Fig. 8

Metal distribution in a pepper leaf (C. annuum, cultivar ‘Kozy Roh’). The leaf was measured in a single cycle with 600 ms integration time per point and 15 µm point distance. Measured with He atmosphere in the hutch but air in the measuring chamber. Maps of photosynthetic parameters for the same leaf before and after radiation are shown in Fig. 5. Gaussian smoothing was applied to all element maps (sigma = 1 for Ca, sigma = 3 for all other elements). The element maps of this figure are semi-quantitative (0 = black, maximum = white), obtained by spectral deconvolution but without normalization to a standard. Images are then in detector counts instead of concentration units. The zoomed image of the Ca map shows the epidermal guard cells, which are known to contain high Ca, confirming the high resolution of the µXRF measurement