摘要
为了阐明硝化抑制剂双氰胺(DCD)对稻田固氮蓝藻生长和生理生化特征的影响,为二者在稻田的合理使用提供理论依据,本文研究了DCD胁迫下稻田固氮蓝藻——类珠藻(Aliinostoc sp.YYLX235)的生长、光合作用、固氮酶活性、抗氧化酶活性和氧化损伤特征。结果表明,100~300 mg·L^(-1)DCD对类珠藻的生长具有明显的抑制作用。当DCD浓度为50 mg·L^(-1)时,类珠藻的细胞活力和固氮活性均显著降低。类珠藻光合系统对DCD胁迫表现出应激效应,具体表现为光合色素含量增加、光合系统Ⅱ电子传递效率提高。类珠藻细胞内超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性与培养体系DCD浓度呈正相关;当DCD浓度为200~300 mg·L^(-1)时,类珠藻细胞内氧化-抗氧化系统失去平衡,藻细胞受到氧化性损伤。DCD对类珠藻的固氮活性具有极强的抑制效应。本研究结果显示,硝化抑制剂DCD对农田固氮蓝藻的生长、细胞活力和固氮活力均具有较强的负面影响,在生产过程中固氮蓝藻菌肥需要与DCD错峰使用。
In order to elucidate the effects of nitrification inhibitor dicyandiamide(DCD)on physiological and biochemical characteristics of paddy diazotrophic cyanobacteria and provide a theoretical basis for reasonable application of DCD and diazotrophic cyanobacteria in paddy fields,the variations of growth,photosynthesis,nitrogenase activity,activities of antioxidative enzymes,and oxidative damage characteristics of a paddy diazotrophic cyanobacterium Aliinostoc sp.YYLX235 under DCD stress were investigated.The results showed that the growth of Aliinostoc sp.YYLX235 was inhibited by DCD at concentrations of 100~300 mg·L^(-1).The activities of cellular vitality and N_(2)-fixation significantly decreased at a DCD concentration of 50 mg·L^(-1).The photosystem Ⅱ of Aliinostoc sp.YYLX235 exhibited hormetic effects under DCD stress,with characteristics of increasing cellular pigment contents and improvement of electron transfer efficiency.The activities of superoxide dismutase(SOD)and catalase(CAT)in cells of Aliinostoc sp.YYLX235 were positively correlated with DCD concentration in the medium.The oxidative-antioxidative system in cells of Aliinostoc sp.YYLX235 lost balance when DCD concentration ranged from 200 mg·L^(-1)to 300 mg·L^(-1),resulting in oxidative damage to algal cells.The results of this study indicate that DCD has strong negative effects on growth,cellular vitality,and N 2-fixation activity of paddy diazotrophic cyanobacteria.Thus,the application of diazotrophic cyanobacteria-based bio-fertilizer and DCD should be s taggered.
作者
陈红宇
邵继海
陈杰锋
蒋越西
Chen Hongyu;Shao Jihai;Chen Jiefeng;Jiang Yuexi(College of Environment and Ecology,Hunan Agricultural University,Changsha 410128,China;College of Resources,Hunan Agricultural University,Changsha 410128,China)
出处
《生态毒理学报》
CAS
CSCD
北大核心
2024年第3期331-341,共11页
Asian Journal of Ecotoxicology
基金
国家自然科学基金资助项目(32071647)。
关键词
双氰胺
固氮蓝藻
氧化损伤
光合系统
固氮酶
dicyandiamide
diazotrophic cyanobacteria
oxidative damage
photosynthetic system
nitrogenase
