New applications for an old lignified element staining reagent.
The use is reported of Mirande's reagent in epifluorescence microscopy which permits a clear distinction between cellulosic and lignified tissues. Homogeneous Prespermatophytae and gymnosperm xylem appeared entirely green with Mirande's reagent under ultraviolet excitation, whereas heteroxyled angiosperm wood showed a mixed pink and blue-green colour. This coloration was due to the fluorescence of cellulose, since certain elements in dicotyledonous wood (parenchyma, fibres, xylem rays) are not entirely lignified. Monocotyledonous (Poaceae) lignin showed an intense blue fluorescence due to hydroxycinnamic acids bound to the cell wall. The method showed that lignification occurs first in the middle lamella, and later in the secondary wall of xylem cells. In addition, this staining technique proved useful in the study of lignin and suberin deposition in response to various stress factors.
Mondolot
L
L
Laboratoire de Botanique, Phytochimie et Mycologie, UMI-CNRS, UPR 9056, Faculté de Pharmacie, Montpellier, France.
Roussel
J L
JL
Andary
C
C
D002482:Cellulose / Q000032:analysis / Q000378:metabolism; D008031:Lignin / Q000032:analysis / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000379:methods; D008860:Microscopy, Ultraviolet; D018514:Plant Structures / Q000737:chemistry / Q000378:metabolism*; D013194:Staining and Labeling / Q000379:methods*
D002482:Cellulose; D008031:Lignin