| Abstract Detail
Stress Tolerance Chaffai, Radhouane [1], Tekitek, Ali [1], Marzouk, Brahim [3], El Ferjani, Ezzedine [4]. Aluminum induced alterations in polar lipid fatty acid composition in maize (Zea mays L.). Al is one of the most important factors limiting plant growth in acid soils. Al treatments (50-500 μM) resulted in severe morphological alterations in roots, as shown by shortening of the secondary roots in the subapical zone and swollen root apices. We examined the effect of Al (100 μM) on the fatty acid composition of the root and shoot polar lipids. The total fatty acids in roots showed a decreased double bond index (DBI). This finding indicates that Al binding to membrane lipids may induce a decrease in the membrane fluidity, an important aspect of Al avoidance mechanisms. The total lipids (TL) decreased by 49%, while, by contrast, phospholipids (PL): phosphatidylcholine (PC) and phosphatidylinositol (PI) increased to approximately threefold. Al exposure led to a two-fold increase in MGDG content as well as 69% increase in steryl lipids (SL) compared with control plants. Moreover, Al treatment led to an increase of the MGDG/DGDG ratio (from 0.45 to 1.06) and a decrease in the SL/PL ratio (from 2.64 to 1.52). These changes may be necessary for optimum membrane function under Al stress. The fatty acids of shoot polar lipids, particularly PG showed a similar overall increase in the unsaturation levels as indicated by the double bond index. The results also indicated an increase in content of PI and PG, and a decrease in PC in shoots of plants grown in the presence of Al. However, Al markedly reduced content of glycolipids: MGDG and DGDG. We conclude that Al binding and/or interaction with membrane lipids may have deleterious effects on the membrane function, leading to lower nutrient uptake and to the growth inhibition.
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1 - Faculty of sciences Bizerte, Life Sciences, Zarzouna, Bizerte, 7021, Tunisia
2 - Faculty of sciences Bizerte, Life Sciences, Zarzouna, Bizerte, 7021, Tunisia
3 - Aromatic and Medicinal Plants Unit, Biotechnologic Center, Borj-Cedria Technopol, Hammam-Lif, BP. 901, 2050, Tunisia
4 - Faculty of Sciences Bizerte, Zarzouna, Life Sciences, Bizerte, 7021, Tunisia
Keywords:
Aluminum
fatty acids
polar lipids
Zea mays L..
Presentation Type: Poster:Posters for Topics
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P77002
Abstract ID:43 |
