红芽香椿脂质过氧化及渗透调节特征对不同中性盐胁迫及恢复期的响应

Response of Toona sinensis to different neutral salt stress and recovery period

土壤盐渍化往往导致植物细胞膜的损伤以及细胞渗透调节能力的变化。红芽香椿(Toona sinensis)是珍贵的木本蔬菜,食用和经济价值高。以往研究多关注盐胁迫及干旱胁迫对香椿生理生化的影响,但是对盐胁迫恢复期的研究较少。为了研究盐胁迫及恢复期对其细胞膜脂质过氧化及渗透调节能力造成的影响,本研究分别用浓度0.1%、0.2%和0.3%的NaCl及Na_(2)SO_(4)溶液对章丘赵八洞种源的一年生红芽香椿苗进行胁迫,并测定其叶片丙二醛、可溶性糖、脯氨酸等系列指标变化,结果表明:①胁迫造成的丙二醛含量变化在恢复期更能体现不同盐种类的效应,NaCl胁迫去除后一周丙二醛含量均低于胁迫前,而Na_(2)SO_(4)胁迫去除后虽丙二醛含量有所下降,但均高于胁迫前。②Na_(2)SO_(4)胁迫造成丙二醛含量在胁迫期上升而在恢复期下降的变化趋势,而NaCl胁迫则未有明显的时间性特征。③从胁迫造成的可溶性糖变化特点看,胁迫浓度越高,恢复期渗透调节能力越弱。NaCl胁迫下,胁迫期与恢复期可溶性糖含量均明显低于胁迫前。而Na_(2)SO_(4)胁迫下则先上升后下降,恢复期与胁迫结束期的升降转折点出现在0.2%和0.3%浓度之间。④各个浓度的Na_(2)SO_(4)以及低浓度NaCl(0.1%和0.2%)胁迫造成了脯氨酸含量随时间明显下降的趋势,而高浓度NaCl(0.3%)胁迫对脯氨酸含量的影响并不大,除0.1%NaCl胁迫组外,恢复期脯氨酸含量均有所增加,其中0.3%NaCl胁迫处理组含量最高,显著高于对照及各个胁迫时期。

Soil salinization often results in the damage of plant cell membrane and the change of cell osmotic regulation ability.Toona sinensis is an important and precious woody vegetable with high edible value and economic value.Previous studies focused on the physiological and biochemical effects of over-salt stress and drought stress on T.sinensis,but there were few studies on the effect of salt stress in recovery period.In order to study the effects of salt stress on lipid peroxidation and osmotic regulation of cell membrane,one-year-old T.sinensis seedings from Zhaoba Dong,Zhangqiu District,Jinan City provenances were subjected to stress with 0.1%,0.2%and 0.3%NaCl and Na_(2)SO_(4)solutions,and a series of indexes such as malonaldehyde,soluble sugar and proline were determined.The results showed that:(1)the change of malondialdehyde(MDA)content induced by NaCL stress could better reflect the effect of different kinds of salt in the recovery stage.The MDA content was lower one week after NaCl stress was removed than that before NaCl stress,while the MDA content was decreased after NA_(2)SO_(4) stress was removed,but all of them were higher than that before the stress.(2)Under Na_(2)SO_(4)stress,the content of MDA increased in the stress stage and decreased in the recovery period,while NaCl stress had no obvious time characteristic.(3)From the characteristics of the change of soluble sugar content caused by stress,the higher the stress concentration,the weaker the osmotic regulation ability in the recovery period.Under NaCl stress,the soluble sugar content in stress stage and recovery period was significantly lower than that of the control.However,under Na_(2)SO_(4)stress,soluble sugar content first increased and then decreased,and the turning point in recovery appeared between 0.2%and 0.3%.(4)Different concentrations of Na_(2)SO_(4)and low concentration of NaCl(0.1%and 0.2%)stress caused an obvious trend of decreasing proline content over time,while high concentration of NaCl(0.3%)stress had no significant effect on proline content,except 0.1%NaCl stress group was the highest,which was significantly higher than that of the control group and each stress period.