耐镉阿氏芽孢杆菌缓解水稻受镉胁迫的研究  

Study on the mitigation of cadmium stress in rice by cadmium-resistant Bacillus aryabhattai

作　　者：范美玉 黎妮[2] 贾雨田 张超[2] 王伟平[2] 杨志伟[1] FAN Mei-yu;LI Ni;JIA Yu-tian;ZHANG Chao;WANG Wei-ping;YANG Zhi-wei(College of Life Sciences,Capital Normal University,Beijing 100048,China;State Key Laboratory of Hybrid Rice,Hunan Hybrid Rice Research Center,Changsha 410125,China)

机构地区：[1]首都师范大学生命科学学院,北京100048 [2]湖南杂交水稻研究中心,杂交水稻国家重点实验室,长沙410125

出　　处：《农业环境科学学报》2021年第2期279-286,共8页Journal of Agro-Environment Science

基　　金：湖南省农业科技创新资金项目(2018QN03);长沙市科技计划项目(kq1801033)。

摘　　要：为了探究阿氏芽孢杆菌T61缓解水稻受镉胁迫的效应,运用96孔板法、电感耦合等离子体质谱法、比色法测定菌株T61的镉耐受性、镉去除率和植物促生性;利用绿色荧光蛋白标记的T61,观察菌株在水稻上的定殖;利用蘸根法施加T61菌剂,观察其降低水稻籽粒镉积累的效应。结果表明:菌株T61对Cd2+的最大耐受浓度达到500μmol·L^(-1);在含镉液体培养基中培养24 h后,菌株T61对Cd2+的去除率超过50%。菌株T61可以合成植物促生性物质吲哚乙酸(6.2μg·mL^(-1))和铁载体(46.6μmol·L^(-1)),并具有溶磷能力(37.1μg·mL^(-1))。菌株T61可以在水稻根和茎上定殖。大田条件下,T61菌剂可以降低营养期水稻茎叶丙二醛含量和抗氧化酶活性,并使水稻728B和NX1B籽粒中的镉含量分别降低13.5%和11.2%。研究表明,阿氏芽孢杆菌T61是一株具有植物促生性的耐镉细菌,可以缓解某些水稻品种遭受的镉胁迫,在镉污染稻田的微生物修复方面具有一定的应用前景。In order to explore the efficacy of Bacillus aryabhattai T61 in mitigating cadmium stress on rice,the Cd tolerance,removal rate,and plant growth promotion traits of T61 bacteria were determined using 96-well plate assays,inductively coupled plasma mass spectrometry,and colorimetric methods.A T61-eGFP strain was used to observe the colonization of T61 in rice plants.The T61 inoculum was applied using the dipping root method,to observe its effect of reducing Cd accumulation in rice grains.Results showed that T61 had a maximum Cd2+tolerance concentration of up to 500 mmol·L^(-1).The Cd2+removal rate of T61 was more than 50%after being cultured in liquid medium containing Cd2+for 24 hours.T61 could synthesize plant growth promoting substances,such as indoleacetic acid(6.2μg·mL^(-1))and siderophore(46.6μmol·L^(-1)),and had the ability to dissolve inorganic phosphate(37.1μg·mL^(-1)).It was confirmed that T61 could colonize rice roots and shoots.Under field conditions,the application of T61 inoculum could reduce malondialdehyde content and the activities of antioxidant enzymes in rice shoots in the vegetative stage and decrease the Cd content in 728B and NX1B grains by 13.5%and 11.2%,respectively.Therefore,Bacillus aryabhattai T61 is a Cd-tolerant bacterium with plant growth promoting traits,which can alleviate Cd stress in some rice cultivars,and has application prospects in the microbial remediation of Cd-contaminated paddy fields.

关 键 词：镉污染 水稻 芽孢杆菌 植物促生性 抗氧化酶 生物修复 

分 类 号：S511[农业科学—作物学] X17[环境科学与工程—环境科学]