摘要
研究了外源草酸对热胁迫下辣椒叶片中细胞膜相对透性、谷胱甘肽 (GSH)和抗坏血酸 (AsA)含量变化以及Ca2 + 分布的影响。结果表明 :热胁迫使叶肉细胞膜相对透性升高 ,草酸处理则减轻升高幅度。热胁迫使叶片中GSH和AsA含量下降 ;草酸处理则使二者在热胁迫下含量下降幅度较小。常温下辣椒叶肉细胞的焦锑酸钙沉淀颗粒主要分布于液泡、胞间隙和叶绿体中 ,热胁迫下液泡、细胞间隙中减少 ,但在细胞核和细胞质中出现 ;经过草酸处理的叶肉细胞 ,焦锑酸钙沉淀颗粒在胞间隙中明显增多 。
The changes in electrolyte leakage, ascorbate (AsA) and glutathione (GSH) contents, along with the Ca 2+ distribution in oxalate treated pepper ( Capsicum annuum L. cv. Xiang yan10) leaves under heat stress were investigated. The electrolyte leakage caused by heat stress in oxalate treated leaves was lesser than that in the control, which shows that the treatment with oxalate could lessen the damage of cell membrane caused by heat stress (Fig.1). The amount of GSH and AsA in oxalate treated leaves under heat stress was higher than that in the control leaves (Figs.2, 3). In the control pepper seedlings growing under normal temperature, the deposits of calcium antimonate, an indicator for Ca 2+ localization, were observed within the vacuoles, intercellular spaces, and the chloroplasts (PlateⅠ 1).Under the same conditin, the amount of Ca 2+ precipitates in intercellular spaces in oxalate treated mesophyll cells was higher than that in the control (PlateⅠ 5). The number of Ca 2+ particles in intercellular spaces in both the control and the oxalate treated mesophyll cells decreased when the seedlings were heat stressed at 40℃(PlateⅠ 3, 4, 7, 8); But the number of Ca 2+ particles in intercellular spaces decreased to a lesser extent in the oxalate treated seedlings than in the control; and the ultrastructure of mesophyll cells in the oxalate treated pepper seedlings was damaged also to a lower degree.
基金
湖北省自然科学基金资助 (99J0 84)
