Poster: Heavy metals & phytoremediation

Abs # 48: Temporal aspects of aluminum exclusion in loblolly pine seedlings.

Presenter:	Moyer-Henry, Kari A., kari_moyer@ncsu.edu
Authors	Moyer-Henry, Kari A. (A)   Jennette, Michael W. (A)   Johannes, Eva  (B)   Allen, Nina S. (B)   Rufty, Thomas W. (A)
Affiliations:	(A): North Carolina State University, Crop Science Dept (B): North Carolina State University, Botany Dept.

Past experiments by our group have shown that loblolly pine (Pinus taeda) possesses a high level of tolerance to Al. In a hydroponics culture system with strict pH control, primary root extension of crop species like soybean, barley, wheat, and corn is strongly inhibited at 20 to 30 μM Al⁺³, but pine is inhibited only about 30% at 2000 μM Al⁺³. In the current experiments, we examine Al sensitivity of lateral roots over time and their ability to exclude Al from the growth centers during lateral root extension. The fluorescent stain lumogallion is used to localize Al in lateral root tips and adjacent cells of the primary root including the pericycle. Initial experiments have indicated that Al exclusion is a primary mechanism of Al tolerance, and replacement series experiments with other species suggest substantial binding of Al in the rhizosphere. Experiments begin to evaluate the possible involvement of organic acids in the Al tolerance responses.