Studies of metal uptake, especially iron, into protein bodies of Capsella and Lycopersicon seeds
Energy dispersive X-ray analysis was used to investigate metal uptake into the globoid crystals of Capsella and Lycopersicon seeds. Capsella seeds were taken from the curbside of a major roadway where metal contamination was highest, 5 m from the curb where less metal contamination occurs, and from an area well away from any roadways. Globoid crystals in Capsella protein bodies generally contained P, K, Ca, and Mg. No uptake of Pb or any other toxicant metals into the globoid crystals was found. Globoid crystals from the radicles and cotyledons of seeds produced by plants growing near the curb generally contained Fe whereas seeds of plants growing 5 m back from the curb contained traces of Fe in globoid crystals in certain tissues. Seeds of plants growing farthest from any roadway contained no Fe in their globoid crystals. Seeds of Lycopersicon were grown in metal-contaminated soil obtained near a smelter, a 1:1 mixture of this contaminated soil and regular potting soil, and a control. Globoid crystals from control seeds generally contained P, K, and Mg, while Ca, Mn, and (or) Fe were present occasionally. Control endosperm globoid crystals did not contain Fe. No pollutant metals were taken up into the globoid crystals. Iron which was present in the contaminated soil was found in the globoid crystals of the endosperm in those seeds obtained from plants grown in contaminated soil. Also, although Fe-containing globoid crystals were specifically located throughout the embryo in control seeds, there was no evidence that seeds of plants grown in contaminated soil contained more Fe in these areas.