外源SA、GSH对Cd胁迫下绵毛水苏生理和生长的影响

Effects of Exogenous Salicylic Acid and Glutathione on Physiological and Growth of Stachys lanata Under Cadmium Stress

为探究不同外源物质对Cd胁迫下绵毛水苏生理和生长的缓解效果,采用盆栽试验研究叶面喷施不同浓度水杨酸(SA)(0.5、1.0、1.5、2.0 mmol·L^(-1))和谷胱甘肽(GSH)(0.1、0.2、0.3、0.4 mmol·L^(-1))对300 mg·kg^(-1)Cd胁迫下绵毛水苏幼苗生长、渗透调节物质、抗氧化酶活性以及Cd含量等的影响。结果表明,外源SA和GSH改善了植物的叶色,提高了叶面积和萌蘖能力,并增加了地下、地上部干物质积累量。除0.4 mmol·L^(-1)GSH处理第3天外,外源SA和GSH处理均提高了可溶性糖、可溶性蛋白和游离脯氨酸等渗透调节物质的含量,最高增幅分别为16.06%、14.13%、311.39%(SA)和50.28%、12.77%、313.77%(GSH);此外,SA和GSH分别使抗氧化酶(SOD、POD和CAT)活性最高增幅依次达57.39%、38.51%、26.81%和85.00%、60.77%、50.21%。绵毛水苏吸收的Cd主要累积在根部,外源SA对Cd吸收无明显影响,而GSH抑制了Cd向地上部的转运。综上可知,SA和GSH对Cd胁迫下的绵毛水苏均具有缓解作用,以1.5 mmol·L^(-1)SA和0.3~0.4 mmol·L^(-1)GSH效果较佳。本研究结果对绵毛水苏应用于Cd污染土壤植物修复具有重要意义。

In order to explore the alleviating effects of exogenous substance on physiological and growth of Stachys lanata under Cadmium stress,a pot experiment was conducted to investigate the effects of SA(0.5,1.0,1.5 and 2.0 mmol·L^(-1))and GSH(0.1,0.2,0.3 and 0.4 mmol·L^(-1))on seedling growth,osmotic adjustment substances,three antioxidant enzyme activities and Cadmium content of S.lanata under the 300 mg·kg^(-1)Cd stress.The results showed that SA and GSH made the leaf color better,and increased the leaf area,the tiller capacity,the dry matter accumulation in underground and above ground parts;Except for 0.4 mmol·L^(-1)GSH treatment on the 3 rd day,SA and GSH increased the content of the soluble sugar,the soluble protein and the free proline,and the highest amplitude of the three indexes was 16.06%,14.13%,311.39%(SA)and 50.28%,12.77%,313.77%(GSH),respectively;The amplitude of activity of antioxidant enzymes(SOD,POD and CAT)was 57.39%,38.51%,26.81%(SA)and 85.00%,60.77%,50.21%(GSH),respectively;The absorption of cadmium mainly concentrated in the root.SA had no significant effect on Cd absorption,while GSH inhibited Cd transport to the shoots.In conclusion,SA and GSH can alleviate the stress of S.lanata to Cd and the effect was better with 1.0 to 1.5 mmol·L^(-1)SA and 0.3 to 0.4 mmol·L^(-1)GSH treatment.The result are important to phytoremediation of Cd contaminated soil by Stachys lanata.