AUTHOR=Xu Jianwen , Chen Yihan , Qian Luofeng , Mu Rong , Yuan Xi , Fang Huimin , Huang Xi , Xu Enshun , Zhang Hongsheng , Huang Ji 

TITLE=A Novel RNA-Binding Protein Involves ABA Signaling by Post-transcriptionally Repressing ABI2

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00024

DOI=10.3389/fpls.2017.00024

ISSN=1664-462X

ABSTRACT=<p>The <italic>Stress Associated RNA-binding protein 1</italic> (<italic>SRP1</italic>) repressed by ABA, salt and cold encodes a C2C2-type zinc finger protein in <italic>Arabidopsis</italic>. The knock-out mutation in <italic>srp1</italic> reduced the sensitivity of seed to ABA and salt stress during germination and post-germinative growth stages. In contrast, <italic>SRP1</italic>-overexpressing seedlings were more sensitive to ABA and salt compared to wild type plants. In the presence of ABA, the transcript levels of ABA signaling and germination-related genes including <italic>ABI3. ABI5. EM1</italic> and <italic>EM6</italic> were less induced in <italic>srp1</italic> compared to WT. Interestingly, expression of <italic>ABI2</italic> encoding a protein phosphatase 2C protein were significantly up-regulated in <italic>srp1</italic> mutants. By <italic>in vitro</italic> analysis, SRP1 was identified as a novel RNA-binding protein directly binding to 3′UTR of <italic>ABI2</italic> mRNA. Moreover, transient expression assay proved the function of SRP1 in reducing the activity of luciferase whose coding sequence was fused with the <italic>ABI2</italic> 3’UTR. Together, it is suggested that SRP1 is involved in the ABA signaling by post-transcriptionally repressing <italic>ABI2</italic> expression in <italic>Arabidopsis</italic>.</p>