不同绿藻对模拟酸雨胁迫的生理生化响应特征

Physiological and biochemical responses of different species of chlorophyta to simulated acid rain stress

以东海潮间带绿藻优势种为试验材料,测定其最大光化学量子产量(maximal photochemical quantum yield of PSⅡ,Fv/Fm)、可溶性糖含量及抗氧化酶活性等指标,研究不同强度模拟酸雨(pH分别为6.3、5.6、4.5、4.0、3.5)胁迫下绿藻优势种生理生化响应。结果表明:1)随着模拟酸雨酸度和处理时间增加,2种浒苔、4种石莼、史氏刚毛藻和刺松藻的Fv/Fm抑制幅度增大;2)pH 4.5的模拟酸雨降低藻体中叶绿素a、类胡萝卜素和可溶性糖含量,降幅为浒苔>石莼>刺松藻>史氏刚毛藻。而可溶性蛋白含量有所增加,且随时间延长愈加显著,史氏刚毛藻增幅高于其他绿藻。3)pH 4.5的模拟酸雨抑制绿藻中超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)活性,但提高其过氧化物酶(peroxidase,POD)活性,且处理时间与POD活性正相关,与SOD、CAT活性负相关。研究表明pH 4.5能作为模拟酸雨胁迫潮间带绿藻优势种的试验条件,史氏刚毛藻对模拟酸雨耐受性最佳,石莼比浒苔具有更好的抗酸雨胁迫能力。

The maximal photochemical quantum yield of PSⅡ(Fv/Fm),soluble sugar contents and antioxidant enzyme activity were determined by using dominant species of chlorophyta in the intertidal zone of the East China Sea.The physiological and biochemical responses of dominant species of chlorophyta under simulated acid rain(pH 6.3,5.6,4.5,4.0,3.5,respectively)were studied.The results showed that:1)the simulated acid rain inhibited Fv/Fm of Ulva prolifera and Ulva intestinalis,the remaining green seaweeds of Ulva,Cladophora stimpsonii and Codium fragile,and the inhibition amplitude increased with the increase of acidity and treatment time;2)simulated acid rain at pH 4.5 reduced the contents of chlorophyll a,carotenoids and soluble sugar,and the decrease amplitude was green seaweeds of Ulva>C.fragile>C.stimpsonii.but the contents of soluble protein increased,which became more significant as time went on,and the increase amplitude of C.stimpsonii was higher than that of other green seaweeds;3)simulated acid rain at pH 4.5 inhibited the activities of superoxide dismutase(SOD)and catalase(CAT),but increased the activities of peroxidase(POD)of seaweeds,and the treatment time was positively correlated with the activities of POD,but negatively correlated with the activities of SOD and CAT.In summary,pH 4.5 can be used as physiological and biochemical test conditions for dominant species of chlorophyta to simulated acid rain stress,C.stimpsonii exhibited higher tolerance to simulated acid rain,compared with U.prolifera and U.intestinalis,the remaining green seaweeds of Ulva has higher tolerance to simulated acid rain.