Fig. 5
Molecular characterization of the expression pattern and transcriptional responses of BnaNLA1s to different N supply levels. a The qRT-PCR assay results showing the expression pattern of BnaNLA1s. b, c Transcriptional profiling of BnaNLA1s to N limitations (b) and N resupply (c). The heat maps show the mRNA levels (FPKM values) of BnaNLA1s that were identified by the transcriptome sequencing, and the curve diagram present the relative expression levels of BnaNLA1s that were validated by qRT-PCR assays. Regarding the NO3−-depletion treatments, the rapeseed seedlings that were cultivated under high NO3− (9.0 mM) for 10 d were then transferred to low NO3− (0.30 mM). At 0 h, 3 h and 72 h, the shoots and roots of the seedlings were individually sampled. Reagrding the NO3− resupply treatments, the B. napus seedlings that were hydroponically cultivated under high NO3− (9.0 mM) for 9 d were then transferred to NO3−-free solution for 3 d. The seedlings were sampled after being treated with 9.0 mM NO3− for 6 h, respectively. Values denote means (n = 3), and error bars indicate standard error (SE) values. d Gene co-expression network analysis of BnaNLA1s. Cycle nodes represent genes, and the size of the nodes represents the power of the interrelation among the nodes by degree values. Edges between two nodes represent the interactions between genes. e Identification of the putative cis-acting regulatory elements (CREs) of the 2.0-kb genomic sequences upstream the start codon (ATG) of BnaNLA1s. Over-representation of the CREs in the gene promoters, which is delineated by the WordArt program. The bigger the font size, the more the CREs