MPK6 Kinase Regulates Plasma Membrane H+-ATPase Activity in Cold Acclimation.

Ilian Giordano Ponce-Pineda,Francisco Morales-Cedillo,Sobeida Sánchez-Nieto,Laura Carmona-Salazar,Araceli Peña-Moral,Marina Gavilanes-Ruíz,Dora Cano-Ramírez,Ángel Arturo Guevara-García,Mariana Saucedo-García

doi:10.3390/ijms22126338

Abstract

Cold and freezing stresses severely affect plant growth, development, and survival rate. Some plant species have evolved a process known as cold acclimation, in which plants exposed to temperatures above 0 °C trigger biochemical and physiological changes to survive freezing. During this response, several signaling events are mediated by transducers, such as mitogen activated protein kinase (MAPK) cascades. Plasma membrane H+-ATPase is a key enzyme for the plant cell life under regular and stress conditions. Using wild type and mpk3 and mpk6 knock out mutants in Arabidopsis thaliana, we explored the transcriptional, translational, and 14-3-3 protein regulation of the plasma membrane H+-ATPase activity under the acclimation process. The kinetic analysis revealed a differential profiling of the H+-ATPase activity depending on the presence or absence of MPK3 or MPK6 under non-acclimated or acclimated conditions. Negative regulation of the plasma membrane H+-ATPase activity was found to be exerted by MPK3 in non-acclimated conditions and by MPK6 in acclimated conditions, describing a novel form of regulation of this master ATPase. The MPK6 regulation involved changes in plasma membrane fluidity. Moreover, our results indicated that MPK6 is a critical regulator in the process of cold acclimation that leads to freezing tolerance and further survival.

Highlights

Plants are organisms that are constantly exposed to different biotic and abiotic stresses
We describe that Arabidopsis mpk3 and mpk6 mutants displayed a plasma membrane H+-ATPase activity with different features in terms of kineticsand gene expression upon low temperature treatment
Arabidopsis thaliana is a plant that can acclimate to cold temperatures [36]

Summary

Introduction

Plants are organisms that are constantly exposed to different biotic and abiotic stresses. A key enzyme for cell homeostasis is the plasma membrane H+-ATPase, a H+ pumping protein that establishes a transmembrane H+ gradient at the expense of ATP hydrolysis. Increased levels of gene expression, protein amount, or activity of the plasma membrane H+-ATPase were reported after low temperature exposures in fig leaf gourd plants at 6 ◦C [12], in suspension/cultured sugar beet cells at 0 ◦C [13], in cucumber roots at 10 ◦C [14], in camelina and rapeseed plants at 2 ◦C [15], and in barley seedlings at 5 ◦C [16]. Relative gene expression of AHA1 and AHA2 plasma membrane H+-ATPase isoforms increased after 12 h at 4 ◦C, coinciding with a rise in the amounts of plasma membrane H+-ATPase and 14-3-3 proteins [19]

Methods

Results

Conclusion