Effects of iron plaque on roots of rice on growth and metal concentration of seeds and plant tissues when cultivated in excess copper

Abstract

To cite this article: S. Greipsson (1994) Effects of iron plaque on roots of rice on growth and metal concentration of seeds and plant tissues when cultivated ABSTRACT: Deposition of iron (Fe) plaque on roots of rice before exposure to excess of copper (Cu) was found to lessen the toxic effects of Cu. In the excess of Cu, plants with Fe plaque had significantly greater dry weight of roots and leaves, longer leaves, and roots, and higher concentration of Fe in leaves than plants without plaque. In the excess of Cu, plants without Fe plaque had more leaves showing chlorosis than plants with plaque. Iron plaque on roots appeared to be beneficial for seed formation, since plants with plaque grown without exposure to excess Cu had highest seed weight, although differences were not significant. In the excess Cu solution, plants with plaque had significantly more Fe in seeds and more Cu in roots and in the DCB (dithionite-citrate-bicarbonate) wash than plants without plaque.

Influence of external zinc and phosphorus supply on Cd uptake by rice (Oryza sativa L.) seedlings with root surface iron plaque

“…1), and the present study indicates that the contribution of iron plaque to plant Cd uptake was minor and the roots may have been the main tissue acting as a barrier to plant Cd uptake. These results differ from others (Chen et al 2006;Batty et al 2000;Greipsson 1994Greipsson , 1995Liu et al 2004b) but agree with our conclusions (Liu et al 2007) and those of Liu et al (2005) who also found that root tissue was the main barrier to As uptake by rice plants when arsenite was supplied. Similar results were also reported for metal uptake by other wetland plants, for example Pb and Cd uptake by Typha latifolia (Ye et al 1998), Cu, Zn and Pb uptake by water hyacinth (Vesk et al 1999), and Fe, Mn, Cu and Zn uptake by Juncus bulbosus (Chabbi 1999).…”

“…However, no visible Fe toxicity symptoms were observed even though root dry weight decreased at Fe50 (Table 1), indicating that roots were more sensitive to the external Fe supply. In the literature, decreases (Ye et al 2001;Liu et al 2007) or increases (Greipsson and Crowder 1992;Greipsson 1994Greipsson , 1995 or no changes in root dry weight have been reported in response to pre-treatment to induce the formation of iron plaque on root surfaces. The distributions of P and Zn in different plant parts were in contrast with that of Cd (Fig.…”

“…However, the effects of iron plaque on plant elemental uptake are controversial. Some workers have suggested that iron plaque can sequester metal(loid)s such as Al and As on root surfaces of rice and thus depress their translocation to the shoots (Batty et al 2000;Chen et al 2006;Greipsson 1994Greipsson , 1995Liu et al 2004b). Others have shown that iron plaque has little effect on Cd uptake (Liu et al 2007), and some have demonstrated that iron plaque can act as a P reservoir to enhance plant P uptake (Liang et al 2006;Zhang et al 1999).…”

“…Iron plaque therefore has chemical properties similar to those of iron oxides in the soil and can thus sequester both cations and anions and alter the uptake and accumulation of elements by plants. Iron plaque on rice root surfaces has been shown to sequester As (Liu et al 2004a,b andLiu et al 2005), Al (Chen et al 2006) and Se (Zhou et al 2007), alleviate toxicities of Cu, Ni and Zn to plants (Greipsson 1994(Greipsson , 1995Greipsson and Crowder 1992) and enhance Zn uptake when the amount of iron plaque was up to 12.1 g kg −1 root dry weight (Zhang et al 1998) and P uptake up to 24.5 g kg −1 root dry weight when Fe(OH) 3 was supplied to induce the formation of iron plaque (Zhang et al 1999). However, studies have also suggested that iron plaque is not the main barrier to Cd uptake by rice (Liu et al 2007).…”

Copper and nickel uptake, accumulation and tolerance in Typha latifolia with and without iron plaque on the root surface

“…It has not been accepted that iron plaque acts entirely as an external barrier to toxic metals; it might influence tolerance in other ways, such as leading to a higher concentration of 'active iron' within leaves (Greipsson, 1995), as well as absorbing and immobilizing metals. Although the relationship between iron plaque on roots and metal absorption and accumulation by plants has been studied in recent years , 1990Greipsson & Crowder, 1992;Otte et al, 1989Otte et al, , 1991St-Cyr, Fortin & Campbell, 1993;Greipsson, 1994), this relationship is still unclear. Typha latifolia L. is a common and productive wetland plant of world-wide geographical distribution.…”