The interaction between UDP-glycosyltransferase and CIPK11 regulates low nitrogen response in tobacco

Low-nitrogen (LN) stress limits tobacco yield and quality, identifying LN tolerance genes is essential for efficient green production. Our study systematically characterized NtLNRU (Low Nitrogen Response UGT) and verified its function in LN stress. Its transcripts were significantly induced within 3 h of LN supply and peaked at 12 h. Hydroponic assays ofNtLNRU overexpression (OE) lines showed that root length, root dry weight and root/shoot ratio increased by 101.6 %, 167.8% and 151.3%, respectively, relative to wild-type (WT) under LN stress. Total leaf nitrogen and nitratenitrogen rose by 18.4% and 39.0%, respectively. Transcriptome analysisof OE lines identified 1936 up-regulated and2992down-regulated genesunder LN stress. KEGG enrichment highlighted “phenylpropanoid biosynthesis”, “nitrogen metabolism” and “alanine, aspartate and glutamate metabolism”. Weighted gene co-expression network analysis suggested a CBL-interacting protein kinase 11(NtCIPK11), peroxidase 3 and stress enhanced protein 2 may interact with NtLNRU.Subsequent yeast two-hybrid and luciferase complementation experiments confirmed NtLNRUinteracted with NtCIPK11.We propose that NtLNRUinteracts with NtCIPK11 toregulateLN toleranceby promoting root development and up-regulating genes for nitrogen utilization in tobacco.The study provides a novel gene resource for breeding tobacco cultivars facingnitrogen deficiency stress.