铝胁迫对黑麦草根系抗氧化酶活性和丙二醛含量的诱导特征研究

以多花黑麦草(Lolium multiflorum)为试材,通过水培试验方法,研究不同浓度梯度铝胁迫对黑麦草幼苗根系抗氧化酶活性和丙二醛含量的诱导特征,从而揭示黑麦草根系耐铝机制。结果表明:(1)在整个试验过程中,SOD、POD、CAT活性变化规律相一致。当铝浓度介于0~50 mg L-1范围内,SOD、POD、CAT在整个实验过程中活性显著增加(P<0.05),高于对照,并在50 mg L-1铝浓度处理下,活性达到最大;当铝浓度为100 mg L-1时,SOD、POD、CAT在铝处理时间≤8 h时活性显著增加(P<0.05),高于对照,在铝处理时间>8 h时活性明显降低(P<0.05),低于对照;当铝浓度介于100~500 mg L-1范围内,SOD、POD、CAT在整个实验过程中活性先升高(≤8 h)后降低(>8 h),均明显低于对照(P<0.05)。(2)MDA含量变化趋势同SOD、POD、CAT活性变化趋势正好相反。当铝浓度介于0~50 mg L-1范围内,MDA在整个实验过程中含量显著降低(P<0.05),低于对照,并在50 mg L-1铝浓度处理下,含量达到最小;当铝浓度为100 mg L-1时,MDA在铝处理时间≤8 h时含量显著降低(P<0.05),低于对照,在铝处理时间>8 h时含量明显升高(P<0.05),高于对照;当铝浓度介于100~500 mgL-1范围内,MDA在整个实验过程中含量先降低(≤8 h)后升高(>8 h),均明显高于对照(P<0.05)。研究结果表明黑麦草根系在短时间内对铝胁迫有一定的耐性,并且耐受范围随着铝处理时间的延长而变小。

Study on Characteristics of Antioxidant Enzymes Activities and MDA Contents in Lolium multiflorum Roots Induced by Aluminum Stress

Planted in hydroponics,the Lolium multiflorum seedlings were treated with different Al concentrations so as to study the characteristics of antioxidant enzymes activities and MDA contents in L.multiflorum roots,and thus to reveal their mechanisms.The results showed:(1) Throughout the experiment,SOD,POD and CAT activities changed in line with each other.When the concentration of Al was in the range of 0-50 mg L-1,compared with those of control,the SOD,POD and CAT activities increased significantly throughout the experiment(P < 0.05),and their activities attained the maxima when Al concentration was 50 mg L-1.Under the 100 mg L-1 Al concentration,compared with the control,the SOD,POD and CAT activities were significantly higher than control within 8 hours(P <0.05) and thereafter significantly decreased and was lower than control(P < 0.05).When the concentration of Al was in the range of 100-500 mg L-1,enzyme activities increased firstly within 8 hours,and then decreased after 8 hours,and were significantly lower than control(P<0.05).(2) The changing trend of MDA contents was just opposite to SOD,POD and CAT activities.When the concentration of Al was in the range of 0-50 mg L-1,compared with the control,the MDA contents were significantly lower(P < 0.05) throughout the experiment,and they attained the minimums when Al concentration was 50 mg L-1.Under the 100 mg L-1 Al concentration medium,compared with the control,the MDA contents were significantly lower within 8 hours(P < 0.05) and thereafter significantly higher after 8 hours(P < 0.05).When the concentration of Al was in the range of 100-500 mg L-1,they decreased firstly within 8 hours,then increased after 8 hours,and all of them were significantly higher than control group(P<0.05).It was concluded that the L.multiflorum roots had some Al tolerance in a short time,and the tolerance range decreased with the increasing treatment time.