Study On Physiological Response Of Saussurea Ussuriensis Maxim.to Pb Stress

Based on the context of the global heavy metal pollution crisis, heavy metalpollution problems are increasingly concerned all over the world, research on heavymetal pollution on plants is gradually increasing. Among them, there are studies ofheavy metal stress induced changes in the structure of the plant, such as plant height,leaf area, leaf thickness and root length, biomass, and other indicators of measurement;beside there are also many researchs on physiological indicators response of heavymetal content, such as chlorophyll content and the activity of antioxidant enzymeswere mensurated; in addition, researchs about heavy metals in the regulation of generesearch from the molecular level are abundant. However, recent relevant research isincrease, but there is litter study about physiological index of Saussurea ussuriensisMaxim. under Pb stress which distribute in lead polluted area Longnan and nonpolluted area Gannan. This paper studied physiological index of Saussurea ussuriensisMaxim. under Pb stress which distribute in lead polluted area Longnan and nonpolluted area Gannan to explore the Saussurea resistant ecological adaptationmechanism of lead by water culture method.The seeds and plant of lead polluted area Longnan and non polluted area Gannanwere treated with different Pb treatment contention (50、100、200、400、800、1600mg·L-1) compared with the control group, the results show that,1) The germination index of lead polluted area Longnan increase under thelower Pb treatment contention, but decrease under the higher Pb treatment contention;while, with increase of Pb treatment contention the germination index of non pollutedarea Gannan were decreased.2) The chlorophyll content and the soluble protein content of lead polluted areaLongnan increase under the lower Pb treatment contention, but decrease under thehigher Pb treatment contention; while, with increase of Pb treatment contention thechlorophyll content and the soluble protein content of non polluted area Gannan lowerthan control group.3) Both plant of lead polluted area Longnan and non polluted area Gannan did suffer certain damages with increase of Pb treatment contention, so content of MDAand H2O2increased in different extent. The increase of MDAand H2O2content of leadpolluted area Longnan was bigger than that of non polluted area Gannan.4) To counter the damage of Pb stress activation of antioxidant enzyme in plantof lead polluted area Longnan and non polluted area Gannan enhanced first, and thandecreased due to the ability of plant to repair damage to Pb stress reached the limitwith increase of Pb treatment contention. Nonetheless, the maximum of Pb treatmentcontention that plant of lead polluted area Longnan could bear was always higher thanthat of non polluted area Gannan.5) The soluble sugar and Pro content of both lead polluted area Longnan andnon polluted area Gannan were all increased first and than decreased with increase ofPb treatment contention.The ability of Saussurea ussuriensis Maxim. in lead polluted area Longnan toresistance damage of Pb stress was better than that of non polluted area Gannan, itmeans that the long-term growth in the environment of heavy metal lead Saussureaussuriensis Maxim. in lead polluted area Longnan generated adaptive evolution,formed a heavy metal resistant ecotype.