转柠檬酸合成酶基因苜蓿耐铝性研究

Research on Aluminum Tolerance of Citrate Synthase Transgenic Alfalfa

【目的】通过对渝苜1号转柠檬酸合成酶(CS)基因和对照株的根尖进行耐铝性试验,旨在找到转基因苜蓿耐铝性的适宜条件,明确转基因株较对照株表现出来的耐铝效果。【方法】以对照株和转CS基因4号苜蓿为材料,设计0、5、15、30和50μmol·L-15个氯化铝浓度梯度,每个处理3个重复,测量前3d根尖的伸长情况。【结果】在5个氯化铝浓度下,对照株和转基因株在第1天的根尖伸长都显著的高于第2天和第3天;转基因株第2天在15、30和50μmol·L-13个氯化铝浓度下的根尖伸长显著高于第3天,而对照株的根尖在第2天和第3天基本停止伸长。随着铝浓度升高,根尖伸长受阻越严重。对照株在15μmol·L-1铝处理的第1天根尖还能基本正常伸长,但在第2天即使5μmol·L-1铝处理,根尖伸长已严重受阻,这说明对照株耐铝浓度低于15μmol·L-1。而转基因株当氯化铝浓度达到30μmol·L-1时,根尖伸长才开始明显受阻(P<0.05)。【结论】渝苜1号CS转基因苜蓿的耐铝条件为氯化铝浓度15-30μmol·L-1,处理2d;转基因苜蓿相对于对照株表现出明显的耐铝性。

【Objective】 An experiment on root tip tolerance of non-transgenic control （CK） and citrate synthase （CS） transgenic plants from Medicago sativa L. cv. Yumu No.1 was conducted to find out the suitable conditions for Al-tolerance and to examine the Al-tolerance of the transgenic plants relative to the control plants. 【Method】 Using CS transgenic alfalfa No.4 and the control plant as materials,five AlCl3 concentration gradients were designed which were 0,5,15,30,and 50 μmol·L-1,each with three replicates,the root tip elongation in the first three days was measured. 【Result】 The root tip elongation of transgenic and control plants on the first day was significantly higher than on the second and the third day in all five AlCl3 concentrations. The root tip elongation of transgenic plants at 15,30,and 50 μmol·L-1 AlCl3 concentrations on second day was significantly higher than on the third day,while the root tip of control plant almost stopped elongating on the second and third day. With increased Al concentrations,the root tip elongation was inhibited seriously. The root tip of control plants in 15 μmol·L-1 Al treatment could elongate normally on the first day,while the elongation was seriously suppressed even if in 5 μmol·L-1 Al treatment on second day,indicating that the Al concentration the control plants could be tolerant of was less than 15 μmol·L-1. When the AlCl3 concentration increased to 30 μmol·L-1,the root tip elongation of transgenic plants was significantly suppressed （P0.05）. 【Conclusion】 Al-tolerance conditions of transgenic alfalfa in Medicago sativa L. cv. Yumu No.1 were 15-30 μmol·L-1 AlCl3 concentrations for 2 days. Compared to the control,the transgenic alfalfa showed a significant resistance to Al.