Data Sheet 2_Divergent profiles of rhizosphere soil carbon and nitrogen cycling in Pinus massoniana provenances with different types of carbon storage.xlsx

IntroductionIn subtropical China, P. massoniana is a timber tree species which have a great potential for carbon sequestration. However, few studies have investigated how varying levels of carbon storage in P. massoniana provenances affect the soil microbial functional potential related to nutrient cycling within the rhizosphere.
MethodsIn this investigation, metagenomic sequencing was employed to explore the differences in carbon and nitrogen cycling capabilities among rhizosphere microbial communities within P. massoniana provenances, categorized by high, medium, and low levels of carbon storage.
ResultsOur findings revealed a significant increase in the relative abundance of Acidobacteriota and Ascomycota by 23 and 61%, respectively, whereas Basidiomycota significantly decreased by 8% in the rhizosphere of P. massoniana provenances with high carbon storage compared with those with low carbon storage. The variability in carbon storage among P. massoniana provenances was linked to marked disparities in the presence of key genes essential for carbon and nitrogen cycling within their rhizosphere soils.
DiscussionNotably, in P. massoniana provenances characterized by high carbon storage, the rhizosphere presented a significantly elevated presence of genes associated with carbon decomposition, carbon assimilation, methane generation, and denitrification, in stark contrast to provenances with medium and low carbon storage. Furthermore, P. massoniana provenances with high carbon storage rates presented increased transformation and availability of soil carbon and nitrogen, along with increased potential for ecological restoration. Moreover, the rhizosphere soil nitrification of P. massoniana provenances with low carbon storage surpassed that of other provenances, leading to increased available nitrogen content and elevated nitrate leaching risk. In the P. massoniana rhizosphere, critical soil factors, including soil organic carbon (SOC), total nitrogen (TN), pH, and nitrate nitrogen (NO3−-N) content, significantly shape the functionality of genes associated with carbon and nitrogen cycling. In conclusion, our study lays a scientific foundation for establishing P. massoniana plantations and identifying P. massoniana provenances with superior ecological value and potential.

引言：在中国亚热带地区，马尾松（Pinus massoniana）是一种兼具固碳（carbon sequestration）潜力的优质用材树种。然而目前鲜有研究探讨马尾松种源（provenances）间不同碳储量水平，如何影响其根际（rhizosphere）土壤中与养分循环（nutrient cycling）相关的微生物功能潜力。
方法：本研究采用宏基因组测序（metagenomic sequencing）技术，探究按碳储量高低划分为高、中、低三组的马尾松种源根际微生物群落的碳、氮循环功能差异。
结果：研究结果显示，相较于低碳储量马尾松种源，高碳储量种源的根际土壤中酸杆菌门（Acidobacteriota）和子囊菌门（Ascomycota）的相对丰度分别显著提升23%和61%，而担子菌门（Basidiomycota）的相对丰度则显著下降8%。马尾松种源间的碳储量差异，与其根际土壤中碳、氮循环关键功能基因的丰度分布存在显著关联。
讨论：值得注意的是，与中、低碳储量种源相比，高碳储量马尾松的根际土壤中，与碳分解、碳同化、产甲烷及反硝化（denitrification）相关的基因丰度显著升高。此外，高碳储量马尾松种源的土壤碳氮转化效率与有效性均得到提升，同时其生态修复潜力也有所增强。反观低碳储量马尾松种源，其根际土壤的硝化作用（nitrification）强于其他组种源，导致有效氮含量升高且硝酸盐淋失风险增加。在马尾松根际土壤中，土壤有机碳（soil organic carbon, SOC）、全氮（total nitrogen, TN）、pH值及硝态氮（nitrate nitrogen, NO3−-N）含量等关键土壤因子，可显著调控碳、氮循环相关功能基因的表达功能。综上，本研究为马尾松人工林营建以及筛选具有优异生态价值与潜力的马尾松种源提供了科学依据。