铝毒对不同耐铝性大麦品种初生根的影响差异

Different effects of aluminum toxicity on primary roots of two barley cultivars with different aluminum-tolerance

为揭示耐铝机制在大麦铝毒中的生物学功能,以耐铝大麦品种沪麦8号和铝敏感品种嵊县无芒六棱为研究材料,经不同铝浓度(0、50、100和150μmol/L Al Cl_3)处理后,分别测定大麦初生根活跃吸收面积、质膜透性、游离脯氨酸和丙二醛的含量,以及超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)、Ca^(2+)-ATP酶和Mg^(2+)-ATP酶等的活性,分析铝毒对不同耐铝性大麦初生根的影响差异。结果表明:与空白对照相比,铝毒胁迫对2个不同耐铝性大麦品种的各类生理学指标的影响总体呈相似的变化趋势;但铝毒对耐铝品种沪麦8号初生根的活跃吸收面积、质膜透性、Ca^(2+)-ATP酶和Mg^(2+)-ATP酶活性的抑制作用明显比铝敏感品种嵊县无芒六棱小,并且沪麦8号的SOD和CAT活性高于嵊县无芒六棱;相反,嵊县无芒六棱的游离脯氨酸和丙二醛含量高于沪麦8号。这些研究结果表明,大麦耐铝品种和敏感品种对铝毒胁迫的生理响应具有较大差异,揭示了耐铝机制在大麦铝毒胁迫中的功能,为进一步剖析大麦铝毒和耐铝机制提供了新的观点。

To reveal the biological role of aluminum（Al）-tolerant mechanism in barley Al toxicity,the Altolerant cultivar Humai 8 and Al-sensitive cultivar Shengxian awnless six-rowed barley（Shengxian 6）were used as experimental materials,and treated with different concentrations of Al Cl_3（0,50,100 and 150μmol/L）.The active absorbing area,cell membrane permeability,contents of free proline and malondialdehyde（MDA）,and the activities of superoxide dismutase（SOD）,catalase（CAT）,peroxidase（POD）,Ca^2＋-ATPase,and Mg^2＋-ATPase in primary roots of barley were examined to analyze different effects of Al toxicity on the primary roots of two barley cultivars with different Al-tolerance.The results showed that,compared with the control,the effects of Al toxicity on multiple physiological indexes displayed similar changes in the two barley cultivars with different Altolerance;however,the inhibitory effects of Al toxicity on the active absorbing area,cell membrane permeability,and activities of Ca^2＋-ATPase and Mg^2＋-ATPase in Al-tolerant cultivar Humai 8 were lower than those in Alsensitive cultivar Shengxian 6,and the activity levels of SOD and CAT in Humai 8 were higher than those in Shengxian 6.By contrast,the contents of free proline and MDA in Shengxian 6 were higher than those in Humai 8.These results suggest that Al-tolerant and Al-sensitive barley cultivars differentially respond to Al toxicity at the physiological level,revealing the role of Al-tolerant mechanisms in barley Al toxicity,and providing a new insight into dissecting Al toxicity and Al-tolerant mechanisms in barley.