Direct mapping of morphological distribution of syringyl and guaiacyl lignin in the xylem of maple by time-of-flight secondary ion mass spectrometry
Article first published online: 16 NOV 2011
© 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd
The Plant Journal
Volume 69, Issue 3, pages 542–552, February 2012
How to Cite
Saito, K., Watanabe, Y., Shirakawa, M., Matsushita, Y., Imai, T., Koike, T., Sano, Y., Funada, R., Fukazawa, K. and Fukushima, K. (2012), Direct mapping of morphological distribution of syringyl and guaiacyl lignin in the xylem of maple by time-of-flight secondary ion mass spectrometry. The Plant Journal, 69: 542–552. doi: 10.1111/j.1365-313X.2011.04811.x
- Issue published online: 25 JAN 2012
- Article first published online: 16 NOV 2011
- Accepted manuscript online: 6 OCT 2011 03:56PM EST
- Received 16 July 2011; revised 29 September 2011; accepted 3 October 2011.
- mass spectrometric imaging;
- Acer micranthum
Lignin, one of the main structural polymer of plant cell walls, varies in amount and monomeric composition among tissue and cell types, as well as among plant species. However, few analytical methods are available that can conveniently and accurately determine the morphological distribution of lignin units at the cellular level. In this report, we used time-of-flight secondary ion mass spectrometry (TOF-SIMS) to directly map guaiacyl (G) and syringyl (S) lignin units in several successive growth rings of the maple xylem. TOF-SIMS imaging and a semiquantitative approach revealed clear difference in the annual distribution of lignins between the fiber and vessel. While the vessel walls were constantly G-rich with varied S/G ratios through a growth ring, the fibers showed fairly regular annual distribution of lignins in which the earlywood was S-rich with an almost constant S/G ratio and the latewood was G-rich resulting from a decrease of the S unit. The reliability of TOF-SIMS results was demonstrated by its high correlation with the results of thioacidolysis on radial distribution of the S/G ratio in several contiguous tree rings and also in the latewood and earlywood of each ring. These results indicate that TOF-SIMS allows direct visualization of lignin composition in plant tissues.