水杨酸对刚毛藻生长的抑制作用

Growth Inhibition of Salicylic Acid on Cladophora oligoclona

近年来刚毛藻快速增殖与泛滥成灾对养殖水体和饮用水源造成了严重影响,为探究快速处理方法,选取寡枝刚毛藻(Cladophora oligoclona)为受试对象,采用不同浓度的水杨酸(0、0.2、0.25、0.3、0.35和0.4 g·L^(-1))进行处理,测定了叶绿素a(Chl a)含量、光合系统Ⅱ(PSⅡ)最大光化学效率(F_(v)/F_(m))、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、蛋白和丙二醛(MDA)含量等指标,并观察了细胞显微结构的变化。结果表明,水杨酸能抑制刚毛藻生长,随水杨酸浓度升高,刚毛藻Chl a含量逐渐降低,呈现明显剂量效应关系;暴露96 h后,0.4 g·L^(-1)水杨酸对刚毛藻生长抑制率可高达73.64%,96 h半数效应浓度(96 h-EC_(50))为0.262 g·L^(-1)。0.2~0.4 g·L^(-1)水杨酸处理后,藻细胞F_(v)/F_(m)显著降低(P<0.01),MDA含量显著升高(P<0.01),SOD、POD酶活性和可溶性蛋白含量显著降低(P<0.01)。与对照组相比,水杨酸处理后藻细胞颜色逐渐变黄发白,蛋白核数量减少。上述结果表明,水杨酸是通过影响细胞叶绿素含量和降低藻细胞PSⅡ的光合活性,导致藻体同化产物减少;同时使膜脂过氧化加剧,细胞抗氧化酶活性受抑制,最终表现为对刚毛藻生长的抑制作用。鉴于此,水杨酸具有被开发成刚毛藻快速增殖抑制剂的潜力。

In recent years,the rapid proliferation of Cladophora has severely affected aquaculture water and drinking water.In order to develop the methods to inhibit the rapid proliferation of Cladophora,Cladophora oligoclona was selected as the experimental object,treated with different concentrations(0,0.2,0.25,0.3,0.35 and 0.4 g·L^(-1))of salicylic acid.The content of chlorophyll a(Chl a),the maximum photochemical efficiency of photosynthetic systemⅡ(F_(v)/F_(m)),the activities of superoxide dismutase(SOD)and peroxidase(POD),the contents of protein and malondialdehyde(MDA)were measured,and the microscopic structure of algal cells were also observed.The results showed that salicylic acid could inhibit the growth of C.oligoclona,and the content of Chl a decreased gradually with the increase of salicylic acid concentration,which demonstrated a significant dose-effect relationship.After 96 h exposure,the inhibition rate of C.oligoclona reached 73.64%under the treatment of 0.4 g·L^(-1)salicylic acid.The 96 h median effect concentration(96 h-EC_(50))on C.oligoclona was 0.262 g·L^(-1).Compared with the control group,salicylic acid with 0.2~0.4 g·L^(-1)could significantly decrease F_(v)/F_(m)(P<0.01),the activity of SOD and POD(P<0.01),and the protein content(P<0.01),while the content of MDA significantly increased(P<0.01).After treatment with salicylic acid,the color of algae cells gradually turned yellow and white,and the number of pyrenoid decreased.It was concluded that salicylic acid damaged the photosynthetic systemⅡand reduced its photosynthesis efficiency,which resulted in the decrease of algal assimilation products.The integrity of the membrane system was destroyed and the enzyme activity of the cellular antioxidant system was inhibited.Eventually,the growth of C.oligoclona was inhibited.In view of this,salicylic acid has the potential to be developed as an inhibitor of the rapid proliferation of C.oligoclona.