¹⁴N and ¹⁵N imaging by SIMS microscopy in soybean leaves

Abstract

Summary— The distribution of 15 N and 14 N compounds in cryofixed and resin embedded sections of soybean ( Glycine max L) leaves was studied by SIMS microscopy. The results indicate that, with a mass resolution M /Δ M higher than 6000, images of the nitrogen distribution can be obtained from the mapping of the two secondary cluster ions 12 C 14 N − and 12 C 15 N − , in samples of both control and 15 N‐labeled leaves. The ionic images were clearly related to the histological structure of the organ, and allow the detection of 14 N and 15 N at the subcellular level. Furthermore, relative measurements of the 12 C 14 N − and 12 C 15 N − beams made possible the quantification of the 15 N atom% in the various tissues of the leaf.