| 摘要: |
| 【目的】研究根区不同温度处理对3种黄瓜幼苗碳氮代谢及相关酶活性的影响，为冬季黄瓜生产提供理论依据。【方法】以黄瓜品种津优35号自根苗（以下简称“自根”）、黑籽南瓜嫁接苗（以下简称“黑籽”）、白籽南瓜嫁接苗（以下简称“白籽”）为试材，通过自行研制的根区温度控制装置，将黄瓜幼苗生长期的根区温度分别控制在适温（18～20 ℃，对照）、亚适温（13～15 ℃）、低温（8～10 ℃）条件下，研究根区不同温度对黄瓜幼苗碳氮代谢及相关酶活性的影响。【结果】(1)亚适温和低温处理降低了黄瓜幼苗叶片的Rubisco酶、蔗糖磷酸合成酶（SPS）、蔗糖合成酶（SS）活性，其中低温处理下以上3种酶的活性最低。(2)随着根区温度的降低，黄瓜叶片中淀粉、蔗糖、果糖含量逐渐降低。(3)亚适温和低温处理抑制了黄瓜叶片和根系中硝酸还原酶（NR）、谷氨酰胺合成酶(GS)、 谷氨酸合成酶（GOGAT）活性，低温处理下以上3种酶活性与对照相比均存在显著差异。（4）亚适温和低温处理降低了黄瓜叶片和根系中铵态氮、硝态氮含量，增加了可溶性蛋白和脯氨酸含量。（5）亚适温和低温处理下，“黑籽”的碳氮代谢相关酶活性及物质含量高于“白籽”和“自根”，低温处理下“黑籽”的可溶性蛋白和脯氨酸含量最高，“自根”的可溶性蛋白和脯氨酸含量最低。【结论】亚适温和低温处理均抑制了黄瓜幼苗碳氮代谢相关酶的活性及物质含量，增加了根系和叶片中可溶性蛋白、脯氨酸含量；此外，低温胁迫对“黑籽”的影响最小，其抗逆性最强，“白籽”次之，“自根”的抗逆性最弱。 |
| 关键词: 黄瓜幼苗 根区温度 碳代谢 氮代谢 |
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| 基金项目:国家自然科学基金项目(31060269)；内蒙古自治区科技计划项目(20110710)；教育部博士点基金项目(20101515110005); 山西省煤基重点科技攻关项目(FT201402-09) |
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| Effects of root-zone temperature on carbon and nitrogen metabolism and activities of related enzymes of cucumber seedlings |
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SUN Shijun,FU Chongyi,CUI Shimao,et al
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| Abstract: |
| 【Objective】This paper analyzed the effects on temperature on carbon and nitrogen metabolism and activities of related enzymes of three cucumber seedlings to provide basis for winter production of cucumbers.【Method】Cucumber varieties including Jinyou No.35 (“The root”),black seed grafting pumpkin (“Black seed”) and white seed grafting pumpkin (“White seed”) were selected and the temperatures at night were set to suitable (18-20 ℃),suboptimal (13-15 ℃) and low (8-10 ℃) by a self-developed ground temperature control device.Then,the effects on carbon and nitrogen metabolism and activities of related enzymes were analyzed.【Result】(1) Suboptimal temperature and low temperature reduced the activities of Rubisco enzyme,sucrose phosphate synthase (SPS) and sucrose synthase (SS) of cucumber seedlings,with the lowest activities in low temperature treatment.(2) With the decrease of root zone temperature,the contents of starch,sucrose and fructose in leaves decreased gradually.(3) Suboptimal temperature and low temperature reduced the activities of nitrate reductase (NR),glutamine synthetase (GS) and glutamate synthetase (GOGAT) in leaves and roots.Significant differences were obtained between the low temperature and control.(4) Suboptimal temperature and low temperature reduced the contents of ammonium nitrogen and nitrate nitrogen in leaves and roots,while increased the contents of soluble protein and proline.(5) Suboptimal temperature and low temperature reduced carbon and nitrogen metabolism and activities of related enzymes and contents of different substances in “Black seed” were higher than those in “White seed” and “The root”.Under low temperature condition,“Black seed” had the lowest contents of proline and soluble protein while “The root” had the lowest.【Conclusion】Suboptimal temperature and low temperature reduced the activities of enzymes related to carbon and nitrogen metabolism and increased the contents of soluble protein and proline in roots and leaves.“Black seed” was affected the least by low temperature with the strongest resistance followed by “White seed” and “The root”. |
| Key words: cucumber seedlings root-zone temperature carbon metabolism nitrogen metabolism |
