Constitutive salicylic acid accumulation in pi4kIII beta 1 beta 2 Arabidopsis plants stunts rosette but not root growth

0432723 - ÚEB 2015 RIV US eng J - Journal Article
Šašek, Vladimír - Janda, Martin - Delage, E. - Puyaubert, J. - Guivarc'h, A. - Maseda, Encarnación López - Dobrev, Petre - Caius, J. - Valentová, O. - Burketová, Lenka - Zachowski, A. - Ruelland, E. … Total 13 authors
Constitutive salicylic acid accumulation in pi4kIII beta 1 beta 2 Arabidopsis plants stunts rosette but not root growth.
New Phytologist. Roč. 203, č. 3 (2014), s. 805-816. ISSN 0028-646X. E-ISSN 1469-8137
R&D Projects: GA ČR(CZ) GAP501/11/1654
Institutional support: RVO:61389030
Keywords : Arabidopsis * dwarf phenotype * hormone transduction
Subject RIV: CE - Biochemistry
Impact factor: 7.672, year: 2014

Phospholipids have recently been found to be integral elements of hormone signalling pathways. An Arabidopsis thaliana double mutant in two type III phosphatidylinositol-4-kinases (PI4Ks), pi4kIII beta 1 beta 2, displays a stunted rosette growth. The causal link between PI4K activity and growth is unknown. Using microarray analysis, quantitative reverse transcription polymerase chain reaction (RT-qPCR) and multiple phytohormone analysis by LC-MS we investigated the mechanism responsible for the pi4kIII beta 1 beta 2 phenotype. The pi4kIII beta 1 beta 2 mutant accumulated a high concentration of salicylic acid (SA), constitutively expressed SA marker genes including PR-1, and was more resistant to Pseudomonas syringae. pi4kIII beta 1 beta 2 was crossed with SA signalling mutants eds1 and npr1 and SA biosynthesis mutant sid2 and NahG. The dwarf phenotype of pi4kIII beta 1 beta 2 rosettes was suppressed in all four triple mutants. Whereas eds1 pi4kIII beta 1 beta 2, sid2 pi4kIII beta 1 beta 2 and NahG pi4kIII beta 1 beta 2 had similar amounts of SA as the wild-type (WT), npr1pi4kIII beta 1 beta 2 had more SA than pi4kIII beta 1 beta 2 despite being less dwarfed. This indicates that PI4KIII beta 1 and PI4KIII beta 2 are genetically upstream of EDS1 and need functional SA biosynthesis and perception through NPR1 to express the dwarf phenotype. The slow root growth phenotype of pi4kIII beta 1 beta 2 was not suppressed in any of the triple mutants. The pi4kIII beta 1 beta 2 mutations together cause constitutive activation of SA signalling that is responsible for the dwarf rosette phenotype but not for the short root phenotype.
Permanent Link: http://hdl.handle.net/11104/0237094