Visualizing the distribution of elements within barley leaves by energy dispersive X-ray image maps (EDX maps)



X-ray image maps of transverse sections of barley leaf blades were compared with individual X-ray emission spectra from vacuoles of barley leaf mesophyll, epidermis and parenchymatous bundle sheath cells. Both forms of X-ray analysis revealed distinct patterns in element distribution within the leaf blade. Calcium and Cl predominated within the epidermal cell vacuoles whilst P appeared mainly in the mesophyll cell layer. Apparent accumulation of S and Mg within the bundle sheath cell vacuoles is discussed in relation to xylem unloading and sulphur assimilation.