Asparagine Synthetase 1 regulates rice seminal root elongation via jasmonic acid metabolism.

We uncovered a previously unrecognized role of asparagine synthetase 1 (ASN1) in regulating rice root elongation. The plant root system is crucial for water and nutrient acquisition. Amino acids play pivotal roles in regulating root development. In this study, we uncovered a role of asparagine synthetase 1 (ASN1) in regulating rice root development. Histological analysis of asn1 mutants showed a shortened root length resulting from reduced cell proliferation rates in the root apical meristem. Metabolite profiling indicated that jasmonic acid (JA) metabolism exhibited the most significant alterations in asn1 mutants. Remarkably, exogenous JA led to a greater reduction in root length in asn1 mutants, whereas JA inhibitor restored the mutant root elongation to wild type levels. Transcriptomic analysis further identified substantial perturbations in phytohormone signaling pathways in L1 mutants. Haplotype analysis revealed genetic differentiation of OsASN1 among rice subspecies, and its allelic variants may contribute to the natural diversity of seminal root length. Together, these findings elucidate a functional interplay between OsASN1 and root architecture, demonstrating that OsASN1 regulates root elongation through the modulation of JA homeostasis.