| Autor: |
Bakshi A; Indian Institute of Rice Research, Rajendranagar, Hyderabad 500030, Telangana, India.; Global Institute for Food Security, Saskatoon, SK S7N 0W9, Canada., Moin M; Indian Institute of Rice Research, Rajendranagar, Hyderabad 500030, Telangana, India.; Agri Biotech Foundation, PJTS Agricultural University Campus, Rajendranagar, Hyderabad 500030, Telangana, India., Gayatri MB; Department of Animal Biology, University of Hyderabad, Hyderabad 500046, Telangana, India., Reddy ABM; Department of Animal Biology, University of Hyderabad, Hyderabad 500046, Telangana, India., Datla R; Global Institute for Food Security, Saskatoon, SK S7N 0W9, Canada., Madhav MS; Indian Institute of Rice Research, Rajendranagar, Hyderabad 500030, Telangana, India.; Central Tobacco Research Institute, Rajahmundry 533105, Andhra Pradesh, India., Kirti PB; Agri Biotech Foundation, PJTS Agricultural University Campus, Rajendranagar, Hyderabad 500030, Telangana, India.; Department of Plant Sciences, University of Hyderabad, Hyderabad 500046, Telangana, India. |
| Abstrakt: |
The target of rapamycin (TOR) protein phosphorylates its downstream effector p70kDa ribosomal protein S6 kinases (S6K1) for ribosome biogenesis and translation initiation in eukaryotes. However, the molecular mechanism of TOR-S6K1-ribosomal protein (RP) signaling is not well understood in plants. In the present study, we report the transcriptional upregulation of ribosomal protein large and small subunit ( RPL and RPS ) genes in the previously established TOR overexpressing transgenic lines of rice (in Oryza sativa ssp. indica , variety BPT-5204, TR-2.24 and TR-15.1) and of Arabidopsis thaliana (in Col 0 ecotype, ATR-1.4.27 and ATR-3.7.32). The mRNA levels of RP genes from this study were compared with those previously available in transcriptomic datasets on the expression of RP s in relation to TOR inhibitor and in the TOR -RNAi lines of Arabidopsis thaliana . We further analyzed TOR activity, i.e., S6K1 phosphorylation in SALK lines of Arabidopsis with mutation in rpl6 , rpl18 , rpl23 , rpl24 and rps28C, where the rpl18 mutant showed inactivation of S6K1 phosphorylation. We also predicted similar putative Ser/Thr phosphorylation sites for ribosomal S6 kinases (RSKs) in the RPs of Oryza sativa ssp. indica and Arabidopsis thaliana. The findings of this study indicate that the TOR pathway is possibly interlinked in a cyclic manner via the phosphorylation of S6K1 as a modulatory step for the regulation of RP function to switch 'on'/'off' the translational regulation for balanced plant growth. |
