Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion in Henan Province, College of Water Resource and Environment Engineering, Nanyang Normal University, Nanyang 473061, China.
Int J Environ Res Public Health. 2022 Dec 6;19(23):16309. doi: 10.3390/ijerph192316309.
To explore the mechanism by which the plant growth-promoting bacterium sp. SR-9 improves sweet sorghum tolerance and enriches soil cadmium (Cd) under pot conditions, the effect of strain SR-9 inoculation on the microbial community of sorghum rhizosphere soil was analyzed by metagenomics. Gene expression in sweet sorghum roots was analyzed using transcriptomics. The results showed that strain SR-9 promoted the growth of sweet sorghum and improved the absorption and enrichment of Cd in the plants. Compared with the uninoculated treatment, the aboveground part and root dry weight in strain SR-9 inoculated with sorghum increased by 21.09% and 17.37%, respectively, and the accumulation of Cd increased by 135% and 53.41%, respectively. High-throughput sequencing showed that strain SR-9 inoculation altered the rhizosphere bacterial community, significantly increasing the relative abundance of Actinobacteria and Firmicutes. Metagenomic analysis showed that after inoculation with strain SR-9, the abundance of genes involved in amino acid transport metabolism, energy generation and conversion, and carbohydrate transport metabolism increased. KEGG functional classification showed that inoculation with strain SR-9 increased the abundance of genes involved in soil microbial metabolic pathways in the rhizosphere soil of sweet sorghum and the activity of soil bacteria. Transcriptome analysis identified 198 upregulated differentially expressed genes in sweet sorghum inoculated with strain SR-9, including those involved in genetic information processing, biological system, metabolism, environmental information processing, cellular process, and human disease. Most of the annotated differentially expressed genes were enriched in the metabolic category and were related to pathways such as signal transduction, carbohydrate metabolism, amino acid metabolism, and biosynthesis of other secondary metabolites. This study showed that plant growth-promoting bacteria can alter the rhizosphere bacterial community composition, increasing the activity of soil bacteria and upregulating gene expression in sweet sorghum roots. The findings enhance our understanding of the microbiological and botanical mechanisms by which plant growth-promoting bacterial inoculation improves the remediation of heavy metals by sorghum.
为了探索植物促生菌 sp. SR-9 提高甜高粱耐受性和在盆栽条件下富集土壤镉（Cd）的机制，通过宏基因组学分析了菌株 SR-9 接种对高粱根际土壤微生物群落的影响。使用转录组学分析了甜高粱根系中的基因表达。结果表明，菌株 SR-9 促进了甜高粱的生长，提高了植物对 Cd 的吸收和富集。与未接种处理相比，接种菌株 SR-9 的甜高粱地上部分和根干重分别增加了 21.09%和 17.37%，Cd 积累量分别增加了 135%和 53.41%。高通量测序显示，菌株 SR-9 接种改变了根际细菌群落，显著增加了放线菌和厚壁菌门的相对丰度。宏基因组分析表明，接种菌株 SR-9 后，参与氨基酸转运代谢、能量产生和转化以及碳水化合物转运代谢的基因丰度增加。KEGG 功能分类显示，接种菌株 SR-9 增加了甜高粱根际土壤中土壤微生物代谢途径的基因丰度和土壤细菌的活性。转录组分析鉴定出 198 个在接种菌株 SR-9 的甜高粱中上调的差异表达基因，包括参与遗传信息处理、生物系统、代谢、环境信息处理、细胞过程和人类疾病的基因。注释的差异表达基因大多富集在代谢类别中，与信号转导、碳水化合物代谢、氨基酸代谢和其他次生代谢物的生物合成等途径有关。本研究表明，植物促生菌可以改变根际细菌群落组成，增加土壤细菌的活性，并上调甜高粱根系中的基因表达。研究结果增强了我们对植物促生菌接种提高高粱修复重金属能力的微生物和植物机制的理解。
