Transcriptome-based mining and expression profiling of low-Nitrogen-responsive transcription factors in yellowhorn (Xanthoceras sorbifolia Bunge)

Nitrogen (N) deficiency affects various pathways in plants, while transcription factors (TFs) play crucial roles in regulating metabolic processes. However, there is restricted information about the activation of TFs in trees subjected to low-N stress. We assessed these functions by identifying and predicting TFs in yellowhorn, a high-quality raw material for the production of biodiesel, under low-N stress. We performed comparative transcriptome analysis to study the overall expression of TFs in yellowhorn under different N concentrations. A total of 56 TF families, including 1,873 TF genes, were identified. Among them, 410 (approximately 22%) TFs were detected at significantly higher or lower differential expression levels in both N deficiency treatments than in normal N conditions. We then sorted eight TF families (593 TFs) related to N stress based on previous studies and determined whether they respond to low-N stress. Further phylogenetic and conservative analyses showed that TFs in yellowhorn were clustered according to their phylogenetic affinity, providing a better understanding of their functional diversity. Protein interaction and Gene Ontology (GO) analyses predicted that TFs mainly functioned in hormone conduction, oxidative stress and defense responses. In addition, some TFs involved in salicylic acid signaling, jasmonic acid signaling and antioxidant stress pathways were significantly expressed, implying that these components may help yellowhorn adapt to N deficiency. This study contributes to a better understanding of the complex mechanism of TFs in response to low-N stress in yellowhorn and lays a foundation for exploring yellowhorn TFs genes involved in low-Nitrogen-responsive.