Open AccessRole of Arabidopsis At PI 4Kγ3, a type II phosphoinositide 4‐kinase, in abiotic stress responses and floral transition
Author(s) -
Akhter Salina,
Uddin Mohammad N.,
Jeong In S.,
Kim Dae W.,
Liu XiaoMin,
Bahk Jeong D.
Publication year - 2016
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12376
Subject(s) - arabidopsis , biology , autophosphorylation , arabidopsis thaliana , kinase , abiotic stress , microbiology and biotechnology , brassinosteroid , phosphatidylinositol , abiotic component , mutant , biochemistry , protein kinase a , gene , paleontology
Summary Phosphoinositides ( PI s) are essential metabolites which are generated by various lipid kinases and rapidly respond to a variety of environmental stimuli in eukaryotes. One of the precursors of important regulatory PI s, phosphatidylinositol (PtdIn) 4‐phosphate, is synthesized by PtdIns 4‐kinases ( PI 4K). Despite its wide distribution in eukaryotes, its role in plants remains largely unknown. Here, we show that the activity of At PI 4K γ 3 gene, an Arabidopsis ( Arabidopsis thaliana ) type II PtdIn 4‐kinase, is regulated by DNA demethylation and some abiotic stresses. At PI 4Kγ3 is targeted to the nucleus and selectively bounds to a few PtdIns. It possessed autophosphorylation activity but unexpectedly had no detectable lipid kinase activity. Overexpression of At PI 4K γ 3 revealed enhanced tolerance to high salinity or ABA along with inducible expression of a host of stress‐responsive genes and an optimal accumulation of reactive oxygen species. Furthermore, overexpressed At PI 4K γ 3 augmented the salt tolerance of bzip60 mutants. The ubiquitin‐like domain of At PI 4Kγ3 is demonstrated to be essential for salt stress tolerance. Besides, At PI 4Kγ3‐overexpressed plants showed a late‐flowering phenotype, which was caused by the regulation of some flowering pathway integrators. In all, our results indicate that At PI 4Kγ3 is necessary for reinforcement of plant response to abiotic stresses and delay of the floral transition.