Physiology of sensitivity and tolerance of crop plants to high manganese availability in the root environment

Abstract

Frontispiece. Synchrotron-based micro X-ray fluorescence images of manganese (Mn), calcium (Ca), and zinc (Zn) distribution in trifoliate leaves of cowpea and soybean grown in complete nutrient solution with 30 µM Mn and in lower alternate leaves of sunflower and expanded leaves of white lupin at 400 µM Mn. In cowpea and soybean, the small red flecks indicate Mn accumulation in the apoplast, small green spots of Ca accumulation in vacuoles, small green angular spots of Ca oxalate, and the larger red and green areas of Mn and Ca accumulation associated with necrosis. Sunflower trichomes accumulate Mn and Ca. In white lupin, the yellow to orange spots indicate the accumulation of both Mn and Ca in vacuoles. The distance and colour scales apply to all images.