谷子及其根际土壤微生物群落对铬胁迫的响应机制  

Response mechanisms of millet and its rhizosphere soil microbial communities to chromium stress

作　　者：白雪[1] 李玉靖 景秀清 赵晓东 畅莎莎 荆韬羽 刘晋汝 赵鹏宇 BAI Xue;LI Yu-Jing;JING Xiu-Qing;ZHAO Xiao-Dong;CHANG Sha-Sha;JING Tao-Yu;LIU Jin-Ru;ZHAO Peng-Yu(College of Biological Sciences and Technology,Taiyuan Normal University,Jinzhong,Shanxi 030619,China)

机构地区：[1]太原师范学院生物科学与技术学院,山西晋中030619

出　　处：《植物生态学报》2023年第3期418-433,共16页Chinese Journal of Plant Ecology

基　　金：山西省重点研发项目(20163D221008-1);山西省高等学校科技创新项目(2020L0535);服务流域生态治理产业创新学科集群建设(山西省“1331工程”)。

摘　　要：重金属铬(Cr)污染对农田中农作物产生毒害作用并破坏土壤微生物群落稳态,但不同农作物及其根际土壤微生物群落对Cr胁迫的响应机制均有所差异。该研究在时间序列上分析Cr胁迫对谷子(正名:粱, Setaria italica)长势、谷子差异表达基因(DEGs)的功能途径及土壤微生物群落结构和功能等方面的影响,阐明谷子及土壤微生物群落的响应机制,为Cr胁迫下的谷子生长及污染土壤的生态修复治理提供理论依据。基于室内盆栽实验,以谷子幼苗和种植谷子的土壤为实验材料,在Cr胁迫前(CK)及胁迫后6 h和6 d (Cr_6h、Cr_6d)的时间序列上分别进行样本采集,同时测量幼苗生理性状指标及土壤理化指标。通过转录组分析,研究Cr胁迫时间序列上谷子幼苗基因表达及所富集的功能途径的变化趋势;通过高通量测序分析,研究Cr胁迫时间序列上土壤微生物群落结构、物种多样性、群落功能的动态变化过程及与土壤理化性质的相关性。结果发现:1)转录组分析结果表明Cr胁迫诱导基因表达上调(上调DEGs 54%);Gene Ontology (GO)富集分析表明DEGs在CK和Cr_6h、Cr_6h和Cr_6d样本对中与光合作用相关的基因的表达显著下调;在Cr_6h和Cr_6d样本对中与防御和损伤调控相关的基因的表达显著上调,细胞壁及细胞膜和细胞分裂相关基因的表达下调。2)高通量测序结果表明Cr胁迫时间序列上土壤细菌与真菌在门、属水平组成变化显著;细菌群落α多样性呈现出由应激到稳定的阶段性变化特征(CK、Cr_6h和Cr_6d的Shannon多样性指数分别为6.09、5.93和6.05;Simpson多样性指数分别为0.0068、0.0078和0.0068;Chao多样性指数分别为2818.49、2630.73和2 769.38),而真菌群落α多样性显著下降(Shannon-Wiener多样性指数分别为4.17、3.81和3.23);细菌与真菌群落的β多样性在Cr胁迫时间序列的分布差异显著。3)土壤理化性质与微生物群落相关性分析表明土壤Aims Heavy metal chromium(Cr)contamination has toxic effects on crops and will disrupt soil microbial community homeostasis in agricultural soils.Nevertheless,the mechanisms underlying the responses of different crops and their rhizosphere soil microbial communities to Cr stress were different.By using time series data,this study analyzed the effects of Cr stress on‘Jingu 21’growth,functional pathways of differentially expressed genes(DEGs)in cereals and soil microbial community structure and function.Our objective was to elucidate the response mechanism of millet(Setaria italica)and soil microbial community,and provide a theoretical basis for the growth of cereals under Cr stress and the ecological restoration of the contaminated soil.Methods We collected millet seedlings and soil samples from the pot experiments with planted millet before(CK)and 6-hour and 6-day after Cr stress(Cr_6h,Cr_6d),and determined the physiological traits of seedlings and soil physicochemical properties.The gene expression and the functional pathways enriched in the seedlings were investigated by transcriptome analysis;the dynamics of microbial community composition,structure,diversity as well as function in time series and their correlations with soil physicochemical properties were studied by high-throughput sequencing analysis.Important findings 1)Transcriptome analysis showed that Cr stress induced up-regulation of gene expression(54%for up-regulated DEGs);GO enrichment analysis showed that DEGs significantly down-regulated the expression of photosynthesis-related genes in CK&Cr_6h,Cr_6h&Cr_6d samples,and also significantly up-regulated the expression of defense and damage regulation-related genes,and down-regulated the expression of cell wall and cell membrane and cell division-related genes in Cr_6h&Cr_6d samples.2)High-throughput sequencing revealed a significant change in the composition of soil bacterial and fungal communities at the phylum and genus level during the time series of Cr stress.Theαdiversity of bacterial comm

关 键 词：重金属胁迫 时间序列 ‘晋谷21号’ 微生物群落 高通量测序 转录组分析 

分 类 号：X173[环境科学与工程—环境科学] S154.3[农业科学—土壤学] S515[农业科学—农业基础科学]