Fig. 4

Effects of P and Zn supply on transcriptome profiling of lateral roots emerging from the primary roots of maize. Inbred line B73 were grown in a hydroponic solution containing different combinations of P and Zn for 7 days. A Diagram of sampling position. The red-dotted box indicates the sampling location on the primary root for RNA-seq. Scale bars = 1 cm. B Expression pattern clustering of differentially expressed genes (DEGs) in response to +P-Zn and -P-Zn compared with +P+Zn. Cluster 1: specifically induced by +P-Zn; Cluster 2: specifically repressed by +P-Zn; Cluster 3: specifically induced by -P-Zn; Cluster 4: specifically repressed by -P-Zn (cluster 4, 1344 genes); Cluster 5: different response to +P-Zn and -P-Zn than to +P + Zn. The gradient color scale indicates gene expression levels, which were normalized by the Z-score of gene expression across the three samples. C Gene ontology (GO) enrichment of DEGs in cluster 1. The scatter plot displays the 20 highest enriched terms. The enrichment factor is the ratio of DEG numbers in the GO entry term to all gene numbers in this pathway term. The point size represents the number of genes in the pathway; the point color meant –log₁₀(P-value). D List of genes involved in the auxin signaling pathway in cluster 1. The gradient color scale indicates gene expression levels, which were normalized by the Z-score of gene expression across three samples