Author
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Wang, Shiow |
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Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/19/2004 Publication Date: 8/10/2006 Citation: Wang, S.Y. 2006. Effect of plant growth temperature on membrane lipds in strawberry (fragaria x ananassa duch).. Scientia Horticultureae, vol. 108: pp.35-42. Interpretive Summary: The quality of strawberry fruit is greatly influenced by temperature during the growing season. However, we do not know the mechanisms through which the growing temperatures exert their effects. Since it is known that the adaptation of plants to the climate and the quality of fruits are related to the membrane lipids in the cells, we elected to study the changes of the composition of membrane lipids and fatty acids as affected by the growing temperatures. We have identified the predominant membrane lipids and fatty acids in leaves, roots, and fruit of two cultivars of strawberry. We have also found that strawberry fruit grown under cooler temperatures contained higher amounts of good lipids than those grown under warmer temperatures. This information is helpful in understanding the role of membrane lipids in regulating strawberry plant growth in different temperature zones. It is possible that the quality of strawberry fruit can be mediated by changes in growing temperatures. Thus, the information obtained from this research is valuable for the other scientists and growers who are working on strawberry. Technical Abstract: Changes in membrane lipid composition are important in the acclimation of plants. The influence of four day/night growing temperature combinations (18/12, 25/12, 25/22, 30/22 oC) on membrane lipids of Earliglow and Kent strawberry (Fragaria x ananassa Duch.) were studied. The monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG) were the major galactolipids in the strawberry leaves. Earliglow contained a higher amount of galactolipids in the leaves than Kent. The major phospholipids in the strawberry leaves, roots, and fruit were phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylglycerol (PG), and phosphatidylethanolamine (PE). PC and PE were the two predominant phospholipids in the strawberry. The leaves and fruit of Earliglow contained higher amounts of phospholipids compared to those of Kent, whereas 'Kent' strawberry roots had higher phospholipids. Palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2), and alpha-linolenic (C18:3) acids were major fatty acids in galacto- and phospholipids of the 'Earliglow' and 'Kent' strawberry. PC is very rich in linolenic acid in leaves compared to the fruit and root tissues. PC had the highest ratio of unsaturated to saturated fatty acids among all phospholipids. There was a significant increase in the content of galactolipids (MGDG, DGDG) and phospholipids (PC, PI, PG and PE) and unsaturation of their fatty acids in the cool day/night growth temperature. Increasing day/night growth temperatures decreased MGDG/DGDG ratios. The shifts in saturation and composition of fatty acids observed with strawberry may be adaptation responses of plants to the temperature changes. |
