万年县古稻原产区细菌多样性分析及功能预测

Bacterial diversity exploring and functional prediction in ancient rice original-producing region of Wannian County, China

  • 摘要: 为探讨我国古稻原产区独特的土壤微生态环境, 本研究以江西省万年县古稻原产区及邻近区域稻田为研究对象, 采用16S rDNA高通量测序技术和FAPROTAX功能预测分析了细菌群落结构及功能, 并探究影响细菌群落结构与功能特性的关键土壤理化因子。结果显示, 古稻原产区土壤除了包含更高含量的有效氮和Cu, 其他理化因子与邻近区域并未表现出明显的差异。古稻原产区的细菌群落特征与其他区域的差异性主要体现在种群组成上, 而不是细菌丰度(基于荧光定量PCR技术)和Alpha多样性。与邻近区域相比, 古稻原产区土壤中包含更高相对丰度的厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidota), 及更低相对丰度的酸杆菌门(Acidobacteriota)和硝化螺旋菌门(Nitrospirota)。此外, 古稻原产区细菌类群表现出更强的碳代谢(包括甲醇氧化、发酵、纤维素分解和碳氢化合物降解等)能力和更弱的氮(包括硝化作用和N2O反硝化等)、硫代谢潜力。进一步的分析发现, 细菌的群落和功能潜力特征除了受土壤营养元素的影响, 还受pH和多种重金属元素(如Cd、Cu、Hg、Ni)的影响。本研究解析了古稻原产区微生态环境的特异性, 明确了其稻田土壤拥有更高的碳周转和氮储能力, 为未来推广优质水稻种植和改善农田生态系统提供了理论参考。

     

    Abstract: Rice (genus Oryza) is the world’s largest food crop, and China has a long history of rice cultivation with widespread rice distribution. This study investigated the unique soil microecological environment of ancient rice-producing regions in China by examining the rice-producing areas around Wannian County. This study analyzed the structure and function of bacterial communities using 16S rDNA high-throughput sequencing technology and FAPROTAX function prediction while exploring the critical factors affecting them. The results showed that while there were no significant differences in physicochemical parameters (including pH, cation exchange capacity, organic matter, total phosphorus, available potassium, available phosphorus, Cr, Pb, Hg, Ni and As) between the ancient rice-producing area and the neighboring regions, this area had higher levels of total nitrogen (2.41 g∙kg−1), available nitrogen (289.57 mg∙kg−1) and copper (57.6 mg∙kg−1). The bacterial community characteristics were primarily different in composition rather than abundance (based on 16S rDNA fluorescence quantitative PCR technology) and alpha diversities (including ACE index, Chao1 index, Shannon index, Simpson index, and PD_whole_tree index) using 51 bacterial phyla found in the study area showed that Proteobacteria (22.17%), Chloroflexi (19.31%), Acidobacteria (16.95%), and Actinobacteria (13.46%) were the most abundant. Specifically, soils in the original rice-producing area contained a higher relative abundance of Firmicutes (5.80%) and Bacteroidota (2.98%), whereas Acidobacteriota (13.83%) and Nitrospirota (2.24%) had low abundances. For the dominant bacterial genera (>1%), soils in the original rice-producing area had a higher relative abundance of Xanthobacteraceae_unclassified (3.44%), Conexibacter (1.79%) and Methylocystis (1.83%), while Acidobacteriales_norank (3.09%), Thermofovibrionia_norank (1.37%), Candidatus_Solibacter (0.08%), Bryobacter (0.88%) and Holophagae_Subgroup_7_norank (0.88%) were low (not significant, P>0.05). In addition, the bacterial taxa in the ancient rice-producing area displayed a higher capacity for carbon metabolism (including methanol oxidation, fermentation, cellulolysis, methanotrophy, hydrocarbon degradation, and methylotrophy) but a weaker potential for nitrogen (such as denitrification, nitrous oxide denitrification, nitrite denitrification, nitrate denitrification, nitrite respiration, nitrate respiration, and nitrogen respiration) and sulfur metabolism (such as anoxygenic photoautotrophic sulfur-oxidizing and dark oxidation of sulfur compounds). Further analysis revealed that soil nutrient elements (e.g., cation exchange capacity, organic matter, total nitrogen, available nitrogen, available potassium, and available phosphorus), pH, and heavy metal elements (e.g., Cd, Cu, Hg, and Ni) influenced the characteristics and functional potential of the bacterial community. In conclusion, the distinctiveness of the soil environment in the ancient rice-producing area stemmed primarily from the higher availability of nitrogen and copper, with the bacterial community showing a higher potential for carbon metabolism than nitrogen metabolism. Our study found that not only were the physical and chemical environments of paddy soil in ancient rice original-producing regions different from those in other study areas, but that the microorganisms enriched there had a higher carbon turnover and nitrogen storage capacity. Together, these factors constituted a unique soil microecological environment in ancient rice-producing regions. This study provides a valuable theoretical reference for high-quality rice cultivation and environment-friendly field management practices.

     

/

返回文章
返回