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A t RH 57, a DEAD ‐box RNA helicase, is involved in feedback inhibition of glucose‐mediated abscisic acid accumulation during seedling development and additively affects pre‐ribosomal RNA processing with high glucose
Author(s) -
Hsu YiFeng,
Chen YunChu,
Hsiao YuChun,
Wang BingJyun,
Lin ShihYun,
Cheng WanHsing,
Jauh GuangYuh,
Harada John J.,
Wang CoShine
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12371
Subject(s) - abscisic acid , mutant , rna helicase a , arabidopsis thaliana , microbiology and biotechnology , chemistry , biology , helicase , biochemistry , rna , gene
Summary The A rabidopsis thaliana T ‐ DNA insertion mutant rh57‐1 exhibited hypersensitivity to glucose ( G lc) and abscisic acid ( ABA ). The other two rh57 mutants also showed G lc hypersensitivity similar to rh57‐1 , strongly suggesting that the G lc‐hypersensitive feature of these mutants results from mutation of A t RH 57 . rh57‐1 and rh57‐3 displayed severely impaired seedling growth when grown in G lc concentrations higher than 3%. The gene, A t RH 57 ( A t3g09720), was expressed in all A rabidopsis organs and its transcript was significantly induced by ABA , high G lc and salt. The new A t RH 57 belongs to class II DEAD ‐box RNA helicase gene family. Transient expression of A t RH 57‐ EGFP (enhanced green fluorescent protein) in onion cells indicated that A t RH 57 was localized in the nucleus and nucleolus. Purified A t RH 57‐ H is protein was shown to unwind double‐stranded RNA independent of ATP in vitro . The ABA biosynthesis inhibitor fluridone profoundly redeemed seedling growth arrest mediated by sugar. rh57‐1 showed increased ABA levels when exposed to high G lc. Quantitative real time polymerase chain reaction analysis showed that A t RH 57 acts in a signaling network downstream of HXK 1 . A feedback inhibition of ABA accumulation mediated by A t RH 57 exists within the sugar‐mediated ABA signaling. A t RH 57 mutation and high G lc conditions additively caused a severe defect in small ribosomal subunit formation. The accumulation of abnormal pre‐r RNA and resistance to protein synthesis‐related antibiotics were observed in rh57 mutants and in the wild‐type C ol‐0 under high G lc conditions. These results suggested that A t RH 57 plays an important role in r RNA biogenesis in A rabidopsis and participates in response to sugar involving G lc‐ and ABA signaling during germination and seedling growth.