铀对蚕豆幼苗光合特性和呼吸代谢的毒害机理  

Toxic mechanism of uranium on photosynthetic characteristics and respiratory metabolism of Vicia faba L.

作　　者：刘泽伟 赖金龙 李俊柯 丁峰 张宇 罗学刚[1,3] LIU Ze-wei;LAI Jin-long;LI Jun-ke;DING Feng;ZHANG Yu;LUO Xue-gang(School of Life Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;College of Environment and Resource,Southwest University of Science and Technology,Mianyang 621010,China;Engineering Research Center of Biomass Materials,Ministry of Education,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学生命科学与工程学院,四川绵阳621010 [2]西南科技大学环境与资源学院,四川绵阳621010 [3]西南科技大学生物质材料教育部工程研究中心,四川绵阳621010

出　　处：《农业环境科学学报》2020年第9期1916-1924,共9页Journal of Agro-Environment Science

基　　金：国民核生化灾害防护国家重点实验室公开基金项目(SKLNBC2019-21)。

摘　　要：为探究铀(U)胁迫对植物光合作用和呼吸代谢的毒害作用,采用溶液培养法,用含有不同浓度铀(0、5、10、15、20、25μmol·L-1)的溶液处理蚕豆幼苗72 h后,通过组织切片和扫描电镜观察根系结构的变化,并测定蚕豆幼苗的叶绿素含量、光合参数以及根系活力,另取高浓度铀处理组(U-25μmol·L-1)与对照组(U-0μmol·L-1)的根系进行转录组测序(RNA-seq)。结果表明:在不同浓度的铀胁迫下,铀向地上部的转移极少,其转移系数小于0.01,过量的铀累积明显破坏了根系的结构。此外,铀胁迫下蚕豆幼苗的光合效率降低,但根系活力增加。RNA-seq结果表明,与光合作用和呼吸代谢调控相关的基因中,共有117个基因差异表达,其中,光合作用中与光反应途径、卡尔文循环途径及光呼吸途径相关的基因表达以下调为主(90个DEGs;3个上调,87个下调);呼吸代谢中参与线粒体电子传递过程的相关基因表达以上调为主(27个DEGs;23个上调,4个下调)。研究表明,高浓度的铀胁迫抑制了蚕豆幼苗的光合作用,但增强了其根系的呼吸代谢,这可能是蚕豆对铀毒害的一种适应机制。This study aims to explore the toxicity of uranium(U)stress on photosynthesis and respiratory metabolism in plants.In this experiment,seedlings of Vicia faba L.were treated with different concentrations of U(0,5,10,15,20μmol·L-1 and 25μmol·L-1)for 72 h.Physiological and biochemical analyses were conducted,and the roots of the high-concentration U treatment group and the control group were selected using RNA-seq.The results showed that under different concentrations of U stress,U rarely transferred to the aboveground part of the plant,its transfer coefficient was less than 0.01,and the excess U accumulation clearly damaged the root structure.In addition,the leaf photosynthetic efficiency of Vicia faba L.decreased,but the root activity increased under U stress.These processes are regulated by related genes.The results of transcriptome sequencing showed that there were 117 differentially expressed genes(DEGs)involved in photosynthesis and respiratory metabolism.The expression of photosynthesis-related genes was mainly down-regulated(90 DEGs,3 up and 87 down),while that of respiratory metabolism-related genes was mainly up-regulated(27 DEGs;23 up and 4 down).Therefore,this research shows that the photosynthesis of Vicia faba L.is inhibited and the respiration is enhanced under high-concentration U treatment.

关 键 词：铀(U) 光合作用 呼吸代谢 转录组 蚕豆 

分 类 号：X171.5[环境科学与工程—环境科学]