抗氧化酶和植物螯合肽对苎麻重金属Cd胁迫的应答  

Responses of Ramie to Antioxidant Enzymes and Plant Chelating Peptides to Cd Stress

作　　者：全芮萍 陈建福 张蕾 许明志 杨瑞芳[1] 佘玮[1] 崔国贤[1] QUAN Ruiping;CHEN Jianfu;ZHANG Lei;XU Mingzhi;YANG Ruifang;SHE Wei;CUI Guoxian(College of Agronomy,Hunan Agricultural University,Changsha,Hunan 410128,China)

机构地区：[1]湖南农业大学农学院,湖南长沙410128

出　　处：《热带作物学报》2022年第5期1023-1031,共9页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金项目(No.31871673);财政部和农业农村部国家现代农业产业技术体系——国家麻类产业技术体系项目(No.CARS-16-E11)。

摘　　要：为了探究抗氧化酶和植物螯合肽在苎麻耐镉生理机制中的作用,本研究以苎麻耐性品种‘川苎8号’为实验材料,对其进行5、25、50mg/L的镉处理,7d后分别测定其生物量、镉含量、抗氧化酶活性、植物螯合肽含量以及相关基因表达量。结果表明5 mg/L镉处理‘川苎8号’的株高、根长与生物量受到促进,25、50 mg/L镉处理下‘川苎8号’的株高、根长与生物量受到抑制,‘川苎8号’主要将镉积累在根部,不同镉处理下转运系数均小于1,25 mg/L镉处理时镉积累量与转运系数均显著高于其他处理;镉胁迫后‘川苎8号’地上部和地下部超氧化物歧化酶(SOD)活性显著升高,丙二醛(MAD)活性显著降低,过氧化氢(H2O2)含量显著上升;5、25 mg/L镉处理时地下部植物螯合肽(PCs)与谷胱甘肽(GSH)含量显著低于对照,50 mg/L镉处理时高于对照但未达到显著差异;PCs和GSH在地上部和地下部承担着不同的解毒作用;各浓度处理的地上部BnPCS1相对表达量均与镉含量呈极显著正相关(P<0.01),高浓度(25、50 mg/L)处理的地上部BnGCL1相对表达量与镉含量呈正相关(P<0.01);低浓度(5 mg/L)处理下SOD活性显著高于对照,与各部位镉含量均呈极显著正相关(P<0.01),高浓度镉处理时地下部SOD活性与镉含量呈极显著负相关(P<0.01),地下部PCs含量与镉含量呈极显著正相关(P<0.01)。综合分析说明,‘川苎8号’在低浓度镉胁迫时主要通过激活抗氧化酶活性消除细胞中自由基的毒害,高浓度镉胁迫时通过调节抗氧化酶活性和PCs与GSH合成解除镉的毒害。In order to explore the role of antioxidant enzymes and plant chelating peptides in the physiological mechanism of ramie tolerance to cadmium,Cd-tolerant ramie variety‘Chuanzhu 8’was treated with 5,25,50 mg/L cadmium,and the biomass,cadmium content,antioxidant enzyme activity,plant chelating peptide content and related gene expression were assayed seven days later.The plant height,root length and biomass treated with 5 mg/L cadmium were promoted,and the plant height,root length and biomass treated with 25,50 mg/L cadmium were affected.Cadmium was mainly accumulated in the root,the transport coefficient under different cadmium treatment was less than one,and the cadmium accumulation and transport coefficients under 25 mg/L cadmium was significantly higher than that of other treatments.The superoxide dismutase(SOD)activity significantly increased,the,malondialdehyde(MAD)activity significantly decreased in cadmium stress.The hydrogen peroxide(H2O2)content significantly increased,the underground plant chelating peptides(PCs)and glutathione(GSH)content was significantly lower than that of the control under 5 mg/L and 25 mg/L cadmium treatments,and was higher than that of the control under 50 mg/L cadmium,but did not reach a significant difference.PCs and GSH had different detoxification effects in aboveground and underground parts.The relative expression of aboveground BnPCS1 and cadmium content under various concentration treatments were extremely significantly positively correlated(P<0.01),and the relative expression of aboveground BnGCL1 at a high concentration(25 mg/L and 50 mg/L)was positively correlated with cadmium content(P<0.01).SOD activity under low concentration(5 mg/L)was significantly higher than that of the control,and had the same cadmium content in all parts.There was a very significant positive correlation(P<0.01).The SOD activity and cadmium content in the underground was extremely significantly negatively correlated(P<0.01)when treated with high concentration of cadmium,and the PCs content and

关 键 词：苎麻 镉 抗氧化酶 植物螯合肽 

分 类 号：S563.1[农业科学—作物学]