| 摘要: |
| 【目的】研究干旱胁迫对地梢瓜琥珀酸合成代谢的影响，为其琥珀酸开发利用提供理论依据。【方法】以地梢瓜和雀瓢幼苗为试材，设对照（土壤含水量为田间最大持水量（24.44%）的65%~70%，下同）、轻度（45%~50%）、中度（25%~30%）和重度（5%~10%）4个干旱胁迫处理，测定不同处理根、茎、叶中琥珀酸含量和琥珀酸合成酶活性，比较不同处理各指标的变化，分析琥珀酸与其合成酶的关联性。【结果】（1）琥珀酸在地梢瓜和雀瓢的根、茎、叶中均有分布，地梢瓜不同器官中的琥珀酸含量表现为叶>根>茎，而雀瓢则表现为叶>茎>根。（2）随着干旱程度的加重，地梢瓜和雀瓢叶、根中的琥珀酸含量先增加后减少，以中度干旱胁迫处理下最大。（3）地梢瓜和雀瓢叶中α-酮戊二酸脱氢酶(α-KGDH)、琥珀硫激酶(STK)、琥珀酸脱氢酶(SD)、谷氨酸脱羧酶(GAD)活性和γ-氨基丁酸(GABA)含量均在重度干旱胁迫处理下最大。（4）相关性分析表明，地梢瓜和雀瓢叶中琥珀酸含量与 GABA和SD活性呈负相关。【结论】适度干旱胁迫能够促进地梢瓜和雀瓢琥珀酸的积累。轻度和中度干旱胁迫下，琥珀酸合成以三羧酸循环途径(TCA)为主，重度干旱胁迫下以γ-氨基丁酸代谢支路(GABA shunt)为主。 |
| 关键词: 地梢瓜 雀瓢 干旱胁迫 琥珀酸 γ-氨基丁酸 |
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| 基金项目:国家自然科学基金项目（31760570，31101541，31160393）；内蒙古自然科学基金项目(2015MS0359)；内蒙古农业大学博士启动基金项目(BT09-17)；公益性行业(农业)科研专项(201203004) |
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| Effect of drought stress on succinic acid biosynthesis in Cynanchum thesioides |
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ZHANG Xiaoyan,YANG Zhongren,ZHANG Fenglan,et al
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| Abstract: |
| 【Objective】This paper studied the effects of drought stress on succinic acid biosynthesis in Cynanchum thesioides to provide basis for development and utilization of succinic acid.【Method】Succinic acid content and enzymes activity of succinic acid biosynthesis in roots,stems and leaves of C. thesioides were measured and analyzed under 4 different drought treatments including control (soil water content was 65%-70% of the maximum field water holding capacity (24.44%)),mild (45%-50%),moderate (25%-30%) and severe (5%-10%).The changes of various indexes were compared,and the correlation between succinic acid and its synthetic enzymes was analyzed.【Result】 (1) Succinic acid was distributed in leaves,roots and stems of C.thesioides(Freyn) K.Schum.and C.thesioides (Freyn) K. Schum. var.australe (Maxim.) Tsiang et P.T.Li.In the former,the order was leaves＞roots＞stems,while in the latter the order was leaves＞stems＞roots.(2) With the increase of drought stress,the contents of succinic acid in C. thesioides leaves and roots first increased and then decreased with the highest under moderate drought stress.(3) The activities of α ketoglutaric dehydrogenase (α-KGDH),succinatethiokinase (STK), succinate dehydrogenase (SD) and glutamate decarboxylase (GAD) and contents of γ-aminobutyric acid (GABA) in C. thesioides leaves were the highest under severe drought stress.(4) The correlation analysis showed that there was negative correlation between succinic acid and activities of GABA and SD in leaves.【Conclusion】Suitable drought stress improved the accumulation of succinic acid in C. thesioides.Tricarboxylic acid cycle (TCA) was the main process for biosynthesis of succinic acid under mild and moderate drought stress,while GABA shunt dominated under severe drought stress. |
| Key words: Cynanchum thesioides (Freyn) K. Schum. Cynanchum thesioides (Freyn) K. Schum. var.australe (Maxim.) Tsiang et P.T.Li. drought stress succinic acid γ-aminobutyric acid |
