The Expression of Phosphorus-Responsive Genes Is Related to Root Hair Growth

The study investigated the expression of genes in Brassica carinata that are responsive to phosphorus (P) deficiency, which is known to cause longer root hairs for better soil nutrient exploitation. The genes of interest, identified through sequencing, were homologous to a leucine-rich repeat protein kinase (LRR), a 14-3-3 family transcription factor, and a proline-rich family protein (PRP) from Arabidopsis thaliana. The study found that root hair length increased under phosphorus and nitrogen deprivation but not with potassium deficiency. The expression of LRR and PRP genes was upregulated in phosphorus and nitrogen-deprived conditions, while the 14-3-3 gene did not show a consistent response. Upon altering phosphorus supply, root hair length and gene expression of LRR and PRP changed accordingly, with P-deficiency inducing and P-addition inhibiting their expression. The 14-3-3 gene expression increased with both P-removal and P-resupply, with a transient repression observed after 3 hours. These findings suggest that LRR and PRP genes may play a role in promoting root hair growth in response to P-deficiency, while the 14-3-3 gene might be involved in a general stress response mechanism.