The Arabidopsis thaliana trehalose-6-phosphate phosphatase gene AtTPPI regulates primary root growth and lateral root elongation

Roots are the main organs through which plants absorb water and nutrients. As the key phytohormone involved in root growth, auxin functions in plant environmental responses by modulating auxin synthesis, distribution and polar transport. The gene can improve root architecture, and mutants have significantly shortened primary roots. However, the mechanism underlying the short roots of the mutant and the upstream signaling pathway and downstream genes regulated by are unclear. Here, we demonstrated that the gene could promote auxin accumulation in -overexpressing plants. By comparing the transcriptomic data of and wild-type roots, we found several upregulations of auxin-related genes, including , and , may play an important role in the gene-mediated auxin transport signaling pathway, ultimately leading to changes in auxin content and primary root length. Moreover, increased expression can regulate primary root growth and lateral root elongation under different concentration of nitrate conditions. Overall, constitutive expression of increased auxin contents and improved lateral root elongation, constituting a new method for improving the nitrogen utilization efficiency of plants.