Warming and elevated ozone alter root traits, shift mycorrhizal fungal community and stimulate organic carbon decomposition

Authors: QIU, YUNPENG - Nanjing Agricultural University; GUO, LIJIN - Hainan University; XU, XINYU - Nanjing Agricultural University; ZHANG, LIN - Nanjing Agricultural University; CHEN, MENGFEI - Nanjing Agricultural University; ZHANG, KANGCHENG - Nanjing Agricultural University; ZHAO, YEXIN - Nanjing Agricultural University; Burkey, Kent; SHEW, DAVID - North Carolina State University; ZOBEL, RICHARD - North Carolina State University; ZHANG, YI - Nanjing Agricultural University; HU, SHUIJIN - North Carolina State University

Submitted to: Science Advances
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2021
Publication Date: 7/9/2021
Citation: Qiu, Y., Guo, L., Xu, X., Zhang, L., Chen, M., Zhang, K., Zhao, Y., Burkey, K.O., Shew, D., Zobel, R., Zhang, Y., Hu, S. 2021. Warming and elevated ozone alter root traits, shift mycorrhizal fungal community and stimulate organic carbon decomposition. Science Advances. 7 (28): eabe9256. https://doi.org/10.1126/sciadv.abe9256.
DOI: https://doi.org/10.1126/sciadv.abe9256

Interpretive Summary: Climate change consists of multiple interacting components including rising temperatures and increased air pollutants such as ozone. These factors directly impact plant growth and crop yields. However, much less is understood about the effects of temperature and ozone in the larger agroecosystem, particularly at the root-soil interface where carbon cycles and carbon sequestration are regulated. A collaboration of North Carolina State University, USDA-ARS, and Chinese colleagues showed that elevated temperature, elevated ozone, and the combination all reduce soybean root biomass, reduce root interactions with beneficial fungi, and favor the formation of fine roots. The overall effect was stimulation of organic carbon decomposition. These findings suggest that rising temperature and elevated ozone pollution may reduce the capacity to sequester carbon in the soil.

Technical Abstract: Climate warming and elevated ozone (eO3) are important climate change components that can affect plant growth and plant-microbe interactions. However, the resulting impact on soil carbon (C) dynamics, as well as the underlying mechanisms, remains unclear. Here, we show that warming, eO3, and their combination induce tradeoffs between roots and their symbiotic arbuscular mycorrhizal fungi (AMF) and stimulate organic C decomposition in a nontilled soybean agroecosystem. While warming and eO3 reduced root biomass, tissue density, and AMF colonization, they increased specific root length and promoted decomposition of both native and newly added organic C. Also, they shifted AMF community composition in favor of the genus Paraglomus with high nutrient-absorbing hyphal surface over the genus Glomus prone to protection of soil organic C. Our findings provide deep insights into plant-microbial interactive responses to warming and eO3 and how these responses may modulate soil organic C dynamics under future climate change scenarios.