作 者 ：陈涛;王贵美;沈伟伟;李小珍;祁建民;徐建堂;陶爱芬;刘晓倩
期 刊 ：植物科学学报 2011年 29卷 4期 页码：493-501
Keywords:Kenaf(Hibiscus cannabinus L.), Salt stress, Antioxidant enzymes,
摘 要 ：为研究不同盐胁迫时间和不同盐浓度胁迫对红麻(Hibiscus cannabinus L.)幼苗的生长及抗氧化酶活性的影响,探寻红麻耐盐的生理机制,为盐碱地种植红麻提供科学依据,本研究对红麻幼苗进行了两种不同条件的盐胁迫处理。一种将红麻幼苗在0(对照组)、140 mmol/L NaCl的半强度Hoagland营养液下分别处理3、6、9 d,另一种是在0(对照组)、70、140、200 mmol/L NaCl的1/2 Hoagland营养液下处理6 d,分别测定两种盐胁迫条件下植株的鲜重、根长、茎长、叶片H2O2、丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)活性。结果显示:(1)在第一种处理条件下,随着盐胁迫时间的延长,处理组红麻幼苗的鲜重相对于对照分别减轻了19.63%、19.35%和39.03%,株高则分别降低了25.59%、19.17%和18.48%,处理组的SOD活性先增后减,POD活性先减后增,MDA和H2O2的含量、CAT和GR活性基本随胁迫时间的增长而增高。(2)在第二种处理条件下,随着胁迫盐浓度的增加,处理组鲜重相对于对照分别减轻了16.79%、19.35%和44.73%,株高则分别降低了11.21%、19.17%和23.62%,处理组SOD活性都稍高于对照,但三者无显著差异,POD活性先减后增,MDA和H2O2的含量、CAT和GR活性基本上随着盐浓度增加而增加。实验表明,在两种不同条件的盐胁迫下,红麻幼苗受盐害的程度基本上随胁迫时间和盐浓度的增加而加重。处理组植株的SOD和POD活性较对照组增加不明显,甚至有所降低,而CAT和GR活性则相对较高,CAT和GR可能在红麻幼苗抵御盐害时起较重要作用。
Abstract:Kenaf is a Hibiscus member in the Malvaceae family,and exhibits fast growth,high-yield,and strong stress adaptability.The aim of the present research was to study the effect salt concentration stress on the growth and antioxidant enzyme activity of Kenaf seedlings,and further explore the physiological mechanisms of salt tolerance.Kenaf seedlings were subjected to 0 mmol/L and 140 mmol/L NaCl for 3 d,6 d and 9 d in half strength Hoagland nutrient solution and as well as 0 mmol/L,70 mmol/L,140 mmol/L,200 mmol/L NaCl concentrations for 6 d.Following treatment,weight,root length,stem length,leaf H2O2,and malondialdehyde(MDA) content,as well as the activity of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT) and glutathione reductase(GR),of the fresh plant samples weremeasured.The results showed that(1) Fresh weight of the treated groups were reduced by 19.63%,19.35% and 39.03%,respectively with length of treatment.Plant height decreased by 25.59%,19.17% and 18.48%,respectively.In addition,SOD activity first increased and then decreased,while POD activity showed the opposite trend.The content of MDA and H2O2,and CAT and GR activity had positive correlations with stress time compared to the controls.(2) With the increase in stress concentration,fresh weight of the treatment groups was reduced by 16.79%,19.35% and 44.73%,respectively.In addition,plant height decreased by 11.21%,19.17% and 23.62%,respectively.The SOD activity was higher than the control group;however,no significant differences were observed among the three.The contents of MDA and H2O2,and the activity of CAT and GR increased with time,but POD activity first decreased and then increased.The effects of salt stress of the kenaf seedlings increased with time and salt concentration when treating with different NaCl concentrations.The SOD and POD activities increased slightly,or even decreased,while the CAT and GR activities were relatively higher.Both CAT and GR may play an important role when responding to salt stress of kenaf seedlings.
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