Author
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Wang, Shiow |
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Submitted to: Journal of Plant Growth Regulation
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/28/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Water deficit is one of the main environmental factors limiting plant growth and crop production. Drought causes visible injuries to leaves, induces stomatal closure, leaf rolling and osmotic adjustment. Water stress causes a faster decline in the chlorophyll and protein content, altering both the structure and function of membranes. These results showed that a substantial number of drought effects on strawberry plants can be mimicked by external application of methyl jasmonate. Jasmonic acid and its methyl ester (methyl jasmonate) are naturally occurring plant growth regulators. When exogenously applied to plants, jasmonate reduced transpiration, lessened the reduction of membrane lipids content, enhanced the activities of oxygen scavenging enzymes, and maintained a higher amount of the ascorbic acid content under water stress. These results indicate that jasmonate treated plants are more resistant to water stress. This research contributes to our understanding on stress physiology and is of interest to other scientists. Technical Abstract: The effect of methyl jasmonate (MJ) on changes in membrane lipid composition and activities of oxygen scavenging enzymes under water stress was studied in strawberry leaves. Under water stress, MJ treatment reduced transpiration and malondialdehyde (MDA) content. In addition, treatment with MJ under water stress lessened the reduction of membrane lipids, glycolipids [monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG)], phospholipids [phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylinositol (PI)]. In water deficit conditions, MJ treatment alleviated the decline in the degree of fatty acid unsaturation and the ratio of linolenic (18:3) to linoleic acid (18:2). MJ also reduced the increase of peroxidase (EC 1.11.1.7; POD) activity under water stress. Compared to control (untreated) leaves under water deficit conditions, higher activities of catalase (EC 1.11.1.6; CAT), superoxide dismutase (EC 1.15.1.1;SOD) and ascorbic acid content were detected in the MJ treated leaves. These results indicate that MJ treated plants are more resistant to water stress. |
