic components (pinosylvins) during heartwood formation -with lumen sided surfaces and pits more impregnated than the cell wall itself (Felhofer et al, 2018). This final impregnation step of the cell wall, filling up free spaces, and sealing the pit channels will improve stability and longevity in a similar manner as observed in heartwood of trees.…”

Section: Maturation Of the Shell By Impregnation And Dehydrationmentioning

confidence: 69%

From the Soft to the Hard: Changes in Microchemistry During Cell Wall Maturation of Walnut Shells

et al. 2020

Self Cite

View full text Add to dashboard Cite

The walnut shell is a hard and protective layer that provides an essential barrier between the seed and its environment. The shell is based on only one unit cell type: the polylobate sclerenchyma cell. For a better understanding of the interlocked walnut shell tissue, we investigate the structural and compositional changes during the development of the shell from the soft to the hard state. Structural changes at the macro level are explored by X-ray tomography and on the cell and cell wall level various microscopic techniques are applied. Walnut shell development takes place beneath the outer green husk, which protects and delivers components during the development of the walnut. The cells toward this outer green husk have the thickest and most lignified cell walls. With maturation secondary cell wall thickening takes place and the amount of all cell wall components (cellulose, hemicelluloses and especially lignin) is increased as revealed by FTIR microscopy. Focusing on the cell wall level, Raman imaging showed that lignin is deposited first into the pectin network between the cells and cell corners, at the very beginning of secondary cell wall formation. Furthermore, Raman imaging of fluorescence visualized numerous pits as a network of channels, connecting all the interlocked polylobate walnut shells. In the final mature stage, fluorescence increased throughout the cell wall and a fluorescent layer was detected toward the lumen in the inner part. This accumulation of aromatic components is reminiscent of heartwood formation of trees and is suggested to improve protection properties of the mature walnut shell. Understanding the walnut shell and its development will inspire biomimetic material design and packaging concepts, but is also important for waste valorization, considering that walnuts are the most widespread tree nuts in the world.

show abstract

Section: Maturation Of the Shell By Impregnation And Dehydrationmentioning

confidence: 69%

From the Soft to the Hard: Changes in Microchemistry During Cell Wall Maturation of Walnut Shells

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The CH wag of CC is found as a strong IR band at 956 cm −1 (Figure ). Reduced symmetry of the molecule results in some Raman activity, which has been demonstrated to be useful for distinguishing pinosylvins . Out‐of‐phase‐CH‐out‐of‐plane bending (Φ10a) is assigned to the IR band at 936 cm −1 .…”

Section: Resultsmentioning

confidence: 99%

Infrared and Raman spectra of lignin substructures: Coniferyl alcohol, abietin, and coniferyl aldehyde

Bock

Gierlinger

2019

J Raman Spectroscopy

Self Cite

View full text Add to dashboard Cite

Anatomical and chemical information can be linked by Raman imaging. Behind every pixel of the image is a Raman spectrum, which contains all the information as a molecular fingerprint. Yet to understand the spectra, the bands have to be assigned to components and their molecular structures. Although the lignin distribution is easily tracked in plant tissues, the assignment of the spectra is not good enough to allow in‐depth analysis of the composition. Assignments of three lignin model compounds were derived from polarization measurements and quantum‐chemical computations. Raman spectra of coniferyl alcohol crystals showed orientation dependence, which helped in band assignment. Abietin showed a Raman spectrum that was very similar to the spectrum of coniferyl alcohol, whereas its IR spectrum was very different due to bands of the sugar moiety. The Raman spectrum of coniferyl aldehyde is affected by the crystal order of molecules. All three compounds show much stronger band intensities than unconjugated single aromatic rings, indicating that the bulk of the lignin structure has significantly reduced contribution to Raman band intensities. Therefore, it is possible to highlight certain structures of lignin with Raman spectroscopy, because low amounts of a compound do not necessarily mean weak features in the spectrum.

show abstract

“…3 and 4). Raman spectroscopy used together with image analysis software might provide us with a way to detect different tones of colouration in heartwood related to the parenchymal source from where SMs are derived, along with the area (fraction %) the shaded regions occupy (see Felhofer et al, 2018).…”

Section: Secondary Metabolites Of Heartwood and Sapwoodmentioning

confidence: 99%

Using the CODIT model to explain secondary metabolites of xylem in defence systems of temperate trees against decay fungi

et al. 2019

View full text Add to dashboard Cite

Background In trees, secondary metabolites (SMs) are essential for determining the effectiveness of defence systems against fungi and why defences are sometimes breached. Using the CODIT model (Compartmentalization of Damage/Dysfunction in Trees), we explain defence processes at the cellular level. CODIT is a highly compartmented defence system that relies on the signalling, synthesis and transport of defence compounds through a three-dimensional lattice of parenchyma against the spread of decay fungi in xylem. Scope The model conceptualizes ‘walls’ that are pre-formed, formed during and formed after wounding events. For sapwood, SMs range in molecular size, which directly affects performance and the response times in which they can be produced. When triggered, high-molecular weight SMs such as suberin and lignin are synthesized slowly (phytoalexins), but can also be in place at the time of wounding (phytoanticipins). In contrast, low-molecular weight phenolic compounds such as flavonoids can be manufactured de novo (phytoalexins) rapidly in response to fungal colonization. De novo production of SMs can be regulated in response to fungal pathogenicity levels. The protective nature of heartwood is partly based on the level of accumulated antimicrobial SMs (phytoanticipins) during the transitionary stage into a normally dead substance. Effectiveness against fungal colonization in heartwood is largely determined by the genetics of the host. Conclusion Here we review recent advances in our understanding of the role of SMs in trees in the context of CODIT, with emphasis on the relationship between defence, carbohydrate availability and the hydraulic system.We also raise the limitations of the CODIT model and suggest its modification, encompassing other defence theory concepts. We envisage the development of a new defence system that is modular based and incorporates all components (and organs) of the tree from micro- to macro-scales.

show abstract

Antifungal stilbene impregnation: transport and distribution on the micron-level

Cited by 22 publications

References 72 publications

From the Soft to the Hard: Changes in Microchemistry During Cell Wall Maturation of Walnut Shells

From the Soft to the Hard: Changes in Microchemistry During Cell Wall Maturation of Walnut Shells

Infrared and Raman spectra of lignin substructures: Coniferyl alcohol, abietin, and coniferyl aldehyde

Using the CODIT model to explain secondary metabolites of xylem in defence systems of temperate trees against decay fungi

Contact Info

Product

Resources

About