酸铝胁迫对栝楼根系生长及铝积累的影响

针对南方酸性红壤对作物的生长造成的不利影响,采用水培方式,研究酸铝环境0、100、300、500、1000μmol·L-1Al3＋pH4.5,处理7d对长兴栝楼根系生长及铝积累的影响。测定指标包括根系活力、质膜透性、抗氧化酶类活性（过氧化物酶POD、过氧化氢酶CAT、抗坏血酸过氧化物酶APX、愈创木酚过氧化物酶GPX、超氧化物歧化酶SOD）及其同工酶、过氧化氢（H2O2）含量、根尖铝含量的影响。结果表明：随着铝处理浓度升高,根系活力增大,根系质膜透性无显著变化;POD、CAT、APX酶活升高,GPX和SOD活性降低,多种抗氧化酶都有多条同工酶谱带出现;根尖相对铝含量升高,桑色素染色情况显示,荧光梯度与铝含量测定结果一致,并观察到根尖以上根毛处细胞凸起较之平整排列的根细胞更容易积累铝。栝楼对南方酸性红壤具有较强的适应能力,其体内抗氧化酶系统及根尖吸收、积累铝的机制对缓解铝毒害起着重要作用。

Effects of Acid Aluminum Stress on Root Growth and Aluminum Accumulation of Trichosathes kirilowii Maxim

Adverse effect on crop growth is caused by south red soil with high Al concentration.The aim of this work is to investigate the effects of acid aluminum stress on root growth and aluminum accumulation of Trichosathes kirilowii Maxim by water planting.Seedlings were treated with different concentrations,0,100,300,500,1 000 μmol·L-1 of aluminium chloride,at pH 4.5 for 7 d.Following treatment the parameters investigated in root tissue were root vigor,plasma membrane permeability,activities of antioxidant enzymes named peroxidase（POD）,catalase（CAT）,ascorbate peroxidase（APX）,guaiacol peroxidation（GPX）,superoxide dismutase（SOD） and their isozyme electrophoresis,hydrogen peroxide content,relative aluminum content.With the increasing of Al3＋ concentration,the activities of POD,CAT and APX increased but the activities GPX and SOD decreased;most of the antioxidant enzymes had several electrophoretic bands;plasma membrane permeability had no significant difference;root vigor increased remarkably.Determining relative content of aluminum had the same result by comparing with that of morin staining more aluminum accumulated in the cells of root hair than that in closely arranging cells.Antioxidant enzymes system and aluminum accumulation mechanism play important role in resisting Al toxicity for the growth of T.kirilowii.