Yu Yongjie, Zhang Jianwei, Petropoulos Evangelos, Baluja Marcos Q, Zhu Chunwu, Zhu Jianguo, Lin Xiangui, Feng Youzhi
College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
Front Microbiol. 2018 Jun 1;9:1139. doi: 10.3389/fmicb.2018.01139. eCollection 2018.
The species-specific responses of plant growth to elevated atmospheric CO concentration (eCO) could lead to N limitation and potentially influence the sustainability of ecosystem. Questions remain unanswered with regards to the response of soil N-fixing community to eCO when developing high-yielding agroecosystem to dampen the future rate of increase in CO levels and associated climate warming. This study demonstrates the divergent eCO influences on the paddy diazotrophic community between weak- and strong-responsive rice cultivars. In response to eCO, the diazotrophic abundance increased more for the strong-responsive cultivar treatments than for the weak-responsive ones. Only the strong-responsive cultivars decreased the alpha diversity and separated the composition of diazotrophic communities in response to eCO. The topological indices of the ecological networks further highlighted the different co-occurrence patterns of the diazotrophic microbiome in rice cultivars under eCO. Strong-responsive cultivars destabilized the diazotrophic community by complicating and centralizing the co-occurrence network as well as by shifting the hub species from to in response to eCO. On the contrary, the network pattern of the weak-responsive cultivars was simplified and decentralized in response to eCO, with the hub species shifting from under aCO to under eCO. Collectively, the above information indicates that the strong-responsive cultivars could potentially undermine the belowground ecosystem from the diazotrophs perspective in response to eCO. This information highlights that more attention should be paid to the stability of the belowground ecosystem when developing agricultural strategies to adapt prospective climatic scenarios by growing high-yielding crop cultivars under eCO.
植物生长对大气中二氧化碳浓度升高（eCO）的物种特异性反应可能导致氮限制，并可能影响生态系统的可持续性。在开发高产农业生态系统以减缓未来二氧化碳水平上升速度和相关气候变暖时，土壤固氮群落对eCO的反应问题仍未得到解答。本研究表明，eCO对弱响应和强响应水稻品种的稻田固氮群落有不同影响。响应eCO时，强响应品种处理的固氮丰度增加幅度大于弱响应品种。只有强响应品种在响应eCO时降低了α多样性并使固氮群落组成发生分离。生态网络的拓扑指数进一步突出了eCO条件下水稻品种中固氮微生物组不同的共现模式。强响应品种通过使共现网络复杂化和集中化，以及响应eCO时将枢纽物种从 转变为 ，从而破坏了固氮群落的稳定性。相反，弱响应品种的网络模式在响应eCO时被简化和分散，枢纽物种从aCO条件下的 转变为eCO条件下的 。总体而言，上述信息表明，强响应品种可能从固氮菌角度在响应eCO时破坏地下生态系统。该信息突出表明，在通过在eCO条件下种植高产作物品种来制定适应未来气候情景的农业策略时，应更加关注地下生态系统的稳定性。
