Hg^(2+)对豌豆幼苗生长和生理代谢的影响

The Influence of Hg^(2+) on Seedlings Growth and Physiological Metabolism of Pea

用不同浓度的Hg2+处理豌豆种子,研究其对种子活力、幼苗生长及生理指标的影响.结果表明,Hg2+ 能降低种子活力,抑制幼苗生长,当Hg2+ 浓度为10-5,10-4,10-3 mol/L时,种子活力指数分别比对照组降低了25.08%,51.05%和76.11%,单株鲜重降低19.64%,42.86%和67.86%.随Hg2+ 浓度的升高,幼苗根系活力和叶片硝酸还原酶活性降低,叶绿素和可溶性蛋白质含量下降,当Hg2+ 浓度为10-4,10-3 mol/L时,根系活力分别下降16.98%和48.58%,硝酸还原酶活性分别下降16.06%和22.70%,叶绿素含量分别降低19.55%和13.69%,可溶性蛋白质含量分别降低19.28%和22.25%;豌豆叶片膜脂过氧化产物丙二醛(MDA)含量增加,Hg2+浓度为10-3 mol/L时,MDA的含量比对照组增加85.69%;超氧化物歧化酶(SOD)活性先升后降,当Hg2+ 浓度为10-5 mol/L时,SOD活性达到最大,比对照组提高20.0%;过氧化物酶(POD)活性升高,过氧化氢酶(CAT)活性降低,当Hg2+浓度为10-3 mol/L时,POD活性比对照组提高96.31%,CAT 活性比对照组降低21.80%.随Hg2+浓度的升高,根系过氧化物同工酶的表达受到抑制.

The pea seeds were soaked in the solution with different concentration of Hg^(2+), the effects of Hg^(2+)on seeds vigor, seedlings growth and physiological metabolism were investigated. The results showed that Hg^(2+) could inhibit seeds vigor and seedling growth of pea. Compared with the contrast, when the concentration of Hg^(2+) were 10^(-5), 10^(-4) and 10^(-3)mol/L, the vigor index were decreased 25.08% , 51.05% and 76.11% respectively, the fresh weight of single plant were reduced 19.64% , 42.86% and 67. 86%.With the increase concentration of Hg^(2+), the root vigor, activity of nitrate reductase, the contents of chlorophyll and soluble protein were rapidly reduced in the leaves of pea seedlings. When the concentration of Hg^(2+) were 10^(-4) and 10^(-3)mol/L, the root vigor dropped by 16.98% and (48.58%) respectively, the activity of nitrate reductase dropped by 16.06% and 22.70%, the content of chlorophyll were reduced 19.55% and 13.69%, the content of soluble protein were reduced 19.28% and 22.25%. With the increase concentration of Hg^(2+), the malondialdehyde (MDA) content in leaves were raised, when the concentration of Hg^(2+) was 10^(-3)mol/L ,the content of MDA increased 85.69%. The activities of superoxide dismutase (SOD) fall after rising, it reached the highest when the concentration of Hg^(2+)was 10^(-5)mol/L, increased 20.0%.The activities of peroxidase (POD) in leaves were raised, but the activity of catalase (CAT) was decreased, when the concentration of Hg^(2+) was 10^(-3)mol/L, POD activity improved 96.31% relatively to the contrast, CAT activity reduced 21.80%. The expression of isoperoxidase patterns in root was suppressed.