Circadian Rhythm and Nitrogen Metabolism Participate in the Response of Boron Deficiency in the Root of .

Boron (B) deficiency has been shown to inhibit root cell growth and division. However, the precise mechanism underlying B deficiency-mediated root tip growth inhibition remains unclear. In this study, we investigated the role of , a gene encoding a boric acid channel, in (). is expressed in the lateral root cap and contributes to B acquisition in the root tip. Downregulation of enhances B sensitivity in , resulting in reduced shoot biomass and impaired root tip development. Transcriptome analysis was conducted on root tips from wild-type (QY10) and RNAi lines to assess the significance of B dynamics in meristematic cells during seedling growth. Differentially expressed genes (DEGs) were significantly enriched in plant circadian rhythm and nitrogen (N) metabolism pathways. Notably, the circadian-rhythm-related gene exhibited a similar B regulation pattern in to that observed in . Furthermore, mutants with disrupted circadian rhythm (//) displayed heightened sensitivity to low B compared to the wild type (Col-0). Consistent with expectations, B deficiency significantly disrupted N metabolism in roots, affecting nitrogen concentration, nitrate reductase enzyme activity, and glutamine synthesis. Interestingly, this disruption was exacerbated in lines. Overall, our findings highlight the critical role of B dynamics in root tip cells, impacting circadian rhythm and N metabolism, ultimately leading to retarded growth. This study provides novel insights into B regulation in root tip development and overall root growth in .