Effects of low-temperature stress during heading stage on carbon and nitrogen allocation in paddy eco-system of northeastern China

Abstract Background and aims In high-latitude area, climate change has resulted in frequent chilling stress which affects rice sustainable production as well as changes carbon (C) and nitrogen (N) allocation in paddy ecosystem. However, the response characteristics of C and N allocation in paddy ecosystem to low-temperature stress during key growth stage are not fully understood. Methods A rice pot experiment of two varieties combined with 13C and 15N isotope labelling method was conducted to evaluate how low-temperature stress at heading stage affects rice yield, above- and below-ground C and N partitioning, and soil C and N changes. Results Low-temperature stress significantly reduced rice grain yield of JN809 (sensitive to low-temperature stress) and J88 (resistant to low-temperature stress) varieties 27.6% and 21.4%, respectively, Low-temperature stress was prone to increase C and N accumulation in stems and leaves of rice and soil. The low temperature tolerance variety (J88) reduced the effects of low temperature stress on rice yield and the allocation of C and N between soil and rice Conclusion Low-temperature during rice heading stage significantly hindered transportation of C assimilate and absorbed N from soil. Low temperature tolerant variety reduced the effect of low temperature chilling stress on rice yield, and C and N allocation. Present study provides a basis for rice breeding and cultivation techniques that can enhance rice resilience and adaptability to climate change, as well as optimize C and N sequestration practices in rice fields to ensure high yields and resource use efficiency.