链状亚历山大藻赤潮衰亡的生理调控  

Physiological regulation related to the decline of Alexandrium catenella

作　　者：马金华[1] 孟希[2] 张淑[1] 隋正红[1] 王津果[1] 周伟[1] 常连鹏[1] 

机构地区：[1]中国海洋大学海洋生物遗传学与育种教育部重点实验室,青岛266003 [2]南京农业大学园艺学院,南京210095

出　　处：《生态学报》2013年第13期3978-3986,共9页Acta Ecologica Sinica

基　　金：山东省自然科学基金重点项目(ZR2011DZ002);高校博士点基金(20100132110007)

摘　　要：研究了链状亚历山大藻在对数生长期、衰亡期、高氮、低氮条件下,藻细胞中可溶性蛋白含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)、过氧化氢(H2O2)和还原型谷胱甘肽(GSH)含量、光合速率和呼吸速率、DNA降解、端粒酶活性的变化。结果表明:在衰亡期、高氮、低氮条件下链状亚历山大藻细胞中可溶性蛋白、GSH含量、光合速率和呼吸速率下降;SOD活性(低氮条件除外)、H2O2、MDA含量上升;端粒酶活性和DNA Ladder随着藻细胞生长而变化,并在衰亡时期,出现了明显的DNALadder。研究结果显示链状亚历山大藻衰亡过程的反应表现为:蛋白质合成受阻或降解,产生大量氧化中间产物(MDA,H2O2等),抗氧化系统被激活,GSH等非酶抗氧化物质被大量消耗,SOD等酶抗氧化物被激活;另外表现为光合速率和呼吸速率下降;同时活性氧自由基(Reactive Oxygen Species,ROS)的积累诱发了细胞凋亡,核酸内切酶被激活,选择性降解染色质DNA。推测低氮、高氮条件均可以加快藻细胞的衰亡的生理过程,链状亚历山大藻的赤潮衰亡是一种有序的死亡过程。Over the last several decades,harmful algal blooms（HABs） have emerged as a global environmental problem because of their more frequent occurrence and because of the threat they pose to the health of humans and other organisms.Great efforts have been made to elucidate the ecological and biological features of red tide events,using approaches ranging from molecular and cell biology to large-scale field surveys,numerical modeling,and remote sensing from space.However,studies on the molecular mechanisms of red tides,including those involved in their decline phase,are still limited.Researchers believe that the decline phase of red tides represents a process of programmed cell death（PCD）.PCD,which is controlled by multiple factors,is an active,gene-regulated process that has evolved in most organisms.Alexandrium catenella is an important causative dinoflagellate associated with HABs and paralytic shellfish poisoning.In this study,we determined physiological and biochemical indices of A.catanella including soluble protein content,superoxide dismutase（SOD） activity,malondialdehyde（MDA） content,reduced glutathione（GSH） content,hydrogen peroxide（H2O2） content,photosynthetic rate,respiratory rate,DNA laddering,and telomerase activity.These biochemical analyses were conducted using cells of A.catenella collected after different periods of growth and under different growth conditions（i.e.,with different concentrations of nitrogen in the medium）.There were differences in several parameters between the decline phase and the logarithmic phase.There was an increase in peroxidation in A.catenella during the decline phase and under low-and high-nitrogen conditions.This was characterized by increased SOD activity（except under low-nitrogen growth conditions）,MDA content,and H2O2 content,and decreases in soluble protein content,GSH content,photosynthetic rate,and respiratory rate.The results suggested that excessive reactive oxygen was the main reason for the decline of A.catenella.Based on these experi

关 键 词：链状亚历山大藻 衰亡 生理调控 

分 类 号：X173[环境科学与工程—环境科学]