干旱预处理对八宝景天响应镉铜胁迫的影响  

Effects of PEG pretreatment on physiological metabolism of Sedum Spectabile Boreau under cadmium and copper stress

作　　者：鲜靖苹[1] 刘伍强 崔笑玲 庄静静 王晓冰 XIAN Jing-ping;LIU Wu-qiang;CUI Xiao-ling;ZHUANG Jing-jing;WANG Xiao-bing(School of Biological Engineering,Xinxiang University,Xinxiang 453000,Henan,China)

机构地区：[1]新乡学院生物工程学院,河南新乡453000

出　　处：《西北师范大学学报（自然科学版）》2023年第5期96-105,共10页Journal of Northwest Normal University(Natural Science)

基　　金：河南省科技攻关项目(232102321054);河南省新乡市科技攻关项目(GG2020017)。

摘　　要：为探究干旱预处理对八宝景天响应镉铜胁迫的影响,将八宝景天幼苗分别用0%,5%,10%,15%,20%,25%(对应水势分别为0,-0.05,-0.15,-0.30,-0.50,-0.77MPa)的PEG-6000溶液模拟干旱胁迫预处理后,分别用150mg·kg^(-1)的Cu^(2+)和20mg·kg^(-1)的Cd^(2+)胁迫液培养,然后测定八宝景天幼苗叶片的光合色素含量、丙二醛(MDA)含量、游离脯氨酸含量、可溶性糖含量及抗氧化酶(APX,CAT,SOD,POD)活性.结果表明,镉胁迫下10%(-0.15MPa)PEG预处理和铜胁迫下5%(-0.05MPa)PEG预处理可以有效提高八宝景天的光合色素含量,降低MDA含量,增加可溶性糖含量和游离脯氨酸含量,提高抗氧化酶活性.相对于空白(CK)组,10%PEG预处理对八宝景天地上部镉含量和铜含量以及镉、铜转运系数的促进效果最为明显,地上部镉含量和铜含量分别比CK增加了3.87%和3.59%;镉和铜转运系数分别增加了15.4%和5.8%.以上结果表明,干旱预处理下八宝景天在遭受逆境胁迫时,受到多种生理生化的调节,其生理指标的动态变化是八宝景天应答逆境因子胁迫的重要调节机制,体现了其对逆境胁迫的适应能力以及在多种逆境胁迫下的交叉适应能力.The effects of PEG pretreatment on physiological characteristics of Sedum Spectabile Boreau seedlings under cadmium and copper stress were studied by pot experiment.The experimental seedlings were dealt with 0%,5%,10%,15%,20%and 25%(the corresponding water potential was 0,-0.05,-0.15,-0.30,-0.50 and-0.77 MPa,respectively)PEG-6000 pretreatment nutrient solutions,respectively,and then the seedlings were cultured separately by stress solutions containing 150 mg·kg-1 Cu 2+and 20 mg·kg^(-1) Cd^(2+),respectively.Then,the leaf chlorophyll content,activities of antioxidant enzyme(such as catalase(CAT),superoxide dismutase(SOD),guaiacol peroxidase(POD)and ascorbate peroxidase(APX)),contents of osmoregulation substances,such as proline,soluble sugar and malondialdehyde(MDA)in leaves were determined.The test results showed that the 10%(-0.15 MPa)PEG pretreatment under the Cd 2+stress and the 5%(-0.05 MPa)PEG pretreatment under the Cu 2+stress could effectively increase the leaf chlorophyll contents of Sedum Spectabile Boreau seedlings,reduce the contents of MDA,increase the content of soluble sugar and proline,increase the activities of antioxidant enzymes.Compared with blank(CK)group,the promotion effect of 10% PEG pretreatment on aboveground Cd content and Cu content as well as the transfer coefficient of Cd and Cu was the most obvious,and the aboveground Cd content and Cu content increased by 3.87% and 3.59%,respectively,compared with CK group.The transfer coefficients of cadmium and copper increased by 15.4% and 5.8%,respectively.The above results showed that the Sedum Spectabile Boreaudealt by PEG pretreatment under stress was regulated by various physiological and biochemical factors.The dynamic changes of physiological indexes were important regulatory mechanisms for Sedum Spectabile Boreau in respons to stress,which reflected its adaptability to stress and its cross-adaptation ability under various stresses.

关 键 词：八宝景天 PEG预处理 镉胁迫 铜胁迫 

分 类 号：S682.33[农业科学—观赏园艺]