title: Role of Arabidopsis AtPI4Kγ3, a type II phosphoinositide 4-kinase, in abiotic stress responses and floral transition.
abstract: Phosphoinositides (PIs) 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 PIs, phosphatidylinositol (PtdIn) 4-phosphate, is synthesized by PtdIns 4-kinases (PI4K). Despite its wide distribution in eukaryotes, its role in plants remains largely unknown. Here, we show that the activity of AtPI4Kγ3 gene, an Arabidopsis (Arabidopsis thaliana) type II PtdIn 4-kinase, is regulated by DNA demethylation and some abiotic stresses. AtPI4Kγ3 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 AtPI4Kγ3 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 AtPI4Kγ3 augmented the salt tolerance of bzip60 mutants. The ubiquitin-like domain of AtPI4Kγ3 is demonstrated to be essential for salt stress tolerance. Besides, AtPI4Kγ3-overexpressed plants showed a late-flowering phenotype, which was caused by the regulation of some flowering pathway integrators. In all, our results indicate that AtPI4Kγ3 is necessary for reinforcement of plant response to abiotic stresses and delay of the floral transition.
authors: Division of Applied Life Sciences (BK21 Plus program), Graduate School of Gyeongsang National University, Jinju, Korea.
authors: Salina
authors: S
authors: Akhter
authors: Division of Applied Life Sciences (BK21 Plus program), Graduate School of Gyeongsang National University, Jinju, Korea.
authors: Mohammad N
authors: MN
authors: Uddin
authors: Division of Applied Life Sciences (BK21 Plus program), Graduate School of Gyeongsang National University, Jinju, Korea.
authors: In S
authors: IS
authors: Jeong
authors: Division of Applied Life Sciences (BK21 Plus program), Graduate School of Gyeongsang National University, Jinju, Korea.
authors: Dae W
authors: DW
authors: Kim
authors: Division of Applied Life Sciences (BK21 Plus program), Graduate School of Gyeongsang National University, Jinju, Korea.
authors: Xiao-Min
authors: XM
authors: Liu
authors: Division of Applied Life Sciences (BK21 Plus program), Graduate School of Gyeongsang National University, Jinju, Korea.
authors: Jeong D
authors: JD
authors: Bahk
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000040:Abscisic Acid / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects / Q000235:genetics; D035264:Flowers / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D017440:Photoperiod; D000072417:Protein Domains; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D054712:Salinity; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000378:metabolism; D013379:Substrate Specificity / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D012965:Sodium Chloride; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D019870:1-Phosphatidylinositol 4-Kinase; C000612822:PI4Kgamma3 protein, Arabidopsis
keywords: UBL domain; abiotic stress; flowering time; phosphoinositide kinase; reactive oxygen species