植物生态学报 ›› 2004, Vol. 28 ›› Issue (3): 326-332.DOI: 10.17521/cjpe.2004.0048

• 论文 • 上一篇    下一篇

温度逆境交叉适应对葡萄叶片膜脂过氧化和细胞钙分布的影响

王利军, 李绍华, 李家永, 杨树华, 刘允芬, 石玉林   

  • 发布日期:2004-03-10
  • 通讯作者: 王利军

PEROXIDATION OF MEMBRANE LIPID AND CALCIUM DISTRIBUTION IN GRAPE MESOPHYLL CELLS DURING CROSS ADAPTATION TO TEMPERATURE STRESSES

WANG Li-Jun, LI Shao-Hua, LI Jia-Yong, YANG Shu-Hua, LIU Yun-Fen, SHI Yu-Lin   

  • Published:2004-03-10
  • Contact: XIAO Yi-An HE Ping and LI Xiao-Hong

摘要:

研究了高温锻炼对低温胁迫下和低温锻炼对高温胁迫下葡萄(Vitis vinifera)叶片中丙二醛(MDA)、谷胱甘肽(GSH)和抗坏血酸(AsA)含量变化以及细胞中Ca2+分布的影响。结果表明: 高(低)温胁迫使正常生长的叶片丙二醛含量升高, GSH和AsA含量下降,低(高)温锻炼预处理能减少MDA含量,提高GSH和AsA含量,抑制了由于温度胁迫引起MDA含量升高和GSH和AsA下降趋势。常温下葡萄叶肉细胞的Ca2+主要分布于液泡、细胞间隙中;高温胁迫和低温胁迫后,细胞质中聚集大量Ca2+沉淀颗粒,液泡中和细胞间隙Ca2+沉淀颗粒减少,叶绿体超微结构被破坏,Ca2+稳态平衡遭到破坏。高温锻炼后细胞质出现大量的Ca2+沉淀颗粒,主要来源于细胞间隙,低温锻炼后细胞质也出现大量的Ca2+沉淀颗粒,主要来源于液泡,两者的叶绿体超微结构都完整;高温锻炼的叶片经过低温胁迫和低温锻炼的叶片经过高温胁迫后,细胞间隙和液泡内Ca2+沉淀颗粒增加,细胞质中Ca2+沉淀颗粒很少,叶绿体较完整,Ca2+稳态平衡得以维持。推测高低温锻炼能够通过Ca2+启动抗逆基因表达和维持细胞中Ca2+稳态平衡来交叉适应低高温的胁迫。

Abstract:

Changes in the membrane protective system and Ca2+ homeostasis in young grape (Vitis vinifera) plants during the enhancement of chill resistance with heat acclimation and heat resistance with cold acclimation were examined to explore the mechanism of cross adaptation to temperature stress. MDA content in heat (cold) acclimated leaves by cold (heat) stress was less than that in the non-acclimated control plants which showed that heat (cold) acclimation could alleviate the damages of cell membrane caused by cold (heat) stress. Higher leaf levels of glutathione (GSH) and ascorbate acid (AsA) also were found with pre-cold (heat) acclimation under heat (cold) stress than in the non-acclimated control plants. Cold and heat stresses have been shown to cause transient elevated levels of cytosolic free Ca2+, but there is little evidence showing that Ca2+ homeostasis was maintained in cross adaptation, a crucial factor for confirmation of the existence of cross adaptation and the elucidation of the mechanisms of cross adaptation. Ca2+-homeostasis was demonstrated by examining Ca2+ distribution using the cytochemical method of the calcium antimonite precipitation. The results revealed calcium was distributed mainly within the vacuole and intercellular spaces at the optimum growth temperature. When the plants were treated by either heat or cold acclimation for 3 h, calcium levels in the cytoplasm increased dramatically. Meanwhile, deposits in the vacuole concentrated in the tonoplast and deposits in the intercellular space decreased after heat acclimation whereas, after cold acclimation, the deposits in vacuole decreased significantly but did not change in the intercellular space. These results indicate that heat acclimation mostly pumped Ca2+ out of intercellular spaces whereas cold acclimation pumped Ca2+ out of vacuoles. These results revealed two physiological phenomena: on one hand, heat (cold) acclimation increased Ca2+ in cytoplasm to increase the integrity of membranes under cold (heat) stress; on the other hand, increased Ca2+ in the cytoplasm induced the expression of GSH and AsA genes increasing GSH and AsA levels.When non-acclimated plants were stressed at 44 ℃ or -3 ℃ for 3 h, compared to control plants, more Ca2+ particles were located in the inner side of the plasma membrane, fewer Ca2+ particles were in the intercellular spaces and vacuole, the plasma membrane and chloroplast showed signs of damage, and chloroplast ultrastructure was destroyed. However, when heat acclimated plants were exposed to chilling stress at -3 ℃ for 3 h and cold-acclimated plants were exposed to heat stress at 44 ℃ for 3 h, more Ca2+ particles were found in the intercellular spaces and in vacuoles and few Ca2+ particles were on the inner side of the plasma membrane. Cell membranes and chloroplasts were not destroyed. These results indicate that too much intracelluar Ca2+ can be pumped off in heat-acclimated cells under cold stress or cold-acclimated cells under heat stress but cannot be pumped off in non-acclimated cells, suggesting that calcium homeostasis is very important in grape mesophyll cells during cross adaptation to temperature stress.