TY - JOUR N2 - Abstract NH4+ is an important N-source which regulates plant growth and development. However, the underlying mechanism of NH4+ uptake and its-mediated signaling is poorly understood. Here, we performed phosphoproteomic studies using the titanium dioxide (TiO2)-mediated phosphopeptides collection method together with LC-MS analysis. The results indicated that phosphorylation levels of 23 and 43 peptides/proteins involved in diverse aspects, including metabolism, transport and signaling pathway, were decreased and increased respectively after NH4+ treatment in rice roots. Among 23 proteins detected, IDD10, a key transcription factor in ammonium signaling, was identified to reduce phosphorylation level of S313 residue. Further biochemical analysis using IDD10-GFP transgenic plants and immunoprecipitation assay confirmed that NH4+ supply reduces IDD10 phosphorylation level. Phosphorylation of ammonium transporter 1;1 (AMT1;1) was increased upon NH4+ treatment. Interestingly, phosphorylation of T446, a rice specific residue against Arabidopsis was identified. It was also established that phosphorylation of T452 is conserved with T460 of Arabidopsis AMT1;1. Yeast complementation assay with transformation of phosphomimic forms of AMT1;1 (T446/D and T452/D) into 31019b strain revealed that phosphorylation at T446 and T452 residues abolished AMT1;1 activity, while their plasma membrane localization was not changed. Our analyses show that many proteins were phosphorylated or dephosphorylated by NH4+ that may provide important evidence for studying ammonium uptake and its mediated signaling by which rice growth and development are regulated. L1 - http://czasopisma.pan.pl/Content/81858/PDF/03_zhu.pdf L2 - http://czasopisma.pan.pl/Content/81858 PY - 2015 IS - No 2 DO - 10.1515/abcsb-2015-0022 A1 - Xiao Feng Zhu A1 - Wan Hui Cai A1 - Jin Hee Jung A1 - Yuan Hu Xuan PB - Biological Commission of the Polish Academy of Sciences – Cracow Branch VL - vol. 57 DA - 2015[2015.01.01 AD - 2015.12.31 AD] T1 - NH4+-mediated Protein Phosphorylation in Rice Roots UR - http://czasopisma.pan.pl/dlibra/publication/edition/81858 T2 - Acta Biologica Cracoviensia s. Botanica ER -