NH4+ Suppresses NO3–-Dependent Lateral Root Growth and Alters Gene Expression and Gravity Response in OsAMT1 RNAi Mutants of Rice (Oryza sativa)

Autor: Vikranth Kumar, Sung Hoon Kim, Ryza A. Priatama, Jin Hee Jeong, Moch Rosyadi Adnan, Bernet Agung Saputra, Chul Min Kim, Byoung Il Je, Soon Ju Park, Ki Hong Jung, Kyung Min Kim, Yuan Hu Xuan, Chang-deok Han
Rok vydání: 2020
Předmět:
Zdroj: Journal of Plant Biology. 63:391-407
ISSN: 1867-0725
1226-9239
DOI: 10.1007/s12374-020-09263-5
Popis: The AMT1 family comprises major ammonium transporters in rice roots. In this study, we utilized AMT1 RNAi mutants (amt1) to explore how AMT1 affects NH4+- and NO3–-mediated morphological development and NH4+-responsive gene expression in roots. In the presence of NH4+, amt1 showed inhibition of NO3–- dependent lateral root development. The inhibitory action of NH4+ on lateral root growth was independent of the NO3– concentrations supplied to amt1 roots. The results of split root assays indicated that NH4+ exerts systemic action in inhibiting NO3–-dependent lateral root development in amt1. Further study with NAA and NOA, a potent auxin flux inhibitor, suggested that perturbation of membrane dynamics might not be the primary cause of the inhibitory action of NH4+ on NO3–-mediated lateral root growth in amt1 mutants. RNA-seq analysis of NH4+-responsive genes showed that approximately half of DEGs observed in wild-type roots were not detected in the DEGs of amt1 roots. Gene ontology enrichment analysis suggested that the expression of specific functional gene groups were affected by amt1 during the early response to NH4+. Auxin-responsive gene expression and root gravity responses were altered in amt1. This study demonstrated that AMT1 affects the interactions not only between ammonium and nitrate in lateral root growth but also between auxin and NH4+ in rice roots.
Databáze: OpenAIRE
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