汞胁迫对菹草无菌苗生理代谢的影响

摘要

以菹草(Potamogeton crispus L.)无菌苗为实验材料,研究其在不同浓度汞(Hg2+)的胁迫下,光合色素含量、叶绿体自发荧光强度、ATP酶活性及相关矿质营养元素(Ca、Mg、Na、K、Fe)的含量变化以及可溶性蛋白含量的变化,以探讨Hg2+胁迫对菹草无菌苗光合系统及相关生理指标变化的影响.研究表明:随着Hg2+浓度的增加,各种光合色素的含量均呈现下降的趋势,叶绿体自发荧光强度逐渐减弱；Na/K逐渐增大,Na+K+-ATP酶活性逐渐降低,Ca2+ Mg2+-ATP酶活性呈先升后降趋势；可溶性蛋白含量先升后降.结果表明,菹草无菌苗在Hg2+胁迫下,光合及其它正常的生理过程遭到破坏,功能紊乱.%Sterile seedlings of Potamogelon crispus L. Were cultured by tissue culture technique. They were exposed to 0, 5, 10, 15, 20 μmol/L Hg+ respectively for 3 days and analyzed with reference to its toxic impact on total chloroplyll content, chloroplyll autofluorescence, the ATPase activity and mineral nutrition absorption under lab conditions. Results revealed that with increasing Hg2+ concentration, the intensity of chloroplyll autofluorescence and chlorophyll decreased gradually. The content of soluble protein increased under 5 μmol/L Hg2+ stress, and then followed by a decline in the present of higher concentration of Hg2+ , which was the same as the change of Ca2+ Mg2 + -ATPase activity. Na +K + -ATPase also decreased with the rise of Hg2+ concentration. The absorption of Na, K, Ca, Mg was affected under Hg2 + stress. It was concluded that photo system and normal physiological metabolism were disordered.