摘要
研究水稻中花11及其汞耐性突变体对土壤汞的耐性差异和引起差异的主要原因.采用盆栽土培试验,研究不同浓度Hg2+处理对野生型和突变体生长发育、产量、叶绿素含量、净光合速率、丙二醛(MDA)含量、水稻各器官Hg2+浓度和主要抗氧化酶活性的影响.结果表明:野生型和突变体经Hg2+胁迫后表型上有显著差异,突变体对Hg2+的耐性大于野生型.Hg2+对野生型生长发育和产量的抑制作用明显大于突变体;随着Hg2+浓度的增加,野生型叶绿素、净光合速率下降速度更快;突变体叶片中超氧阴离子(O2)产生速率和过氧化氢(H2O2)积累量低于野生型,野生型叶片膜脂过氧化程度更高;野生型和突变体的超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性及野生型的愈创木酚过氧化物酶(G-POD)活性、突变体的抗坏血酸过氧化物酶(APX)活性均呈现先上升后下降的趋势;而突变体的G-POD活性和野生型的APX活性呈现上升趋势.与突变体相比,野生型叶片中抗氧化酶活性受到更显著抑制;突变体较强的抗氧化胁迫能力与其对Hg2+的耐性密切相关.
A pot experiment was conducted to investigate the difference between wild type （Oryza sativa L. subsp. Japonica, cv. Zhonghua 11） and a Hg^2＋-tolerant mutant in Hg tolerance mechanisms by comparing the growth, yield, Hg^2＋ concentration, chlorophyll content, net photosynthesis rate, MDA content, activities of major antioxidant enzymes. The results indicated that the mutant was more tolerant to Hg^2＋ . The growth and yield of wild type was more inhibited than those of the mutant. With increasing concentration of Hg^2＋ , the chlorophyll content, net photosynthesis rate decreased more rapidly in wild type. Hg^2＋ induced more O2- generation and more H2O2 accumulation in wild type compared with mutant. Thus, wild type had higher level of lipid peroxidation. The activities of SOD, CAT in leaves of wild type and the mutant increased under lower Hg^2＋ concentration, but decreased under higher Hg^2＋ level. G-POD activity of the mutant and APX activity of wild type both increased with increasing Hg^2＋ level. The activities of antioxidant enzymes were more inhibited in wild type than those in the mutant. It can be concluded that higher tolerance of the mutant to oxidative stress plays an important role when the plants are exposed to Hg^2＋ stress.
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2008年第1期57-64,共8页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
国家重点基础研究发展规划“973”资助项目(2002CB10804)
关键词
汞
水稻
突变体
耐性
抗氧化酶
mercury （Hg）
rice （Oryza sativa L. ）
mutant
tolerance
antioxidant enzyme
