de Silva Kithmee, Coelho Camila, Gao Jenny, Brooks Matthew D
Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA.
Department of Biology, New York University, New York, New York, 10003, USA.
Plant J. 2025 May;122(3):e70211. doi: 10.1111/tpj.70211.
Nitrogen and light availability are well-known to influence photosynthesis, having both individual and synergistic effects. However, the regulatory interactions between these signaling pathways, especially the transcription factors (TFs) that perceive and integrate these cues, remain to be elucidated. Arabidopsis grown in a matrix of nitrogen and light treatments exhibited distinct physiological and transcriptomic responses. Notably, the effect of nitrogen dose on biomass, nitrogen use efficiency, carbon-to-nitrogen ratio, and gene expression was highly dependent on light intensity. Genes differentially expressed across the treatments were enriched for photosynthetic processes, including the pentose-phosphate cycle, light-harvesting, and chlorophyll biosynthesis. TFs coordinating photosynthesis, carbon-to-nitrogen balance, and nitrogen uptake were identified based on motif enrichment, validated binding data, and gene regulatory network analysis. Dynamic light-by-nitrogen responses were found for TFs previously linked to either nitrogen or light signaling, which now emerge as regulatory hubs that integrate these signals. Among these TFs, we identified bZIP and MYB-related family transcription factors as pivotal players in harmonizing photosynthesis, nitrogen assimilation, and light responses. The transcription factors unveiled in this study have the potential to unlock new strategies for optimizing photosynthetic activity and nutrient-use efficiency in plants.
众所周知，氮素和光照有效性会影响光合作用，既有单独作用，也有协同作用。然而，这些信号通路之间的调控相互作用，尤其是感知和整合这些信号的转录因子，仍有待阐明。在氮素和光照处理组合条件下生长的拟南芥表现出不同的生理和转录组反应。值得注意的是，氮素剂量对生物量、氮素利用效率、碳氮比和基因表达的影响高度依赖于光照强度。不同处理间差异表达的基因在光合过程中富集，包括磷酸戊糖途径、光捕获和叶绿素生物合成。基于基序富集、验证的结合数据和基因调控网络分析，确定了协调光合作用、碳氮平衡和氮素吸收的转录因子。发现先前与氮素或光照信号相关的转录因子存在动态的氮素-光照响应，它们现在成为整合这些信号的调控枢纽。在这些转录因子中，我们确定bZIP和MYB相关家族转录因子是协调光合作用、氮素同化和光照响应的关键因子。本研究中揭示的转录因子有可能为优化植物光合活性和养分利用效率开辟新策略。
