铝胁迫下大豆根系有机酸积累的特性

为探讨铝胁迫对大豆根系有机酸累积的影响,以大豆品种粤春03-3为研究对象,通过水培方法进行不同时间的铝处理,分别测定大豆根系的相对生长率、以及距根尖0~2和2~4 cm根段的铝含量、苹果酸浓度、柠檬酸浓度和草酸浓度等。结果表明:铝处理明显抑制了大豆根系的生长。随着铝处理时间的延长,0~2 cm根段的铝含量明显降低,而2~4 cm根段的铝含量明显增加。另外,铝胁迫对不同根段的有机酸累积的影响也不同。铝处理6 h显著提高了大豆根系的苹果酸浓度,但对柠檬酸和草酸浓度均无明显影响。铝处理12 h后,0~2 cm根段中3种有机酸的浓度在铝处理和对照之间均无明显差异,但2~4 cm根段的苹果酸浓度和草酸浓度均明显高于对照。说明苹果酸和草酸在大豆根系铝毒的内部忍耐机制中起着重要作用。

Effects of Aluminum (Al) on Organic Acid Accumulation in Soybean Roots

The objective of this study was to evaluate the effects of aluminum (Al) on the response of organic acids accumulation in soybean roots.One soybean genotype YC03-3 was treated with or without Al.The relative root growth rate and Al accumulation in different root segments were investigated.Furthermore,the concentration of three types of organic acid including malate,citrate and oxalate were measured.Results showed that the soybean root growth was significantly inhibited by Al treatment.The Al content decreased in the 0-2 cm root segment,while increased in the 2-4 cm root segment with the Al treatment period increased.Furthermore,the organic acid concentrations in different root segments were divergently affected by Al treatment.Short period of Al treatment (6 h) didn't affect the citrate and oxalate concentration in soybean roots,but significantly increased the malate concentration in roots.After 12 hours of Al treatment,the concentration of three organic acids in 0-2 cm root segments were not significantly altered.However,the malate concentration and the oxalate concentration in the 2-4 cm root segments were significantly higher than that in control.Therefore,malate and oxalate accumulation might affect internal Al tolerance of soybean roots.