摘要: |
【目的】基于高通量技术和功能预测研究水稻根际细菌群落主要生理代谢过程基因表达水平及其对高温胁迫的响应特征。【方法】通过盆栽试验对拔节期水稻进行7天的高温胁迫处理,提取根际土壤微生物DNA进行高通量测序,结合PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States)功能预测进行细菌菌群分析、基因注释及功能分类。【结果】与对照相比,高温胁迫促进了一些丰度相对较低的细菌门类(如:芽孢单菌门、浮霉菌门、Latescibacteria、螺旋菌门、Microgenomates和Candidatus_Berkelbacteria)的富集,提高了细菌多样性和细菌菌群之间共生关系的比例。细菌中活性基因主要源于变形菌门,其次是酸杆菌门、放线菌门和绿弯菌门。基于COG功能分类数据库发现,对照与高温胁迫处理土壤中表达量最高的基因均为新陈代谢相关的基因,其次是参与细胞加工和信号传递的基因。但高温胁迫提高了参与细胞运动、信号传导机制、胞内运转、分泌和囊泡运输和细胞壁/膜/器形成基因的相对丰度;却降低了参与氨基酸运输和代谢、脂质转运和代谢、次生代谢生物合成以及翻译的相关基因的丰度。【结论】高温胁迫虽未改变根际细菌菌群结构,但提高了细菌群群多样性,加强了细菌菌群的共生关系,显著影响参与细胞的周转,代谢以及蛋白质合成的基因表达。 |
关键词: 高温胁迫;水稻;根际细菌;生理代谢;功能基因 |
DOI: |
分类号:S154.1 |
基金项目:国家重点研发计划(2018YFC1508301-2),中国农业科学院基本科研业务费专项(FIRI2019-02-01和FIRI2017-16) |
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Effect of heat stress on rhizobacteria diversity and functional metabolism diversity of rice |
Qiu Hu-Sen, Zhen Bo, Zhou Xin-Guo
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Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences
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Abstract: |
In general, rice crop can resist heat stress by regulating physiological and biochemical processes. The metabolism processes affect soil microenvironment and the structure and function of microbial community especially in rizhosphere via changing root sediment morphology and content. Meanwhile, rhizospheric bacteria can change soil nutrient form by adjusting their functional metabolism process, and then affect rice root absorption of soil nutrient and crop defense ability to external environment stress. To make clear the response of rhizobacteria functional metabolism to environmental stress is important for better understanding of soil ecosystem service function and biogeochemistry cycle. 【Objective】 Response of gene expression profiles that define the physiological metabolic processes of rhizobacteria to heat stress were revealed by using high-throughput technique and functional prediction. 【Method】 Based on pot experiments, heat stress was conducted for 7 days in rice jointing stage. The bacterial flora analysis, gene annotation and function classification are performed in conjunction with the PICRUSt (Phylogenetic Information of Common by Construction of States) and high-throughput sequencing. 【Result】 Compared with the control, heat stress promotes the enrichment of relatively low abundance bacterial classes (such as Gemmatimonadetes, Planctomycetes, Latescibacteria, Spirochaetae, Microgenomates, and Candidatus_Berkelbacteria), and the bacterial diversity. Also, heat stress promotes the increases of the number and percentage of positive links (bacteria-bacteria) between taxa. Most of the transcripts of bacteria were derived from Proteobacteria, and followed by Acidobacteria, Actinobacteria, and chlorobi. Based on the COG functional classification database, the main active genes were those correlated with metabolism and cellular processes and signaling in both control and heat stress treatments. However, heat stress increased the relative abundance of genes that participated in cell motility, signal transduction mechanisms, intracellular trafficking, secretion, and vesicular transport, and cell wall/membrane/envelope biogenesis. While, heat stress decreased the relative abundance of genes that participated in amino acid transport and metabolism, lipid transport and metabolism, secondary metabolites biosynthesis, transport and catabolism, and transcription. 【Conclusion】 In conclusion, heat stress had no effect on the rhizobacteria flora, but increased bacterial Shannon diversity, strengthens the symbiotic relationship of bacterial flora, and significantly affected the gene expression involved in bacterial growth and death, metabolism, and protein synthesis. |
Key words: heat stress; rice; rhizobacteria, physiological metabolism; functional genes. |