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生态学杂志 ›› 2011, Vol. 30 ›› Issue (05): 1013-1017.

• 汞的生物地球化学专辑 • 上一篇    下一篇

汞胁迫对白骨壤(Avicennia marina\)幼苗生理生态的影响

袁彦婷,丁振华**,张玲   

  1. 厦门大学生命科学学院,福建厦门361005
  • 出版日期:2011-05-08 发布日期:2011-05-08

Impacts of mercury stress on Avicennia marina seedlings eco-physiology.

YUAN Yan-ting, DING Zhen-hua, ZHANG Ling   

  1. School of Life Sciences, Xiamen University, Xiamen 361005, China
  • Online:2011-05-08 Published:2011-05-08

摘要: 为了解红树植物的重金属抗性机制,对白骨壤(Avicennia marina)幼苗进行不同浓度Hg2+(1、5、10、50、100 mg·L-1)的胁迫实验,测定并分析了Hg2+胁迫对白骨壤幼苗叶片的光合作用和抗氧化酶活性的影响。结果表明:叶片净光合速率随着胁迫时间的延长而降低,高浓度(≥50 mg·L-1)Hg2+胁迫下叶片的净光合速率低于中低浓度胁迫,且高浓度胁迫的叶片净光合速率在48 h后快速下降;叶片净光合速率与胞间二氧化碳浓度呈极显著负相关,叶绿素含量随Hg2+浓度的增加而降低。气孔导度在不同浓度胁迫下反应不同,低浓度Hg2+对白骨壤幼苗光合的影响可能是气孔因素,中高浓度Hg2+对白骨壤幼苗光合作用的抑制主要是非气孔因素。低浓度Hg2+胁迫,白骨壤幼苗叶片SOD、POD活性升高,表现了一定的抗逆性,而高浓度表现为抑制作用,基本在100 mg·L-1 Hg2+胁迫下活性达到最低值。说明Hg2+可以抑制白骨壤叶片的光合活性,高浓度Hg2+胁迫削弱了白骨壤的活性氧清除能力,植物极易受到伤害。

关键词: 分子微生物生态学, 分子生物技术, 微生物生态学

Abstract: In order to understand the heavy metals resistance mechanism of mangrove, a stress experiment with the seedlings of mangrove species Avicennia marina from Fujian Province was conducted to study the impacts of different concentration (1, 5, 10, 50, and 100 mg·L-1) mercury (Hg2+) on the seedlings leaf photosynthesis and antioxydase activities. With the increase of added Hg2+ concentration and exposure time, the seedlings leaf net photosynthetic rate (Pn) and chlorophyll content decreased. Under the stress of high concentration Hg2+ (≥50 mg·L-1), the decrement of Pn was higher than that under the stress of low concentration Hg2+, and the Pn decreased rapidly after 48 h. There was a significantly negative correlation between Pn and extracellular carbon dioxide concentration (Ci). The chlorophyll content decreased with increasing  Hg2+ concentration. The stomatal conductance (Gs) had different responses to the stress of different  Hg2+ concentration. At low  Hg2+ concentration, stomatal factors could limit the photosynthesis; while at high  Hg2+ concentration, non-stomatal factors could be the main causes inhibiting photosynthesis. Low  Hg2+ concentration promoted the activities of superoxide dismutase and peroxidase, while high  Hg2+ concentration inhibited the activities of the two enzymes, being the lowest under the stress of 100 mg Hg2+·L-1. All the results implied that Hg2+ could inhibit the leaf photosynthesis of A. marina, and high concentration Hg2+ impaired the active oxygen elimination capability of A. marina, making the plants easily to be damaged.

Key words: Molecular microbial ecology, Molecular technique, Microbial ecology