Aluminum-induced alterations in lipid composition of microsomal membranes from an aluminum-resistant and an aluminum-sensitive cultivar of Triticum aestivum

Abstract

1996. Aluminum-induced alterations in lipid composition of microsomal membranes from an aluminum-resistant and an aluminum-sensitive cuitivar of Tritieum aestivum. -Physio]. Plant. 96: 683-691.We have studied tiie effect of aluminum (Al) on the lipid composition of microsomal membranes isolated from 5-mm root tips of an Al-resistant (FT 74!) and an Al-sensitive (Katepwa) cultivar of Tritieum aestivum L. Exposure of both genotypes to 10 and 50 nM AlCl, for 1 day bad no effect on lipid composition: however, decreases in pbospholipids and increases in monogalactosyl diacyiglycerols, free sterois. fi"ee fatty acids and triacylglycerols were obsen^ed with prolonged exposure '[3 days) to 50 ^M AlClj. Several genotype-specific changes were also obsen'ed under these conditions. The content of digalactosyl diacylglycerols increased by 66.7% in Katepwa. but decreased slightly in PT 741. Tbus. the ratio of monogalactosyl diacylglycerols to digalactosyl diacylglycerols increased by 46.2'?'r in PT 741, but decreased by 2I.37r in Katepwa. Genotype-specific differences were aiso observed in ster>'I iipids. Treatment with Al induced a 70.2% increase in sterylglucosides and a 23.3% increase in aeylated sterylglucosides in Katepwa. In contrast, a 18.9% decrease in aeylated steryiglucosides and no cbanges in sten'lglueosides were observed in PT 741. Our limited understanding of the effect of membrane composition on membrane structure and function makes it difficult to predict iiow these ciianges relate to At toxicity and resistance. Wbile it is possible thai many changes reflect the toxic effects of Al. we believe that cbanges obsen.'ed only in the Al-resistant genotype could contribute to continuotis growth in the face of Ai stress.

Relative abundance of Δ5‐sterols in plasma membrane lipids of root‐tip cells correlates with aluminum tolerance of rice

“…Although the difference between tolerant and sensitive cultivars was small, similar data have been reported previously for wheat cultivars. That is, a lower phospholipids/D 5 -sterols ratio in control root tips was observed in the Al-tolerant cultivar (Zhang et al 1996). In addition, Ryan et al (2007) recently reported that genetically modified Arabidopsis thaliana with altered membrane lipids showed greater Al tolerance.…”

Alteration of plasma membrane lipids in aluminum-resistant and aluminum-sensitive wheat genotypes in response to aluminum stress

“…Despite the high pH of experimental solutions used in their study (pH 5.3, 5.4 and 6.1), which raises questions about the solubility and speciation of Al in treatment solutions (Kinraide 1991), they found that Al increased the content of phosphatidylcholine (PC) relative to that of phosphatidylethanolamine (PE). Recently, Zhang et al (1996) examined the lipid composition of microsomai membranes from 5-mm root tips of an Al-resistant (PT741) and an Al-sensitive (Katepwa) genotype of T. aestivum and found several genotype-specific changes in response to AI stress (pH 4.3), including an increase in digalactosy! diacylglycerols (DGDG), sterylglucosides (SG) and acylated sterylglucosides (ASG) in Katepwa, but a slight decrease in DGDG and ASG in FT741.…”

Effect of phosphate on aluminium-inhibited growth and signal transduction pathways in Coffea arabica suspension cells

“…Aluminium toxicity may affect lipid composition [47,48] through regulation of lipid kinase enzymes in the plasma membrane [22]. Phosphate deprivation is known to decrease lipid composition in the plasma membrane [34], but no research has been done on the effect of Pi on lipid kinase activity.…”