@ARTICLE{Bieniasz_Anna_The_2022,
 author={Bieniasz, Anna and Tulik, Mirela},
 volume={Vol. 64},
 number={No 2},
 journal={Acta Biologica Cracoviensia s. Botanica},
 pages={65-74},
 howpublished={online},
 year={2022},
 publisher={Biological Commission of the Polish Academy of Sciences – Cracow Branch},
 abstract={The investigation described herein discusses the morpho-anatomical characteristics of xylem parenchyma cells of European ash stems undergoing heartwood formation. The research material comprised of cross and radial sections of wood obtained from stems at breast height of 91-year-old ash trees, half of which had visible ash dieback symptoms. The radial section of the wood samples was stained with acetocarmine to detect nuclei and with I2KI solution to observe starch grains in parenchyma cells, both of radial and axial systems. Additionally, microscopic slides were stained with Alcianblue Safranin-O, and fluorescence microscopy was applied to detect lignified cell walls. The color of sapwood and heartwood distinctly differed – heartwood extracts were detected in approx. 47 rings. Most of the parenchyma cells had nuclei present in both wood zones. Also starch grains were detected in the majority of the tree rings of the researched samples. All of the xylem parenchyma cell walls of axial and radial systems were lignified. The research revealed that lignification, parenchyma cells death and the release of heartwood extracts are processes remote in time and space. Furthermore, parenchyma cell walls lignification did not figure as a sign of the upcoming parenchyma cells death. Based on the current research, ash dieback disease might slightly impact the development paths of parenchyma cells. Compared with scores reported for other trees, European ash parenchyma cells longevity is indeed remarkable.},
 type={Article},
 title={The Longest Living Xylem Cells Locked in Lignified Cell Walls – the Case of Xylem Parenchyma in European Ash ( Fraxinus excelsior L.) Stems},
 URL={http://journals.pan.pl/Content/127130/PDF-MASTER/2022-02-ABC-05.pdf},
 doi={10.24425/abcsb.2022.143383},
 keywords={heartwood formation, lignification, parenchyma cells longevity, programmed cell death, wood anatomy, xylogenesis},
}