2种鼠尾草对CdCl₂胁迫的耐受性比较及生理机制的研究

Study on Tolerance Comparison of Two Salvia to CdCl₂ Stress and Its Physiological Mechanism

为了研究2种鼠尾草对CdCl2胁迫的耐受性差异并分析这种差异的生理机制,采用水培的方式,研究不同浓度CdCl2(0、60、100、140、180 mg?L?1)处理对美丽鼠尾草(Salvia meiliensis)、贵州鼠尾草(Salvia. Cavaleriei)生长情况、叶片抗氧化酶活性,根部质膜H+-ATP酶和质膜Ca2+-ATP酶活性以及氮(N)、磷(P)含量的影响。结果显示:1) 贵州鼠尾草地上部分、地下部分以及植株的干重在CdCl2浓度为140 mg?L?1时低于对照,而美丽鼠尾草地上部分、地下部分以及植株的干重在CdCl2浓度为100 mg?L?1时就低于对照;2) 随着CdCl2浓度的增加,贵州鼠尾草叶片的过氧化物酶(POD)和过氧化氢酶(CAT)活性受到的促进作用逐渐增强,而美丽鼠尾草POD和CAT活性所受的促进作用分别在CdCl2浓度为100、180 mg?L?1时开始减弱;3) 2种鼠尾草Ca2+-ATP酶活性均在CdCl2浓度为140 mg?L?1时受到抑制,但是贵州鼠尾草质膜Ca2+-ATP酶活性受抑制程度小于美丽鼠尾草,贵州鼠尾草质膜H+-ATP酶活性在CdCl2浓度为180 mg?L?1时受到抑制,而美丽鼠尾草质膜H+-ATP酶活性在CdCl2浓度为100 mg?L?1时就受到抑制;4) 贵州鼠尾草N、P含量在CdCl2的浓度为180 mg?L?1时低于对照,而美丽鼠尾草N、P含量在CdCl2的浓度为140 mg?L?1时就低于对照。研究表明,贵州鼠尾草POD和CAT这2种抗氧化酶对CdCl2胁迫的耐受性高,使其质膜过氧化程度低于美丽鼠尾草,同时贵州鼠尾草根部质膜Ca2+-ATP酶和H+-ATP酶活性对CdCl2胁迫的耐受性强,使其N、P吸收受抑制程度低于美丽鼠尾草;是贵州鼠尾草对CdCl2胁迫的耐受性高于美丽鼠尾草的原因。

Through the water cultivation,effects of treatments with different concentrations of CdCl2(0,60,100,140 and 180 mg?L?1)on growth,antioxidant enzyme activities of leaves,activities of H+-ATPase and Ca2+-ATPase in the plasma membrane of root,as well as N and P contents of Salvia meiliensis and Salvia cavaleriei were studied in order to compare the tolerance difference between two Salvia to the stress of CaCl2and analyze the physiological mechanism.The result showed that:1)When the concentration of CdCl2 was 140 mg?L?1,dry weights of the over ground part,underground part and the plant of S.cavaleriei are lower than those in the control;2)With the increase of CdCl2 concentration,the accelerating effects on activities of CAT and POD in S.cavaleriei had been gradually enhanced,but the accelerating effects on activities of POD and CAT in S.meiliensis had been weakened respectively when the concentration of CdCl2 was 100 and 180 mg?L?1;3)The activity of Ca2+-ATPase both in two kinds of salvia was inhibited when the concentration of CdCl2 was 140 mg?L?1.But the degree of inhibition on the activity of Ca2+-ATPase in S.cavaleriei was less than that in S.meiliensis.The activity of H+-ATPase in the plasma membrane of S.cavaleriei was inhibited when the concentration of CdCl2 was 180 mg?L?1.However,the activity of H+-ATPase in the plasma membrane of S.meiliensis was inhibited just when the concentration of CdCl2 was 100 mg?L?1;4)N and P contents of S.cavaleriei had lower than those in the control when the concentration of CdCl2 was 180 mg?L?1.But N and P contents of S.meiliensis were lower than those in the control just when the concentration of CdCl2 is 140 mg?L?1.This research shows that the tolerance levels of POD and CAT,these two kinds of antioxidase,in S.cavaleriei to the stress of CdCl2 were very high so that the peroxidation degree of its plasma membrane is lower than that of S.meiliensis.Besides,the tolerance of activities of Ca2+-ATPase and H+-ATPase in the root plasma membrane of S.cavaleriei to the stress of CdCl2 is very strong so that its degree of inhibition on N and P absorption is lower than that on S.meiliensis.It’s also the reason why the tolerance of S.cavaleriei to the stress of CdCl2 is higher than that of S.meiliensis.