Abstract
Andropogon virginicus L. is a wild plant which shows a high tolerance to Al. Four tolerant mechanisms shown below were involved in this plant. 1) Low Al uptake in root tip. 2) High transportation of toxic Al from root to shoot not to accumulate it in root. 3) Accumulation of Al to trichome in leaf. 4) Induction of anti-peroxidation enzymes by Al stress to suppress oxidative damage. Especially 2) and 3) may be very unique mechanisms of this plant.
Nitric oxide (NO) generally has a function in signal transduction under various stresses in many organisms. Andropogon was investigated whether NO has a similar function under Al, Cd, Cr, Cu and Zn stress in this study. Production of NO was only observed by Al, but not by others. Moreover, NO was not detected in any other tested gramineae plants by the metal treatments. Furthermore, function of NO for Al tolerance in Andropogon was studied. Oxidative damage was suppressed under Al stress by an addition of cPTIO which is an inducer of NO production, while DNA fragmentation was not suppressed. These results suggested that NO production is an Al specific response in Andropogon, and is partially related to tolerance mechanism.
