摘要
为探讨龙葵(Solanum nigrum L.)耐镉(Cd)机理,采用基质培养法,研究了50μmol·L^-1 Cd(CdCl2·2.5H2O)处理120 d对其生长和叶片细胞壁果胶、木质素含量、多聚半乳糖醛酸酶(PG)、纤维素酶(Cx)、NADH-过氧化物酶(NADH-POD)、愈创木酚过氧化物酶(GPOD)和松柏醇过氧化物酶(CAPX)活性以及质外体汁液中过氧化氢(H2O2)含量和GPOD、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)和超氧化物歧化酶(SOD)活性的影响。结果表明,与对照相比,Cd处理显著抑制了龙葵地上和地下部的伸长生长、降低了根的干物质积累(P<0.05),但茎的分枝增多,叶面积、叶绿素含量、净光合速率和胞间CO2浓度无显著变化(P>0.05);细胞壁结合酶NADH-POD、GPOD和CAPX活性以及果胶含量显著增高(P<0.05),而PG活性显著下降(P<0.05),Cx活性和木质素含量无显著变化(P>0.05);质外体汁液中H2O2含量显著增加(P<0.05),GPOD和SOD同工酶谱及活性无显著变化(P>0.05);CAT同工酶谱带增宽,APX同工酶谱带数增加,二者活性均显著升高(P<0.05)。说明50μmol·L^-1 Cd较长时间处理龙葵植株,其地上部分生长仍处于良好状态,表现出对Cd毒害的耐性,这与Cd处理后叶片细胞壁果胶含量和结合酶GPOD以及质外体汁液中APX、CAT活性升高有关,推测这是龙葵耐Cd的一种机理。
To investigate the cadmium tolerance mechanism of Solanum nigrum L.,a substrate culture experiment was conducted to study the effects of 50μmol·L^-1 Cd(CdCl2·2.5H2O)treatment on the contents of pectin and lignin,the activities of polygalacturonase(PG),cellulase(Cx),NADH-peroxidase(NADH-POD),guaiacol peroxidase(GPOD)and coniferylalcohol peroxidase(CAPX)in cell wall,and the content of hydrogen peroxide(H2O2)and the activities of superoxide dismutase(SOD),catalase(CAT),ascorbic acid oxidase(APX)in apoplast sap.The results showed that after 50μmol·L^-1 Cd treatment for 120 days,compared with the control,the length of shoot and root were inhibited,and the biomass of root was decreased(P<0.05),but the leaf area,chlorophyll content(SPAD),net photosynthetic rate(Pn)and intercellular CO2 concentration(Ci)showed no significant difference(P>0.05).In the cell wall of leaves,the activity of NADH-POD,GPOD and CAPX and the pectin content were all significantly increased(P<0.05),the PG activity was decreased(P<0.05),and Cx activity and lignin content showed no significant difference(P>0.05).In the apoplast sap of leaves,H2O2 content increased significantly(P<0.05),and the activity and isozyme band of GPOD and SOD weren't significantly influenced(P>0.05),but the activities of APX and CAT increased(P<0.05)with more isozyme band number and enhanced isozyme band,respectively.In conclusion,the pectin,H2O2-producing NADH-POD and H2O2-consuming GPOD in cell wall,and H2O2-consuming APX and CAT in apoplast sap might play major roles in Cd tolerance of Solanum nigrum L.
作者
王小明
陈爱玲
董璐
石玉军
郑刘长
赵连慧
张瑞琪
张芬琴
WANG Xiaoming;CHEN Ailing;DONG Lu;SHI Yujun;ZHENG Liuchang;ZHAO Lianhui;ZHANG Ruiqi;ZHANG Fenqin(College of Life Science and Engineering, Hexi University, Zhangye 734000, China;Key Laboratory of Hexi Corridor Resources Utilization of Gansu, Zhangye 734000, China)
出处
《浙江农业学报》
CSCD
北大核心
2020年第5期816-823,共8页
Acta Agriculturae Zhejiangensis
基金
国家自然科学基金(31560072)
2019年甘肃省高等学校教学质量与教学改革工程和创新创业教育改革项目(143)。
关键词
龙葵
质外体
酶活性
Cd耐性
Solanum nigrum L.
apoplast
enzymes activity
cadmium tolerance