缺镁胁迫对‘砂糖橘’植株矿质养分及抗氧化酶的影响

Influences of Magnesium Deficiency on the Mineral Nutrient Status and Anti-oxidant Enzymes of ‘Shatangju' Plants

试验采用珍珠岩基质培养法,研究缺镁胁迫对枳砧‘砂糖橘’植株的矿质养分吸收和抗氧化活性等生理生化过程的影响。结果表明:与对照相比,缺镁处理90 d导致‘砂糖橘’植株叶片叶绿素含量显著降低;N、P、K、Mg含量降低,但都未达到显著水平,其中镁含量下降幅度最大,为23.0%;另外,缺镁处理3个月后发现N、P和Mg含量都降低,而钾含量增加了2倍多。缺镁胁迫引起叶片中过氧化氢和MDA含量增加,相应地导致POD和CAT活性提高,但是SOD活性未受影响,APX活性变化也无规律。这些数据表明,90 d的缺镁胁迫能够引起‘砂糖橘’植株叶片中活性氧的累积,POD和CAT可能参与了活性氧的清除。

The influences of magnesium （Mg） deficiency on the physio-biochemical processes of‘Shatangju’ plants on trifoliate orange rootstock, e.g. uptake of mineral nutrients and anti-oxidant enzyme activities, were studied using perlite as substrate. The results showed that compared with the control, the treatment of Mg deficiency for 90 days significantly decreased the chlorophyll contents in the leaves of ＇Shatangju＇ plants. And the contents of N, P, K and Mg declined without significant difference, among which the maximum reduction（23.0%） was found in Mg content. Besides, at the end of the treatment of Mg deficiency, the contents of N, P and Mg decreased, but not K. Mg deficiency induced the increase in the H2O2 and MDA contents, and accordingly increased the POD and CAT activities, however, SOD activity was not affected and the change in APX activity was stable. These data indicate that Mg deficiency for 90 days can induce the accumulation of reactive oxygen species （ROS） in the leaves of‘Shatangju’ plants, and that POD and CAT are possibly involved in scavenging ROS.