摘要
为探究谷田土壤中细菌群落对铬(Cr)胁迫的响应特征,以种植‘晋谷21号’谷子(Setaria italica)的土壤为试验材料,通过Illumina MiSeq高通量测序技术,分析Cr(1 mmol·L^(-1)Cr^(6+))胁迫前(CK组)及胁迫后6 h(Cr_6h)与6 d(Cr_6d)的谷田土壤中细菌群落的组成及多样性、群落构建机制及KEGG代谢通路活性的变化。结果表明:Cr胁迫后不同时间节点,谷田土壤中细菌群落在门水平和属水平的优势菌比例差异显著;α多样性呈阶段性变化特征,其中Shannon指数在Cr_6h下降,在Cr_6d上升(CK为6.07、Cr_6h为5.92、Cr_6d为6.04),Simpson指数变化趋势则相反(CK为0.006 8、Cr_6h为0.007 8、Cr_6d为0.006 8)。Cr胁迫后细菌群落的beta NTI值持续降低(CK、Cr_6h、Cr_6d分别为-2.68、-2.11、-1.91),群落构建在CK和Cr_6h阶段由确定过程驱动(|betaNTI|>2),而在Cr_6d阶段主要由随机过程驱动(|betaNTI|<2);边数量和平均度显著下降,平均路径长度持续显著上升,同一模块中的细菌群落以正相关为主。研究表明,Cr胁迫显著影响了谷田土壤中的细菌群落。随着Cr胁迫时间的延长,细菌群落构建由确定过程驱动逐渐转变为由随机过程驱动;细菌的共生网络规模变小,菌群间响应速度变慢,且以共生关系为主导。
To investigate the response mechanism of bacterial communities in farmland soil to chromium(Cr)stress,soil planted with“Jingu 21”millet(Setaria italica)was used as the experimental material in this study.Samples were acquired before Cr stress(CK group)and after 6 h(Cr_6h)and 6 d(Cr_6d)of 1 mmol∙L^(-1) Cr^(6+)stress.The composition,diversity,assembly process,and KEGG metabolic pathway activity of bacterial community in the soil under Cr stress were analyzed using Illumina MiSeq high-throughput sequencing.The results revealed that there were significant differences in the proportion of dominant bacteria at phylum and genus levels in the bacterial communities under different durations of Cr stress.Theαdiversity varied in stages,for example the Shannon index decreased at Cr_6h and increased at Cr_6d(6.07 at CK,5.92 at Cr_6h,and 6.04 at Cr_6d),whereas the Simpson index exhibited the opposite trend(0.0068 at CK,0.0078 at Cr_6h,and 0.0068 at Cr_6d).After Cr stress,the beta NTI index continued to decrease(−2.68 at CK,−2.11 at Cr_6h,and−1.91 at Cr_6d).The bacterial community assembly processes in CK and Cr_6h stage were dominated by deterministic assembly process(||beta NTI>2),whereas in Cr_6d stage,they were mainly dominated by stochastic assembly process(||beta NTI<2).The number of edges and average degree of bacterial communities decreased significantly,whereas the average path length continued to increase significantly.The symbiosis of the bacterial community in the same module was mainly positively correlated.The above results demonstrated that Cr stress significantly affects the bacterial community in the soil of millet fields.With the duration of Cr stress,the bacterial community assembly processes gradually changed from being dominated by deterministic assembly process to being dominated by stochastic assembly process.The symbiotic network of bacteria became smaller,and the response rate became slower,which was dominated by a symbiotic relationship.The scale of the symbiotic network of bacterial commu
作者
景秀清
赵鹏宇
白雪
邓宁
赵晓东
吴丽华
仪慧兰
JING Xiuqing;ZHAO Pengyu;BAI Xue;DENG Ning;ZHAO Xiaodong;WU Lihua;YI Huilan(College of Biological Sciences and Technology,Taiyuan Normal University,Jinzhong 030619,China;College of Life Science,Shanxi University,Taiyuan 030006,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2023年第6期1294-1304,共11页
Journal of Agro-Environment Science
基金
山西省高等学校科技创新项目(2020L0509)。
关键词
谷田
铬胁迫
细菌群落
群落组成
群落构建机制
millet field
chromium stress
bacterial community
community composition
community assembly process
