IDD10 is Involved in the Interaction between NH4+ and Auxin Signaling in Rice Roots
NH4+ is an important nitrogen resource for rice plants in paddy soil. Therefore, it is likely that NH4+-triggered plant growth interacts with phytohormone-mediated developmental mechanisms. Our previous transcriptomic analysis revealed that many genes involved in auxin signaling and efflux are sensitive to NH4+. In the current study, we found that NH4+ treatment causes a delayed gravity response in rice roots. To further elucidate the interlocking relationship between NH4+ and auxin signaling during root development, we utilized mutants and overexpressors of a key NH4+ signaling transcription factor INDETERMINATE DOMAIN 10 (IDD10), encoding a transcription factor that regulates the expression of NH4+ uptake and N-assimilation genes. We obtained several lines of evidence that auxin affects NH4+-mediated gene expression and root development in rice plants via IDD10. First, the gravity response was delayed in idd10 roots and accelerated in IDD10 overexpressor (IDD10 OX) roots in the absence and (especially) presence of NH4+. Second, idd10 plants showed strong root coiling only in the presence of NH4+. However, treatment of 1-N-naphthylphthalamic acid (NPA), a polar auxin transport inhibitor suppressed the NH4+-specific root phenotype of idd10. Third, the expression of NH4+-responsive auxin-related genes was affected in idd10 and IDD10 overexpressors. Finally, IDD10 expression was induced by IAA and suppressed by NPA. These findings suggest that the gene expression patterns and phenotypes triggered by NH4+ are influenced by the actions of auxin during root development, pointing to a regulatory circuit between NH4+ and auxin signaling that functions in root development in rice.
KeywordsAmmonium Auxin IDD10 Microarray Root growth
Unable to display preview. Download preview PDF.
- Gifford ML, Dean A, Gutierrez RA, Coruzzi GM, Birnbaum KD (2008) Cell-specific nitrogen responses mediate developmental plasticity. P Natl Acad Sci USA 105: 803−808Google Scholar
- Li G, Li B, Dong G, Feng X, Kronzucker HJ, Shi W (2013) Ammoniuminduced shoot ethylene production is associated with the inhibition of lateral root formation in Arabidopsis. J Exp Bot 64: 1413−1425Google Scholar
- Scheible WR, Morcuende R, Czechowski T, Fritz C, Osuna D, Palacios-Rojas N, Schindelasch D, Thimm O, Udvardi MK, Stitt M (2004) Genome-wide reprogramming of primary and secondary metabolism, protein synthesis, cellular growth processes, and the regulatory infrastructure of Arabidopsis in response to nitrogen. Plant Physiol 136: 2483−2499CrossRefPubMedCentralGoogle Scholar
- Wang R, Okamoto M, Xing X, Crawford NM (2003) Microarray analysis of the nitrate response in Arabidopsis roots and shoots reveals over 1,000 rapidly responding genes and new linkages to glucose, trehalose-6-phosphate, iron, and sulfate metabolism. Plant Physiol 132: 556−567PubMedCentralGoogle Scholar
- Xuan YH, Duan FY, Je BI, Kim CM, Li TY, Liu JM, Park SJ, Cho JH, Kim TH, von Wirén N, Han CD (2016) Related to ABI3/VP1-Like 1 (RAVL1) regulates brassinosteroid-mediated activation of AMT1;2 in rice (Oryza sativa). J Exp Bot 68: 727−737Google Scholar