A comparative analysis of fatty acid composition of root and shoot lipids inZea maysunder copper and cadmium stress

Abstract

A comparative analysis of fatty acid composition was conducted in maize (Zea mays L.) under copper and cadmium stress. The unsaturation level (double-bond index) of phosphatidylethanolamine (PE) and digalactosyldiacylglycerol (DGDG) was increased in response to both metal treatments, whereas the phosphatidylinositol (PI), the phosphatidylcholine (PC) showed no significant changes. The Cu-treated roots showed a marked increase (about 2-fold) in the phospholipid (PL) content, while the Cd-treated roots showed a slight but insignificant increase. The steryl lipid SL/PL ratio was markedly decreased in response to Cu stress, and therefore, may indicate an activated phospholipid biosynthesis and turnover, in response to damage caused by Cu stress. The double bond indices of chloroplastic lipids: phosphatidylglycerol (PG), monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG) and sulfoquinovosyldiacylglycerol (SQDG) revealed a similar but not identical pattern of change. The PG and MGDG contents in shoots were markedly decreased under Cu (by 53 and 48%) and Cd (by 78 and 65%) stress. The increase in the malondialdehyde (MDA) content in roots induced by both metals indicates lipid peroxidation. Generally, in the presence of Cu fatty acid composition was markedly modulated but to lesser extent under Cd stress. These results suggest that changes in the fatty acid composition under Cu and Cd stress conditions are metal-specific and may therefore result in differential metal tolerance.

Effect of Petroleum Crude Oil on Mineral Nutrient Elements, Soil Properties and Bacterial Biomass of the Rhizosphere of Jojoba

“…All these stresses lead to increment of MDA. Our results are in agreement with previous reports where MDA increased under soil heavy metal pollution in different plant species [52][53][54].…”

Effect of heavy metals on plasma membrane lipids and antioxidant enzymes of Zygophyllum species

“…The reduction in PC/PE ratio may influence the plasma membrane performance under pollution, because PC and PG have membrane stabilizing effect relative to PE (Thompson 1992, Mansour et al 1994, Salama et al 2007). Our finding supports previous published data where copper and cadmium stress increased PE while they reduced PG content in Zea mays (Chaffai et al 2005, Chaffai et al 2009). Increased PE might have an adaptive value to counterbalance the membrane rigidifying impact of increasing saturated fatty acids (Thompson 1992, Mansour et al 1994, 2002, Salama et al 2007) induced in the current study under heavy metal stress ( Table 6).…”

“…Lipid peroxidation observed in the current work is indicative of heavy metal-induced oxidative stress in both species. Our results are in agreement with previous reports where lipid peroxidation increased under soil heavy metal pollution in different plant species (Chaffai et al 2005, Chaffai et al 2009, Janicka et al 2008. The results of lipid peroxidation were comparable with those of reactive oxygen species scavengers (antioxidant enzyme activities) reported in the following section (Table 3), where the increase in the antioxidant enzyme activities was greater in Z. album than Z. coccineum, in order to alleviate the greater oxidative stress in induced Z. album.…”

New insights on the function of plant acyl carrier proteins from comparative and evolutionary analysis

“…However, the role of ACPs in stress tolerance or resistance has not been reported. As a product of FAS, FA reportedly shows extensive involvement in plant responses to stress [63,64]. In this sense, ACPs probably act indirectly against adverse environments.…”