TY - JOUR T1 - Dual control of MAPK activities by AP2C1 and MKP1 MAPK phosphatases regulates defence responses in Arabidopsis JF - bioRxiv DO - 10.1101/2021.06.03.446911 SP - 2021.06.03.446911 AU - Zahra Ayatollahi AU - Vaiva Kazanaviciute AU - Volodymyr Shubchynskyy AU - Kotryna Kvederaviciute AU - Manfred Schwanninger AU - Wilfried Rozhon AU - Michael Stumpe AU - Felix Mauch AU - Sebastian Bartels AU - Roman Ulm AU - Salma Balazadeh AU - Bernd Mueller-Roeber AU - Irute Meskiene AU - Alois Schweighofer Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/06/03/2021.06.03.446911.abstract N2 - Mitogen-activated protein kinase (MAPK) cascades transmit environmental signals and induce stress and defence responses in plants. These signalling cascades are negatively controlled by specific phosphatases of the type 2C Ser/Thr protein phosphatase (PP2C) and dual-specificity phosphatase (DSP) families that inactivate stress-induced MAPKs; however, the interplay between phosphatases of these different types has remained unknown. Our work reveals that different Arabidopsis MAPK phosphatases, the PP2C-type AP2C1 and the DSP-type MKP1, exhibit both specific and overlapping functions in plant stress responses. Each single mutant and ap2c1 mkp1 double mutant displayed enhanced wound-induced activation of MAPKs MPK3, MPK4, and MPK6, as well as induction of a set of transcription factors. Moreover, ap2c1 mkp1 double mutants show an autoimmune-like response, associated with elevated levels the stress hormones salicylic acid and ethylene, and of the phytoalexin camalexin. Interestingly, this phenotype is reduced in ap2c1 mkp1 mpk6 triple mutants, suggesting that the autoimmune-like response is due to MPK6 misregulation. We conclude that the evolutionarily distant MAPK phosphatases AP2C1 and MKP1 contribute crucially to the tight control of MPK6 activity, ensuring appropriately balanced stress signalling and suppression of autoimmune-like responses during plant growth and development.Highlight Double MAPK phosphatase mutant plants ap2c1 mkp1 exhibit constitutive, autoimmune-like stress responses, dependent on their substrate MAPK MPK6.Competing Interest StatementThe authors have declared no competing interest. ER -