PRJNA276789
Root specific silencing-related and nitrogen-dependent small RNA profiling of Arabidopsis transgenic plants
Small RNAs including microRNAs (miRNAs) and small interfering RNAs (siRNAs) are important regulators of gene expression, in response to environmental stresses and silencing of risky dysfunctional or invading RNAs. The constitutive expression of ammonium transporter (AMT) AtAMT1;1 under a atamt1;1-1 (ko11) mutant background of Arabidopsis thaliana showed higher transcript level in shoots under nitrogen starvation and degradation in roots. Whether the nitrogen- and organ- dependent expression of AtAMT1;1 is regulated by small RNAs remains unknown. To identify potential silencing-related small RNAs, we first compared small RNA profiles between a stable ProAtUBQ10:AtAMT1;1 transgene and the silencing 35S:AtAMT1;1 transgene in ko11 background roots. High throughput sequencing of small RNAs from the roots of 6-week-old hydroponic plants of the two transgenic lines under normal nitrogen supply identified multiple secondary AtAMT1;1 gene-specific siRNAs, which were expressed at high levels in the degraded line. To further investigate the potential nitrogen-dependent small RNAs, we sequenced the library constructed from roots of 6-week-old hydroponic ProAtUBQ10:AtAMT1;1 transgenic plants treated with 4-day nitrogen-depletion before harvest. In contrast, we found no evidence for involvement of endogenous small RNAs. Taken together, our findings provide evidence for important roles of small RNAs in post-transcriptional regulation of AtAMT1;1 transcript stability in roots.