Response of polyamines to heavy metal stress in oat seedlings

Abstract

Polyamine titers in oat seedlings (Avena sativa L.) were evaluated as possible biomarkers for heavy metal stress. The titers were measured in response to the addition of 20 metal salts. Six of those metal salts were chosen for further study: chromium, cobalt, copper, mercury, nickel, and silver. Changes in polyamine titer in response to the addition of the six metal salts were specific for each metal, but were generally smaller when compared to changes in polyamine titer associated with other forms of plant stress reported in the literature. Changes in putrescine titer, over time, were also specific for each metal, but did not correlate well with the changes in the enzymatic activity of its biosynthetic enzyme, arginine decarboxylase. We conclude that polyamine metabolism and arginine decarboxylase activity are not effective as general biomarkers for evaluating heavy metal stress in oat seedlings.

Chromium Stress in Plants: Toxicity, Tolerance and Phytoremediation

“…Chromosomal impairment by Cr(VI) treatments (0.01 mM and 0.1 mM) has been reported in Amaranthus viridis plant tissues, where it regulated the activity of calmodulin that was further responsible for the activation of many key enzymes such as phospholipase and nicotinamide adenine dinucleotide kinase, involved in the chromosomal movement [63]. Furthermore, Cr has also been observed to affect the concentrations of free polyamines in Avena sativa, Brassica napus, and H. vulgare seedlings after treatment with 100 mg/L of Cr(III) for 1-14 days [62,64].…”

High concentrations of zinc and copper induce differential polyamine responses in micropropagated white poplar (Populus alba)

“…In fact, the PA response widely varies, depending upon metal type and concentration, and plant species. For example, increases in free Pu levels in response to various HM, in particular Cu and Zn, have been reported in oat and rice leaves, while in sunflower the diamine decreased (Groppa et al 2003, Hauschild 1993, Lin and Kao 1999, Wettlaufer et al 1991). In most reports, only one time‐point measurement in PA levels has been performed, and often PA conjugates have not been determined, nor have morphological observations been conducted in parallel.…”

“…Moreover, PA overproduction in engineered plants confers increased tolerance to multiple environmental stresses (Capell et al 2004, Kasukabe et al 2004, Roy and Wu 2001). Less is known about the biosynthetic activities, which lead to PA accumulation in response to HM (Balestrasse et al 2005, Groppa et al 2003, Weinstein et al 1986, Wettlaufer et al 1991), while almost nothing is known about the transcription of the related genes.…”